Cu-Catalyzed Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylides with β-Phenylsulfonyl Enones. Ligand Controlled Diastereoselectivity Reversal
作者:Rocío Robles-Machín、María González-Esguevillas、Javier Adrio、Juan C. Carretero
DOI:10.1021/jo902103z
日期:2010.1.1
A catalytic asymmetric procedure for the 1,3-dipolar cycloaddition of (Ε)-β-phenylsulfonyl enones with azomethine ylides to provide highly functionalized pyrrolidine derivatives is described. In the presence of chiral CuI-Segphos catalysts the aducts were obtained with high regio-, diastereo-, and enantioselectivity. Interestingly, a switch from endo to exo selectivity was observed when Segphos or
描述了用于(E)-β-苯基磺酰基烯酮的1,3-偶极环加成与偶氮甲亚胺基化物以提供高度官能化的吡咯烷衍生物的催化不对称方法。在手性Cu I -Segphos催化剂的存在下,以高区域选择性,非对映异构体和对映体选择性获得了加合物。有趣的是,从一个交换机内到外使用SEGPHOS或DTBM-SEGPHOS配体时,观察选择性。