2. Phase transfer catalysis

Consider the case of a substance added to a two-phase system (organic phase and aqueous phase, for example):

• either the substance is not soluble in the organic phase where the reaction takes place, and it can only pass into this phase thanks to a complexing agent that is soluble in it and acts as a transfer agent and catalyst;

• either the substance is soluble in the organic reaction phase but requires the action of a reagent from the other phase to react, with the reaction occurring at the interface; the catalyst then intervenes to return the modified product to the organic phase where the reaction continues.

The behavior, mobility, and reactivity of the substance will depend on the reaction medium (solvent of each phase) and the transfer agent or catalyst. We will therefore...