Nucleophilic addition to acetylenes in superbasic catalytic systems: XI. Transformations of alkali metal hydroxides during vinylation of 1-heptanol with acetylene under elevated pressure

Abstract

Base-catalyzed addition of 1-heptanol to acetylene under elevated pressure of the latter is accompanied by side processes including formation of carboxylic acid salts (alkali metal heptanoates and acetates) with liberation of hydrogen and acetylene polymerization. The rate of acetylene absorption depends on the alkali metal nature and falls down in the series CsOH·H2O ≥ RbOH·H2O > 2KOH·H2O > NaOH > LiOH. Approximately the same order is observed for variation of the rate of deactivation of the catalyst owing to its transformation into metal carboxylate. Dehydration of the catalyst accelerates both vinylation and acetylene polymerization.