Click Reaction in Carbohydrate Chemistry: Recent Developments and Future Perspective

Cu(I)-catalyzed click reaction, a set of powerful and virtually reliable 1,3 dipolar cycloaddition of organic azide and terminal alkyne, has been extensively used in adjoining two entirely different building blocks, enabling an easy access of complex molecular-level architectures, which find exponentially expanding application in diverse disciplines of science ranging from organic synthesis, material sciences, combinatorial chemistry to medicinal chemistry and chemical biology. This highly efficient and reliable protocol has several distinct advantages, the most notable are, its high chemoselectivity, excellent regioselectivity, tolerance to a variety of solvents and functional groups, mild and compatible reaction conditions etc., which address this approach as a straightforward way of establishing covalent connections between different molecules containing various functionalities. Compatibility of Cu(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction with carbohydrate chemistry has led to the development of biologically relevant molecules and diverse neoglycoconjugates and neoglycopolymers. This review highlights the extensive application of the click reaction in carbohydrate chemistry for drug discovery, bioconjugaion study, and for the generation of various simple to complex glycoconjugates such as glycopeptides, polysaccharides, glyco-macrocycles, glyco-arrays, glyco-dendrimers, glyco-clusters and glycopolymers etc., having targeted functional properties and future scope in various branches of science.