Index

Ab initio calculations Acylallenes, vinylketene formationis, carbon suboxide, cumulenones, 209–210 429–433 3-Acyl-4-aminocyclobutenone, ring opening chloroketenes, 333 reaction, 127–128 fluoroalkylketene formation, 326 Acyl chloride ketenes imidoylketenes, 263–267 acrylic acid reactions, 71 ketene electronic states, 6–8 alkynylketene formation, 215 dimerization reactions, 9–12 aminoketenes, 309–310 substituent effects, 13–17 carbon substitution, 227–228 Absorption band assignments, ketene cyclopropylketene formation, 239 infrared spectra, 39–45 dehydrochlorination of, 70 Acetic acid pyrolysis, ketenes from, 57–60 diazo ketone formation, 102–104 Acetone pyrolysis, alkylketenes, 195 electron impact mass spectra, 49–50 6-Acetoxycyclohexa-2,4-dienone imine catalysis, 67 photosolvolysis, ketene formation, Acyl diazo ketones, photolysis, 105 151 Acylfluoroketene, photolysis, 325 Acetoxylketene, dehydrochlorination, 316 Acyl halides, ketene formation from, 65–74 Acetyl chloride, ketene formation from Acylisocyanate, imidoylketene formation, cations and free radicals, 182 266–267 Acetylketenes Acylium clusters, ketene formation, alkynyl ether thermolysis, 157–158 388–389 cycloaddition reactions, 255 Acylketenes [4þ2] cycloadditions, carbonyl groups, carbon substitution, 244–259 529 cycloaddition reactions dioxinone precursor, 153–155 alkynes, 497 from ester enolates, 76 imines, 509 nucleophilic additions, hydration intramolecular cycloadditions, 520–524 mechanisms, 541 diazo ketone formation, ketocarbene N-Acetylpropanamide, ketene formation, rearrangements, 110 168 ester enolate formation of, 81 Acid anhydrides, ketenes from, 61–64 Meldrum acid thermolysis, 161 Acid catalysts, intermolecular [2þ2] oxygen nucleophile reactions, 556 cycloaddition and ketene photolysis, 443–444 dimerization, 455 protonation, ketone electrophilic Acrolein photochemical isomerization, reactions, 584 ethylketene formation, 167 thermolysis of, 448–449 Activated acids, ketene formation from, titanium isopropoxide decomposition, 83 65–74 X-ray studies of, 20–21

Ketenes II, by Thomas T. Tidwell Copyright # 2006 John Wiley & Sons, Inc.

627 628 INDEX

Acylketenes (continued) flash vacuum thermolysis, 49–50 ynamine reaction, 187 fragmentation pathways, 49–50 ynol/ynolates, 378–379 nucleophilic additions, hydration Acyl radicals, ketene reactions, 592–598 mechanisms, 539 1-Adamantyl(carboethoxy)ketene, Alkyl substituents, chiroptical properties dehydrochlorination, 245 of ketenes, 38 Adamantylketenes, dehydrochlorination, Alkyne oxidation, ketene formation, 201 183–185 Addition-elimination sequence, ketene Alkynes, ketene cycloaddition, 495–499 formation, 73 Alkynylcyanoketenes, carbon substitution, Alcohols, bisketene formation and, 406–407, 216 413 Alkynylcyclobutenones, ubiquinone Aldehyde reactions, ketene formation, 188 formation, 124 Aldoketenes Alkynyl ethers intermolecular [2þ2] cycloaddition and boron-substituted ketenes, 384–385 dimerization, 455 oxygen-substituted ketenes, 318 b-propiolactone dimers, 460 thermolysis, ketene formation, 156–159 Aliphatic ketenes ynolate ketenes, 380 nucleophilic additions, hydride reduction, Alkynyl ketenes, carbon substitution, 553 214–219 X-ray studies of, 20 Alkynyl-substituted cyclohexadienone, Alkenes diene-yne ketene formation, 150 chloroketene reactions, 333 Alkynyl(trimethylsilyloxy)ketene, carbon cycloaddition reactions of ketenes, substitution, 216 451–452 Allenes intermolecular [2þ2] cycloaddition, carbon suboxide photolysis, 444–445 453–510 ketene cycloaddition, 492–494 basic mechanisms, 464–472 nucleophilic ketene additions, Wittig nucleophilic, 487–491 reactions, 576–579 rapid reactions, 474–485 Allenylcyclobutenone, torquoselective ring Alkenyl carbene complexes, dienylketenes, opening, 127 391–392 Allenylketenes Alkenylketenes cumulene substitution, 268–272 carbon substitution, 206 intramolecular cycloadditions, Do¨tz reaction and, 171–172 522–523 metal substitution, 392–393 matrix p346-347hotolysis polymer supports for, 623 radical reactions, 596 verbinone photolysis, 132–133 4-Allyl-4-ethoxycyclobutenone, thermolytic X-ray studies of, 20 ketene formation, 128–129 Alkoxide catalyst, bisketene formation, 406 Allyl morpholines, methylketene formation, Alkyl acetoacetate pyrolysis, ketene 202 formation, 82 a-substituted trimethylsilylketene, 358 Alkyl(aryl)ketenes, protonation, ketone a-Amidoketenes, carbon substitution, 251 electrophilic reactions, 583–584 Amines Alkylbromoketene, 339 chiral ketene stereoselectivity, 606 Alkyliodoketene, 339 cyclization Alkylketenes bisketene formation and, 407–408 carbon-substituted structures, 193–203 ketenyl radicals, 280 [4þ2] cycloadditions, 518–519 cyclohexadienone photolysis, 146 INDEX 629

nitrogen nucleophile/electrophile Aromatic stabilization energy (ASE), reactions with ketenes, 560–567 fulvenones, 284 nucleophilic ketene additions, Aroylketenes, thermolytic formation, 258 543–551 Arsenic-substituted ketenes, 368 Aminocarbene complex, ketene formation, Arylalkenylketenes, diazo ketone formation, 172 catalyzed Wolff rearrangement, Aminoketene 100–104 nitrogen substitution, 305–306 Arylalkylketenes nonplanar geometry, 16 carbon substitution, 228 Anionic ketenes, radical ketenyl structures, oxygenation, 589 425–427 polymerization, 601–602 Anisole protonation, cyclohexadienone Arylalkynes, peracid oxidation, ketenes formation, 148 from, 183–185 Anti conformation Aryl bisketenes, metal substitution, 417 allenylketenes, 269–270 a-Aryl-a-cyanomethylketenes, ketene dimerization, 459–460 dehydrochlorination of, 69 vinylketene, 206 Arylhaloketenes, stereoselectivity, 604 Argon matrix Aryliodonium ylides, diazo ketones, ketene benzazetinone thermolysis, 301 formation, ketocarbene bisketene formation, 405 rearrangements, 110 carbon-substituted ketene formation, Arylketenes 226–227 arylacetyl benzotriazole reactions and, 74 oxoquinone methides, 295–296 carbon substitution, 221–234 chromium carbene complex, ketene [4þ2] cycloadditions, 518–519 formation, 175 diazomethane reactions, 619 cumulenone formation, 433 from ester enolates, 76–77 cyclopropenylketene formation, 138 nucleophilic additions carbon substitution, 240 hydration mechanisms, 533–534, 535, cyclopropylideneketene photolysis, 444 538–539 diazo ketone ketene formation, oxygen nucleophile reactions, 556 photochemical Wolff rearrangement, Wittig reactions, 576–577, 578–579 107–110 photoelectron spectra of, 37–38, 438 dimethylketene photolysis, 442 Arylmethylketenes fluoroketene formation, 329 electron transfer oxygenation, 232 6-imino-2,4-cyclohexadien-1-one stereoselectivity, 604–6–5 photolysis, 149 Arylpropynes, oxidation, ketenes from, 184 ketene IR spectra, 41–45, 71 Aryl-substituted bisketenes, 404 ketene photolysis, 441–445 Aryl(trialkyl)silylketenes, Wolff ketenyl radicals, 281–282 rearrangements, 234 (2-nitrophenyl)diazomethane photolysis, Arylvinylketene, carbon-substituted 300 reactions, 230–231 pentafulvenone formation, 287 Asymmetric geometry, intermolecular [2þ2] silylketene formation, 347 cycloaddition of ketenes, alkene Z-bisketenyletehylene, 418 reactions, 477 Arndt-Eistert reaction Azafulvenone, pyrolysis, 302 diazo ketone formation, catalyzed Wolff Azaindenylideneketene, Wolff rearrangement, 100–104 rearrangement of, 289–292 oxygen nucleophile-ketene reactions, 1-Adizocycloheptatrienone, 554–559 (4-cyanobutadienyl)ketene, 145 630 INDEX

Azidoalkylcyclohexendione, dienylketene Bicyclic ketones, hydrogen transfer, 132 formation, 148 Bicyclo[2.2.1]heptan-7-one, ketene Azidoketene, dehydrochlorination, 308 aldehyde formation, 134 Azidoquinones, cyanoketene formation, 219 Bicyclo[2.2.1]heptene, cycloaddition Azoketenes, dehydrochlorination, 308 reactions, 471 Bicyclo[3.2.0]hept-2-en-6-ones, equilibrium B3LYP computational technique, ketene percentages, 466 studies, 12 Bicyclo[3.2.0]heptene, trapping agents, 207 Barton-Quinkert reaction, cyclohexadienone Bicyclo[2.2.2]hexadienone, dimethylketene ring opening, 142–151 formation, 133 Base catalysts, intermolecular [2þ2] Bicyclo[2.1.1]hexan-2-one, 3-butenylketene cycloaddition and ketene formation, 136 dimerization, 455 Bicyclo[2.2.0]-hexanone, photochemical Base-induced formation, acid anhydride ketene formation, 115 pyrolysis of ketenes, 62–64 Bicyclo[2.2.2]octadiene Beckmann rearrangement, cycloaddition of alkynyl(trimethylsilyloxy)ketene ketenes, nucleophilic alkenes, formation, 216 488–489 oxygen-substituted ketenes, 316 Bellus-Claisen rearrangement, oxygen Bicyclo[3.3.0]octadiene, dichloroketene nucleophile ketene reactions, reactions, 336 557–559 Bicyclo [1.1.1]pentan-2-one, photochemical BEMP polymer base, dehydrochlorination of ketene formation, 115 ketenes, 69 Bis(2,4,6-triisopropylphenyl)ketene Benzannulation reactions (‘‘Ditipylketene’’) chromium carbene photolysis, 175–176 diazomethane reactions, 620 ketene stereoselectivity, 611 nucleophilic additions, hydride reduction, Benzazetinone, thermolysis of, 301 552–553 Benzocyclobutenone Bis(3,5-dibromomesityl)ketene, X-ray metal-substituted bisketenes, 412 studies of, 20 oxo-1,2-xylylene formation, 296–297 Bis(acylketene), metal substitution, 415 Benzooxirene, pentafulvenone formation, Bis(alkenyl)ketene, carbon substitution, 206 286–287 Bis(chromium carbene) complexes, Benzopentafulvenone, diazo ketone bisketene formation, 421 photolysis, 289 Bis(chromium) complex, bisketene Benzoylated aminoketenes, ‘‘mu¨nchnone’’ formation, 421–422 tautomers, 306 Bis(diazo) diketone, ketene formation, Benzoylphenylketene photochemical Wolff rearrangement, cycloaddition reactions, 257–258 107–108 multiphotonic dibenzoyldiazomethane Bis(diazo ketones), metal-substituted reaction, 443 bisketenes, 416–417 Benzoylquinine (BQ), ketene catalytic Bisdioxinone asymmetric reactions, 70 bisketene precursors, 418–419 Benzylketenes, stereoselectivity, 610 bsketene formation, 420 Benzyloxyketenes Bis(germyl)ketenes, 354 cycloaddition reactions, 320 Bisketenes imines, 501–506 aryl-substituted complexes, 404 dehydrochlorination, 317 3,5-di-tert-butyl-1,2-b3enzoquinone stereoselectivity, 613–614 photolysis, 148 Bicyclic ketenes, carbon substitution, 198 infrared spectra of, 41–45 INDEX 631

