The iminophosphorane-phosphane Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2): Synthesis, reactivity, and catalytic activity in Suzuki cross-coupling and the homogeneous hydrogenation of olefins

The iminophosphorane-phosphane ligand Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2) (1) has been synthesized by partial imination of bis[2-(diphenylphosphanyl)phenyl] ether (DPEphos) with phosphoryl azide (PhO)(2)P(O)N-3. A similar reaction in a 1:2 stoichiometry affords the bis(iminophosphorane) O-{C6H4PPh2=NP(O)(OPh)(2)}(2) (2). The chalcogen derivatives O{C6H4P(E)Ph-2}(2) [E = S (3) and Se (4)] and Ph2P(E)C6H4OC6H4PPh2=NP(O)(OPh)(2) [E = S (5) and Se (6)] are also synthesized by treating DPEphos and 1 with elemental sulfur and selenium, respectively. The mononuclear complexes trans-[MCl2{kappa(1)-P-Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2)}(2)] [M = Pt (7) Pd (8)] and trans-[Rh(CO)Cl{kappa(1)-P-Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2)}(2)] (12) are prepared by the reaction of 1 with [Pt(COD)Cl-2], [Pd(COD)Cl-2], and [{Rh(CO)2Cl}(2)], respectively. Treatment of 1 with [Pd-2(dba(3))] (dba = di-benzylideneacetone) affords the mononuclear complex [Pd-0{kappa(2)-P,O-Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2}2)] (9) in which ligand 1 coordinates through its P and O centers in a kappa(2)-P,O chelating fashion. The monocoordinated Au-I complex [AuCl{kappa(1)-P-Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2)}] (10) has been prepared by the reaction of 1 and [AuCl(SMe2)] and its structure has been confirmed by X-ray crystallography. The reaction of 1 with [{Rh(COD)Cl}(2)] in the presence of AgOTf affords the cationic Rh-I complex cis-[Rh(COD){kappa(2)-P,O-Ph2PC6H4OC6H4PPh2=NP(O)(OPh)(2)}][OTf] (11). The catalytic activity of the Pd-0 complex 9 has been investigated in Suzuki cross-coupling reactions. Homogeneous catalytic hydrogenation of olefins has also been studied using the cationic Rh-1 complex 11