Baran Group Meeting Kyle W. Knouse JOC Year in Review : 1995 10/14/16 Statistics: Volume 60 1536 papers 8430 pages Top 5 Most Cited Papers: Palladium(0)-Catalyzed Cross-Coupling Reaction of Alkoxydiboron with Haloarenes: Publication Record: A Direct Procedure for Arylboronic Esters Katritzky, A. R. (20) Ishiyama, Tatsuo; Murata, Miki; Miyaura, Norio J. Org. Chem. 1995, 58, 904–912 Paquette, L. A. (15) 902 citations Denmark/Padwa/Marshall/Wong (8) Meyers, A. I. (7) "We need as heterocyclic chemists, to hold our heads Preparation and Characterization of Fulleroid and Methanofullerene Derivatives: Heathcock/Molander (6) high. Society cannot operate efficiently without us. All Hummelen, Jan C.; Knight, Brian W.; LePeq, F.; Wudl, Fred; Yao, Jie; Wilkins, Charles L. the impressive advances of biological chemistry, J. Org. Chem. 1995, 60, 532-538 genetic manipulation, enzymatic transformation, 793 citations Top Movies: antibody recognition, depend on the basic principles of Heterocyclic chemistry." Toy Story Novel Alkaloids from the Sponge Batzella sp.: Inhibitors of HIV gp -Human CD Binding - Alan R. Katritzky 120 4 Braveheart Patil A. D., et al. J. Org. Chem. 1995, 60, 1182-1188 GoldenEye 534 citations Apollo 13 (19/20 publications involved reactions of benzotriazoles) Jumanji Conversion of Arylboronic Acids into Potassium Aryltrifluoroborates: Convenient Precursors of Arylboron Difluoride Lewis Acids Vedejs, E.; Chapman, R. W.; Fields, S. C.; Lin, S.; Schrimpf, M. R. J. Org. Chem. 1995, 60, 3020-3027 Fun facts from 1995 342 citations world population: 5,674,380,000 -record for longest time in space is set, twice (366 days; 488 days) Phosphine-Catalyzed Cycloaddition of 2,3-Butadienoates or 2-Butynoates with -oklahoma city bombing Electron-Deficient Olefins. A Novel [3 + 2] Annulation Approach to Cyclopentenes -man says "Oklahoma was a good idea" then drives tank through Zhang, Chunming; Lu, Xiyan J. Org. Chem. 1995, 60, 2906-2908 Claremont neighborhood. 340 citations -internet becomes available to public (eBay founded, Windows 95 released) - DVD concept released Top Songs: Gangsta's Paradise - Coolio Waterfalls - TLC This Is How We Do It - Montell Jordan Only Wanna Be with You - Hootie & the Blowfish Baran Group Meeting Kyle W. Knouse JOC Year in Review : 1995 10/14/16 Synthesis of Aromatic Heterocycles via Palladium-Catalyzed Annulation of Internal Asymmetric Ring Closure Reactions Mediated by a Chiral C2 Symmetrical Organoselenium Reagent Alkynes ArSe Richard C. Larock," Eul K. Yum, Mark J. Doty, and Kelvin K. C. Sham Robert Deziel* and Eric Malenfant JOC, 1995, 60, 3270-3271 JOC, 1995, 60, 4660-4662 R3 Pd: PdOAc O R Chloride: LiCl, n-Bu4NCl 2 3 R R Base: Na2CO3, NaOAc (77%) 12:1 facial R1 OH selectivity OEt SeX OEt R