metal-complexed preparation, 397–398 ester enolate formation of, 78 metal substitution, 400–422 Blomquist reaction, metal-substituted phosphorus-substituted complexes, ketenes, 416 367–368 Bond alternation, fulvenones, 284 photochemical decarbonylation, 444 Bond angles, molecular structure of ketenes, photoelectron spectra of, 35–38 18–21 polymer supports for, 623–624 Bond distances radical reactions, 595–598 intermolecular [2þ2] cycloaddition of stereoselectivity, 606–607 ketenes, alkene reactions, 478–484 thermal ring opening formation, 357 molecular structure of ketenes, 18–21 thermochemistry of, 24–25 Boron-substituted ketenes, classification and 1,2-Bisketenes structure, 384–386 ketenyl radical formation, 282 Bridged cyclohept-2,4-dien-1-one metal substitution, 400–422 photolysis, cyclopropylketene nucleophilic additions, amination formation, 151 mechanisms, 548–549 2-Bromo acyl chloride, intermolecular 1,2-Bis(ketenylidene)ethylene, 416 [2þ2] cycloaddition and ketene 1,3-Bisketenes, metal substitution, 415 dimerization, 457–458 1,4-Bisketenes a-Bromo-a-alkenylketenes, 340 formation, 402–403 Bromoarylketenes, stereoselective reactions, metal substitution, 415–416 338 1,6-Bisketenes, 352–353 Bromochloroketene, cycloaddition metal substitution, 402–403, 415–416 reactions, 338 1,8-Bisketenes, metal substitution, a-Bromodiphenylacetyl chloride, 415–416 diphenylketene formation, 222 Bis(methylenecyclobutenone), a-Bromoenol phosphates, ketene formation, allenylketenes, 271–272 187 Bis(pentafluorophenyl)ketene, direct acid Bromoketenes, halogen substitution, 331, dehydration, 222 337–340 Bis(phenyliodonium) ylide, bisketene Bromophenylketene, dehydrochlorination, formation, 420 338 Bis(silylated) ketenes, lithium reagents, (bromopy)5-Bromo pyrones, thermolytic 351–352 ketene formation, 163 Bis(silyl)-substituted ketene, 345–346 Bromotrimethylsilylketene Bis(trialkylsilyl) ketenes, 354 classification and formation, 344 ynol/ynolates, 382 halogen substitution, 338–339 Bis(trifluoromethyl)ketene Butadienylketenes, radical reactions, 596 carbon/silicon nucleophilic additions, Butenolides, bisketene formation of, 572–573 406–407 cycloaddition chemistry, 327–328 4-Butenylketenes, radical reactions, 596 dimerization, 461 1-tert-Butoxy-1,3-butadiyne, alkynylketene Bis(trifluoromethyselenyl)ketene, silver salt formation, 215–216 reaction, 387 tert-Butyl alkynyl ethers, ketene formation, Bis(trimethylsilyl)-1,2-bisketene, 403 156–157 neat alcohols and, 406 3,5-di-tert-Butyl-1,2-benzoquinone Bis(trimethylsilyl)ketene photolysis, bisketene formation, carbonylation, 347–348 148 classification and formation, tert-Butyl(carboethoxy)ketene, 343–344 dehydrochlorination, 245 632 INDEX tert-Butylcyanoketene Carbenic centers, carbon-substituted carbon substitution, 219 ketenes, 273–283 cycloaddition kinetics, 483 Carbocationic derivatives alkynes, 495–499 carbon-substituted ketenes, 274–283 allenes, 492–494 ketene photolysis, 443 nitrogen nucleophile/electrophile ketene Carboethoxyketenes reactions, 566 alkyne cycloaddition reactions, 499 (4-tert-Butyl-2,6-dimethylphenyl)mesityl- from ester enolates, 76 ketene, photolysis of, 444 Carbohydrates, chloroketene cycloadditions, di-tert-Butylketene 335 carbon/silicon nucleophilic additions, Carbomethoxyketene 568–574 [4þ2] cycloaddition with imines, 504 diazo ketone thermolysis, 199 oxygen substitution, 313–314 ketene radical reactions, 594 13C nuclear magnetic resonance ketone electrophilic reactions acylium ion shifts, 273–274 oxygenation, 588 alkylketenes, 194 protonation, 581–582 chloroketenes, 332 photolysis, 442–443 ketene physical properties, 27–33 stable properties, 197–198 Carbon atoms, thermolytic ketene formation, tert-butylketene, photochemical Wolff 169 rearrangement, 104–105 Carbon-carbon double bonds 2,6-di-tert-Butyl-4-methylphenyl (BHT) ketene cycloadditions, 452 esters ketene polymerization, 600–602 aryloxide anion-forming ketenes, 229 Carbon dioxide ketene formation from, 78–79 cumulenones, 428–433 2,6-di-tert-Butyl-4-methyoxyphenyl (BHA) ketenyl radicals, anions, and cations, esters, carbon-substituted ketenes, 425–427 229 Carbon monoxide n-Butyltrimethylsilylketene, classification bisketene formation, 400 and formation, 344 cumulenones, 430–433 ketene intermediates, 189 Camphorketene ketene photolysis, 441–442 dehalogenation, 198–199 ketenyl anions, and cations, 425–427 thermolytic formation, 258 ketenyl radicals, 279–280, 425–427 Carbamates, chromium carbene complexes, metal-complexed ketenes, 390–391 178 Carbon nucleophiles, ketene additions, Carbanion decay 568–574 carbon-substituted ketenes, 273–283 Carbon suboxide ketenyl radicals, 282 bisketene formation, 400–401 4-nitrophenylketene formation, 77 cumulenones, 428–433 Carbanion intermediates, ester enolate ketene polymerization, 602 formation of ketenes, 77–81 nucleophilic additions to ketenes, Carbenes hydration mechanisms, 540 cumulenones, 429–433 photolysis, allene formation, 444–445 diazo ketones, 92–93 X-ray studies of, 21 ketene formation, photochemical Wolff Carbon-substituted ketenes rearrangement, 105–110 acylketenes, 244–259 dimesitylketene photolysis, 444 alkenylketenes, 206–213 norbornadiene photolysis, 187 alkylketenes, 193–203 INDEX 633

alkynyl and cyano ketenes, 214–219 CBS-Q calculations, ketene aryl- and heteroarylketenes, 221–234 thermochemistry, 24–25 charged, radical, and carbenic side chains, CD spectra, ketene conformational behavior, 273–283 38 cumulene-substituted ketenes, 268–272 Cerium reagents cyclopropyl-, cyclopropenyl-, and carbon/silicon nucleophilic additions to oxiranylketenes, 237–242 ketenes, 571 fulvenones and cumulenones, 284–292 silylketenes, 351–352 imidoylketenes, 263–267 Cheleotropic fragmentation, ketene oxoquinone methides, oxoxylylenes, and formation, 165–166 related species, 294–303 Chiral alkaloid bases, ketene catalytic Carbonyl carbene complexes asymmetric reactions, 70 alkenylketene chromium complex, Chiral centers, ketene stereoselectivity, 171–179 603–615 nitrogen-substituted ketenes, 305–306 Chiral cyclohexadienone photolysis, Carbonyl groups dienylketene formation, 146 [2þ2] cycloadditions of ketenes, 452 Chiral tertiary amines, ketene catalytic cycloadditions of ketenes, 525–530 asymmetric reactions, 69 nucleophilic additions to ketenes, Chiroptical properties of ketenes hydration mechanisms, 533–541 alkenylketenes, 208 Carboxamide-substituted ketenes cycloaddition kinetics, allenes, 493–494 alkyne cycloaddition reactions, 499 metal-complexed ketenes, 392–393 photochemical Wolff rearrangement, 256 ultraviolet and photoelectron spectra, Carboxylic acids and derivatives 35–38 acid anhydride pyrolysis of ketenes, Chloroalkylketene, cycloaddition reactions, 62–64 nucleophilic alkenes, 487–488 carbon-substituted arylketenes, 224 Chlorocarbonyl(phenyl)ketene, malonyl dehalogenation of a-halo derivatives, dichloride thermolysis, 244–245 ketene formation, 86–89 Chlorocyanoketene, carbon substitution, diazo ketone formation of ketenes, 218 102–104 Chloroformylketene, malonyl dichloride ester-derived ketenes, 76–84 thermolysis, 72 ester enolates, 76–81 Chloroketenes pyrolysis, 81–84 cycloadditions ester enolate formation of ketenes, 78 carbonyl groups, 527–530 ketenes from, 57–60 imines, 506–510 oxygen nucleophile-ketene reactions, nucleophilic alkenes, 490–491 554–559 a-halo carboxylic acid derivatives, 87 stereoselectivity of ketenes, 608 halogen substitution, 331–340 Carboxylketenes, Meldrum’s acid derivative, 4-Chloropyrazolin-5-one, 252 dehydrochlorination, diazo ketene Catalytic dehydration, acetic acid-ketene formation, 164 formation, 57–60 5-Chlorovalerylketene, dehydrochlorination, Catalyzed Wolff rearrangement, diazo 67–68 ketones, ketene formation, 97–104 Chromium carbene complexes Cationic ketenes aminoketenes, nitrogen substitution, formation mechanisms, 181–182 309–310 nitrosative guanine deamination, 303 dienylkettene formation, 172–173 radical ketenyl structures, 425–427 ketene stereoselectivity, 611 634 INDEX

