Cu(I)-catalyzed decarboxylative aldol-type and Mannich-type reactions for asymmetric construction of contiguous trisubstituted and quaternary stereocenters
作者:Liang Yin、Motomu Kanai、Masakatsu Shibasaki
DOI:10.1016/j.tet.2011.05.108
日期:2012.4
The catalytic asymmetric decarboxylative aldol-type reaction between aldehydes and cyanocarboxylic acids and Mannich-type reaction between aldimines and cyanocarboxylic acids were developed. α,α,β-Trisubstituted-β-hydroxy nitriles bearing contiguous all-carbon quaternary and trisubstituted stereocenters were produced with moderate enantio- and diastereoselectivity in the presence of 10 mol % CuOAc–TANIAPHOS
建立了醛与氰基羧酸的催化不对称脱羧醛醇型反应和醛亚胺与氰基羧酸的曼尼希型反应。在醛醇-醛醇中存在10 mol%CuOAc-TANIAPHOS(或DTBM-SEGPHOS)配合物的情况下,以中等对映体和非对映体选择性生产带有连续全碳四元和三元取代立体中心的α,α,β-三取代-β-羟基腈。类型反应。使用5 mol%CuOAc–(R)-DTBM-SEGPHOS络合物在曼尼希型反应中。这些反应通过Cu(I)催化的脱羧亲核试剂的产生而进行,然后将所得的手性Cu-酮丁酰亚胺添加至醛或亚胺中。由于反应是在非常温和的条件下,在接近中性的pH值下进行的,因此该反应适用于多种底物组合,包括芳族和脂族底物。最后,通过简单的酸水解将α,α,β-三取代-β-氨基腈转化为β2,2,3-氨基酸衍生物,而没有任何外消旋化和差向异构化。