Stereocontrolled Creation of All-Carbon Quaternary Stereocenters by Organocatalytic Conjugate Addition of Oxindoles to Vinyl Sulfone
作者:Qiang Zhu、Yixin Lu
DOI:10.1002/anie.201003837
日期:2010.10.11
residues have been prepared (see scheme), and found to be very effective towards the asymmetric addition of 3‐alkyl‐oxindoles to 1,1‐bis(benzenesulfonyl)ethylene. This synthetic protocol has led to the enantioselective synthesis of 3‐alkyl‐3‐aryl‐disubstituted oxindoles and indolines with an all‐carbon quaternary stereogenic center.
Highly Enantioselective Conjugate Addition of 3-Substituted Oxindoles to Vinyl Sulfone Catalyzed by Binaphthyl-Modified Tertiary Amines
作者:Dae Kim、Hyun Lee、Seung Kang
DOI:10.1055/s-0030-1260770
日期:2011.7
The enantioselectiveconjugateaddition reaction of 3-substituted oxindoles with 1,1-bis(benzenesulfonyl)ethylene by binaphthyl-modified bifunctional organocatalysts was investigated. The corresponding Michael adducts, containing a quaternary center at C3 position of the oxindoles, were generally obtained in high yields with excellent enantioselectivities (up to 99% ee).