Cross-Linked Thiazolidine Network as Support for Palladium: A New Catalyst for Suzuki and Heck Reactions

A thiazolidine-based material was used for the first time as support for palladium. The support was prepared by starting from a highly cross-linked thiazolium-based material, obtained by radical oligomerization of a bisvinylthiazolium dibromide salt in the presence of 3-mercaptopropyl-modified silica SBA-15. Palladium was immobilized by treatment with tetrachloropalladate salt. Reduction with sodium borohydride afforded a thiazolidine-based material that acted as ligands for the Pd species. The thiazolidine-based palladium catalyst was fully characterized and, working in only 0.1 mol% amount, displayed good activity in the Suzuki-Miyaura and in the Heck reactions. Several biphenyl and alkene compounds could be prepared in high yields. The catalytic material proved to be fully recoverable and it was representatively used for three times in the Suzuki-Miyaura reaction without showing any decrease in its activity.