Squaramide-catalyzed diastereo- and enantioselective Michael addition of 3-substituted oxindoles to nitroalkenes
作者:Wen Yang、Jingsi Wang、Da-Ming Du
DOI:10.1016/j.tetasy.2012.06.018
日期:2012.7
An efficient diastereo- and enantioselectiveMichaeladdition of 3-substituted oxindoles onto nitroalkenes catalyzed by a bifunctional chiral squaramide catalyst has been developed. This organocatalytic reaction with 2 mol % of catalyst proceeded smoothly to afford 3,3-disubstituted oxindoles in high yields with good diastereoselectivities and enantioselectivities (up to 98:2 dr, 88% ee).