2-position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the -functionalization of a wide range of linear/branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and -amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol-%). As a proof of efficiency, TOFs of up to
Organocatalytic Michael Addition of Aldehydes to Vinyl Sulfones: Enantioselective α-Alkylations of Aldehydes and Their Derivatives
作者:Qiang Zhu、Yixin Lu
DOI:10.1021/ol8019296
日期:2008.11.6
Organocatalyticasymmetric Michael reaction of unmodified aldehydes to vinyl sulfones catalyzed by silylated biarylprolinol afforded the desired Michael products with exceptional enantioselectivity. The described enantioselective addition to vinyl sulfones, in combination with desulfonation, offers a unique, asymmetric entry to alpha-alkylated aldehydes and their derivatives.