Oxidation of phosphine

The standard heat of formation for crystalline H3PO2 is —608.8 kJ/mol (—145.5 kcal/mol) (39). The acid can be prepared by the oxidation of phosphine by iodine and water. 

Oxidation of Phosphines and Phosphine Oxides Phosphinic acids may be prepared by controlled oxidation of primary phosphines, RPH2. In most cases air, oxygen, or hydrogen peroxide is sufficient [162-164] see Eq. (95) ... 

The anaerobic oxidation of phosphines to their oxides by hydroxide ion has been shown to involve the liberation of hydrogen, possibly from the intermediate (21). These oxidations were studied with water-soluble phosphines, since solubility was found to be the main factor controlling the rate of oxidation. The preparation, and detailed n.m.r. spectrum, of PP-dimethyl-P P -diphenyldiphosphine disulphide (22) is a relatively rare example of a study of a mixed disulphide. Many examples of routine oxidation of phosphines to their oxides have appeared. These include the preparation of polyhalogenoarylphosphine oxides using dichromate... 

The dioxygen adduct so formed is highly reactive and will catalyse the oxidation of phosphine to phosphine oxide and isocyanide to isocyanate (77). But clearly a survey of these reactions is not within the scope of this review and is provided elsewhere (7, 77). 

The explosion hazard associated with the usual laboratory preparation from white phosphorus and alkali may be avoided by an alternative method involving oxidation of phosphine with an aqueous iodine solution [1], The commercial 50% solution reacts violently with oxidants. On heating, it decomposes rapidly above 100°C evolving phosphine, which is liable to explode with air. It is recommended it... 

Related to this is the mechanism for the catalytic oxidation of phosphines by water. This reaction plays a role in catalysis in water using water-soluble phosphine ligands. 

A large number of articles have been devoted to kinetic studies of the oxidation of phosphine 236-243) compositions of phosphine under pressure, which are oxidised by water, have been described by Bushmakin and Frost. ... 

By oxidation of phosphine with an aqueous iodine solution ... 

Phosphine ignites in air at 150°C. Impure phosphine containing diphosphine ignites at a lower temperature. Phosphoric acid is produced from oxidation of phosphine ... 

The reactive nature of the Mo02(R2 Dtc)2 complex has been demonstrated in various reactions. The catalytic oxidation of phosphines has been reported (23) and KR and K0 have been determined (Eq. 19). The oxidative... 

NR = nonreactive toward hydrocarbons PO = oxidation of phosphines to phosphine oxides MF — peroxometallacyclic adduct formation with cyanoalkenes NSE — nonstereoselective epoxidation SE=stereoselective epoxidation AE = asymmetric epoxidation HA- hydroxylation of alkanes HB=hydroxylation of arenes OA = oxidation of alcohols to carbonyl compounds K = ketonization of Lermina 1 alkenes SO oxidation of S02 to coordinated S04 MO = metallaozonide formation with carbonyl compounds I = oxidation of isocyanides to isocyanates. 

A large number of Group VIII metal-dioxygen complexes catalyze the oxidation of phosphine to phosphine oxide or isocyanides to isocyanates by molecular oxygen.6,12,56,140,141 146,184 However, their use as catalysts for the oxidation of alkenes generally leads to the same products as those obtained from free radical chain autoxidations.184,196-198... 

D KIE of 6.35 has been observed in the oxidation of a-deuteriomandelic acid by pyri-dinium bromochromate to the corresponding oxo acid. The analysis of the D KIE indicated that the reaction involves a symmetric transition state443. The oxidations of phosphinic and phosphorous acids by pyridinium bromochromate exhibits a substantial primary deuterium KIE444. The hydroxyacids, glycolic, lactic, mandelic and malic acids are oxidized by pyridinium hydrobromide perbromide in acetic acid-water mixtures to oxo acids445. The primary KIE in the oxidation of a-deuteriomandelic acid is kn/kn = 5.07, and it does not exhibit a solvent isotope effect. A mechanism involving hydride ion transfer to the oxidant has been proposed445. 

If the Rh-catalyst is stabilized by a monodentate phosphane ligand, it can be destroyed because the lifetime of the oxidation of phosphine to phosphine oxide is less than 1 h. Yet, if the catalyst is stabilized by a bidentate ligand, and the catalyst has a lifetime of 2-3 h, then it can convert into different species that have no catalytic activity. However, such a synthetic approach would suffer as a result of a short lifetime and a low TON. 

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