Reaction of alkynylsilanes with CuCl in polar solvents leading to alkynyl group transfer from Si to Cu

The reaction of 1-phenyl-2-trimethylsilylethyne with CuCl at 80–100°C in N,N-dimethylformamide (DMF) or N,N-dimethylimidazolidinone (DMI) yielded the alkynylcopper species [Cu2Cl(CCPh)]n (1) in 56–63% yields. Heating 1 at 80°C under aerobic conditions gave 1,4-diphenyl-1,3-butadiyne in 82% yield via an oxidative coupling of the phenylethynyl ligands.