A two-component pericyclic reaction for synthesis of substituted benzofurans and aryl-quaternary carbon bonds.

The reaction shown is presumed to be a new [3,3]-sigmatropic rearrangement involving an O-arylsulfoxonium species or related sulfurane. It allows a sulfoxide and a phenol to be joined and rearranged in one operation at or below room temperature, coupling an aromatic to a quaternary carbon and creating benzofurans or articulated dihydrobenzofurans in a number of examples.