Synthesis, characterization and catalytic evaluation of three new Pd-iminophosphine complexes on Suzuki cross-coupling reactions

Abstract

Three new palladium(II)-iminophosphine complexes, [Pd(L1)(Cl)₂] C1, [Pd(L2)(Cl)₂] C2 and [Pd(L3)(Cl)₂] C3 have been synthesized and successfully characterized by using ¹H-NMR, ¹³C-NMR, ³¹P-NMR, UV–Vis, FT-IR and magnetic susceptibility techniques. Catalytic activities of complexes towards Suzuki–Miyaura C–C coupling reactions between phenylboronic acid and several aryl halides were investigated under several reaction conditions (solvent, temperature, base, reaction time, and type of substrate). Under optimum conditions, achieving high yields of up to 99% was possible. When 1-bromo-4-nitrobenzene was used for complex C1, bromobenzene for complex C2, and bromobenzene for complex C3, product yields of 99, 99, and 98% were achieved, respectively.

Graphical abstract

Three new palladium complexes bearing iminophosphine ligands was synthesized and successfully characterized. Catalytic activities of the synthesized complexes were investigated on Suzuki–Myaura type coupling reaction between phenylboronic acid and several aryl halides. All complexes exhibited good catalytic activities on C–C coupling reactions up to 99% product formations under mild conditions.