Tom A. James

ortho-metallation reactions involving some triphenyl phosphite complexes of osmium

Abstract Osmium triphenylphosphine complexes, OsH4(PPh3)3, OsH2 (CO)(PPh3)3 and OsHCl(CO)(PPh3)3 react with triphenyl phosphite in boiling organic solvents to yield triphenyl phosphite derivatives which subsequently undergo ortho-metallation reactions.

Transition-metal complexes containing phosphorus ligands. Part X. ortho-Metallation reactions involving some triaryl phosphite derivatives of palladium(II) and platinum(II) dihalides

Triaryl phosphite complexes of palladium(II) and platinum(II), MX2[P(OAr)3]2(M = Pd or Pt; X = Cl, Br, or I; Ar = phenyl, p-chlorophenyl, o-, m-, or p-tolyl), react in boiling decalin, with elimination of a molecule of hydrogen halide. HX, to afford ortho-metallated triaryl phosphite derivatives. The tendency to undergo metallation is dependent upon the anionic ligands present and increases I < Br < Cl. The structures and stereochemistry of these products have been determined by i.r. and n.m.r. spectroscopy. Treatment of the ortho-metallated complexes with hydrogen halide in dichloromethane leads to rapid reversal of the ortho-palladation reactions and slow reversal of the ortho-platination reactions. Mechanistic aspects of the ortho-metallation processes are discussed.

Transition-metal complexes containing phosphorus ligands. Part XIV. ortho-Metallation reactions involving some triaryl phosphite derivatives of osmium

Osmium triphenylphosphine complexes, [OsH4(PPh3)3], [OsH2(CO)(PPh3)3], and [OsHCl(CO)(PPh3)3] react with triphenyl phosphite in boiling organic solvents to yield triphenyl phosphite derivatives which subsequently undergo ortho-metallation. Products isolated and characterised include the substituted derivatives [OsHCl(CO)(PPh3)2(p)] and [OsHCl(CO)(PPh3)(p)2], the metallated species [OsCl(pc)(CO)(PPh3)(p)], [OsCl(pc)(CO)(p)2], [OsH(PC)(CO)(PPh3)(p)], and [OsH(pc)(CO)(p)2], and the dimetallated complexes [Os(pc)2(p)2] and [Os(pc)2(CO)(p)][(P)= P(OPh)3; (pc)=(PhO)2P(OC6H4)].

Transition-metal complexes containing phosphorus ligands. Part IX. Triaryl phosphite derivatives of palladium(II) and platinum(II) dihalides

An extensive series of triaryl phosphite derivatives of palladium(II) and platinum(II) dihalides, MX2[P(OAr)3]2(M = Pd or Pt; X = Cl, Br, or I; Ar = phenyl, p-chlorophenyl, o-, m-, or p-tolyl), have been isolated as air-stable crystalline solids by reacting triaryl phosphites, P(OAr)3 and, where appropriate, lithium halides, LiX, with the salts Na2MCl4 in ethanol or the neutral complexes MX2(cyclo-octa-1,5-diene) in benzene solution. The new complexes have been characterised and their stereochemistry investigated by i.r. and n.m.r. spectroscopy. Palladium derivatives containing bulky tri-o-tolyl phosphite or iodide ligands were obtained as trans-isomers or cis–trans mixtures, the remaining complexes occurred predominantly as the cis-isomers. An extensive compilation of 31P n.m.r. data is given.