Dimetallation of phenylacetylene. Selective ortho-substitution

Abstract

Reaction of lithium phenylacetylide with the complex BuLi–Bu^tOK in a mixture of tetrahydrofuran and hexane leads to the ortho-metallated phenylacetylide; subsequent addition of methyl iodide, dimethyl disulphide, trimethylchlorosilane, and selenium gives the corresponding ortho-substituted phenylacetylenes and benzoselenophen.