Palladium(II)-Catalyzed Decarboxylative Difunctionalization of Alkynoic Acids To Access (E)-ß-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)-ß-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)-ß-sulfonylacrylamides.

Stereodivergent Synthesis of (Z)-/(E)-ß-Sulfonylacrylamides via Tandem Difunctionalization of Alkynes with Sulfinates and Isocyanides.

Stereoselective difunctionalizations of the terminal and internal alkynes with various sulfinates and isocyanides have been achieved to prepare (Z)-/(E)-ß-sulfonylacrylamides. The (Z)-ß-sulfonylacrylamides were generated via a one-pot process that involves the reaction of terminal alkynes with sulfinates and isocyanides in the presence of iodine in sequential manner. The (E)-ß-sulfonylacrylamides were prepared in a two-step synthesis via palladium(II)-catalyzed addition of isocyanide to (E)-ß-iodovinylsulfones synthesized from alkynes.