Catalyst Repurposing Sequential Catalysis by Harnessing Regenerated Prolinamide Organocatalysts as Transfer Hydrogenation Ligands
作者:Frederic Bourgeois、Jonathan A. Medlock、Werner Bonrath、Christof Sparr
DOI:10.1021/acs.orglett.9b04033
日期:2020.1.3
A catalyst repurposing strategy based on a sequential aldol addition and transferhydrogenation giving access to enantiomerically enriched α-hydroxy-γ-butyrolactones is described. The combination of a stereoselective, organocatalytic step, followed by an efficient catalytic aldehydereduction induces an ensuing lactonization to provide enantioenriched butyrolactones from readily available starting
Asymmetric Aldol Reaction of α,α-Disubstituted Acetaldehydes Catalyzed by Diphenylprolinol Silyl Ether for the Construction of Quaternary Stereogenic Centers
作者:Yujiro Hayashi、Hiroki Shomura、Qianqian Xu、Martin J. Lear、Itaru Sato
DOI:10.1002/ejoc.201500585
日期:2015.7
The asymmetric cross-aldol reaction of α,α-disubstituted acetaldehydes with commercial ethyl glyoxylate polymer was successfully catalyzed by diphenylprolinolsilylether 3 to generate all-carbonquaternarystereogeniccenters with good enantioselectivity.