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Myers Cyclopropanation Chem 115 Reviews: • Bonding Orbitals in Cyclopropane (Walsh Model): Roy, M.-N.; Lindsay, V. N. G.; Charette, A. B. Stereoselective Synthesis: Reactions of Carbon– Carbon Double Bonds (Science of Synthesis); de Vries, J. G., Ed.; Thieme: Stuttgart, 2011, Vol 1.; 731–817. Lebel, H.; Marcoux, J.-F.; Molinaro, C.; Charette, A. B. Chem. Rev. 2003, 103, 977–1050. Davies, H. M. L.; Beckwith, R. E. J. Chem. Rev. 2003, 103, 2861–2903. Li, A-H.; Dai, L. X.; Aggarwal, V. K. Chem. Rev. 1997, 97, 2341–2372. eS (") eA (") • Applications of Cyclopropanes in Synthesis Carson, C. A.; Kerr, M. A. Chem. Soc. Rev. 2009, 38, 3051–3060. Reissig, H.-U.; Zimmer, R. Chem. Rev. 2003, 103, 1151–1196. Gnad, F.; Reiser, O. Chem. Rev. 2003, 103, 1603–1624. • Cyclopropane Biosynthesis ! Thibodeaux, C. J.; Chang, W.-c.; Liu, H.-w. Chem. Rev. 2012, 112, 1681–1709. de Meijere, A. Angew. Chem. Int. Ed. 1979, 18, 809–886. General Strategies for Cyclopropanation: Introduction • via carbenoids "MCH2X" H HH H H H • via carbenes generated by decomposition of diazo compounds H H H H H H RCHN2 • Cyclopropanes are stable but highly strained compounds (ring strain ~29 kcal/mol). R • via Michael addition and ring closure • C–C bond angles = 60º (vs 109.5º for normal Csp3–Csp3 bonds). • Substituents on cyclopropanes are eclipsed. H–C–H angle is ~120º. As a result, the C–H bonds RCH–LG have higher s character compared to normal sp3 bonds. EWG EWG EWG LG R • Because of their inherent strain, the reactivity of cyclopropanes is more closely analogous to that of alkenes than that of alkanes. RCH2 R EWG LG EWG LG EWG R Lebel, H.; Marcoux, J.-F.; Molinaro, C.; Charette, A. B. Chem. Rev. 2003, 103, 977–1050. James Mousseau, Fan Liu 1 Myers Cyclopropanation Chem 115 Simmons-Smith Reaction –– Zinc Reagents in Cyclopropanation • Diastereoselective cyclopropanation is possible in the presence of directing groups: • Original Report: OH OH OCH3 CH3O H H CH2I2, Zn(Cu) CH2I2, Zn(Cu) H CH I , Zn(Cu) Et O, 35 ºC Et O, 35 ºC 2 2 2 H 2 H (±) 63% (±) (±) ~60% (±) Et2O, 35 ºC 48% H Dauben, W. G.; Berezin, G. H. J. Am. Chem. Soc. 1963, 85, 468–472. Simmons, H. E.; Smith, R. D. J. Am. Chem. Soc. 1958, 80, 5323–5324. • Interestingly, excess carbenoid can reverse the directing effect of alcohols. • Reaction Overview: OZnR' OZnR' OZnR' H H Zn I H R1 "ZnCH I" CH R H 2 2 1 OBn OBn OBn R1 H R H R R2 2 2 Zinc Reagent dr yield Zn(CH I) (1 equiv) >25:1 >95% Butterfly transition state 2 2 EtZnCH2I (9 equiv) 1:>25 >95% Charette, A. B.; Marcoux, J. F. Synlett, 1995, 1197–1207. • The reaction is proposed to proceed through a "butterfly" transition state. • Directed cyclopropanation is also possible in acyclic systems: Simmons, H. E. Org. React. 