7 - Basics of Combinatorial Chemistry

Abstract

The field of “combinatorial chemistry” covers a wide range of interdependent concepts and techniques as diverse as solid-phase synthesis, supported reagents, parallel homogeneous-phase chemistry, solid-phase extractions, and adapted analytical methods. High-throughput synthesis is part of a global drug discovery strategy that usually involves dedicated—often expensive—automated synthesizers, online purification, computational analysis, data handling, as well as high-throughput screening. It relies on the synthesis and screening of large numbers of compounds and involves heavy technological investment. In addition, small-scale parallel-synthesis methods can also speed up and significantly simplify everyday chemistry. Parallel synthesis can indeed be implemented in cheap, readily available apparatus in a routine manner. Another mapping that could help to gain an overview on combinatorial chemistry is based on the philosophical approach, combinatorial synthesis dealing with the preparation of compound mixtures, and parallel synthesis dealing with the synthesis of separate single compounds. Combinatorial chemistry can be carried out both in the solution phase or on a solid support. These two complementary approaches offer valuable solutions to the chemist either on a high throughput automated method or on a laboratory scale. Both solution- and solid-phase approaches present characteristics and requirements that have to be considered before deciding whether the planned synthesis should be carried out with one or the other technique.