Cumyl Ester as the C-Terminal Protecting Group in the Enantioselective Alkylation of Glycine Benzophenone Imine
作者:Tomasz Respondek、Eric Cueny、Jeremy J. Kodanko
DOI:10.1021/ol202939g
日期:2012.1.6
Cumyl ester is an optimal C-terminal protecting group for glycine benzophenone imine in asymmetric alkylation reactions catalyzed by Cinchona chiral phase-transfer catalysts. High levels of enantioselectivity have been obtained (up to 94% ee) with this substrate, which provides an attractive alternative to the analogous tert-butyl ester. N-terminal imines and the C-terminal esters can be cleaved from
枯草酸酯是在金鸡纳手性相转移催化剂催化的不对称烷基化反应中,甘氨酸二苯甲酮亚胺的最佳C端保护基。用该底物已经获得了高水平的对映选择性(高达94%ee),为类似的叔丁酯提供了有吸引力的替代方法。N-末端亚胺和C-末端酯可通过氢解从烷基化产物上裂解,同时保持酸不稳定的侧链保护基。