cat. Pd(0) Indoles R2 I base NR1 Me Me ArSe Ac NHAc N R OH 1,2-dihydro X = OTf R O I Ph isoquinolines R=tBu only see exo product (95%) 29:1 facial 80% selectivity CO2Et CO2H, NHBOC also acceptable nucleophiles OH O t-Bu Benzofurans I 65% Me Me Me Me Me OH O (2,4,6-Triisopropylphenyl)selenium Bromide (TIPPSe-Br). An in Situ-Generated Benzopyrans Reagent for Effecting Highly Selective Ring Closures of Homoallylic Alcohols to 52% I Ph Substituted Tetrahydrofurans Bruce H. Lipshutz* and Timothy Gross CO2Et Me SeAr O JOC, 1995, 60, 3572-3573 CO Me Me Me 2 O Me Me R Isocoumarins OH O I 72% R Me t-Bu Me Me Me SrAr Me SeX Me Me A New Version of the Peterson Olefination R Moncef Bellassoued and Nicolas Ozanne Me Me OH JOC, 1995, 60, 6582-6584 R Me O "a new simplified version of the Peterson olefination" X = Br Me SeAr Me O SiMe3 SeAr Me SiMe SiMe3 R Me R Me Bu SnH Me R 3 R-Li R Me 3 Li R OH O R Me R Me R R Me R R OH PhH, reflux O Me O Me Me SeAr O Me Me R R H R OH O SiMe3 R Solution to 5-endo trig R Me cyclization? R R cat. CsF, DMSO R OSiMe3 100°C Avoids the use of strong organolithium reagents Baran Group Meeting Kyle W. Knouse JOC Year in Review : 1995 10/14/16 An Inexpensive Air-Stable Titanium-Based System for the Conversion of Esters to Total Synthesis of (-)-Thiangazole and Structurally Related Polyazoles Primary Alcohols Peter Wipf* and Srikanth Venkatraman Matthew T. Reding and Stephen L. Buchwald* JOC, 1995, 60, 7224-7229 JOC, 1995, 60, 7884-7890 O Me OH 1. DMP D-Thr-OMe, DCM O 2. Ph3P, I2, NEt3, THF Ses-HN PyBroP, DMAP H Non-Toxic OH Ses-HN OMe 3. MeNH2, MeOH Non-Pyrophoric N Me 60% i A 82% Me H Ti(OPr)4, Workup: BnO O O OBn Me PMHS Si Me NaOH or TBAF R1 O R1 OH - R OMe O Me 1. F Me2N O OBn Tolerant n 2. Coupling, A Me Functional Groups Me2N O N O 74% - O OBn NH-Ses 1. F HN Me O N 2. Coupling, A HO C Me 55% 1. F- 2 O Advantages: HN X OBn 2.Coupling, O -No need for organic solvent Bn MeOBn O X=Br,I -No need for anyhydrous/inert atm. Me 69% HN -inexpensive reagents, Ph Me2N O (byproduct of silicone production) Me O O N Me N O O Me 2 MeO 1. Pd(OH) , H N O PhSeO H, O 2 2 2 N 2. Burgess Me Me benzene, 70 °C O N Me N O 60% 60% Me Me N N A Mild, Regioselective Ketal Claisen Rearrangement Promoted by O Triisobutylaluminum AcSH ? N Scott D. Rychnovsky* and Jennifer L. Lee Me O 56% JOC, 1995, 60, 4318-4318 Me2N Ph O Me OMe i-Bu Al O N Me OH R OMe Me O 3 Me N O S Ph 2 MeSAc Me Me DCM N Me Me PPTS Me Me R N O 0 °C O SAc 1. NH3, MeOH Me S HN Me Me i-Bu Al 2. TiCl4, DCM N Me 3 3. PhSeO H, Me R O 2 Me Me O AlR HN benzene, 70 °C N 3 Me one-pot 89% Me Me OH SAc 60% S Me HN Ph OH O Ph Me OH Me Ph Me Ph ~ 5$ / gram NHSES Orthogonal to Tosyl and Boc HO Me Disadvantageous acid resulted in isomerization, Org. Synth. 