What is Phase-Transfer Catalysis?
Phase-Transfer Catalysis is useful primarily for performing reaction between anions (and certain neutral molecules such as H2O2 and transition metal complexes such as RhCl3) and organic substrates. PTC is needed because many anions (in the form of their salts, such as NaCN) and neutral compounds are soluble in water and not in organic solvents, whereas the organic reactants are not usually soluble in water. The name phase-transfer catalysis does what it says…the catalyst acts as a shuttling agent by extracting the anion or neutral compound from the aqueous (or solid) phase into the organic reaction phase (or interfacial region) where the anion or neutral compound can freely react with the organic reactant already located in the organic phase. Reactivity is further enhanced, sometimes by orders of magnitude (!), because once the anion or neutral compound is in the organic phase, it has very little (if any) hydration or solvation associated with it, thereby greatly reducing the energy
