Disulfidation of alkynes and alkenes with gallium trichloride.

[reaction: see text] Treatment of diphenyl disulfide and terminal alkynes with gallium trichloride afforded (E)-1,2-diphenylthio-1-alkenes selectively (E/Z > 20/1). Alkenes also underwent this reaction to form trans adducts.

A new method for the synthesis of acyltitanium complexes and their application to copper-mediated acylmetallation of carbon-carbon multiple bonds in aqueous media.

Treatment of alpha, beta-unsaturated carbonyl compounds or methyl propargyl ether with acylchlorobis(cyclopentadienyl)titanium in the presence of triethylamine and a copper salt in aqueous THF resulted in acylation of the carbon-carbon multiple bond, yielding the corresponding 1,4-diketones in good yields.