Using Soluble Polymers in Latent Biphasic Systems

A new strategy for carrying out reactions with a soluble polymer-bound reagent or catalyst is described. In this latent biphasic process, a solvent mixture at the cusp of immiscibility is prepared and used to carry out a reaction under homogeneous conditions. Then, after the reaction is complete, this mixture is perturbed by the addition of solvent or some other perturbing agent to produce a biphasic mixture. The product-containing phase is then separated under liquid/liquid conditions from the polymer-containing phase. The generality of this process is demonstrated using both dye-labeled polymers as surrogates for polymer-bound catalysts and with various polymer-bound organic and transition metal catalysts or reagents. In cases where a polymeric catalyst is used, the addition of fresh solvent and substrate reforms the original mixture allowing facile reuse of the catalyst.