Synthesis and coordination of 2-diphenylphosphinopicolinamide

The synthesis and coordination of 2-diphenylphosphinopicolinamide (dpppa 1) is reported. Coordination complexes with Pd, Pt, Ru, Rh, Ir and Au are described. The ligand behaves as a monodentate P donor in complexes such as [PtCl2(dpppa-P-2)], [PdCl(allyl)(dpppa-P)], [RuCl2(p-Cymene)(dpppa-P)], cis-[PtCl2(dpppa-P)(PR3)] and [AuCl(dpppa-P)]. Bidentate P, O coordination was accomplished by reaction of BuLi with [RuCl2(p-Cymene)(dpppa-P)], to give [RuCl(p-Cymene)(dpppa-P,O). P,N donor behaviour was achieved by reaction of a monodentate complex with a halide abstractor [AgBF4] generating [RuCl(p-Cymene)(dpppa-P,N)][ClO4] and [RhCl(eta(5)hCl(eta(5)-C5Me5)(dpppa-P,N)][BF4]. The X-ray structures of dpppa, dpppaO, dpppaS, four monodentate complexes and [RuCl(p-Cymene)(dpppa-P,O) are reported. All of the structures contain intramolecular N-(HN)-N-... hydrogen bonding. (C) 2004 Published by Elsevier Ltd.