Effect of Water in the Trimer‐Cyclisation of Alkynyl Ketone

Abstract

AbstractA trimer‐cyclisation reaction of propiolate esters yielded 1,3,5‐benzenetricarboxylate tri‐esters in water. The reaction proceeded selectively in the presence of secondary or tertiary amine salts in pure water solvent. Other organic solvents, such as dimethyl formamide, tetrahydrofuran, and ethanol, afforded a 1 : 1 adduct of propiolate and amine. The hydrogen bonding characteristics of water stabilised the proposed intermediate in a conformation that promoted the final cyclisation. The synthesis can be successfully conducted in water–a universal and an eco‐friendly solvent.