THE PtP(C6H11)3(C2H4)2 MEDIATED ACTIVATION OF ALDEHYDE C-H BONDS VIA CHELATE-ASSISTED OXIDATIVE ADDITION REACTIONS

Article abstract of DOI:10.1016/0022-328X(85)80038-3

Hydrocarbon solutions of PtPCy3(C2H4)2 (Cy = cyclohexyl) react rapidly with 8-quinolinecarboxaldehyde (1 equiv.) to yield tricyclohexylphosphine quinoline-carboxyl platinum hydride (1) and CH2CH2 (2 equiv.).Compound 1 reacts with CCl4 in hydrocarbons to give PtPCy3(NC9H6CO)Cl (2) and CHCl3.The compound PtPCy3(C2H4)2 also reacts with Ph2P(C6H4-o-CHO) and Ph2As(C6H4-o-CHO) to give PCy3PtPh2P(C6H4-o-CO)(H) (3) and PCy3PtPh2As(C6H4-o-CO)(H) (4), respectively.Compounds 1, 2, 3, and 4 were characterized by infrared and 1H NMR spectra, and the crystal structure of 3 was determined by X-ray diffraction.Crystals of 3 are monoclinic, with space group P2₁/n and Z = 4 with the unit cell dimensions a 9.7936(17), b 14.844(35), c 23.530(64) Angstroem, β 91.817 (18)deg, and V 3419.09(1.36) Angstroem³.The structure is refined to final discrepancy factors of R = 0.055, and R_w = 0.064.The molecular structure of 3 is that ligating atoms are in a plane containing Pt.The position of the hydride was not located crystallographically, but the 1H NMR spectrum of 3, supports the presence of a terminal hydride that is cis to the carbonyl.The IR band of 3 at 2023 cm^-1, which is assigned to ν(Pt-H), and the hydride cleavage reaction of 1 with CCl4, provide evidence for the Pt-H bond.