Abstract
The review gives a systematic account of the most characteristic reactions of heteroaromatic cations and also tropylium and cyclopropenylium salts. The properties of these cations are compared and classified in accordance with three types:
1. reactions involving recyclisation; 2. reactions of substituents in aromatic cations; 3. reactions with retention of the ring. Attention has been concentrated on the recyclisation reactions and studies which have not been described in previous reviews.
The bibliography includes 220 references.