The synthesis methods of phosphorus compounds R4PX, where X is an electronegative group

Abstract

Based on the analysis of literature sources from the beginning of the 21st century to the present, various methods for obtaining phosphorus compounds of the general formula R4PX (X is an electronegative group) have been systematized and described. The present study is a continuation of classical research in the field of chemistry of organic phosphorus compounds in the Laboratory of Chemistry of Organoelement Compounds of South Ural State University. The principal attention is paid to synthesis methods for tetraorganylphosphonium derivatives based on radical redistribution reactions and substitution reactions, which are used to synthesize tetraphenylphosphorus bromide and a series of alkyltriphenylphosphonium arenesulfonates, respectively. It has been shown that the single product of the interaction of triphenylphosphorus dibromide with pentaphenylphosphorus in a benzene solution (1 hour, 25 °C) is tetraphenylphosphonium bromide, isolated from the reaction mixture, yielding 92%. Tetraphenylphosphonium benzenesulfonate has been obtained, yielding 90%, by a substitution re-action from tetraphenylphosphonium bromide and benzenesulfonic acid in water. Using a similar scheme, a series of alkyltriphenylphosphonium arenesulfonates have been obtained with yields up to 92 %: [Ph3PC3H5-cyclo][OSO2Naft-1] (2), [Ph3PCH2СN][OSO2Mez)] (3), [Ph3PCH2СN][OSO2C6H3Сl2-2,5] ∙ ½MeOH (4), [Ph3PCH2OH][OSO2C6H3Сl2-2,5] ∙ H2O (5), [Ph3PEt][OSO2C6H3(NO2)2-2,4] (6), [Ph3P(СH2)2OH] [OSO2C6H3(NO2)2-2,4] (7), [Ph3P(С6H11-cyclo)] [OSO2C6H3(NO2)2-2,4] (8). The complex structures have been proved by IR spectroscopy and X-ray diffraction analysis (XRD). According to the XRD data, crystals of complexes 2–5 have ionic structure; they consist of tetraorganylphosphonium and arenesulfonate anions.