A slight structural modification of a chiral catalyst caused a dramatic reversal in the enantioselectivity of an aldehyde propargylation using alkynyllithium.
Enantioselective alkynylation of carbonyl compounds with trimethoxysilylalkynes catalyzed by lithium binaphtholate
Enantioselective alkynylation of aldehydes and ketones was accomplished using trimethoxysilylalkynes as alkynylating reagents and lithium 3,3′-diphenylbinaphtholate as a catalyst. Optically active propargylic alcohols were obtained in good to high chemical yields and enantioselectivities. Alkynylation of acetylpyridines afforded biologically active pyridyl propargylic alcohols in good enantioselectivities