Asymmetric induction in the Darzens reaction by means of chiral phase-transfer in a two-phase system. The effect of binding the catalyst to a solid polymeric support

Abstract

Reaction of carbonyl compounds with chloromethyl p-tolyl sulphone or with chloro(phenyl)acetonitrile in a two-phase system, in the presence of chiral ammonium salts, affords the corresponding oxirans with 0–2.5% optical yields. The presence of a hydroxy-group β to the ‘onium’ function is essential to achieve asymmetric induction. Asymmetric induction is increased by binding of the catalyst to a polymeric matrix to give optical yields up to 23%.