Selective Azide Oxidation of 1,2-Bis(diphenylphosphino)benzene and Related Ethylenebis(phosphines) to Asymmetric Multifunctional Phosphorus Ligands and Formation of Rhodium(I) Complexes of These Ligands. Structural Characterization of the Prototypical Ligand 1-(((Trimethylsilyl)imino)diphenylphosphorano)-2-(diphenylphosphino)benzene and Its Rhodium(I) Complex:  1-Ph₂PN(SiMe₃)C₆H₄-2-(Ph₂P)Rh(CO)Cl

Abstract

Selective azide mono-oxidation of o-bis(phosphines) such as o-bis(diphenylphosphino)benzene and other bis(phosphines) with cis-substituents on a rigid backbone such as an ethylene structure occurs as the result of the steric control exerted during the azide oxidation (Staudinger) reaction process. The azides used were the trimethylsilyl, 4-cyanotetrafluorophenyl, benzyl, and diphenoxyphosphonyl azides. The prototypical ligand 1-Ph(2)P=N(SiMe(3))-2-(Ph(2)P)C(6)H(4), 2, has been structurally characterized. Crystal data for 2: crystal dimensions, 0.38 x 0.38 x 0.57 mm; space group, monoclinic, P2(1)/c, (No. 14); a = 11.093(5) Å, b = 14.898(5) Å, c = 18.811(2) Å, beta = 102.76(2) degrees, V = 3031 Å(3), Z = 4. Final R, R(w) and GOF values were 0.068, 0.074, and 1.92 respectively. The P=N-SiMe(3) angle was wide, 152.7(3) degrees, and the P=N bond length short (1.529(5) Å) relative to arylated iminophosphoranes but in keeping with the trends for silylated analogs. The iminophosphorane center can be selectively transformed with other agents in a Wittig type reaction converting the azides to the monooxide, monosulfide, etc. The iminophosphoranophosphines are also good complexing agents and the Rh(I) complex derived from 2, 1-Ph(2)P=N(SiMe(3))-C(6)H(4)-2-(Ph(2)P)Rh(CO)Cl, 15 was structurally characterized. Crystal data for 15: crystal dimensions, 0.32 x 0.44 x 0.66 mm; space group, monoclinic, P2(1)/c (No. 14); a = 13.793(3) Å, b = 12.622(11) Å, c = 20.436(6) Å, beta = 105.93(2) degrees, V = 3421.2 Å(3), Z = 4. Final R, R(w), and GOF values were 0.064, 0.061, and 1.45 respectively. The complex shows typical square planar geometry about Rh, a cis phosphine-CO relationship, and no exceptional steric crowding of the coordination site.

New cationic palladium (II) and rhodium (I) complexes of [Ph2PCH2C(Ph)N(2,6-Me2C6H3)]

“…The rhodium-nitrogen bond lengths are all within the same range, for example: 2.138(2) Å (in 2), 2.109(5) Å (in 3), 2.209(4) and 2.229(3) Å (in 4). In 3, the observedRh-CO bond lengths are 1.836(9) and 1.820(9) Å (molecules 1 and 2, respectively), which are slightly shorter than the average value of 1.847 Å , and similar to those found in N/P complexes of the type [RhCl(CO)(L 00 )], where L 00 = chiral ferrocenyl chelating ligands, containing a tertiary phosphine and a pyrazole moiety[56,62,[79][80][81]. The CO group of [Rh(CH 3 CN)(CO)(L)] [BF 4 ] (3) was shown to be coordinated cis to the phosphine group of the ligand.…”

Complexes of Multifunctional Phosphorus Ligands. Rhenium(V) Complexes of the Multidentate Phenoxyphosphine Ligands Bis(o-trimethylsilyloxyphenyl)phenylphosphine and Tris(o-trimethylsilyloxyphenyl)phosphine. Stepwise Elimination of Me3SiX (X = Cl, OEt) from the Metal−Ligand System

“…The Fe or Co coordination chemistry of the trianionic tris(phenolato)phosphine P{O} 3 ligand has been briefly described but no synthetic details were given . As part of our continuing study − of the interaction of heterobifunctional, hemilabile, phosphorus based, hard−soft, ligands with both transition-metal and main group , elements, we were interested in extending the chemistry of the potentially tridentate PhP{OH} 2 and the potentially tetradentate P{OH} 3 ligands to Re(V) precursors. Recently alternate routes to ligands of this type have been described .…”

Synthesis of Polyphosphazenes by a Fast Perfluoroaryl Azide-Mediated Staudinger Reaction

“…Diphosphine 2c was chosen to test whether the aromatic structure would affect the reactivity of the phosphine as extended conjugation may reduce the reactivity of the phosphine . Dichloromethane was initially used as the solvent for the synthesis of polymer 3ac due to the lower solubility of monomer 2c in CH 3 CN; however, the polymerization was incomplete after 1 h as shown by the presence of the phosphine monomer after purification.…”