Chromium carbene complexes (continued) (4-Cyanobutadienyl)ketene, metal-complexed ketenes, 390–391, 398 1-adizocycloheptatrienone stereoselectivity of ketenes, 608 formation, 145 Chromium complexed-ketenes, nucleophilic Cyanoacetyl chloride, cyanoketene additions formation, 217 carbon/silicon nucleophilic additions, 574 Cyanoketenes nitrogen nucleophile/electrophile carbon substitution, 214–219 reactions, 561–564 from ester enolates, 76 Wittig reactions, 577–579 isodesmic comparisons, 217 Claisen rearrangement, cycloaddition of oxygen nucleophile-ketene reactions, ketenes 554–559 alkene reactions, 478–484 Cyano ketenyl cation, 426–427 [4þ2] cycloadditions, 517 Cyanuric chloride, carboxylic acid-ketene Cobalt complex, ketene formation, 172 formation, 59–60 Collisionally activated dissociation (CAD) Cyclic diacylbisketene deprotonated peptides, ketene formation, argon matrix, 419 168 diazo ketone formation, photochemical methylketene formation, 188 Wolff rearrangement, 107–110 resorcinol derivatives, alkenylketene [2þ2] Cycloadditions of ketenes, 450–451 intermediates, 150 carbonyl groups, 525–530 Computational studies intermolecular interactions, 453–510 cycloadditions of ketenes, imine alkenes reactions, 501–510 basic mechanisms, 464–472 ketene dipole moments, 48–49 nucleophilic, 487–491 ketene elucidation, 5–17 rapid reactions, 474–485 molecular and electronic structure and alkynes, 495–499 energy, 5–8 allenes, 492–494 reaction mechanisms and energetics, dienes, 464–472 9–12 dimerization, 453–462 substituent effects, 13–17 imines, 500–510 Concerted pathways, intermolecular [2þ2] Woodward-Hoffmann rules, 451 cycloaddition of ketenes, alkene [3þ2] Cycloadditions of ketenes, basic reactions, 476–484 principles, 513–515 Cope rearrangement, cyclopropylketenes, [4þ2] Cycloadditions of ketenes, 450–451, 240 474 Copper catalysis, diazo ketones, catalyzed alkene reactions, 474–485 Wolff rearrangement, 99–104 basic principles, 516–520 Copper ketenide, 387–388 imine reactions, 504–505 Cotton effect, chiroptical properties of Cycloadditions ketenes, 38 [2þ2] cycloadditions Cumulene structure intermolecular reaction, 453–510 cyanoketene formation, 217 alkenes imidoylketenes, 264 basic mechanisms, 464–472 Cumulene-substituted ketenes, 5–8, 268–272 nucleophilic, 487–491 fluoroketenes, 322 rapid reactions, 474–485 Cumulenones alkynes, 495–499 carbon-substituted ketenes, 284, 292 allenes, 492–494 a-oxoketene, 295 dienes, 464–472 structure and classification, 428–433 dimerization, 453–462 INDEX 635

imines, 500–510 Cyclobutenedione chemistry stereoselectivity of ketenes, bisketenes, 401–402 608–615 ketene dimers, 458 [3þ2] cycloadditions, ketene formation, Cyclobutenones 513–515 allenyl thio ester thermolysis via [4þ2] cycloadditions, ketene formation, vinylketenes, 161 516–520 carbon substituted diphenylketene, alkynyl ether thermolysis, 156–157 225–226 basic reaction mechanisms for ketenes, ketene formation, photochemical and 449–452 thermolytic methods, 114–129 carbonyl groups, ketene formation, ketene molecular dynamics, 9 525–531 solvent effects on ring opening, 119 chloroketenes, 331–340 substituent effects on ring opening, 120 chromium carbene complexes, 178 thermal rearrangement from dehydrochlorination of ketenes, 67–74 cyclobutenedione, 121 diazo ketone formation, photochemical vinylketene formation, 210–211 Wolff rearrangement, 102–104 Cycloheptatrienylketene, dioxinone formation of ketones, 153–155 dehydrochlorination, 239–240 fluoroalkylketene formation, 327 Cyclohexadienones, ketene formation, fluoroketenes, 323 142–151 intramolecular cycloadditions, ketene Cyclohexanone enamines, ester enolate formation, 520–542 formation of ketenes, 80–81 stereoselectivity, 609 Cyclohexylamine, dienylketene formation, nitrogen-substituted ketenes, 309 147 oxo-1,2-xylylene formation, 297 Cyclohexylketene, alkynyl ether phosphorus-substituted ketenes, thermolysis, 158 365–368 2,4,6-Cyclooctatrienone, hexatrienylketene photochemical Wolff rearrangement, formation, 150 ketene formation, 122–123 Cyclopentadienones, cyclopropenylketene sulfur-substituted ketenes, 372–373 formation, 242 trimethylsilylketene, 350, 352 Cyclopentadienylideneketene, cumulenone vinylketene formation, 10 formation, 432 carbon substitution, 211–212 Cyclopentenone photolysis Cycloalkanones, photolysis, ketene cyclopropylketene interconversion, 238 formation, 132–140 ketene formation, 132 Cycloalkenones, ketene formation, 142–151 Cyclopenten-4-one, ketene intermediates, Cyclobutanediones, ketene dimeriziation, 134 460 Cyclopropanocyclopentenone, ketene 1,3-Cyclobutanedione, ketene dimerization, formation, 135–136 453 Cyclopropenium cation, sulfur-substituted Cyclobutanones ketenes, 372 aryl ketene generation, 228–229 Cyclopropenylketenes diphenylketenes, 464 argon photolysis, 138 intramolecular ketene cycloadditions, carbon substitution, 237–242 521–522 Wolff rearrangement, 242 ketene formation, photochemical and Cyclopropyl carboxylate ester, thermolytic methods, 114–129 dichloroketenes, 334 ring opening reactions, thermolytic ketene Cyclopropylideneketenes formation, 160 carbon substitution, 196 636 INDEX

Cyclopropylideneketenes (continued) 4-chloropyrazolin-5-one, diazo ketene a-halo carboxylic acid derivatives, ketene formation, 164 formation, 87 cycloaddition of ketenes photolysis, 444 imine reactions, 505–506 Cyclopropylketenes intramolecular cycloadditions, 523 carbon substitution, 237–242 nucleophilic alkenes, 488–489 diazo ketone formation, catalyzed Wolff cycloheptatrienylketene, 239–240 rearrangement, 100–104 cyclopropylketene formation, 239 radical reactions, 596 diazoalkylketenes, 272 Cyclopropylvinylacyl selenides, ketenyl diethylphosphonoketene, 364 radicals, 278–279 di-tert-butylketene, 197 fluoroketenes, 323 Decarbonylation ketene preparation and isolation, 65–74 benzoylphenylketene photolysis, 443 ketene stereoselectivity, 610–611 carbon-substituted acylketenes, 248–249 metal-substituted bisketenes, 414–415 fluoroketenes, 322 stereoselectivity of ketenes, 604–605 ketene thermolysis, 447–449 sulfur-substituted ketenes, 376 metal-substituted bisketenes, 411–412 trimethylsilylvinylketene, 344 oxygen-substituted ketenes, 314–320 Dehydrohalogenation silylketenes, 355–356 alkenylketenes, 208 Decarboxylation, ketene cycloadditions, cyclopropylideneketene, 196 526–530 fluoroketenes, 323 n-Decyltrimethylsilylketene, 356 ketene preparation and isolation, 65–74 Decomposition rates Density functional theory (DFT) diazo ketone ketene formation alkyne oxidation, ketenes from, 183–185 photochemical Wolff rearrangement, aryl chromium carbene complex, ketene 104–110 formation, 173–175 thermal Wolff rearrangement, 94–97 [4þ2] cycloadditions of ketenes, 518–519 phosphorus-substituted ketenes, 362 cyclopropylketene substituent effects, photochemical ketene formation, 240 cyclobutanones, 116 ketene molecular structure, 6 Dehalogenation ketenide formation, 388 de-(2-naphthyl)ketene, 222 ketenyl radicals, 281 a-halo carboxylic acid derivatives, ketene vinylketene cycloadditions, 10 formation, 86–89 Deuterated ketenes, phhotofragmentation, phenyl(trifluoromethyl)ketene, 328–329 442 Dehydrobromination, ketene generation, Deuterium isotope studies, alkynyl ether 70–71 thermolysis, 156–159 Dehydrochlorination Dewar bicyclo isomer, photochemical acetoxylketene, 316 ketene formation, 163 adamantylketenes, 201 Diacetylketenes alkynylketene formation, 215 carbon-substituted acylketenes, 252 azidoketene, 308 dioxinone thermolysis, 155 benzyloxyketene, 317 Diacyl chloride, metal substituted BHT ester formation of ketene, 342–343 bisketenes, 418 1,4-bisketenes, 402–403 Diacylketenes bromoketenes, 337–340 carbene capture, 256 carbon-substituted acylketenes, 255 carbon substitution, 246–247 chloroketenes, 331–332 spectroscopic analysis, 33 INDEX 637

Dialkylketenes photolysis, 201 dimer photolysis, 56 reaction mechanisms, 90–93 nucleophilic additions, hydration thermal Wolff rearrangement mechanisms, 539–540 diphenylketene formation, 221–222 Diarylalkynes, metal-complexed bisketenes, ketene formation, 93–97 409–410 Wolff rearrangement, overview, 92–93 7,7-Diarylbicyclo[2.2.1]hept-2-enes, kettene Diazomethanes, ketene reactions with, formation, 200 618–620 Diarylketenes Diazomethylketene, cumulene substitution, carbon/silicon nucleophilic additions, 268 570–571 3-Diazo-4-oxocoumarin, carbon-substituted cycloaddition reactions, alkynes, 497–498 ketenes, 227 dehydrochlorination and formation of, 66 Diazulenylketene, thermal Wolff diazo ketone formation, thermal Wolff rearrangement, 226 rearrangement, 94–97 Dibenzofulvenone NRM spectroscopy for, 27–33 carbon substituted diphenylketene, 1,4-Diazabicyclooctane (DABCO), 225 nitrogen-substituted ketenes, 306 zinc dechlorination, 290 Diazoalkanes, [3þ2] cycloadditions of Dibenzoylketene ketenes, 513 furandione pyrolysis, 246 Diazoalkylketenes, cumulene substitution, furandione thermolysis, 164 272 Dibromofuranone, metal-complexed Diazoketene, nitrogen substitution, 306 bisketenes, 411 Diazo ketones Dibromoketene arylketene photelectron spectra, 438–440 a-halo carboxylic acid derivatives, ketene azafulvenone formation, 288 formation, 87–88 carbon-substituted ketenes, 226–234 zinc generation, 339 acylketenes, 246 Di(carboethoxy)ketene, Wolff oxoquinone methides, 296 rearrangement, diazo ketone, chromium carbene complex, 177 256–257 cumulene-substituted ketenes, 268–272 Dichloroketenes cumulenone formation, 431 cycloadditions, 333–335 [3þ2] cycloadditions of ketenes, 514–515 [2þ2] cycloadditions cyclohexylketene formation, 202 alkenes and dienes, 469–471 di-tert-butylketene formation, 199 alkynes, 496 fluoroalkylketene formation, 325–326 imines, 507–508 intramolecular ketene cycloadditions, 524 nucleophilic alkenes, 487–489 ketene formation, 90–110 [3þ2] cycloadditions, 513–515 catalyzed Wolff rearrangement, 97–104 carbonyl groups, 528–529 cyclopropylketene, 239 a-halo carboxylic acid derivatives, 87 diazomethane reactions, 620 halogen substitution, 331–340 epimeric anilide capture, 241 nitrogen nucleophile/electrophile ketene phenylsulfonylketene, 374 reactions, 565–566 phosphorus-substituted ketenes, 362 oxygen nucleophile reactions, 557–559 photochemical ketene formation protonation, ketone electrophilic thermolytic reactions, 117–118 reactions, 582–583 a-trialkylsilylalkenylketenes, 208 stereoselectivity, 608–609 photochemical Wolff rearrangement, sulfur dioxide reactions, 621 104–110 Dicyanoketene, carbon substitution, 219 638 INDEX

