Evidence of the electronic factor for the highly enantioselective catalytic efficiency of Cinchona-derived phase-transfer catalysts.
[structure: see text] The Cinchona alkaloid-derived quaternary ammonium salts containing 2'-N-oxypyridine and 2'-cyanobenzene moieties were prepared and evaluated as phase-transfer catalysts in the enantioselective alkylation of glycine imine ester 1. The N-oxypyridine and cyanobenzene moieties might play an important role to form a rigid conformation by coordinating with H(2)O via hydrogen bonding leading to high enantioselectivity (97 approximately >99% ee), which provides evidence of an electronic factor for the high enantioselective catalytic efficiency in phase-transfer alkylation.
Yoo
Mi-Sook
MS
Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
Jeong
Byeong-Seon
BS
Lee
Jeong-Hee
JH
Park
Hyeung-Geun
HG
Jew
Sang-Sup
SS
D000478:Alkylation; D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry*; D004563:Electrochemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D002930:Cinchona Alkaloids