Phosphine-Catalyzed Asymmetric Synthesis of α-Quaternary Amine via Umpolung γ-Addition of Ketimines to Allenoates
摘要:
A first phosphine-catalyzed enantioselective umpolung gamma-addition of ketimines to allenoates has been developed that provides efficient access to optically active gamma,delta-unsaturated alpha-amino esters and delta-amino esters with a chiral tertiary stereocenter under mild conditions. The salient features of this reaction include general substrate scope, mild conditions, good yields, high enantioselectivity, ease of scale-up to gram scale, and further transformations.
Organocatalytic Asymmetric Biomimetic Transamination: From α-Keto Esters to Optically Active α-Amino Acid Derivatives
作者:Xiao Xiao、Ying Xie、Cunxiang Su、Mao Liu、Yian Shi
DOI:10.1021/ja203138q
日期:2011.8.24
This paper describes an effective chiral base-catalyzed biomimetic transamination of α-ketoesters using simple benzyl amines. A wide variety of α-amino esters containing various functional groups can be synthesized in high enantioselectivity and reasonable yield.