Dicyclohexyl carbodimid (DCC), carboxylic Diisopropylethylamine (DIPEA) acid-ketene formation, 58 ketene cycloadditions, 529–530 Dicyclopropylketene, carbon substitution, ketene stereoselectivity, 610–611 241 Dimerization Dideutroketenes, radical reactions, 598 alkylketenes, 195 Dieckmann-type reactions chloroketenes/dichloroketenes, oxygen nucleophile ketenes, 558 336–337 ynol/ynolates, 381–382 dehydrohalogenation of ketenes and, 66 Dienes intermolecular [2þ2] cycloadditions in [2þ2] cycloaddition of ketenes, 453–510 ketenes, 453–462 basic mechanisms, 464–472 ketene molecular dynamics, 9–12 nucleophilic, 487–491 ketenes, preparation from, 55–56 rapid reactions, 474–485 stereoselectivity of ketenes, 613–615 [4þ2] cycloaddition of ketenes, 520 Dimesitylketenes Diene-yne ketene, alkynyl-substituted carbon/silicon nucleophilic additions, cyclohexadienone cyclization, 150 570–571 Dienylketenes photolysis of, 444 acid anhydride pyrolysis of, 63 X-ray studies of, 20 alkenyl carbene complexes, 391–392 (2,4-Dimethylbenzoyl)formate esters, ketene chromium complexes, 172–173 formation, 168 cycloaddition reactions with imines, 505 3,3-Dimethylcyclopentene, ketene cyclohexadienone interconversion, cycloadditions, 469 143–151 (Dimethylhydridosilyl)ketenes, flash ene-yne epoxide conversion, 397–398 vacuum pyrolysis, 449 nucleophilic additions, amination Dimethylketenes mechanisms, 548–549 alkylketene preparation, 193 radical reactions, 596 bicyclo[2.2.2]jexadienone formation of, ring-opening mechanism, 325 133 stereoselectivity, 606 cycloaddition reactions Diethylketene, stereoselectivity, 612 [2þ2] cycloadditions Diethylphosphonoketene, dimerization, 454 dehydrochlorination, 364 imine reactions, 507 1,1-Diethynyldiene hydration, deprotonated symmetrical dimers, 450 peptides, ketene formation, 168 sytrenes, 483–484 Difluoroketenes [3þ2] cycloadditions, 514 photolysis, 322 dimer pyrolysis, 55–56 X-ray structure, 324 a-halo carboxylic acid derivatives, ketene zinc activation, 323–324 formation, 88–89 Diformylketene, formamide reactions, 250 hydrogen radical reaactions, 593–594 Dihydrobenzophenanthridine, ketone electrophilic reactions, dihydroisoquinoline synthesis, oxygenation, 588 125–126 nucleophilic additions Dihydrofuran, bis(silyl)kettenes, 346 amination mechanisms, 544–545 Dihydroisoquinoline synthesis, ene-yne carbon/silicon nucleophilic additions, ketene formation, 125–126 573 Dihydropyridine-substituted ketene, Wittig reactions, 577–579 eyectrocyclication reaction, 126 photolysis in argon matrix, 442 Dihydropyridone, intramolecular pyrolysis, 447 nucleophilic addition reaction, 126 thermochemistry, 22–25 INDEX 639

Dimethylpropadienone, cumulenone hydride reduction, 552–553 formation, 430–431 nitrogen nucleophile/electrophile Dinaphthylketenes, a-halo carboxylic acid ketene reactions, 565–566 derivatives, 86–89 Wittig reactions, 576–579, 578–579 Dioxinones photolysis of, 443 carbon-substituted acylketenes, 247–248 polymerization, 601 carbon substitution, 247–248 stereoselectivity, 614 ketene formation, 153–155 thermolytic reactions, 446–449 4,4-Diphenylcyclopentenone, keetene zinc reduction characterization, 221 formation, 134 Diphenyloxazolidinyl-substituted ketene, Diphenylcyclopropenone cycloadditions with imines, 507 ketene formation, 166 Dipivaloylketene, X-ray studies of, 20 thermolysis, ketene formation, 190 Dipivalylketene, furandione pyrolysis, 245 2,2-Diphenylcyclopropylketene, Dipole moments photochemical Wolff rearrangement, bisketenes, 402–403 238 ketene measurements, IR and Raman Diphenylketenes spectroscopy, 39–45 boron substitution, 386 ketene physical properties, 48–49 carbon substitution, 225–226 molecular structure of ketenes, 18–21 cycloaddition reactions Disilanylbisketene, 352–353 [2þ2] cyclyadditions, 451 Disilanylketene, 352–353 alkene reactions, 478–484 Distonic dehydrobenzoyl radical cation, with alkenes and dienes, 464–472 carbon-substituted ketenes, 275–276 imine reactions, 500–510 Divinylketenes net [2þ2] cycloaddition, 450 carbon substitution, 213 norbornene, 472 ethenylcyclobutenone formation, 123–124 sytrenes, 483–484 DNA binding reactions, chloroketenes, 336 titanaalene complexes, 395 Do¨tz reaction [3þ2] cycloadditions, 513–514 alkenylketene chromium complex, [4þ2] cycloadditions, 451, 516–518 171–172 carbonyl groups, 530 chromium carbene photolysis, dehydrochlorination preparation of, 66–67 benzannulation, 175–176 diazo ketone formation, thermal Wolff metal-complexed ketenes, 390–398 rearrangement, 93–97 vinylcyclopropyl carbene complex, 179 diazomethane reactions, 618 dimeric structures, 222–223 E-(1,3-butadienyl)ketene, diphenyldiazomethane reaction, 169 dehydrochlorination, 206 electrochemical oxidation, 439 E-7 ketene, ozone photolysis, 143 a-halo carboxylic acid derivatives, 86–89 Electron diffraction, molecular structure of history of, 1 ketenes, 18–21 ketone electrophilic reactions Electronegativities oxygenation, 587–591 chloroketenes, 333 protonation, 581–585 ketene substituent effects, 14–17 lanthanum complexes, 398 Electronic structure nucleophilic additions chiroptical properties of ketenes, 35–38 carbon/silicon nucleophiles, 568–574 diazo ketones, 92–93 carbon/silicon nucleophilic additions, ketenes, 5–8 571–574 Electron impact mass spectra hydration mechanisms, 535 acyl chloride ketenes, 49–50 640 INDEX

Electron impact mass spectra (continued) bicyclic ketone hydrogen transfer, ketene oxidation and reduction, 132–133 438–440 diazo ketone formation of ketenes, 104 Electrophilic reactions photochemical Wolff rearrangement, [2þ2] cycloaddition reactions of ketenes, 105–110 475 ketene preparation, 67 ketones, 580–591 photochemical ketene formation, oxygenation of ketenes, 587–591 cyclobutanones, 116 protonation of ketenes, 580–585 stereoselectivity of ketenes, 607–608 nitrogen reactions with ketenes, 560–567 Esterolysis melt polymerization, ketene Electrospray mass spectrometry formation, 84 diazo ketones, catalyzed Wolff Esters, ketenes from, 76–84 rearrangement, 98–104 ester enolates, 76–81 ketene radical cations, 50–51 pyrolysis, 81–84 Enaminylketenes, flash vaccuum Et3N ketene formation, esterification and, thermolysis, 265 67 Enantioselectivity of lactams, cycloadditions Ethanol, oxygen-substituted ketenes, 316 of ketenes, imine reactions, 501–510 Ethenylcyclobutenone, divinylketene Endo positions, ketene cycloadditions, formation, 123–124 466–468 Ethoxyalkynylsilanes, silylated ketenes and Enediynyl ethyl ether thermolysis, ene-yne polyketenes, 158 ketene, 158–159 Ethoxyketene, oxygen substitution, 313 Ene reactions, alkenylketene formation, 209 Ethoxy(triphenylsilyl)ketene, preparation, Energy changes, ketene radical reactions, 319 592–598 Ethylene, ketene cycloadditions, 485 Ene-yne ketenes Ethylketenes bisalkynyl chromium carbene complex, acrolein photochemical isomerization, 392 167 carbon substitution, ruthenium catalyst, a-halo carboxylic acid derivatives, 212–213 86–89 diazo ketone ketene formation hydrogen radical reaactions, 593–594 matrix photolysis, 211 ketone electrophilic reactions, photochemical Wolff rearrangement, oxygenation, 588 109–110 quinoline derivatives and formation of, 73 dihydroisoquinoline synthesis, 125–126 vinyl and saturated ester formation, 83 enediynyl ethyl ether thermolysis, Ethylphenylketene 158–159 polymer supports for, 624 intramolecular cycloadditions, 523–524 radical reactions, 598 vinylcyclobutenone formation, 123–125 Ethynyl ethers, mass spectrometric analysis, Enolic radicals, ketene reactions, 592–598 159 Enone photolysis, ketene formation, Exo positions ketene cycloadditions, 132–140 467–468 Enthalpy of formation, ketene thermochemistry, 25 Femtosecond time-resolved mass Ester enolates spectrometry, photochemical ketene bisketene formation and, 406–407 formation, ring opening mechanism, fulvenone formation, 291–292 115 ketenes from, 76–81 Fermi resonance, ketenylidenecycloalkane Esterification infrared spectra, 41–45 acyl chloride ketenes, 71 Ferrocenylketene, carbon substitution, 234 INDEX 641

Flash vacuum pyrolysis (FVP) Friedel-Crafts reaction, carbon/silicon allenylketenes, 269–270 nucleophilic additions to ketenes, azafulvenone formation, 287–288 572–573 carbon-substituted acylketenes, Fullerenes 250–251 bisketene formation and, 413 carbon-substituted alkenylketenes, oxidation, ketenes from, 185 206–207, 211 pentaketene formation, 421 cumulenone formation, 431 Fulvenones diazo ketone ketene formation, carbon-substituted ketenes, 96–97 284–292 (dimethylhydridosilyl)ketenes, 449 nitrogen nucleophile/electrophile ketene imidoylketenes, 264 reactions, 564 Meldrum’s acid derivative, nucleophilic additions to ketenes, carboxylketene, 252 hydration mechanisms, 539 oxoquinonemethides, 302 oxyquinone methides and oxoxylylenes, perfluoroketene formation, 325 298–299 Flash vacuum thermolysis (FVT) Furandione carbon-substituted acylketenes, 248 acylketene formation, 246 cyanoketene formation, 217 carbon-substituted arylketenes, enaminylketenes, 265 233–234 oxygen-substituted ketenes, 318–319 dipivalylketene formation, 245 2-pyridylcyanoketene, 233 pseudopericuclic decarbonylation, ketene Flowing afterglow analysis, ynol/ynolate formation, 165 ketenes, 377–382 thermolytic ketene formation, 164 Fluorenylideneketene Furanone, cobalt complex, ketene formation, diazo ketone formation, thermal Wolff 172 rearrangement, 93–97 Furan photolysis/pyrolysis, ketene zinc dechlorination, 290 formation, 167 Fluoroalkylketenes, halogen substitution, Furaquinocin, acid anhydride pyrolysis of 321, 325–329 ketenes, 62–64 Fluoroketenes, halogen substitution, Furaquinocin E, cyclobutenone formation of 321–329 vinylketene, 122 Fluorooxirane irradiation, ketene formation, 166 G3(MP2)//B3LYP, ketene computational Formaldehyde photolysis, oxygen- studies, 16–17 substituted ketenes, 313 Gas phase ion chemistry Formylketene bromoketenes, 337–340 carbon substitution, 244 cumulenones, 429–433 computational studies, 11 ketene oxidation reactions, 437–440 cyclization reactions, 249–250 ketene physical properties, 49–52 cycloaddition reaactions, 255 ketene thermolysis, 447 Formylthioketene, pyrolysis, 259 ketenyl radicals, anions, and cations, 4 Fourier transform mass spectrometry, 26–427 carbon suboxide, cumulenones, nucleophilic additions to ketenes, 429–433 hydration mechanisms, 535 Free radicals oxygen-substituted ketenes, 314 ketene formation from, 181–182 vinylketenes, 206 ketene radical cation spectra, 50–51 ynol/ynolate ketenes, 377–382 Frequency parameters, ketene IR Gas phase IR laser photolysis, frequencies, 40–45 chloroformylketene formation, 72 642 INDEX

