161814-11-5Relevant articles and documents
The first general enantioselective catalytic Diels-Alder reaction with simple (α,β-unsaturated ketones
Northrup, Alan B.,MacMillan, David W. C.
, p. 2458 - 2460 (2002)
The first general approach to enantioselective catalysis of the Diels-Alder reaction with simple ketone dienophiles has been accomplished. The use of iminium catalysis has enabled enantioselective access to a fundamental Diels-Alder reaction variant that
Chiral Lewis Acid-Catalyzed Asymmetric Diels-Alder Reactions of (E)-1-Phenylsulfonyl-3-alken-2-ones with Cyclopentadiene
Wada, Eiji,Pei, Wen,Kanemasa, Shuji
, p. 2345 - 2348 (1994)
Highly enantio- and endo-selective Diels-Alder reactions of (E)-1-phenylsulfonyl-3-alken-2-ones, a new type of chelating dienophile, with cyclopentadiene are achieved by the aid of a catalytic amount of chiral titanium catalysts.Mode of enantioselectiviti
Oxazaborolidinone-catalyzed enantioselective Diels-Alder reaction of acyclic α,β-unsaturated ketones
Singh, Ram Shanker,Adachi, Shinya,Tanaka, Fumi,Yamauchi, Toyonao,Inui, Chieko,Harada, Toshiro
, p. 212 - 218 (2008/09/18)
(Chemical Equation Presented) allo-Threonine-derived O-acyl-β-phenyl- oxazaborolidinones are demonstrated to be powerful and highly enantioselective Lewis acid catalysts for the Diels-Alder reaction of simple acyclic enone dienophiles, expanding the scope of ketone dienophiles and dienes. With 10 to 20 mol % of catalyst, the Diels-Alder adducts are obtained in 76-98% ee with high endo-selectivity. The catalyst exhibits high activity for the reaction with the less reactive β-substituted dienophiles and the less reactive 1,3-cycohexadiene and 1,3-butadiene derivatives. The application of the catalysts to the Diels-Alder reaction of furan is also described.
Asymmetric diels-alder reactions of sulfonyl-functionalized α,β-unsaturated ketones with cyclopentadiene catalyzed by chiral lewis acid
Pei, Wen,Wang, Yu-Guang,Wang, Yong-Jiang,Sun, Li
experimental part, p. 3383 - 3388 (2009/05/07)
Asymmetric Diels-Alder reactions of (E)-1-substituted sulfonyl-3-penten-2- ones with cyclopentadiene catalyzed by a chiral titanium reagent were investigated. The enantioselectivity was studied with different substituents in the position of sulfonyl moiet
Enantioselective diels-alder reaction of acyclic enones catalyzed by allo-threonine-derived chiral oxazaborolidinone
Singh, Ram Shanker,Harada, Toshiro
, p. 3433 - 3435 (2007/10/03)
An allo-threonine-derived O-(p-biphenylcarbonyloxy)-B-phenyl- oxazaborolidinone is demonstrated to be a powerful and highly enantioselective Lewis acid catalyst for the enantioselective Diels-Alder reaction of simple acyclic enone dienophiles, expanding the scope of ketone dienophiles and dienes. With 10-20 mol% of the catalyst, the Diels-Alder adducts are obtained with up to 94 % ee and high endo selectivity. The catalyst exhibits a high activity in the reaction with the less reactive β-substituted dienophiles and the less reactive 1,3-cycohexadiene and 1,3-butadiene derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
Enantioselective transformation of alpha,beta-unsaturated ketones using chiral organic catalysts
-
Page/Page column 12; 14, (2008/06/13)
Nonmetallic organic catalysts are provided that facilitate the enantioselective reaction of α,β-unsaturated ketones. The catalysts are chiral imidazolidinone compounds having the structure of formula (IIA) or (IIB) or are acid addition salts thereof, wherein, in one preferred embodiment, R1 is C1-C6 alkyl, R2is phenyl or 2-methylfuryl, R3 and R4 are hydrogen, and R5 is phenyl optionally substituted with 1 or 2 substituents selected from the group consisting of halo, hydroxyl, and C1-C6 alkyl The chiral imidazolidinones are useful in catalyzing a wide variety of reactions, including cycloaddition reactions, Friedel-Crafts alkylation reactions, and Michael additions.
Asymmetric Lewis Acid-Catalyzed Diels-Alder Reactions of α,β-Unsaturated Ketones and α,β-Unsaturated Acid Chlorides
Hawkins, Joel M.,Nambu, Mitch,Loren, Stefan
, p. 4293 - 4295 (2007/10/03)
(Equation presented) Conformational analysis, van der Waals attractions, and transition structure calculations are combined to design an asymmetric Lewis acid-catalyzed Diels-Alder reaction for simple acyclic α,β-unsaturated ketones and α,β-unsaturated acid chlorides, giving up to 83 and 92% ee, respectively. The two-point-binding chiral recognition mechanism, Lewis acid-Lewis base coordination with boron and a van der Waals attraction with the naphthyl group, uses the inherent enone unit of simple α,β-unsaturated carbonyl compounds, ending the need for auxiliary oxygen binding sites on the dienophile.
Electrochemical Reduction of exo-5-Acetyl-endo-6-trichloromethylbicyclohept-2-ene
Tsuboi, Sadao,Ishiguro, Yasuhiro,Takeda, Akira
, p. 830 - 832 (2007/10/02)
Electrochemical reduction of exo-5-acetyl-endo-6-trichloromethylbicyclohept-2-ene (2) using a mercury cathode gave chemoselectively either the corresponding monochloromethyl or dichloromethyl derivatives in high yields by selecting supporting electrolyte.The reduction of 2 using a lead cathode gave 2-acetyl-3-methylbicyclohepta-2,5-diene and cis-1-(4-vinyl-2-cyclopentenyl)-2-propane together wwith by-products.
PREPARATION DE THIOCETONES ACYCLIQUES α-INSATUREES. DIMERISATION REGIOSELECTIVE EN 4H-DITHIINE-1,3
Beslin, P.,Lagain, D.,Vialle, J.,Minot, C.
, p. 3839 - 3846 (2007/10/02)
α-Unsaturated acyclic thioketones 6 a-d were prepared by a retro-Diels-Alder reaction using flash thermolysis technique.They were detected at low temperature (blue coloured pyrolysate) but dimerize in solution as soon as the temperature rose to -60o (case 6 a-c) and -20o (case 6 d).The structure of 6 d was established by UV and NMR spectra taken at -60o.Dimeric products were proved to be 4H-1,3 dithiin by spectral data and by univocal synthesis of 7 c and 7 d from the corresponding monomeric ketone. 1-3 Dithiin 7 d was isomerized at 190o into the thermodynamic isomer (8).This observed orientation of dimerisation agrees with theorical results obtained from molecular frontier orbital calculations.
