The synthesis of new calix[n]arene quaternary ammonium salts and investigation of their catalytic affinities for three component Mannich-type reactions in water

Two new calix[n]arenes and a non-cyclic analogue substituted with 1-(2-furoyl)piperazine have been synthesized. Moreover, their quaternary ammonium salts have been prepared by treatment with methyl iodide. All of the new quaternary ammonium salts have been employed as catalysts in one-pot Mannich reactions to afford β-aminocarbonyl compounds. The combination of good to excellent yields, the need for a small amount of catalyst and simple work-up, mean that this route can be considered to be green chemistry. © 2014 The Royal Society of Chemistry.