Gas phase pyrolysis, cyanoketene molecular Highest occupied molecular orbital structure, 18–21 (HOMO) Gas phase thermolysis, ketenes, 5–8 ethoxyalkynylsilanes, silylated [2þ2] cycloaddition, 479–480 ketenes and polyketenes, 158 dimerization, 458–459 Gas phase UV spectra, ketenes, 35 oxidation reactions, 437–440 Geometric properties, bisketenes, photoelectron spectra, 37–38 401–402 nucleophilic additions to ketenes, Germylketenes hydration mechanisms, 533–534 classification and formation, 342–357 sulfur-substituted ketenes, 375 nitrogen nucleophile/electrophile Homer-Wadsworth-Emmons reactions, reactions, 562 carbon-substituted ketenes, 229 nucleophilic additions, hydride reduction, Hu¨ckel-Mo¨bius systems, [2þ2] 552–553 cycloaddition reactions of ketenes, Guanine, notrosative deamination, 303 475 Hydration Hafnium ketenylidene complexes, 388 carbon-substituted acylketenes, 254 a-Halo carboxylic acid derivatives, ketene computational studies, 11 dehalogenation, ketene formation, nucleophilic ketene additions, 86–89 mechanisms for, 533–541 Halo derivatives oxygen-substituted ketenes, 315 chloroketenes, olefin bioactivation, 336 silylketenes, 354 dioxinone formation of ketones, 154 sulfur-substituted ketenes, 372 ketene reduction, 440 Hydride reduction, nucleophilic additions to Halogen-substituted ketenes (haloketenes) ketenes, 552–553 chloro- and bromoketenes, 331–340 Hydrogenation, of ketenes, 621 fluoroketenes and fluoroalkyletenes, 1H nuclear magnetic resonance 321–329 alkylketenes, 194 intermolecular [2þ2] cycloaddition and carbon-substituted ketenes, 274–283 ketene dimerization, 458 ketene physical properties, 27–28 Heats of formation, ketene thermochemistry, Hydrogen transfer 22–25 alkynyl ether thermolysis, 156–159 Heavy-atom chain deformation, cycloalkanone photolysis, 132 cumulenones, 430–433 diazo ketone formation, 96–97 Heck cross-coupling reactions, polymer fluoroketenes, 322 supports for ketenes, 622–625 phthalaldehyde photolysis, 297–298 Heptafulvenone, 284, 291–292 Hydroperoxyketene, ozone photolysis, Heteroarylketenes, carbon-substituted 319 alkenylketenes, 221–234 Hydroxyalkynylalkane, chromium carbene Heteroatomic analogues complex, lactone formation, [4þ2] cycloadditions of ketenes, 517 176 oxoquinonemethides, 300 Hydroxycubane, photochemical ketene Hexachlorocyclohexadienone, formation, 118 bromoketenes, 337–338 Hydroxycumulenones, molecular Hexafluoroacetone, fluoroalkylketene structure, 7 formation, 326–327 Hydroxycyclobutenone oxidation, furanone Hexaketene, metal substitution, 411 formation, 123 Hexatrienylketene, 2,4,6-cyclooctatrienone Hydroxycyclopentenone photolysis photolysis, 150 (hydroxycyclopropyl)ketene, 140 INDEX 643

lactone formation, 240 alkynes, 495–499 Hydroxyketene allenes, 492–494 hydration of, 315 dienes, 464–472 nonplanar geometry, 16 dimerization, 453–462 zwitterionic intermediates, 316 imines, 500–510 4-Hydroxyketene, 392 Intramolecular cycloadditions of ketenes Hydroxylketene, alkyne cycloaddition [2þ2] cycloadditions, 479 reactions, 498–499 basic principles, 520–524 Hyperconjugative electron donation, Intramolecular rearrangements silylketene stabilization, 16 carbon-substituted acylketenes, 253–254 H-ZSM-5 zeolite-catalyzed methanol oxygen-substituted ketenes, 318–319 conversion to gasoline, ketene ‘‘Inversely fused’’ bicyclic lactams, ketene intermediates, 186 cycloadditions with imines, 504 Ionization potentials (IPs) IGLO method, ketene physical properties, arylketenes, 438–440 spectroscopic analysis, 29, 33 photoelectron spectra of ketenes, 37–38 Imidoylketenes Iridium complex carbon substitution, 263–267 difluoroketene formation, 324 [4þ2] cycloadditions, 518 metal-substituted ketenes, 393–394 intramolecular cycloadditions, 520–524 Iron ketene complex, trimethylsilylketene, Imines 395–396 [2þ2] cycloadditions of ketenes, 452, Irradiation 500–510 chromium complexes, ketene formation, zwitterionic intermediates, 485 173–174 nitrogen nucleophile/electrophile diazo ketone ketene formation, reactions with ketenes, 560–567 photochemical Wolff rearrangement, 6-Imino-2,4-cyclohexadien-1-one, ketene 107–110 formation, 149 IR-UV double resonance photolysis, ketene Iminoketenes measurements, 39–45 elimination reactions, 301 Isocyanatoketene, cumulene substitution, nitrogen substitution, 308 268, 272 N-Imino-b-lactams, ketene cycloadditions, Isocyanoketene, nitrogen substitution, 308 504 Isodesmic reaction Indenylketene, fulvenone formation, alkylketenes, 193 288–289 carbon-substituted alkenylketenes, 207 Infrared (IR) dissociation, acetic acid-ketene diphenylketene preparation, 221 formation, 57–60 fluoroketene destabilization, 321–322 Infrared (IR) frequency, fluoroketenes, 322 ketene substituent effects, 13–17 Infrared (IR) spectroscopy mercaptoketene, 371 ketene physical properties, 39–45 oxygen-substituted ketenes, 313 phosphorus-substituted ketenes, 361–362 phosphorus-substituted ketenes, 361–362 Infrared laser-powered pyrolysis (IRLPP), silylketenes, 353 ketenes from acid anhydrides, 61–64 Isolable acyl ketene, ynol/ynolates, 378–379 Intermolecular [2þ2] cycloadditions of Isomeric ketenes ketenes, 453–510 cycloaddition with imines, 508 alkenes photolysis, 299 basic mechanisms, 464–472 structure, 6–7 nucleophilic, 487–491 Isopropenyl ester pyrolysis, ketene rapid reactions, 474–485 formation, 81–82 644 INDEX

Isopropenyl ether, cycloadditions of ketenes, a-Ketocarbenes, pentafulvenone formation, nucleophilic alkenes, 489–490 286 Isotope effects b-Keto ester, ketene pyrolysis, 448 ketene cycloadditions, 484–485 Ketoketenes nucleophilic additions to ketenes, decarbonylation, 200 hydration mechanisms, 540 intermolecular [2þ2] cycloaddition and Isoxazol-5(2H)-ones, ketene formation, dimerization, 454–455 alternate routes, 189 polymerization, 602 Isoxazole-substituted ketenes, diazo ketone Ketones. See also Diazo ketones formation, 97 electrophilic reactions, 580–591 Ketene-Cope reaction, diazo ketone oxygenation of ketenes, 587–591 formation, catalyzed Wolff protonation of ketenes, 580–585 rearrangement, 100–104 Kinetic energy release, ketene mass spectra, Ketene dimers, ketene preparation from, 51 55–56 Kohlrausch kinetics, nitrogen nucleophile/ ‘‘Ketene equivalents,’’ cycloaddition electrophile ketene reactions, reactions, 450–451 564–565 Ketene radical cations, mass spectra of, Kowalski procedures, ynolate ketenes, 50–51 379–380 Ketenes historical background, 1–3 b-Lactams theoretical and computational studies, aminoketenes, nitrogen substitution, 391 5–17 azoketene dehydrochlorination, 308 molecular and electronic structure and a-bromo-a-alkenylketenes, 340 energy, 5–8 di-tert-butylketene and formation of, reaction mechanisms and energetics, 197–198 9–12 diphenylketene cycloaddition, 450 substituent effects, 13–17 ketene cycloaddition facility, 450–451 Ketenimes, nucleophilic additions, Wittig imine reactions, 500–510 reactions, 578–579 ketene formation, 71–74 Keteniminylketene, cumulene substitution, nitrogen-substituted ketenes, 310 268, 271–272 phenylketene generation, 223–224 Ketenyl acylium ions, carbon-substituted polymer supports for ketene reactions, ketenes, 276–283 622–625 Ketenylidenecycloalkanes, infrared spectra, stereoselectivity of ketenes, 612–615 41–45 sulfur-substituted ketenes, 372 Ketenylidene phosphoranes, 366–367 ynol/ynolates, 380 Ketenyl infrared (IR) stretching a-Lactones, arylmethylketenes, 232 frequencies, ketene physical b-Lactones properties, 27–33 acid anhydride pyrolysis of ketenes, 62–64 Ketenyloxyl radical, possible formation of, alkylketenes, 194–195 319 aryl chromium carbene complex, ketene Ketenyl radicals, anions, and cations, formation, 175 425–427 bisketene formation and, 408–409 b-Keto acids, intermolecular [2þ2] chromium carbene complex, cycloaddition and ketene hydroxyalkynylalkane reaction, dimerization, 456 176–177 Ketocarbenes, rearrangements, routes for, [2þ2] cycloaddition of ketenes, 453–462 110 carbonyl groups, 525–530 INDEX 645

