Palladium(II)-Catalyzed Decarboxylative Difunctionalization of Alkynoic Acids To Access ( E )-β-Sulfonylacrylamides and DFT Study.

A palladium(II)-catalyzed regio- and stereoselective difunctionalization of alkynoic acids has been achieved using sodium sulfinates and isocyanides to synthesize ( E )-β-sulfonylacrylamides. The reaction proceeds via decarboxylative isocyanide addition, followed by sulfonylation. This three-component process works well with aromatic, heteroaromatic, and aliphatic alkynoic acids with good functional group tolerance and excellent regio- and stereoselectivity. DFT calculations were carried out to explain the reaction mechanism and the stereoselective formation of ( E )-β-sulfonylacrylamides.