Aminophosphine–palladium(II) complexes: Synthsesis, structure and applications in Suzuki and Heck cross-coupling reactions

Reaction of furfurylamine with 1 or 2 equivalents of PPh2Cl in the presence of Et3N, proceeds under anaerobic conditions in thf to give furfuryl-2-(N-diphenylphosphino)amine, Ph2PNHCH2-C4H3O, 1 and furfuryl-2-(N,N-bis(diphenylphosphino)amine), (Ph2P)2NCH2-C4H3O, 2, respectively. The reactions of 1 and 2 with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or Pt(CH3)2(cod) yield complexes [M(Ph2PNHCH2-C4H3O)2Cl2] (M = Pd 1a, Pt 1b), [Pt(Ph2PNHCH2-C4H3O)2(CH3)2] (1c), and [M((Ph2P)2NCH2-C4H3O)Cl2] (M = Pd 2a, Pt 2b), [Pt((Ph2P)2NCH2-C4H3O)(CH3)2] (2c), respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Representative solid-state structures of 2a and 2b were also determined by X-ray single crystal diffraction technique. Furthermore, the palladium complexes 1a and 2a were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction affording biphenyls and trans-stilbenes, respectively.