Highly Enantioselective Synthesis of α-Alkyl-alanines via the Catalytic Phase-Transfer Alkylation of 2-Naphthyl Aldimine <i>tert</i>-Butyl Ester by Using <i>O</i>(9)-Allyl-<i>N</i>(1)-2‘,3‘,4‘-trifluorobenzylhydrocinchonidinium Bromide
作者:Sang-sup Jew、Byeong-Seon Jeong、Jeong-Hee Lee、Mi-Sook Yoo、Yeon-Ju Lee、Boon-saeng Park、Myoung Goo Kim、Hyeung-geun Park
DOI:10.1021/jo034006t
日期:2003.5.1
Systematic investigations to develop an efficient enantioselective synthetic method for alpha-alkyl-alanine by catalytic phase-transfer alkylation were performed. The alkylation of 2-naphthyl aldimine tert-butyl ester, 1E, with RbOH and O(9)-allyl-N-2',3',4'-trifluorobenzylhydrocinchonidinium bromide, 6, at -35degreesC showed the highest enantioselectivities, up to 96% ee.