Palladium cyclometallated compounds: evaluation of their catalytic activity in cross-coupling reactions

Catalysts are substances that can increase the speed of a chemical reaction and have been widely used in the chemical industry. Palladium is one of the most popular metals in catalysis, and many palladium complexes have been extensively used, in particular, in cross-coupling reactions with carbon-carbon bond formation. Their possible applications as catalysts, along with their uses in biological assays as anticancer agents makes the palladium family of complexes a very interesting and studied one, where the numerous changes in the ligands allows to greatly modulate their properties.

Herein we report the synthesis of several palladium cyclometallated compounds with thiosemicarbazone ligands and bis(diphenylphosphino)methane (dppm). Also, their catalytic activity in the Suzuki-Miyaura cross-coupling reaction will be evaluated, by using 4−bromoacetophenone and phenylboronic acid as reagents; the reaction being monitored by ¹H NMR spectroscopy. A final comparison between the catalytic conversions and the complexes allows to choose the optimal structure.