Copper (II) Mediated Oxidative Alkoxylation of White Phosphorus. Communication 1.

Abstract

White phosphorus has been oxidized by copper (II) acetylacetonate, halides or carboxylates in aliphatic alcohols to yield dialkyl phosphates and trialkyl phosphates under inert atmosphere and mild reaction conditions. Trialkyl phosphite has been observed as unstable organophosphorus intermediate, which is being converted into the main reaction products. In the case of methanolic solutions, the derivatives of two step acidolysis of dimethyl phosphite, monomethyl phosphite and phosphorous acid, have been additionally detected among the reaction products. The influence of the copper (II) oxidants on the kinetics of accumulation and transmutation of organophosphorus products has been explored. The order of oxidative ability of the copper (II) compounds has been established. The major steps of the reaction including (i) the coordination of white phosphorus and alcohol to metal ion and (ii) the redox decomposition of this intermediate complex accompanied by reducing elimination of elementary copper and formation of organophosphorus product have been also suggested.

Copper (II) Catalyzed Oxidative Alkoxylation of White Phosphorus. Communication 2.

“…Our results suggest the following major steps for the catalytic reaction of the oxidative alkoxylation of P 4 : the reduction of As have been shown in the previous communication 1 [3], trialkyl phosphite is dealkylated by an acid generated in situ to give dialkyl phosphite 1a, b (6) and oxidized by CuX 2 to yield trialkyl phosphate 2a,b (7). The proposed mechanisms of the reactions (3) and (7) have been earlier discussed [3]. The methanolic P(III) esters may undergo the stepwise acidolysis into monomethyl phosphite 3b (8) and phosphorous acid (9).…”

“…Thus the same products are obtained in the oxidative alkoxylation of P 4 under both inert [3] and oxygen atmosphere, i.e. oxygen does not directly react with P 4 and participate in formation of organophosphorus compounds.…”

“…In contrast to oxidative ability demonstrated by the copper(II) butyrate and bromide [3], the catalytic activity of Cu(C 3 H 7 CO 2 ) 2 is higher than one of CuBr 2 . In the presence of both copper (II) butyrate and bromide, tributyl prosphite 2a is predominantly obtained (Table, entries 3, 4).…”

“…Special attention will be devoted to the kinetics of accumulation of organophosphorus products and to the molar ratio between catalyst and white phosphorus. communication 1 [3]. Oxygen was dried under CaCl 2 .…”