Copper complexes of optically active bisoxazolines as enantioselective catalysts in cyclopropanation reactions

摘要

An optically active bisoxazoline compound of the formula [I]: wherein R₁ represents an alkyl group, cycloalkyl group, aralkyl group, phenyl group which may be substituted or an alkoxy group and two geminal alkyl groups may be joined together to form a cyclic structure;   R₂ represents an alkyl group , cycloalkyl group, aralkyl group or phenyl group which may be substituted;   R₃ represents a hydrogen atom, (C2-C4)alkyl group or cycloalkyl group; and   the asterisk * represents an asymmetric carbon atom.