1998, 75, 161 Yield Ratio lowering yield and product ratios No Change SESCl, Et N - 49% 75:25 3 NH F NH + Et N NH2 SiMe 2 3 58% 94:6 S 3 Isolate enol ether 69% 96:4 O O Daub, W. G.; JOC, 1983, 48, 3876 H+/ 120 °C 79% 9:91 Relative stability of Tosyl, but can be easily removed with F- Baran Group Meeting Kyle W. Knouse JOC Year in Review : 1995 10/14/16 A new, Titanium-Mediated Approach to Pyrroles: First Synthesis of Lukianol A Diastereoselective Cyclopropanation of Chiral Allylic Alcohols: A More Efficient and Lamellarin O Dimethyl Ether Reagent for the Relative Stereocontrol Alois Furstner,* Holger Weintritt, and Achim Hupperts Andre B. Charette" and Helene Lebel JOC, 1995, 60, 6637-6641 JOC, 1995, 60, 2966-2967 O OH OH OH OH R1 1 2 R1 NH O "low valent R1 R2 R R Ph R Ph R titanium" HN R2 syn:anti New R2 R2 Zn, CH I < 2:1 Sm(Hg), CH2I2 R2 2 2 Conditions Sm(Hg), CH2I2 1:5 to > 200:1 R = Me 7 : 1 1 : 6 R = Ph, t-Bu, 2-naphtyl, CO2Et Et 130 : 1 1 : 1 Bu 150 : 1 1 : 1.4 Method A: Premix TiCl4 and C8K to form (Ti-Graphite) All isolated yeilds > 75% for both new i-Pr > 200 : 1 > 200 : 1 Method B: Add TiCl3 and Zinc directly to subsrate and "old" conditions t-Bu > 200 : 1 > 200 : 1 1. ZnEt2, DCM -10 °C 1. H2O2, NaOH Ar Ar OBn OBn OBn 2. CH2I2, -10 °C O 2. BF3•OEt2, ether (reflux) Ar Ar H2, Pd/C O Ph R 3. NH2OH•HCl, pyridine (reflux) Ph R Ph R Ar Ar O 3. warm to rt 83% N E/Z (1:1) 1: 9 NH2 R = Me Et 1 : 2 Ar O i-Pr 19 : 1 Ar Ar Ar Ar O Ti - graphite, Improved Procedure for the Synthesis of Enantiomerically Enriched Ar Cl CO2Me DME, reflux Cyclopropylmethanol Derivatives O Andre B. Charette,* Sylvie Prescott, and Christian Brochu NH CO Me E/Z (2.5:1) 52% N 2 JOC, 1995, 60,1081-1083 NH2 73% H Scalable as long as -10 °C O CO2Me Me2NOC CONMe2 temperature is maintained Ph OH during addition MeO OMe Ph OH O O HO OH B 93% ee (> 98% yield) Me O (1.1 eq.) Bu O BnO OH Ar Ar Br 1. KO-tBu, H2O, ether Zn(CH2I)2•DME (3-5 eq.) K2CO3, acetone 2. Ac2O, NaOAc, reflux BnO OH DCM, -10 °C reflux MeO C 93% ee (> 98% yield) CO Me 2 N 3. BBr3, DCM O N 2 MeO2C N H 91% O 53% O lukianol A Diastereoselectivity in the Cyclopropanation of 3,3-Bimetallic 8 steps, 12% yield Allylic Alcohols. Preparation of Diastereomeric Cyclopropyl Carbinols via a Simple Oxidation-Reduction Sequence O Mark Lautens* and Patrick H. M. Delanghe R JOC, 1995, 60, 2474-2487 R TMS OMe HO TMS R Sm(Hg), CH I TMS 2 2 OH OH R3Sn R3Sn R3Sn OH 1 : 20 (80%) R R 1. TPAP, NMO, DCM TMS TMS OH OH 2. LAH, THF R3Sn R3Sn 1 : 20 (85%) Baran Group Meeting Kyle W. Knouse JOC Year in Review : 1995 10/14/16 Sodium Diethyldialkynylaluminate, A New Chemoselective Alkynylating Agent Selective, Electrophilic Fluorinations Using N-Fluoro-o-benzenedisulfonimide Jin Hee Ahn, Meyoung Ju Joung, and Nung Min Yoon* Franklin A.