Aromatic reactivity. Part XLIII. Effects of positive poles in protodetrimethylsilylation

Abstract

We have measured the rates of cleavage by a 4:3 v/v mixture of acetic acid and aqueous sulphuric acid at 50·2° of a series of X·C₆H₄·SiMe₃ compounds in which X is a positively charged group. The results, which are consistent with those obtained for nitration, are discussed in terms of strong inductive electron withdrawal by the positive poles, enhanced by (p→d)_π bonding in the case of the PMe₃⁺ and, to a lesser extent, in that of the p-AsMe₃⁺ group.