Fluoride-ion-mediated reactions of trimethylsilylacetylene with carbonyl compounds and terminal acetylenes

Fluoride-ion-mediated reaction of trimethylsilylacetylene with carbonyl com pounds has been thoroughly studied. The products of addition to the C=O bon d were obtained in 15-66% yield, their subsequent silylation and addition t o the second molecule of the carbonyl compound being observed. It has been found that terminal aryl and hetaryl acetylenes undergo silylation in a two -phase-system Me3SiC=CH/CsF/18-crown-6 to afford aryl(hetaryl) trimethylsil ylacetylenes with up to 100% yields. Combining these two reactions, a novel one-pot fluoride-ion-mediate method for the synthesis of 1-trimethylsiloxy -3-aryl(hetaryl)-2-propynes from trimethylsilylacetylene, terminal aryl or hetaryl acetylenes and carbonyl compounds has been elaborated. (C) 1999 Els evier Science S.A. All rights reserved.