Organocatalyzed asymmetric Michael addition by an efficient bifunctional carbohydrate–thiourea hybrid with mechanistic DFT analysis
作者:Chandra S. Azad、Imran A. Khan、Anudeep K. Narula
DOI:10.1039/c6ob02158a
日期:——
core scaffold were synthesized and examined as catalysts for the asymmetricMichael addition reaction of aryl/alkyl trans-β-nitrostyrenes over cyclohexanone and other Michael donors having active methylene. Excellent enantioselectivities (<95%), diastereoselectivities (<99%), and yields (<99%) were attained undersolvent free conditions using 10 mol% of 1d0. The obtained results were explained through
Pyrrolidine-Oxadiazolone Conjugates as Organocatalysts in Asymmetric Michael Reaction
作者:Chandan K. Mahato、Sayan Mukherjee、Mrinalkanti Kundu、Animesh Pramanik
DOI:10.1021/acs.joc.8b02393
日期:2019.1.18
Pyrrolidine-oxadiazolone based organocatalysts are envisaged, synthesized, and utilized for asymmetric Michael reactions. Results of the investigations suggest that some of the catalysts are indeed efficient for stereoselective 1,4-conjugated Michael additions (dr: >97:3, ee up to 99%) in high chemical yields (up to 97%) often in short reaction time. As an extension, one enantiopure Michael adduct has been utilized to
Highly Enantioselective (<i>S</i>)-Homoproline-catalyzed Michael Addition Reactions of Ketones to β-Nitrostyrenes
作者:Dai Terakado、Masako Takano、Takeshi Oriyama
DOI:10.1246/cl.2005.962
日期:2005.7
Being catalyzed by (S)-homoproline a highly enantioselective organocatalytic Michael addition reaction of ketones to β-nitrostyrenes has been achieved.
在(S)-高脯氨酸的催化下,酮与β-硝基苯乙烯的高度对映选择性有机催化迈克尔加成反应已经实现。
The Use ofN-Alkyl-2,2′-bipyrrolidine Derivatives as Organocatalysts for the Asymmetric Michael Addition of Ketones and Aldehydes to Nitroolefins
The direct Michaeladdition of aldehydes and ketones to nitroolefins, catalyzed by N-i-Pr-2,2′-bipyrrolidine, is described. The desired 1,4-adducts are obtained in excellent yields with enantioselectivities up to 95% ee and dr up to 95 : 5 of the syn aldehydeaddition product. An unexpected inversion of diastereoselectivity was observed for the addition of α-hydroxy ketones to β-arylnitroolefins with
Highly Efficient Amine Organocatalysts Based on Bispidine for the Asymmetric Michael Addition of Ketones to Nitroolefins
作者:Zhigang Yang、Jie Liu、Xiaohua Liu、Zhen Wang、Xiaoming Feng、Zhishan Su、Changwei Hu
DOI:10.1002/adsc.200800341
日期:2008.9.5
highly diastereoselective and enantioselective Michael addition of cyclohexanone, acetone and other ketones to nitroolefins was developed by the use of an amine organocatalyst based on bispidine. Additionally, a theoretical study of transition structures revealed that this bispidine-based primary-secondary amine catalyst could serve through an enamine intermediate and H-bond interaction, which was