Scavenger Resins in Solution-Phase CombiChem

Abstract

This chapter provides an overview of the several advances in the solid-phase assisted solution-phase combinatorial synthesis, specifically the use of scavenger resins in assisting the isolation of pure product without the need for chromatography. The most popular methodology for solution-phase combinatorial chemistry is the use of scavenger resins that are also known as polymer-supported quenching/scavenging reagents. Additional methodologies applied for the same purpose of rapid purification include chemical tagging of reagents, solid-phase extraction, and fluorous-phase extraction. Solution-phase combinatorial synthesis provides a homogeneous reaction medium and overcomes the drawbacks of a solid-phase strategy. An easy and reliable purification method is required in solution-phase combinatorial (parallel) synthesis to facilitate automation. The throughput in solution-phase automated synthesis is directly related to the facility of performing, for example, a purification process (work-up), compound separation. During the past several years, polymer-assisted solution-phase synthesis has become the prevalent method for the parallel synthesis of chemical libraries. A key step in the parallel solution-phase combinatorial synthesis of compound collections involves the purification of each member of the library. The possibility of avoiding aqueous work-up, crystallization, and chromatographic procedures makes the whole process more suitable for automation, and enhances its efficiency from economic and ecological viewpoints.