CHIRAL ENAMINES DERIVED FROM 2-(2'-PYRIDO)ACETOPHENONE AND 2-(2'-QUINOLINO)ACETOPHENONE AS LIGANDS IN COPPER(I) CATALYZED ENANTIOSELECTIVE CYCLOPROPANATIONS

Optically active enamines of 2-(2'-pyrido)acetophenone or 2-(2'-quinol ino)acetophenone with (R)-1-phenylethylamine, (R)-1-(1-naphthyl)ethyla mine, (R)-cyclohexylethylamine, and (R)-phenylglycinol were prepared a nd their copper(I) complexes used in the enantioselective cyclopropana tion of styrene with ethyl- and menthyldiazoacetate. Enantioselectivit ies of up to 42% enantiomeric excess were obtained for cis/trans 2-phe nylcyclopropan-1-carboxylic acid ethyl esters, as determined by gas-li quid chromatography (GLC) on chiral chromatographic columns. (C) 1995 Wiley-Liss, Inc.