Highly enantioselective Michael-cyclization cascade promoted by synergistic asymmetric aminocatalysis and Lewis acid catalysis
作者:Chenguang Yu、Yinan Zhang、Shilei Zhang、Jing He、Wei Wang
DOI:10.1016/j.tetlet.2010.01.096
日期:2010.3
The novel dual cooperative asymmetric aminocatalysis and Lewis acid catalysis has been successfully developed for promoting cascade Michael-cyclization reaction with high enantio-, regio- and chemo-selectivity. The simple and practical process affords a one-pot approach to synthetically useful cyclopentenes.
Tandem Cyclization–Michael Reaction by Combination of Metal- and Organocatalysis
作者:José Alemán、Virginia del Solar、Cecilia Martín-Santos、Leticia Cubo、Carmen Navarro Ranninger
DOI:10.1021/jo2013077
日期:2011.9.2
The use of a catalytic amount of platinum complexes (1 mol %) was found to be compatible with different organocatalysts (DABCO or the Jørgensen–Hayashi catalyst) that were used in the functionalization of various activated methylenes. By this method, a series of lactones with C-3 quaternary centers and substitution at C-5 were prepared.
The first examples of one‐pot highly chemo‐ and enantioselectivedynamickineticasymmetrictransformations (DYKATs) involving α,β‐unsaturated aldehydes and propargylated carbon acids are presented. These DYKATs, which proceed by a combination of catalytic iminium activation, enamine activation, and Pd0‐catalyzed enyne cycloisomerization, give access to functionalized cyclopentenes with up to 99 % ee