72095-77-3Relevant articles and documents
Oxidative P-O and P-C Coupling of Butanol with Phosphine in the Presence of Oxidizers and Platinum(IV) and Platinum(II)
Dorfman,Polimbetova,Aibasov
, p. 231 - 247 (2007/10/03)
A butanol solution of Na2PtCl6 at 60-80°C in the presence of p-benzoquinone or NaBrO3 is found to rapidly consume even traces of PH3 until complete reduction of benzoquinone to hydroquinone or NaBrO3 to NaBr, respectively. The nature of products depends on the valence state of platinum and the nature of the oxidizer. Without an oxidizer, platinum(IV) is reduced to platinum(II) with formation of tributyl phosphate, the product of P-O coupling of PH3 with BuOH, while platinum(II) is reduced to platinum(0) with formation of butylbis(α-hydroxybutyl)phosphine oxide Bu(α-PrCHOH)2PO, the product of P-C coupling of PH3 with BuOH. In the presence of benzoquinone, which oxidizes Pt(0) to Pt(II), a P-C bond is formed, while in the presence of sodium bromate, which regenerates Pt(II) to Pt(IV), P-O coupling of PH3 with BuOH occurs. The products and principal steps of this new reaction were studied by the methods kinetics, red-ox potentiometry, chemical modeling, inhibition of free-radical reactions, 31P NMR, IR and X-ray photoelectron spectroscopy, X-ray spectral microanalysis, and gas-liquid chromatography. We showed that the P-C coupling of PH3 with BuOH is promoted by platinum(II) complex, while P-O coupling is promoted by platinum(IV) complex. In the key steps the Pt(II) butoxyphosphide complex PtCl3(OBu)(PH2)- arises from reaction of the Pt(II) phosphide complex with platinum(IV). The red-ox decomposition of intermediate complexes leads to formation of phosphinite (BuO)2PH2 and Pt(II), or (α-hydroxybutyl)phosphine and Pt(0). The catalytic cycles are completed by fast steps of oxidative butoxylation of (BuO)PH2 to (BuO)3PO or by α-hydroxybutylation of (PrCHOH)PH2 to Bu(PrCHOH)2PO, and oxidation of Pt(II) to Pt(IV) with bromate or Pt(0) to Pt(II) with benzoquinone, respectively.
