title: Enantioselective phase-transfer catalytic α-alkylation of 2-methylbenzyl tert-butyl malonates.
abstract: A new asymmetric synthetic method to prepare α,α-dialkylmalonates for the construction of a quaternary carbon center via phase-transfer catalytic (PTC) alkylation has been developed. Enantioselective α-alkylation of 2-methylbenzyl tert-butyl α-methylmalonates under phase-transfer catalytic conditions in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide () afforded the corresponding α,α-dialkylmalonates in high chemical (up to 99%) and optical yields (up to 91% ee), which were selectively hydrolyzed to malonic monoacids under alkali basic conditions for conversion to versatile chiral intermediates.
authors.affiliation: Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Ha
authors.forename: Suckchang
authors.initials: S
authors.lastname: Hong
authors.forename: Cheonhyoung
authors.initials: C
authors.lastname: Park
authors.forename: Yohan
authors.initials: Y
authors.lastname: Park
authors.forename: Jihye
authors.initials: J
authors.lastname: Lee
authors.forename: Mi-hyun
authors.initials: MH
authors.lastname: Kim
authors.forename: Jihoon
authors.initials: J
authors.lastname: Lee
authors.forename: Hyeung-geun
authors.initials: HG
authors.lastname: Park
mesh_terms: D000478:Alkylation; D002384:Catalysis; D008314:Malonates / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D044367:Phase Transition; D013237:Stereoisomerism
chemical_list: D008314:Malonates