The air, water, and highly thermally stable sulfur-containing palladacycles
, mainly derived from the ortho-palladation of benzylic thioethers, are exc
eptional catalyst precursors for the Heck reaction. The reaction can be per
formed with aryl iodides, bromides, and chlorides, with acrylic esters and
styrene, leading to turnover numbers up to 1 850 000.