Resin-Supported Sulfonic Acid

Abstract

There has been a plethora of polymer-supported syntheses since Merrifield began peptide synthesis on the solid phase. [1] Solid-phase organic synthesis (SPOS) has become a very efficient method for production of combinatorial libraries. [2] Resinsulfonic acid is one of the important functional polymer, which is already developed in organic synthesis. [3] Resinsulfonic acids are particularly useful for the removal of basic compounds such as primary, secondary and tertiary amines. On the other hand, they are used as a separator and/or electrolyte in membrane-separated chlor-alkali cells and other electrochemical processes, solid polymer electrolyte fuel cells and batteries. [3a] The use of resinsulfonic acids in organic synthesis was serendipitous. Generally, they are used as Brønsted acid in organic synthesis. Compared to conventional Brønsted acids, they have advantages of recyclability, operational simplicity and they can often be used in just ­catalytic amounts. Of late, resinsulfonic acids such as ­sulfonated polystyrenes (Dowex-50, Amberlite IR-112, ­Permutit-Q) and Nafion-H are commercially available.