An organocatalytic asymmetric multicomponent domino and a conjugated addition reaction to α,β-unsaturated aldehydes are presented. The development is based, first, on an organocatalyzed highlyenantioselective nucleophilic thiol addition to the β-carbon atom in the iminium ion intermediate, followed by an electrophilic amination of the α-carbon atom to the enamine intermediate. The multicomponent reactions
Highly enantioselective aldehyde–nitroolefin Michael addition reactions catalyzed by recyclable fluorous (S) diphenylpyrrolinol silyl ether
作者:Liansuo Zu、Hao Li、Jian Wang、Xinhong Yu、Wei Wang
DOI:10.1016/j.tetlet.2006.05.067
日期:2006.7
A recyclable and reusable (S) diphenylpyrrolinol silyl ether I organocatalyst bearing a n-C8F17 fluorous tag has been demonstrated for promoting the asymmetricMichaeladdition reactions of a wide range of aldehydes with both aryl and alkyl-substituted nitroolefins and excellent levels of enantio- and diastereoselectivities are achieved. The catalyst I can be conveniently recovered by fluorous solid-phase
已证明具有n -C 8 F 17氟标签的可回收和可重复使用的(S)二苯基吡咯啉甲硅烷基醚I有机催化剂可促进多种醛与芳基和烷基取代的硝基烯烃的不对称迈克尔加成反应,并具有极好的水平实现对映和非对映选择性。可以通过氟固相萃取方便地回收催化剂I,然后再使用(最多8个循环),而不会显着降低该方法的催化活性和立体选择性。
Solvent-free Organocatalytic Asymmetric Conjugate Addition of Thiols to α,β-Unsaturated Aldehydes
作者:Takeru Ishino、Takeshi Oriyama
DOI:10.1246/cl.2007.550
日期:2007.4.5
A highly enantioselective asymmetric conjugate addition of thiols to α,β-unsaturatedaldehydes has been achieved catalyzed by newly designed organocatalyst without solvent.