Applications of Click Chemistry in Drug Discovery and Development

Abstract

The thermally induced 1, 3-dipolar cycloaddition of alkynes with azides to obtain 1, 2, 3-triazoles is well known and further developed by Huisgen [1]. A Cu (I)-and Ru (I)-catalyzed variation of this cycloaddition to a regioselective synthesis of 1, 4-and 1, 5-substituted (Scheme 2.1) and functionalized 1, 2, 3-triazoles, respectively (Scheme 2.2), termed as click reaction, was developed independently by Sharpless et al.[2] and Meldal et al.[3] as delineated. In recent years, several groups [4–7] independently reported the use of small organic azides and carbonyl compounds to afford substituted 1, 2, 3-triazoles with high levels of regioselectivity including metal-free, one-pot strategy toward trisubstituted 1, 2, 3-triazoles [8, 9]. Concise New click chemistry methods for the synthesis of 1, 2, 3-triazoles have been reviewed [10, 11].