Oxidation of naphthene hydrocarbons in the presence of boron compounds

Abstract

I.'HJ.: use of boric acid for increasing the selectivity of oxidation of hydrocarbons was first deseribed about 40 years ago [l]. Many papers have since been published in the literature dealing with the study of this reaction [2]. Studies by A. N. Bashkirov ct al. should first of all be mentioned as they had a considerable influenee on the development of the theory and praetieal apl)lieation of oxidation of hydr oearbons with boron-eontaining additives. A. N. Bashkirov and V. V. Kamzolkin [3] proposed the theory of the so-called stop-reagents, according to whieh boric acid stops lhe reaction at the stage of alcohols, combining them into boric esters that are oxidized only with difficulty. A number of scientists [4-6] expressed the view tha t esterifieation of alcohols with boric acid is not a decisive t, tetor in increasing selectivity and that boron compounds are more intensively involved in oxidation. All these results, which are oft.on eonfliet.ing, have not so far been elassified and in spite of the faet that oxidation in the presence of boric acid is carried out on an industrial or semi-industria.l settle, there is no single view i~t exist.enee about the mechanism and role of boron eompotmds. We examined oxidalion of unbra.nehed (cyelohex~ne and eyelododeeane) and branched (metyh'yelohexane) eycloparaffins i~l the prese~we of various boron campaunds such as bori(, anhydride, o r t h o a n d metaboric acid esters eontabling various ah:ohol residues. The main course of the rea.etion is the tbrnmtion of e(n'responding aleohols anti ketones, the overall viehl of which ranges t'rom 80 to !15 tool. o/ in terms ,. / O