NATURE OF THE SPECIES RESPONSIBLE FOR THE HIGH ACTIVITY OF RCOX*2AlX3 COMPLEXES IN REACTIONS WITH ALKANES AND CYCLOALKANES

Article abstract of DOI:10.1007/BF00958832

The reasons for the high reactivity of aprotic organic superacids (AOS) containing an acyl halide and a double molar excess of Lewis acid in reactions with saturated hydrocarbons are studied.The synthesis and spectral properties of two pairs of acyl salts are studied: MstCO⁺AlBr4^- and MstCO⁺Al2Br7^- (Mst = 2,4,6-Me3C6H2) and Ac⁺SbF6^- and Ac⁺Sb2F11^-.Comparison of the reactivities of these salts in cracking of alkanes and isomerization of trimethylenenorbornane demonstrated that the AOS activity is due to generation of acyl salts with a dimeric anion in the slightly polar solutions.Analysis of the 13C NMR spectra suggests that the superacid properties of these salts are due to formation of species containing acyl cations coordinated to the Lewis acid.