About Bases and Superbases

Abstract

Butyllithium requires activation in order to become capable of abstracting a proton from weakly acidic hydrocarbons like cyclopropanes, simple olefins, or arenes. The addition of a stoichiometric amount of potassium tert-butoxide is a most effective means of enhancing the rate of a hydrogen/metal exchange process. The superbasic alkyllithium/potassium alcoholate mixtures are endowed not only with an unsurpassed reactivity but also with a surprisingly high selectivity as evidenced by a series of optionally site-selective arene metalations.