A copper(I)-catalyzed three-component reaction of triethoxysilanes, sulfur dioxide, and alkyl halides

A copper(I)-catalyzed three-component reaction of triethoxysilanes, DABCO center dot(SO2)(2), and alkyl halides is reported for the first time. This transformation provides a convenient and facile route to sulfones under ligand-free conditions catalyzed by copper(I) oxide. The insertion of sulfur dioxide is efficient, and both triethoxyarylsilanes and triethoxyalkylsilanes are practicable during the coupling process. A plausible mechanism is proposed, supported by theoretical calculations.