Copper metal and such gem-dichlorides as a, a-dichloro acid esters, la-e, diphenyldichloromethane, 2, benzal chloride, 3, l, l-dichloroacetone, 4, l, l-dichloro-2-butene, 5, and carbon tetrachloride, 6, were found to undergo a stoichiometric reaction in dimethyl sulfoxide (DMSO) under a mild condition to produce copper carbenoid intermediates via a, a- elimination of dichlorides along with the formation of CUC~~(DMSO)~. Thus, 1 and 2 gave ...
