Synthesis of Indole- and Benzofuran-Based Benzylic Sulfones by Palladium-Catalyzed Sulfonylation of -Iodoaryl Allenes.

A highly efficient palladium-catalyzed domino coupling reaction of -iodoaryl allene with sodium sulfonates under mild conditions is described. This novel method provides a practical protocol to access diverse indole- and benzofuran-containing sulfones by simultaneous construction of C(sp)-C(sp) bond and a C(sp)-S bonds in one pot. The salient features of this transformation include simple operations, broad substrate scope, and good functional group tolerance.