Enhanced activity of polymer-supported phase transfer catalysts

Phase transfer catalysis has been a weapon in the arsenal of synthetic orga nic chemists for over three decades now. While phase transfer catalysts (PT Cs) have found widespread use in the industry, the polymer-supported phase transfer catalysts, also known as triphase catalysts, have not gained indus trial acceptance. Triphase catalysts offer many advantages associated with heterogeneous catalysts such as easy separation from the reaction mixture, reusability, and use in continuous reactors. These significant advantages n otwithstanding, the main reason for the lack of interest in the industry fo r the use of triphase catalysts has been its reduced activity in comparison with soluble-phase transfer catalysts. Due to their heterogeneous nature, triphase catalysts, in general, have lower reactivity. In this paper, we ad dress this issue of reduced activity of triphase catalysts for a specific r eaction, that is, phase transfer esterification of benzyl chloride with aqu eous sodium acetate. It has been found that the triphase catalyst has a hig her reactivity than its soluble analogs. The kinetics of the phase transfer reaction using both soluble and polymer-supported catalysts has been deter mined and the results are presented. (C) 2000 Elsevier Science Ltd. All rig hts reserved.