Oxidative Addition of Pd(0) to Ar−SO₂R Bonds:  Heck-Type Reactions of Sulfones

Phenyl vinyl sulfones and sulfoxides react with Pd(OAc)₂ to form styryl sulfoxides and sulfones according to the first Mizoroki−Heck reaction reported for these thio derivatives. Only sulfones are able to react by using catalytic amounts of Pd (up to 1 mol %) in the presence of Ag₂CO₃. 1,2-Diphenylsulfonyl ethenes, alkynylphenyl sulfones, and other sulfones, less prone to act as acceptors in the Heck-type reactions, can transfer the aryl group to alkyl acrylates forming cinnamic esters.