Ptc technique the two mutually insoluble reagents, one being an organic phase or substrate dissolved in an organic solvent and other being an organic or inorganic salt from a solid or aqueous phase medium, interact with the help of a phase transfer catalyst.
The phase transfer catalyst does the work of extracting the reactive anions from the aqueous phase and transfers them to the organic phase containing the reactant. Subsequently a reaction takes place between transferred reagent or ion-pair with the non transferred reactant within the organic phase 1-2. The concept of multi-sited phase transfer catalyst (QX2) was introduced by Idoux et al. in which they have synthesized phosphonium and quaternary onium ions containing more than one active site per molecule 3.
Recently, the catalytic behavior of multi-site phase-transfer catalysts have been attracted much attention, due to the fact that multiple molecules of the aqueous reactant can be carried into the reaction phase once a reaction cycle. The catalytic efficiency is thus enhanced 4-5.