Pd-Catalyzed Highly Regio- and Stereoselective Formation of C-C Double Bonds: An Efficient Method for the Synthesis of Benzofuran-, Dihydrobenzofuran-, and Indoline-Containing Alkenes

A highly regio- and stereoselective C-C double bond formation reaction via Pd-catalyzed Heck-type cascade process with N-tosylhydrazones has been developed. Various N-tosylhydrazones derived from both ketones and aldehydes are found to be efficient substrates to provide di- and trisubstituted olefins with high regio- and stereoselectivity. Furthermore, this reaction has a good functional group tolerance and different benzofuran-, dihydrobenzofuran-, and indoline-containing alkene products were obtained with high selectivity.