Efficient Synthesis of Vinyl Sulfones by Manganese-Catalyzed Decarboxylative Coupling of Cinnamic Acids with Aromatic Sulfinic Acid Sodium Salts

An efficient synthesis of vinyl sulfones is described. Reactions of cinnamic acids with aromatic sulfinic acid sodium salts in the presence of a catalytic amount of manganese(II) acetate tetrahydrate (5 mol%) in dimethyl sulfoxide (DMSO) afforded the desired vinyl sulfones in good to excellent yields. Notably, the reaction does not need any base or iodide as additive. The use of DMSO as the solvent and running the reaction under air are critical in achieving good yields.