diphenylketene cycloaddition reactions, Macrocyclic lactams, nitrogen nucleophile/ 450 electrophile reactions, 562–565 ketene molecular dynamics, 9–12 Maganese ketene complexes, 396–397 trimethylsilylketene formation, 350–351 Magnetic susceptibility exaltation, ynol/ynolates, 379–380 fulvenones, 284 Lactone formation Malherbe-Bellus rearrangement, oxygen difluoroketenes, 322 nucleophile ketene reactions, oxygen nucleophile reactions, 555–559 557–559 photochemical ketene formation, 139 Malonic acids, acid anhydride pyrolysis of stereoselectivity of ketenes, 610–615 ketenes, 63 Lanthanum enolate, ketene polymerization, Masochistic steric effect, cycloaddition 601 reactions of ketenes, 466 Laser-ablated metal atoms, ketenide Mass spectrometry formation, 388 ethynyl ethers, 159 Laser flash photolysis fluoroketenes, 323 cyclohexadienones, ketene formation, 145 ketene physical properties, 49–52 ketene/bisketene infrared spectra, 41–45 Meldrum acid derivatives Lewis acids alkenylketene formation, 209 carbon-substituted ketenes, 277 cumulenone formation, 431 ketene cycloadditions, 526 cyanoketene formation, 217 nitrogen nucleophile/electrophile ketene diazo ketone ketene formation, reactions, 563–564 photochemical Wolff rearrangement, Linkage-isomeric ketene complex, 396 107–108 Lipase enzyme, silylketene formation, 358 dioxinone formation of ketones, Liquid ketene irradiation, 444 154–155 Lithium compounds flash vacuum pyrolysis, carboxylketene, bis(silylated) ketenes, 351–352 252 carbon/silicon nucleophilic reactions, imidoylketenes, 264–265 569 ketene cycloadditions, imines, 509 ester enolate formation of ketenes, 79 nitrosoketene formation, 307 ketene computational studies, 11–12 pyrolysis, ketene formation, 448 ketene cycloadditions, 527–530 silylketenes, 354 nucleophilic additions to ketenes, hydride thermolysis, acylketene formation, 161 reduction, 552–553 trifluoroacetylketene, 257 silylketene formation, 348 Mercaptoketene, 371 ynol/ynolates, 381–382 Mesitylketene, nucleophilic additions, Lithiumketene, stabilization properties, hydration mechanisms, 538 387 Mesitylphenylketene Lowest unoccupied molecular orbital carbon/silicon nucleophilic reactions, (LUMO) 569–570 ketenes, 5–8 computational studies, 11–12 [2þ2] cycloaddition, 479–480 X-ray studies of, 20 dimerization, 458–459 Mesoionic species, carbon-substituted oxidation reactions, 437–440 acylketenes, 251 nucleophilic additions to ketenes, Metal carbene complexes, ketenes from, hydration mechanisms, 533–534 171–179 Lumiphotosantonin, photochemical Metal ketenides, classification, 387–389 rearrangement to photosantonic acid, Metal oxides, [3þ2] cycloadditions of 139–140 ketenes, 515 646 INDEX

Metal-substituted ketenes Microwave spectroscopy bisketenes, 397–398 alkyl- and arylketenes, thermal Wolff boron-substituted ketenes, 384–386 rearrangement, 200 electropositive substituents, 387–389 cyanoketene formation, 217 metal-complexed ketenes, 389–398 fluoroketenes, 322 stabilization of, 387–389 ketene dipole moments, 48–49 ynols and ynolates, 377–382 molecular structure of ketenes, 18–21 Methane, ketene substituent effects, Mixed ketenes, carbon substitution, 13–17 227–228 Methoxymethyl esters, ketene formation, 80 Molecular beam electronic resonance, Methyl benzoate, ynol/ynolates, 382 ketene dipole moments, 48–49 Methyl diazo malonate, pyrolysis and ketene Molecular ion peaks, ketene mass spectra, formation, 448 50 5-Methyl-1,5-hexadiene-3-one, Molecular orbital calculations. See also 3-butenylketene formation, 136 Highest occupied molecular orbital; Methylketenes Lowest unoccupied molecular orbital acid anhydride pyrolysis of, 62 diazo ketones, 92–93 dehydrochlorination, 202 intermolecular [2þ2] cycloaddition of fluoroketene destabilization, 321–322 ketenes, alkene reactions, 477–484 a-halo carboxylic acid derivatives, metal-complexed bisketenes, 410 86–89 metal-complexed ketenes, 391–398 hydrogen radical reaactions, 593–594 Molecular structure of ketenes infrared spectra of, 40 determination techniques, 18–21 intermolecular [2þ2] cycloaddition and molecular orbital calculations, 5–8 dimerization, 454–457 Monoalkylketenes ketone electrophilic reactions dimerization, 196 oxygenation, 588 intermolecular [2þ2] cycloaddition and protonation, 581 dimerization, 454–455 nucleophilic additions, Wittig reactions, Monoketenes 576–577 metal substitution and, 416 stereoselectivity, 610, 614–615 thermochemistry of, 24–25 thermochemistry, 22–25 Monophenyl bisketene, metal substitution, vinyl and saturated ester formation, 83 403 Methyl(phenyl)ketene, stereoselectivity, 605 Mukaiyama’s reagent 5-Methyl-pyrones, thermolytic ketene bisketene formation, 420 formation, 163 carboxylic acid-ketene formation, 59 Methylrhenium trioxide, alkyne oxidation, intramolecular ketene cycloadditions, ketenes from, 183–184 522–523 Methylthioketene ketene cycloadditions substituent effects, 372 carbonyl groups, 530–531 Wolff rearrangement, 371 imine reactions, 507–510 (Methylthio)phenylketene, 372 Mulliken population analysis, intermolecular Micelle reactivity, ester enolate formation of [2þ2] cycloaddition of ketenes, ketenes, 78 alkene reactions, 477–484 Michael addition reactions, ester enolate ‘‘Mu¨nchnone’’ tautomers formation of ketenes, 79 benzoylated aminoketenes, 306 Microwave-assisted Wolff rearrangement, nitrogen-substituted ketenes, 311 diazo ketone ketene formation, Muonated methyl radicals, liquid ketene 95–97 irradiation, 444 INDEX 647

Naphthol Nitroxyl radicals, ketene reactions, chromium carbene complex, ketene 594–598 formation, 175 ‘‘No Barrier Theory,’’ hydration ketene formation and, 72 mechanisms, nucleophilic additions photochemical ketene formation, to ketenes, 533 cyclobutenone mechanisms, 118 Nonafulvenone, 284 Naphthoquinone-substitued porphyrins, Norbornadiene cyclobutenone formation of ketene cycloadditions, 471–472 vinylketene, 121 metal substituted bisketenes, 417 Naphthoquinone synthesis, ketene thermolytic ketene formation, 162 formation, 120 Norbornene, ketene cycloadditions, 471 Naphthylketenes Norbornylideneketene cycloaddition reactions diazomethane reactions, 619–620 alkynes, 498 dimeric structure, 55–56 [4þ2] cycloadditions, 517–518 ring-opening polymerization formation, radical reactions, 596 187 ‘‘Near-concerted’’ processes, ketene Norrish type 1 photocleavage cycloadditions, 468 bicyclic keto sulfide photolysis, 133 Negative ion mass spectroscopy, ynolate cycloalkanone photolysis, 132 ketenes, 380 photochemical ketene formation, ring Neopentyl(methyl)ketene, dimerization, 459 opening mechanism, 114–129 ‘‘Neutral hyperconjugation,’’ ketene Novolac-diazonaphthoquinone resists, physical properties, spectroscopic carbon-substituted ketenes, 227 analysis, 29–33 Nuclear magnetic resonance spectroscopy Niobium complex, ketene formation, (NMRS), ketene physical properties, 394–395 27–33 Nitrate radicals, ketene reactions, 597 Nucleophilic alkenes, ketene cycloaddition, Nitric oxide 487–491 bisketene formation and, 413 intramolecular cycloadditions, 522–523 ketenyl radicals, anions, and cations, Nucleophilic ketene additions 425–427 amination mechanisms, 543–551 Nitrogen matrix, chromium carbene hydration mechanisms, 533–541 complex, ketene formation, 175 preparative aspects, 551–574 Nitrogen nucleophiles/electrophiles, ketene carbon and silicon nucleophiles, additions, 560–567 568–574 Nitrogen-substituted ketenes hydride reduction, 552–553 basic properties, 305–311 nitrogen nucleophiles and electrophiles, stereoselectivity, 610 560–567 Nitroketenes, formation of, 306–307 oxygen nucleophiles, 554–559 Nitronate-substituted ketenes, Wittig reactions, 576–579 photochemical rearrangement, Nucleus independent chemical shifts, 265–266 fulvenones, 284 Nitrones, ynol/ynolates, 381–382 (2-Nitrophenyl)diazomethane, photolysis in Oligomeric products, chloroketenes, 337 argon matrix, 300 Oligonucleotides, diazo ketone formation, 4-Nitrophenylketene, from ester enolates, 77 photochemical Wolff rearrangement, Nitrosoketene, formation of, 307 101–104 Nitroso(phenyl)ketene, nitric oxide Organolithium reagents, keten reactions formation, 307 with, 569 648 INDEX

Organometallic reagents, ketene additions, stereoselectivity, 610 570 structure and classification, 313–320 Osmium tetroxide, [3þ2] cycloadditions of Oxyl radical side chains, ketene studies, ketenes, 515 281 Oxazinone Ozone photolysis imidoylketene formation, 266 di-tert-butylketene, 198 photochemical ketene formation, 163–164 cyclohexadienone formation, 143 Oxetanones, trimethylsilylketene formation, ketone electrophilic reactions, 588 349–350 oxygen-substituted ketenes, 319 Oxidation reactions alkynes, ketenes from, 183–185 Palladium catalysts E-7 ketene production, 143 bromoketene formation, 339 ketenes ketene [2þ2] cycloaddition, 465–466 alternate formation routes, 189 Parent ketene (CH2CO), historical mechanisms of, 437–440 development of, 1 Oxiranylketenes Pentafulvenone, structural properties, 284– carbon substitution, 237–242 292 oxygen nucleophile reactions, 558–559 Pentamethyleneketene photochemical Wolff rearrangements, 242 intermolecular [2þ2] cycloaddition and Oxirene intermediate dimerization, 457 diazo ketones, 92–93 photolysis, 56 ketene thermolysis, 447–448 Peracid oxidation, arylalkynes, ketenes Oxirene intermediates, ketene photolysis, from, 183–185 441–442 Perfluorinated ketene, ketone electrophilic a-Oxoketene reactions, 590–591 carbon substitution, 295 Perfluoroalkylaldoketene, acid dehydration, nucleophilic addition, hydration 326 mechanism, 541 Perfluoroketene, flash vacuum pyrolysis, 325 g-Oxoketene, protonation, ketone Pericyclic mechanisms, ketene formation electrophilic reactions, 582 from ester pyrolysis, 81–84 3-Oxomethylenene-6-methylene-1, Perkin conditions 4-cyclohexadiene, photolysis of, acid anhydride pyrolysis of ketenes, 299–300 62–64 5-Oxo-2,4-pentadienes, molecular structure, intramolecular ketene cycloadditions, 7 522 Oxoquinone methide Perpendicular, carbon/silicon nucleophilic carbon-substituted ketenes, 294–303 additions to ketenes, 572 ester enolate formation, 77–78 Phenol photoisomers, cyclohexadienones, Oxoxylylenes, carbon-substituted ketenes, 143 294–303 Phenoxyketenes Oxygenation of ketenes, electrophilic cycloaddition reactions, 465 reactions, 587–591 polymer supports for, 624 17O nuclear magnetic resonance, ketene stereoselectivity, 613 physical properties, 27–33 Phenyl acetate, ester pyrolysis and ketene Oxygen nucleophiles formation, 83 carbon-substituted acylketenes, 249 b-Phenylalkenylketene, intramolecular ketene additions, 554–559 cycloadditions, 523 Oxygen-substituted ketenes Phenylalkylketenes, carbon-substituted cycloadditions with imines, 503–504 reactions, 230 INDEX 649

