Growing Advances and Applications of Click Reactions

  Examination of nature’s favorite molecules revealed that nucleic acids, proteins and polysaccharides are condensation polymers of small subunits stitched together by carbon ± heteroatom bonds. Taking clue from the natures approach, a set of powerful, highly reliable and selective reactions were developed for the rapid synthesis of useful new compounds, an approach called as “click reactions”.  Thus click chemistry is a modular synthetic approach that utilizes the most practical and reliable chemical transformations. Its applications are increasingly found in all aspects of drug discovery, ranging from lead finding through combinatorial chemistry and target-template in situ chemistry, to proteomics and DNA research, using bioconjugation reactions. One of the reactions of click chemistry i.e. copper (I)-catalyzed 1, 2, 3-triazole forming reaction has become the gold standard of click chemistry due to its reliability, specificity and biocompatibility of the reactants. The triazole products are more than just passive linkers; they readily associate with biological targets, through hydrogen bonding and dipole interactions. This review gives a brief overview about some of the advances and applications of these click reactions.