1973, 20, 1–133. OH OH OH CH • Zinc cyclopropanating reagents can be generated in various ways. Both Zn metal and ZnEt can be Et2Zn, CH2I2 3 2 CH3 CH3 used. CH Cl , –10 °C H 2 2 H 97% : • Many zinc reagents for cyclopropanation have been developed: 130 1 Charette, A. B.; Lebel, H. J. Org. Chem. 1995, 60, 2966–1967. • Diastereoselectrive cyclopropanation has been used in tandem asymmetric organozinc additions: O O I Zn I I EtO Zn Zn F C P I 3 Zn Zn 1. HBEt , PhCH , 23 ºC I H3C EtO 2 3 I I OH Simmons 2. Et2Zn, i-PrCHO ZnEt2, CH2I2 OH and Smith Denmark Furukawa Shi Charette CH3 H3C CH3 Ph CH Cl , 23 ºC CH3 Ph 2 2 Ph O CH3 N H CH3 Highly reactive OH carbenoid for Highly stable carbenoid 75%, 99% ee H3C (4 mol%) General applicability unreactive alkenes dr >20:1 –78 ! –10 ºC Kim, H. Y.; Lurain, A. E.; Garcia-Garcia, P.; Carroll, P. J.; Walsh, P. J. J. Am. Chem. Soc. 2005, 127, 13138–13139. James Mousseau, Fan Liu 2 Myers Cyclopropanation Chem 115 • Asymmetric Simmons-Smith Reaction Using Chiral Auxiliaries • Stoichiometric Promoter for Asymmetric Simmons-Smith Cyclopropanation • Allylic alcohols: • A chiral dioxaborolane auxiliary prepared from tetramethyltartramide and butylboronic acid has been shown to be effective in the asymmetric cyclopropanation of allylic alcohols. • A hydrogen peroxide work-up is employed to remove boron side-products. OBn OBn Et Zn, CH I O 2 2 2 O A (1.1 equiv) BnO O Ph BnO O Ph BnO BnO H OH toluene, –35 ! 0 ºC OH Zn(CH2I)2, DME, CH2Cl2 98%, dr >50:1 OH OH 0 ! 23 ºC 1. Tf O, C H N >98%, 93% ee 2 5 5 then 30% aq H O 2. 2 2 via OBn DMF, H2O, C5H5N Me 160 ºC, 90% O Et BnO O OBn via O BnO Me O O H3C O HO Ph N(CH ) EtZn Zn O N(CH ) O 3 2 C + BnO (H3C)2N 3 2 B H I BnO 2 CHO O O O O H B Zn O N(CH3)2 A I Charette, A. B.; Côté, B.; Marcoux, J.-F. J. Am. Chem. Soc. 1991, 113, 8166–8167. n-Bu Ph H • Allylic amines: Charette, A. B.; Juteau, H.; Lebel, H.; Molinaro, C. J. Am. Chem. Soc. 1998, 120, 11943–11952. Ph OH Ph OH • Allylic alcohols are cyclopropanated selectively: Et2Zn, CH2I2 H3C N Ph H3C N Ph CH2Cl2, 0 °C CH3 CH3 ent-A (1.1 equiv) 95%, dr = 98:2 CH3 CH3 CH3 H3C Zn(CH2I)2, DME, CH2Cl2 H3C H H3C Aggarwal, V. K.; Fang, G. Y.; Meek, G. Org. Lett. 2003, 5, 4417–4420. then 30% aq H O OH 2 2 80%, 95% ee OH • ",#-Unsaturated carbonyls: 1. (EtO)3CH, NH4NO3 (cat.) H C EtOH, 23 ºC 3 O Nicolaou, K. C.; Sasmal, P. K.; Rassais, G.; Reddy, M. V.; Altmann, K. H.; Wartmann, M.; O'Brate, H3C H CO2i-Pr O A.; Giannakakou, P. Angew. Chem. Int. Ed. 2003, 42, 3515–3520. O 2. OH CO2i-Pr CO2i-Pr • The cyclopropanation of allenic alcohols affords spiropentane derivatives: i-PrO2C OH Et2Zn, CH2I2 C5H5NH•OTs, C6H6 hexanes, –20 °C OH 80 ºC, 79% A (1.1 equiv) MO Et OH Et Zn(CH2I)2, DME, CH2Cl2 C Et H H3C O H pTSA, THF Et H –10 ! 