title: Enantioselective synthesis of (R)- and (S)-alpha-alkylcysteines via phase-transfer catalytic alkylation.
abstract: 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.
authors.affiliation: Research Institute of Pharmaceutical Science and College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
authors.forename: Taek-Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Yeon-Ju
authors.initials: YJ
authors.lastname: Lee
authors.forename: Byeong-Seon
authors.initials: BS
authors.lastname: Jeong
authors.forename: Hyeung-geun
authors.initials: HG
authors.lastname: Park
authors.forename: Sang-sup
authors.initials: SS
authors.lastname: Jew
mesh_terms: D000478:Alkylation; D002384:Catalysis; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: D003545:Cysteine