Water-soluble calixarenes as new inverse phase-transfer catalysts. Their application to aldol-type condensation and Michael addition reactions in water

Aldol-type condensation and Michael addition reactions of activated methyl and methylene compounds in aqueous NaOH solution have been developed without the need for any added organic solvents. The water-soluble calix[n]arenes, which contain trimethylammoniomethyl groups on the upper rim, were used as inverse phase-transfer catalysts, resulting in the corresponding products in good to excellent yields.