23 ºC Et H C CO2i-Pr Et 3 H O then 10% aq NaOH H O, 65 ºC 70%, 97% ee O 2 yield not provided CO2i-Pr 90%, dr = 97:3 Mash, E. A.; Nelson, K. A. J. Am. Chem. Soc. 1985, 107, 8256–8258. Charette, A. B.; Jolicoeur, E.; Bydlinkski, G. A. S. Org. Lett. 2001, 3, 3293–3295 Mori, A.; Arai, I.; Yamamoto, H. Tetrahedron 1986, 42, 6447–6458. James Mousseau, Fan Liu 3 Myers Cyclopropanation Chem 115 • The dioxaborolane promoter can be used to prepare 1,2,3-trisubstituted cyclopropanes. • Unfunctionalized alkenes can undergo asymmetric Simmons–Smith cyclopropanation in presence of • In the example shown, the intermediate borinate was used directly for Suzuki coupling: a valine/proline dipeptide. • Selectivity is higher for trisubstituted alkenes than for disubstituted alkenes. O O (H3C)2N N(CH3)2 Ph C (1.25 equiv) Ph O CO2CH3 BocHN 1. Et2Zn 2. A (1.2 equiv) O O Et2Zn, CH2I2 N Ph OH Ph OZnEt B n-Bu CH2Cl2, 0 ºC Ph O 0 ºC, CH2Cl2 H3C CH3 ZnEt 83%, 90% ee absolute stereochemistry C not reported O O n-Bu 3. EtZnI•OEt , CHI H (H C) N N(CH ) 2 3 H B 3 2 3 2 B-Zn Exchange CH2Cl2, –78 ! –40 ºC Long, J.; Yuan, Y.; Shi, Y. J. Am. Chem. Soc. 2003, 125, 13632–13633. O ZnI Ph O O H B Ph O n-Bu • Catalytic Enantioselective Simmons-Smith Cyclopropanation Reactions ZnEt • Chiral bis-sulfonamides have been used to direct asymmetric Simmons–Smith reactions of allylic 4. Pd(PPh3)4 alcohols: (5 mol%) Ph PhI, KOH Ph OH D (10 mol %) THF, 65 ºC 59%, 92% ee, >20:1 dr Et Zn, ZnI , Zn(CH I) 2 2 2 2 NHSO2CH3 OH OH CH2Cl2, 0 ºC Zimmer, L. E.; Charette, A. B. J. Am. Chem. Soc. 2009, 131, 15624–15626. NHSO CH 92%, 89% ee 2 3 • Homoallylic ethers can be cyclopropanated using a zinc phosphate, prepared in situ from a chiral D phosphoric acid: B (1.2 equiv) OBn Et2Zn, CH2I2 OBn Denmark, S. E.; O'Connor, S. P. J. Org. Chem. 1997, 62, 584–594. CH2Cl2, 0 ºC 85%, 93% ee • "Taddolates" can also be used: E Et Et B via E (25 mol %) O O Ar Ar = Ar Zn(CH I) , 4Å MS Ph Ph OH 2 2 OH O O O O Ph Ph P P CH2Cl2, 0 ºC O O O OH O OZnCH I Ti 2 85%, 92% ee i-PrO Oi-Pr Ar Ar Charette, A. B.; Molinaro, C.; Brochu, C. J. Am. Chem. Soc. 2001, 123, 12168–12175. Lacasse, M.-C.; Poulard, C. Charette, A. B. J. Am. Chem. Soc. 2005, 127, 12440–12441. James Mousseau, Fan Liu 4 Myers Cyclopropanation Chem 115 • A bifunctional Al-complex is an effective cyclopropanation catalyst and is believed to bind both the • Telluronium ylides can also be used: Zn and the allylic alcohol: ligand (10 mol%) Et2AlCl (10 mol%) H3C TBDPSO TBDPSO 1. LiTMP, HMPA CO2Et OH + Et Zn, CH I OH Te TMS 2 2 2 THF, toluene, –95 ºC CH Cl , 23 ºC 2 2 CH TMS 3 2. CO Et 99%, 90% ee 2 O ligand O 81%, 97% ee NH N via O OH HO I Ph Ph N N Zn Al Liao, W.-W.; Li, K.
