Highly Enantioselective Synthesis of
α-Alkyl-alanines via the Catalytic
Phase-Transfer Alkylation of 2-Naphthyl
Aldimine tert-Butyl Ester by Using
O(9)-Allyl-N(1)-2‘,3‘,4‘-trifluorobenzylhydrocinchonidinium Bromide
posted on 2003-05-02, 00:00authored bySang-sup Jew, Byeong-Seon Jeong, Jeong-Hee Lee, Mi-Sook Yoo, Yeon-Ju Lee, Boon-saeng Park, Myoung Goo Kim, Hyeung-geun Park
Systematic investigations to develop an efficient
enantioselective synthetic method for α-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 −35 °C showed the highest enantioselectivities, up to 96% ee.