Phenylbenzoylketene, diazo diketone Phenylvinylketene, cyclohexadienone photolysis, 55–256 interconversion, 143 Phenylchloroketene, cycloadditions, Phosphaketene ylides, 366–367 nucleophilic alkenes, 490–491 Phosphine complexes Phenyldiazomethane photolysis, ketene cycloaddition reactivities, phenylketene formation, 226 481–482 Phenyldimethylsilylketene, 358 nucleophilic alkenes, 491 Phenylethylketenes linkage-isomeric ketenes, 396 n-butyllithium addition, 231 Phosphonate-substituted diazo ketones, carbon/silicon nucleophilic additions, thermal decomposition, 96–97 573 Phosphonium ions, gas phase reaction, polymerization, 601–602 ketene formation, 83–84 radical reactions, 596 31P nuclear magnetic resonance, stereoselectivity, 607 phosphorus-substituted ketenes, Phenylethynol, phenylketene generation, 361–362 224 Phosphorus-substituted ketenes, Phenylethynylketene, photochemical Wolff classification and formation, rearrangement, 214–215 361–369 Phenylhydroxyketene, photolysis of, Phosphoryl chlorides, ketene formation, 64 314 Phosphoryl-substituted ketenes, rate Phenylketenes constants, 365 carbon substitution, 221–234 Photochemical ketene reactions [3þ2] cycloadditions, 513 alternate routes for, 160–169 dehydrohalogenation reaction, 69 cycloalkanone and enone photolysis, ester enolate formation, 79 132–140 nucleophilic additions cyclobutanones/cyclobutenones, amination mechanisms, 546–547 114–129 hydration mechanisms, 535 cyclohexadienones and cycloalkenones, protocol of Lectka, 223 142–151 protonation, ketone electrophilic dioxinone-based ketenes, 153–155 reactions, 585 Photochemical Wolff rearrangement radical reactions, 596–598 cyclopropylketene formation, 239 stereoselectivity, 612 diazo ketone formation 1,3-thiazolidine reaction, 186–187 carbon-substituted acylketenes, Wolff rearrangement, sulfur ylides, 251–252 190 carbon-substituted arylketenes, ynol/ynolate structures, 378 231–232 zinc dehalogenation, 221 carboxamide-substituted ketenes, 256 Phenylmethylketenes catalyzed Wolff rearrangement, carbon substitution, 231 101–104 iridium-alkyne complex, 394 decomposition problems, 104–110 stereoselectivity, 603–615 diphenylketene formation, 225–226 Phenyl radicals, ketene radical reactions, gold surface adsorption, 203 593 a-trialkylsilylalkenylketenes, 208 Phenylsulfonylketene, 374 2,2-diphenylcyclopropylketene, 238 Phenyl(trifluoromethyl)ketene, formylketene, 244 dehalogenation, 328–329 oxiranylketenes, 242 Phenyltrimethylsilylketene, classification pentafulvenone formation, 285–292 and formation, 344 phenylethynylketene formation, 214–215 650 INDEX

Photochemical Wolff (continued) ethoxyalkynylsilane thermolysis, 158–159 silylketenes, 345 polymerization reactions, 601–602 stereoselectivity of ketenes, 609 UV spectra of, 35 Photodissociation of ketenes, 441–445 Polymerization of ketenes, 600–602 Photoelectron spectroscopy (PES) Polymer supports, ketene reactions using, bisketenes, 402–403 622–625 ketene chiroptical properties, 35–38 Positive charge buildup, ketene Photoexcited ketenes, internal conversion, cycloaddition kinetics with alkenes, 442 482 Photofragmentation, deuterated ketenes, Post-Hartree-Fock calculations, ketene 442 molecular structure, 6 Photoionization mass spectrometry, ketene Potassium dicarbonyl, ynol/ynolate ketenes, physical properties, 51 378 Photolithographic applications Proline-derived ketenes, cycloaddition with carbon-substituted ketenes, 227 imines, 508 fulvenone transformation, 288 Propandienone, cumulenone formation, Photolysis 430–431 chromium complexes, ketene formation, b-Propiolactone dimers, ketene 173 cycloadditions, 460–461 ketene dimers, 56 Propylene imine, silylketene formation, ketenyl radicals, 278 348–349 Phthalaldehyde photolysis, hydrogen Proton abstraction, ketene computational transfer, 297–298 studies, 10–11 Phthalidimido-tert-butylketene, nitrogen Proton affinities, ketene thermochemistry, substitution, 306 22–25 Phthalimido ketenes, stereoselectivity, 605, Protonation 613 ketene molecular dynamics, 10 Phthalylketene, nitrogen substitution, 309 ketene photolysis, 443 Picosecond infrared (IR) detection, diazo ketone electrophilic reactions, 580–585 ketone ketene formation, Pseudopericyclic decarbonylation photochemical Wolff rearrangement, [4þ2] cycloadditions of ketenes, 518 107–110 furandione, ketene formation, 165 p-bonding imidoylketenes, 263–267 [2þ2] cycloaddition reactions of ketenes, 2-Pyranone photolysis, alkenylketene 475 formation, 210 metal-complexed ketenes, 389–398 Pyran ring opening, ketene formation, 125 Platinum(II) catalysts Pyridine ring electrocyclization, ketene bisketene formation, 419 formation, 126 phosphorus-substituted ketenes, 367 2-Pyridylcyanoketene, flash vacuum Platinum-substituted ketenes, 388 thermolysis, 233 PM3 calculated IR frequencies Pyridylketenes carbon-substituted ketenes, 277 nucleophilic additions diazo ketone ketene formation, amination mechanisms, 546–547 photochemical Wolff rearrangement, hydration mechanisms, 540 107–108 Wolff rearrangement, 232 Polar solvents, diazo ketone ketene 3-Pyridyl(methyl)ketenee, Wolff formation, 95–97 rearrangement, 232 Polyketenes Pyrimidones, photochemical ketene from cations and free radicals, 182 formation, 163–164 INDEX 651

Pyrolysis Regiochemistry, ketene [2þ2] cycloaddition, acid anhydride-ketene formation, 61–64 479–480 alkylketene preparation, 195 Regioselectivity, Z-dibenzoylethylenes, 137 dimethylketene thermolysis, 447 Resonance structures esters, ketene formation from, 81–84 diazo ketones, ketene formation, ketene dimers, 55–56 90–93 ketene formation, alternate routes, 189 ketene dipole moments, 48–49 2-Pyrone photolysis, photochemical ketene ketene IR frequencies, 40–45 formation, 162–163 ketene molecular orbitals, 5–6 Pyrrole substituents, chromium carbene substituent effects, 15–17 complex, 177 Resorcinol derivatives, trimethylsilylketene formation, 351 Quaternary carbon structure, ketene Reversibility, ketene cycloadditions, formation, 175 452 o-Quinone thermolysis, ketene formation, Rhodium catalysts 149 diazo ketones, catalyzed Wolff Radical anions and cations rearrangement, 98–104 carbon-substituted ketenes, 273–283 oxygen-substituted ketenes, 319 cumulenones, 430–433 phosphorus-substituted ketenes, 363 cyclohexadienones and dienylketenes, 148 silylketenes, 355–356 di-tert-butylketene, 198 thio-substituted ketenes, 372–373 ketene oxidation, 437–440 Ring closure ketene reduction, 439–440 bisketenes, 404–405 ketenyl structures, 425–427 cycloadditions of ketenes, nucleophilic Radical ketene reactions, 592–598 alkenes, 489–491 Raman spectroscopy, ketene physical Ring opening mechanism properties, 39–45 boron-substituted ketenes, 386 Rate constants cyclohexadienone ketene formation, bisketene ring closure, 404–405 142–151 ketene cycloadditions guanine diazotization, 277 alkenes, 468, 480–482 oxygen-substituted ketenes, 314–315 enol ethers, 480–481 photochemical ketene formation, 114–129 ethoxypropene, 481 ynol/ynolate classification, 377–382 phosphines, 481–482 Rotational spectra, ketene measurements, nucleophilic additions to ketenes 39–45 amination mechanisms, 545–546 Ruthenium catalyst hydration mechanisms, 535–538 bisketene formation and, 407 phosphoryl-substituted ketenes, 365 metal-substituted ketenes, 397–398 Reaction mechanisms Rydberg states, chiroptical properties of halogen-substituted ketenes, 333 ketenes, 35–38 ketene computational studies, 9–12 nucleophilic additions to ketenes, Selected ion flow tube (SIFT) reaction, amination mechanisms, 549–550 ketene radicals, 51–52 Reactive ketenes, dehydrochlorination, Selenoxide derivative photolysis, ketene 67–68 formation, 167 Reduction of ketenes Selenyl esters, ketenyl radicals, mechanisms for, 439–440 278–279 nucleophilic additions, hydride reduction, Short-lived ketenes, spectroscopic analysis, 552–553 33 652 INDEX

Shuttle mechanism Solvent effects phenyketene formation by cyclobutenone ring opening, 119 dehydrochlorination, 69–70 ketene cycloadditions, imine reactions, phenylketene generation, 223 502–503 Side chain reactions nucleophilic additions to ketenes, carbon-substituted ketenes, 273–283 hydration mechanisms, 540 dioxinone formation of ketones, 154 ynol/ynolate ketenes, 378–382 s-bonding, metal-complexed ketenes, Solvent polarity rate 389–398 exo/endo cycloaddition stsereochemistry, b-Silicon effect, silylketene stabilization, 16, 467–468 346 ketene dimerization, 461–462 29Si nuclear magnetic resonance, ketene norbornadiene, 472 physical properties, 29–33 Spirocyclopentenone, photochemical ketene Silicon nucleophiles, ketene additions, formation, 139 568–574 Squaric acid, bisketene formation, 405 Silicon-substituted ketenes, 387 Stabilization energy (SE) Silver salts ketene substituent effects, 13–17 diazo ketones, catalyzed Wolff metal-substituted ketenes, 387–389 rearrangement, 97–104 Stannylketenes, 342–357 metal ketenides, 387 boron substituents, 385 Silyl(alkenyl)ketene, 345 nucleophilic additions, hydride reduction, a-Silylated alkenylketenes, 354 552–553 Silylated para-benzoquinone, vinylketene Stepwise reaction pathways, intermolecular formation, 212 [2þ2] cycloaddition of ketenes, Silylated vinylketenes, 358 alkene reactions, 476–484 Silyl enol ether, cycloadditions of ketenes, Stereoselectivity nucleophilic alkenes, 489–490 diazo ketone formation Silylgermyl ketenes, 354 catalyzed Wolff rearrangement, Silylketenes 101–104 classification and formation, 342–357 photochemical Wolff rearrangement, cycloadditions, carbonyl groups, 528 105–110 ethoxyalkynylsilane thermolysis, 158–159 dioxinone formation of ketones, 153–155 mass spectra of, 50 ketene chiral centers, 603–615 nucleophilic additions, hydride reduction, ketene cycloadditions, 451 552–553 alkenes, 479–484 photochemical Wolff rearrangement, carbonyl groups, 527–530 345 imine reactions, 502–510 physical properties, spectroscopic phosphorus-substituted ketenes, 365–366 analysis, 29–33 photochemical ketene formation, stabilization energy, 16, 346–347 cyclobutanone thermolysis, 115 X-ray studies of, 20–21 Steric interactions ynol/ynolates, 382 bicyclic ketone hydrogen transfer, 132 Silyloxy-substituted ketenes, 214–219, 319 cycloaddition reactions of ketenes, 466 b-Silyl substituents, Norrish Type I cleavage alkene reactions, 474–485 of ketones, 132 ketene physical properties, spectroscopic Simple ketenes, thermochemistry, 22–25 analysis, 29–33 Smith-Hoehn reaction, intramolecular Stretching frequencies ketene cycloadditions, 523 HCl/HBr, ketene formation, 71–72 Sodioketene, stabilization energy, 15–17 ketene IR spectra, 41–45 INDEX 653

