Enantioselective synthesis of α-halo-α-alkylmalonates via phase-transfer catalytic α-alkylation.
A new enantioselective synthetic method for α-halo-α-alkylmalonates is reported. α-Alkylation of diphenylmethyl tert-butyl α-halomalonates under phase-transfer catalytic conditions (solid KOH, toluene, -40 °C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide (5 mol%) afforded diphenylmethyl tert-butyl α-halo-α-alkylmalonates in very high chemical yields (up to 99%) and optical yields (up to 93% ee).
Research Institute of Pharmaceutical Science and College of Pharmacy, Seoul National University, Seoul 151-742, S. Korea. hgpk@snu.ac.kr.
Suckchang
S
Hong
Minsik
M
Kim
Myunggi
M
Jung
Min Woo
MW
Ha
Myungmo
M
Lee
Yohan
Y
Park
Mi-hyun
MH
Kim
Taek-Soo
TS
Kim
Jihoon
J
Lee
Hyeung-geun
HG
Park
D000478:Alkylation; D002384:Catalysis; D008314:Malonates / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D044367:Phase Transition; D013237:Stereoisomerism
D008314:Malonates