Chemistry of cyclopropene II: Formation and reactions of 1‐potassio‐, 1‐sodio‐and 1‐lithiocyclopropene in liquid ammonia

Abstract

Abstract 1‐Metallocyclopropene is instantaneously and nearly quantitatively formed on addition of cyclopropene to an at least equimolar amount of alkali amide in liquid ammonia. Alkylation yields mono‐ and dialkylated cyclopropenes. On standing, 1‐metallocyclopropene slowly converts into a mixture of 1‐metallo‐,2‐cyclopropylcyclopropene, 1,2‐dicyclopropylcyclopropene and cyclopropylidenecyclopropane, in a yield that greatly depends on the reaction conditions. A detailed kinetic study has made it possible to select optimum reaction conditions for the formation of each of these products. A route has been developed for the synthesis of monoalkylated and 1,2‐dialkylated cyclopropenes, either with identical or with different alkyl groups.