Styrenes, ketene cycloaddition kinetics, diazo ketones, 93–97 483–484 cyclopropylketenes, 241–242 Substituent effects diphenyl ketene formation, 221–222 cyclobutenone ring opening, 120 diazulenylketene, 226 diazo ketones, ketene formation, 90–93 ketene decarbonylation, 448 fluoroketene destabilization, 321–322 metal-substituted bisketenes, 417 on ketenes, 13–17 oxygen-substituted ketene formation, 106 infrared spectroscopic analysis, 40–45 phosphorus-substituted ketenes, 363–365 metal-complexed ketenes, 389–398 polymer-bound ketene, 357 Sulfoxide derivative photolysis, ketene thiadiazocycloheptanone, ketene formation, 167 formation, 199 Sulfur dioxide, ketene reactions with, 621 Thermochemistry of ketenes, 22–25 Sulfur-substituted ketenes Thermolytic ketene formation classification, 371–375 alkynyl ether thermolysis, 156–159 stereoselectivity, 610 alternate routes for, 160–169 Suzuki cross-coupling reactions, polymer cycloalkanone and enone photolysis, 132– supports for ketenes, 622–625 140 Syn conformation cyclobutanones/cyclobutenones, ketene dimerization, 459–460 114–129 vinylketene, 206 cyclohexadienones and cycloalkenones, ‘‘Syndnones,’’ photolysis of, 307–308 142–151 dioxinone-based ketenes, 153–155 Tantalum complex, ketene formation, 394– reaction mechanisms, 446–449 395 Thiadiazocycloheptanone, thermal Wolff TEMPO aminoxyl radical rearrangement, 199 1,4-bisketene formation, 402–403 1,3-Thiazolidine reaction, phenylketenes, ketene radical reactions, 594–598 186 pentafulvenone formation, 287–292 Thioesters, ketenyl radicals, 279 Terephthalyl chloride, bisketene formation Thioketene, molecular structure and, 414 determination of, 18–21 Tetraketene Thiophene derivatives, cumulenone metal-substituted bisketenes and, 405 formation, 431–432 X-ray studies of, 20 Thiophosphorylketene, 364 Tetraketone, ketene formation, 166 Thorium complex, silylated metalloxy Tetramethylcyclopropylideneketene, ketenes, 347 dehalogenation, 196–197 Three-phase test of reaction intermediates, Tetramethylketene ester enolate formation of ketenes, cyclopentenyl ketone formation of, 134 80 photolysis, 56 Thulium acetate hydrate, acetic acid-ketene 2,3,5,6-Tetra(trimethylsilyl)-1,4- formation, 58 benzoquinone, ketene formation, 149 Thymine hydroxylase, covalent Thermal intramolecular cyclization, acyl modification, ketene formation, 184 chloride ketenes, 201 Time-resolved infrared (TRIR) analysis Thermal Wolff rearrangement carbon-substituted phenylketenes, 224 alkyl- and arylketenes, microwave diazo ketone ketene formation, irradiation, 200 photochemical Wolff rearrangement, arylketene photelectron spectra, 438–440 106–107 boron-substituted ketenes, 385–386 ketene/bisketene infrared spectra, 41–45 [4þ2] cycloadditions of ketenes, 518–519 phenylethynyllketene, 214–215 654 INDEX

Time-resolved infrared (continued) iron ketene complex, 395–396 phenylhydroxyketene, 314 ketone electrophilic reactions, phenylketenes, ynol/ynolate ketenes, 378 protonation, 581, 584 short-lived ketenes, 33 oxetanone formations, 349–350 Titanium oxide surfaces, acetic acid-ketene pyrolysis of, 342 formation, 58 stereoselectivity, 611 Torquoselectivity Zwitterionic intermediate, 357 allenylcyclobutenone, 127 Trimethylsilyl-substituted dienylketene, ring opening of cyclobutenones, thermolysis, 354–355 photochemical ketene formation, Trimethylsilylvinylketene, 119 dehydrochlorination, 344 Tosylate anhydrides, ketene formation, Triphenylarsenylideneketene, 369 63–64 2,2,3-Triphenylcyclobutanone, Transesterification, dioxinone, 250 photochemical ketene formation, 2,5-(Trans-4-octenyl)-bridged p- 116 benzoquinone, ketene formation, 2,2,4-Triphenylcyclobutenone, 138–139 photochemical ketene formation, 118 Triafulvenone, structural properties, Triphosgene, carboxylic acid-ketene 284–285 formation, 59 Trialkylamine, dehydrochlorination of Triplet ketocarbenes, photochemical Wolff ketenes, 69 rearrangement, 105–110 a-Trialkylsilylalkenylketenes, Triplet oxygen, ketene electrophilic photochemical formation, 208 additions, 590 Trialkylsilyl(aryl)ketenes, Wolff Tungsten-substituted ketenes, 369 rearrangements, 355 Two-photon absorption, diazo ketone ketene Trialkylsilylketenes, Wittig reagents, 351 formation, photochemical Wolff Triazoline photolysis, tricyclic ketone rearrangement, 109–110 formation, 165 Tricyclic ketones, thermolytic ketene Ultraviolet (UV) spectroscopic analysis formation, 160 ketene chiroptical properties, 35–38 Triflate carbonylation, alkenylketene nucleophilic additions to ketenes, formation, 212 hydration mechanisms, 535–538 Trifluoroacetylketene, Meldrum acid Unimolecular dissociation, ketene derivatives, 257 photolysis, 442 Trifluoromethylmalonate esters, Unsaturated groupings, ketene fluoroketene formation, 329 cycloadditions, 465 Trimethylgermylketene, diazomethane Unsymmetrical ketenes, dimerization, 459 reactions, 619 Uranium oxide, acetic acid-ketene Trimethylsilyl ester pyrolysis, ketene formation, 58 formation, 82–83 Trimethylsilylketenes Valine-derived ketenes, nitrogen alkynyl ether thermolysis, 156–157 substitution, 309 carbonylation, 347–348 Verbinone photolysis, alkenylketene cycloaddition reactions, 350, 352 formation, 132–133 carbonyl groups, 528 Vibrational spectra, ketene measurements, nucleophilic alkenes, 488–489 39–45 dehydrochlorination and formation of, 66 Vinylcyclobutenone diazomethane reactions, 346, 619 ketene formation, 120 dimerization resistance, 346 vinyl ene-yne ketone formation, 123–125 INDEX 655

Vinylcyclopropyl carbene complex, ketene trimethylsilylketene, 342 formation, 179 Wolff rearrangement Vinylcyclopropylketenes, photochemical 1-adamantyl(carboethoxy)ketene, 245 Wolff rearrangement, 239 arylalkylketene formation, 230 Vinyl esters, ketene formation, 83 aryl(trialkyl)silylketenes, 234 Vinyl ethers, ketene cycloaddition, benzopentafulvenone, 289 nucleophilic alkenes, 487–491 bisketene formation, 401 3-(2-Vinyl)indolylcarbene complexes, bis(trimethylsilyl)ketene, 343–344 ketene formation, 178 di-tert-butylketene formation, 199 Vinylketenes carbon-substituted phenylketenes, as alkenylketene parent, 206–213 224–22 alkynyl ether thermolysis, 157–158 chiral ketene stereoselectivity, 606 allenyl thio ester thermolysis via, 161 cyclopropenylketene, 242 carbocation derivatives, 276 cyclopropylketene preparation, 238 chromium carbene complex, 176 diazo ketones, ketene formation collisionally activated dissociation of alternative routes, 110 resorcinol derivatives, alkenylketene catalyzed rearrangement, 97–104 intermediates, 150 overview, 92–93 cyanoketene formation, 218 oxygen-substituted ketenes, 318–319 cycloaddition reactions, 10 photochemical, 104–110 alkynes, 495–499 3-pyridyl(methyl)ketenee, 232 cyclobutanone photolysis, 117 thermal rearrangement, 93–97 cyclobutenone ring opening, 118–129 fluoroalkylketene formation, 326–327 cyclobutenone thermal rearrangement, 121 ketene cycloadditions intramolecular cycloadditions, 520–524 with carbonyls, 531 ketone electrophilic reactions, with imines, 504 protonation, 581 ketene mass spectra, 51 mass spectra of, 51 ketene structure, 2–3 metal-complexed ketenes, 390–398 computational studies, 6–7 microwave spectrum, 18 methylthioketene, 371 molecular structure, 7 pentafulvenone formation, 284–292 oxygen nucleophile reactions, 555 phenylsulfonylketene, 374 tricarbonyl iron complex, 393 phosphorus-substituted ketenes, 362 Vinylogous Wolff rearrangement photochemical ketene formation, 3-butenylketene formation, 136 vinylogous catalyst, 116–129 photochemical ketene formation, trialkylsilyl(aryl)ketenes, 355 cyclobutanones, 116–129 vinylketenes, intramolecular Vinyl phosphate, fluoroketene formation, 325 cycloadditions, 521 Vinyl-substituted acyl radicals, carbon- Woodward-Hoffmann rules substituted ketenes, 278–279 intermolecular [2þ2] cycloaddition of ketenes Water-soluble cyclohexadienones, amino alkene reactions, 474–485 acids and potolysis of, 146 dimerization, 455 Wittig reaction ketene cycloadditions, 451 BHT ester formation of ketene, 78–79 nucleophilic ketene additions, Xenon matrix, ketene IR spectra, 41–45 576–579 X-ray diffraction silylketene cycloadditions, carbonyl allenylketenes, 269–270 groups, 528 molecular structure of ketenes, 20 656 INDEX

Ylides, nitrogen nucleophile/electrophile Zwitterionic intermediates ketene reactions, 564–565 aminocarbene complex, 172 Ynamine reaction, acylketene formation, bis(trifluoromethyl)ketenes, 328 187 carbon-substituted acylketenes, 246 Ynolates cycloadditions of ketenes, 469–470 collisionally activated dissociation of alkenes, 480–484 resorcinol derivatives, alkenylketene allenes, 493–494 intermediates, 150 imine reactions, 500–510 ketenyl radicals, anions, and cations, nucleophilic alkenes, 488–491 425–427 cyclohexylamine reaction, 147 silylketene formation, 349 diphenylketenes, 464–465 structure and classification, 377–382 ketene dimerization, 459–460 Ynols, structure and classification, 377–382 metal-substituted bisketenes, 412 methylketene dimerization, 456 Z-dibenzoylethylene, ketene formation, nucleophilic additions 136–137 dienylketenes, amination mechanisms, Zinc activation 548 arylalkylketene formation, 230 oxygen nucleophile reactions, chloroketenes, 332–333 557–559 cycloaddition of ketenes, alkynes, 495– oxygen-substituted ketenes, 316 499 pentafulvenone formation, 287, dibromoketenes, 339 291–292 difluoroketenes, 323–324 phosphorus-substituted ketenes, fluorenylideneketene, 290 365–366 a-halo carboxylic acid derivatives, ketene photochemical ketene formation, 116 formation, 87 stereoselectivity of ketenes, 603–615 Zirconium ketenylidene complexes, 388 trimethylsilylketene, 357