100 Years of Carbocations and their Significance in Chemistry

Abstract

The centennial of the first report of a stable carbocation, the triphenylmethyl cation, serves as the occasion to give a perspective based on recollections of authors search. This included development of general methods to prepare persistent long-lived carbocations in superacidic media, realization of the general concept of carbocations including trivalent and five or higher coordinated ions, as well as their role and significance in chemistry. One of the most original and significant ideas in organic chemistry was the suggestion by Meerwein that carbocations might be intermediates to the course of reactions that start from nonionic reactants and lead to nonionic covalent products. The idea that ionization of alkyl fluorides to stable alkyl cations could be possible with an excess of strong Lewis acid fluoride that also serves as solvent while studying the boron trifluoride–catalyzed alkylation of aromatics with alkyl fluorides.