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Unique reactivity of α,β‐unsaturated carboxylic acid imidazolides: Catalytic asymmetric synthesis of α,β‐epoxy esters and α,β‐epoxy carboxylic acid derivatives
Author(s) -
Nemoto Tetsuhiro,
Tosaki ShinYa,
Ohshima Takashi,
Shibasaki Masakatsu
Publication year - 2003
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.10205
Subject(s) - epoxy , chemistry , catalysis , carboxylic acid , chirality (physics) , organic chemistry , alkyl , enantiomer , yield (engineering) , aryl , reactivity (psychology) , chiral symmetry breaking , physics , materials science , quantum mechanics , nambu–jona lasinio model , metallurgy , quark , medicine , alternative medicine , pathology
Catalytic asymmetric synthesis of α,β‐epoxy esters and α,β‐epoxy carboxylic acid derivatives is described. Catalytic asymmetric epoxidation of α,β‐unsaturated carboxylic acid imidazolides using La–BINOL–Ph 3 As=O complex gave the corresponding α,β‐epoxy peroxy tert ‐butyl esters, which were directly converted to the α,β‐epoxy methyl esters by adding methanol to the reaction. This catalytic system had broad generality for epoxidation of various substrates. With the use of 5–10 mol% of the catalyst, both β‐aryl and β‐alkyl‐substituted‐α,β‐epoxy methyl esters were obtained in up to 91% yield and in up to 93% enantiomeric excess. In addition, efficient transformations of α,β‐epoxy peroxy tert ‐butyl esters into the α,β‐epoxy amides, α,β‐epoxy aldehydes, and γ,δ‐epoxy β‐keto esters are also reported. Chirality 15:306–311, 2003. © 2003 Wiley‐Liss, Inc.