III International Conference

PP-I-4MECHANISM OF THE COPPER SALTS CATALYZED OXIDATION OF WHITEPHOSPHORUS BY ORGANIC PEROXIDES IN ALCOHOLSAbdreimova R.R., Akbayeva D.N., Faizova F.Kh.D.V. Sokolsky Institute of Organic Catalysis and Electrochemisrty MS&HE RK,Almaty, Republic of KazakhstanE-mail: abdreimioce@nursat.kzOrganic peroxides, R’OOR”, are considered simple and universal sources of radicalspecies. The decomposition of peroxides is strongly accelerated by transition metal ions. Avariety of highly efficient and environmentally appealing oxidative catalytic processes havebeen developed using and organic peroxides as ecobenign and efficient oxidants [1]. Scarceattention has been however focused on the oxidation of white phosphorus (P 4 ) by organicperoxides. This presentation sheds some light in this area giving an account of our studies onthe stoichiometric and catalytic oxidation of P 4 by organic peroxides (dibenzoyl peroxide and3-chloroperoxybenzoic acid) in aliphatic alcohols (MeOH, n-BuOH) at 40-60 o C underanaerobic conditions.Without adding any metal promoter, the reaction results in the formation of a mixture ofdi- and monoalkyl hydrogen phosphonates (1 and 2) and trialkyl phosphates (3). Generally,the P(III) species are the major products of the reaction whereas the P(V) derivatives areusually produced in limited amount. The molecule of peroxide does not directly interact withP4, but rather initiates the reaction generating radical species via homolysis of the O-O bonds.Once formed, the R’O ● (or R”O ● ) radicals may easily react with ROH to generate RO ●radicals, a powerful oxidants towards inorganic and organic substrates, which cansuccessfully promote the radical oxidation of white phosphorus. The simple stoichiometriesaccounting for the formation of each reaction product are given below in equations 1 – 3.P 4 + 6R'OOR" + 12ROH 4P(O)H(OR) 2 + 4R'OH + 4R"OH + 2R'OR + 2R"OR (1)1P(O)H(OR) 2 + R'OH P(O)H(OH)(OR) + R'OR (2)12P(O)H(OR) 2 + R'OOR" + ROH P(O)(OR) 3 + R'OH + R"OH (3)13In the presence of catalytic amounts of copper(II) salts (CuX 2 ; X = Cl, acac,C 3 H 7 COO), the oxidative alkoxydation of P 4 promoted by organic peroxides is significantlyenhanced with increasing of the reaction rate up to eight times. Noticeably, under optimized13