Enantioselective synthesis of (R)- and (S)-alpha-alkylcysteines via phase-transfer catalytic alkylation.
We reported efficient enantioselective synthetic methodologies for (R)-alpha-alkylcysteines and (S)-alpha-alkylcysteines. The phase-transfer catalytic alkylation of 2-phenyl-2-thiazoline-4-carboxylic acid tert-butyl ester and 2-o-biphenyl-2-thiazoline-4-carboxylic acid tert-butyl ester, in the presence of chiral catalysts (1 or 2), gave the corresponding alkylated products, which could be hydrolyzed to provide (R)-alpha-alkylcysteines (67->99% ee) and (S)-alpha-alkylcysteines (66-88% ee), respectively.
Kim
Taek-Soo
TS
Research Institute of Pharmaceutical Science and College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
Lee
Yeon-Ju
YJ
Jeong
Byeong-Seon
BS
Park
Hyeung-geun
HG
Jew
Sang-sup
SS
D000478:Alkylation; D002384:Catalysis; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D013237:Stereoisomerism
D003545:Cysteine