Biphasic Catalysis for Sustainable Alkene Epoxidation

Abstract

This article highlights the epoxidation of alkenes by molecular catalysts in biphasic liquid–liquid media. We showcase strategies for a precise control of the phase behavior of both the catalyst and the substrate, which is dominated by phase‐transfer‐enabling surfactants. The focus is set on the rationale of phase transfer and the efficiency of catalyst recycling. Principally, it is possible to transfer the catalyst to either the aqueous or the organic phase, depending on the type of surfactant and on the requirements for the reaction, for example, catalyst activity versus catalyst recycling. We present these two basic concepts with respect to the type of phase transfer and the interactions between catalyst and surfactant, the catalyst activity, and the possibility for efficient and green catalyst recycling.