https://doi.org/10.1351/goldbook.P04536
The phenomenon of rate enhancement of a reaction between @[email protected] located in different phases (immiscible liquids or solid and liquid) by addition of a small quantity of an agent (called the 'phase-transfer @[email protected]') that extracts one of the reactants, most commonly an @[email protected], across the @[email protected] into the other phase so that reaction can proceed. These catalysts are salts of '@[email protected]' (e.g. tetraalkylammonium salts) or agents that complex inorganic cations (e.g. @[email protected] @[email protected]). The @[email protected] @[email protected] is not consumed in the reaction although an @[email protected] does occur.