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    Revised Group Additivity Values for Enthalpies of Formation (at 298 K) of Carbon– Hydrogen and Carbon–Hydrogen–Oxygen Compounds Cite as: Journal of Physical and Chemical Reference Data 25, 1411 (1996); https://doi.org/10.1063/1.555988 Submitted: 17 January 1996 . Published Online: 15 October 2009 N. Cohen ARTICLES YOU MAY BE INTERESTED IN Additivity Rules for the Estimation of Molecular Properties. Thermodynamic Properties The Journal of Chemical Physics 29, 546 (1958); https://doi.org/10.1063/1.1744539 Critical Evaluation of Thermochemical Properties of C1–C4 Species: Updated Group- Contributions to Estimate Thermochemical Properties Journal of Physical and Chemical Reference Data 44, 013101 (2015); https:// doi.org/10.1063/1.4902535 Estimation of the Thermodynamic Properties of Hydrocarbons at 298.15 K Journal of Physical and Chemical Reference Data 17, 1637 (1988); https:// doi.org/10.1063/1.555814 Journal of Physical and Chemical Reference Data 25, 1411 (1996); https://doi.org/10.1063/1.555988 25, 1411 © 1996 American Institute of Physics for the National Institute of Standards and Technology. Revised Group Additivity Values for Enthalpies of Formation (at 298 K) of Carbon-Hydrogen and Carbon-Hydrogen-Oxygen Compounds N. Cohen Thermochemical Kinetics Research, 6507 SE 31st Avenue, Portland, Oregon 97202-8627 Received January 17, 1996; revised manuscript received September 4, 1996 A program has been undertaken for the evaluation and revision of group additivity values (GAVs) necessary for predicting, by means of Benson's group additivity method, thermochemical properties of organic molecules. This review reports on the portion of that program dealing with GAVs for enthalpies of formation at 298.15 K (hereinafter abbreviated as 298 K) for carbon-hydrogen and carbon-hydrogen-oxygen compounds.
  • Experimental and Ab Initio Studies of Formation, Thermolysis, and Molecular and Electronic Structures of 3,6-Diphenyl-1-Propanesulfenimido-1,2,4,5-Tetrazine

    Experimental and Ab Initio Studies of Formation, Thermolysis, and Molecular and Electronic Structures of 3,6-Diphenyl-1-Propanesulfenimido-1,2,4,5-Tetrazine

    J. Am. Chem. Soc. 2000, 122, 2087-2095 2087 Nucleophile-Induced Intramolecular Dipole 1,5-Transfer and 1,6-Cyclization: Experimental and ab Initio Studies of Formation, Thermolysis, and Molecular and Electronic Structures of 3,6-Diphenyl-1-propanesulfenimido-1,2,4,5-tetrazine Piotr Kaszynski*,† and Victor G. Young, Jr.‡ Contribution from the Organic Materials Research Group, Department of Chemistry, Vanderbilt UniVersity, NashVille, Tennessee 37235, and X-ray Crystallographic Laboratory, Department of Chemistry, UniVersity of Minnesota, Twin Cities, Minnesota 55455 ReceiVed NoVember 1, 1999 Abstract: Reaction of dichlorobenzaldazine (2) with sodium azide followed by 1-propanethiol/Et3N furnished tetrazine ylide 1 as the main product. The structure of this unprecedented ylide was confirmed with single- crystal X-ray analysis [C17H17N5S, monoclinic P21/na) 6.8294(4) Å, b ) 13.6781(9) Å, c ) 17.5898(12) Å, â ) 90.666(1)°, Z ) 4] and favorably compared with the results of ab initio calculations. The mechanisms of formation of the ylide and its thermal decomposition to 2,5-diphenyltetrazine (5) were investigated using ab initio methods and correlated with the experimental observations. The results suggest that formation of 1 involves intramolecular cyclization of a nitrile imine and thermolysis of 1 might generate a sulfenylnitrene. The formation of 1 is considered to be the first example of a potentially more general reaction. Introduction Results and Discussion Intramolecular reactions of 1,3-dipoles provide one of the Synthesis of 1. 3,6-Diphenyl-1-propanesulfenimido-1,2,4,5- most versatile ways to construct heterocyclic rings.1 Among tetrazine (1) was obtained in a one-pot reaction.