Thermoregulated liquid/liquid catalyst separation and recycling

Considerable effort has been done to overcome the loss of catalyst in homogeneously catalysed processes. In this contribution we describe five recycling concepts for thermoregulated catalyst separation and recycling: fluorous biphasic systems (FBS), thermoregulated phase transfer catalysis (TRPTC), soluble polymer-based catalysis, thermoregulated microemulsions and temperature-dependent multicomponent solvent systems (TMS). Each of these concepts has its own special advantages like low catalyst leaching or simple process engineering but also drawbacks like usage of expensive special solvents or complex and expensive catalysts. In this context, TMS systems exhibit most advantages of the other concepts combined with the possibility to use common and cheap solvents as well as numerous classical molecular catalysts. Therefore, TMS systems are expected to be one of the most promising thermomorphic recycling concepts for industrial scale. 1 Introduction 2 Recovery Strategies for Fluorous Catalysts 3 Thermoregulated Phase-Transfer Catalysts 4 Soluble Polymer-Bound Catalysts 5 Thermoregulated Microemulsions 6 Temperature-Dependent Multicomponent Solvent Systems 6.1 Solvent Selection for Temperature-Dependent Multicomponent Solvent Systems 6.2 Different Types of Temperature-Dependent Multicomponent Solvent Systems 6.3 Examples of Use 7 Conclusions