PI.068 RuII/PdII heterobimetallic complexes as multifunctional catalysts for mechanistically distinct reactions: Heck, ROMP and vinyl polymerization of norbornene

Resumo

The heterobimetallic complexes have emerged as a versatile tool in the development of new multifunctional catalysts to couple different polymerization mechanisms through a dual catalysis. In this work, new complexes based on heterobimetallic complexes combining a Ru metal center to Pd, were developed as pre catalysts for different polymerization mechanisms: ROMP and vinyl polymerization of norbornene and for Heck reaction. The Pd monometallic complexes [Pd(4-aminopyridine)(tsc)] were synthesized from the reaction of the respective thiosemicarbazone ligands, and 4-aminopyridine in the presence of Et3N.

The heterobimetallic complexes of the type [RuCl2(p-cymene)(m-4-aminopyridine)Pd(tsc)] were synthesized from the equimolar reaction between [RuCl2(p-cymene)]2 and the respective palladium complexes. The synthesized complexes were characterized by ¹H NMR. Initial tests on Heck reactions of norbornadiene (NBD) proved to be successful. Quantitative conversions were achieved for Pd- 1 complex when molar ratios of [Cat.]/[PhI]/[NBD] = 1/418/1344 were employed at 120°C for 16h.