Macrocyclic Pd(II) dithiolate complexes as catalysts in Heck reactions

The supramolecular palladium dithiolate complexes, Pd₂(dppe)₂{S(C₆H₄)_nS}]₂(OTf)₄ and Pd₂(dppe)₂(SCH₂C₆H₄CH₂S)]₄(OTf)₈ (dppe = 1,2-bis(diphenylphosphino)ethane) has been investigated as highly stable and robust catalysts in Heck C-C coupling reactions. The arylation of butyl acrylate and styrene with various aryl bromides under optimized catalytic systems, showed excellent yield and turnover number (410,000) of the products. The tetranuclear complexes showed slightly higher catalytic activity than the octanuclear complex.