Asymmetric Organocatalytic Benzylation of α,β-Unsaturated Aldehydes with Toluenes
作者:Luca Dell'Amico、Xavier Companyó、Tricia Naicker、Thomas M. Bräuer、Karl Anker Jørgensen
DOI:10.1002/ejoc.201300899
日期:2013.8
direct organocatalytic enantioselective benzylation by using toluenes and α,β-unsaturatedaldehydes is presented. The reaction is catalyzed by tert-butyldimethylsilyl-protected diphenylprolinol in the presence of a mild organic base and proceeds with excellent yields and enantioselectivities up to >99 % ee. This reactivity is based on a synergistic effect between the iminium ion intermediate and the
A Strategy Enabling Enantioselective Direct Conjugate Addition of Inert Aryl Methane Nucleophiles to Enals with a Chiral Amine Catalyst under Mild Conditions
作者:Tengfei Li、Jin Zhu、Deyan Wu、Xiangmin Li、Sinan Wang、Hao Li、Jian Li、Wei Wang
DOI:10.1002/chem.201300304
日期:2013.7.8
Nitro‐charged activation: An organocatalytic enantioselectiveconjugateaddition of aryl methyl nucleophiles to enals has been developed to produce ubiquitous chiral benzylic building blocks (see scheme; TES=triethylsilyl). Taking advantage of the strongly electron‐withdrawing nature of nitro groups, which can be conveniently transformed into other functionalities, this functionality was incorporated