Cu(I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition (CuAAC), popularly known as the “click reaction”, serves as the most potent and highly dependable tool for facile construction of simple to complex architectures at the molecular level. Click-knitted threads of two exclusively different molecular entities have created some really interesting structures for more than 15 years with a broad spectrum of applicability, including in the fascinating fields of synthetic chemistry, medicinal science, biochemistry, pharmacology, material science, and catalysis. The unique properties of the carbohydrate moiety and the advantages of highly chemo- and regioselective click chemistry, such as mild reaction conditions, efficient performance with a wide range of solvents, and compatibility with different functionalities, together produce miraculous neoglycoconjugates and neoglycopolymers with various synthetic, biological, and pharmaceutical applications. In this review we highlight the successful advancement of Cu(I)...

Cu-Catalyzed Click Reaction in Carbohydrate Chemistry

This Review summarizes close to 500 primary publications and surveys published since 2000 about the syntheses and diverse bioactivities of C-glycopyranosyl (het)arenes. A classification of the preparative routes to these synthetic targets according to methodologies and compound categories is provided. Several of these compounds, regardless of their natural or synthetic origin, display antidiabetic properties due to enzyme inhibition (glycogen phosphorylase, protein tyrosine phosphatase 1B) or by inhibiting renal sodium-dependent glucose cotransporter 2 (SGLT2). The latter class of synthetic inhibitors, very recently approved as antihyperglycemic drugs, opens new perspectives in the pharmacological treatment of type 2 diabetes. Various compounds with the C-glycopyranosyl (het)arene motif were subjected to biological studies displaying among others antioxidant, antiviral, antibiotic, antiadhesive, cytotoxic, and glycoenzyme inhibitory effects.

C-Glycopyranosyl Arenes and Hetarenes: Synthetic Methods and Bioactivity Focused on Antidiabetic Potential

Iodine-catalyzed transformation of molecules containing oxygen functional groups

Copper(I)-catalyzed 1,3-dipolar cycloaddition between organic azides and terminal alkynes, commonly known as CuAAC or click chemistry, has been identified as one of the most successful, versatile, reliable, and modular strategies for the rapid and regioselective construction of 1,4-disubstituted 1,2,3-triazoles as diversely functionalized molecules. Carbohydrates, an integral part of living cells, have several fascinating features, including their structural diversity, biocompatibility, bioavailability, hydrophilicity, and superior ADME properties with minimal toxicity, which support increased demand to explore them as versatile scaffolds for easy access to diverse glycohybrids and well-defined glycoconjugates for complete chemical, biochemical, and pharmacological investigations. This review highlights the successful development of CuAAC or click chemistry in emerging areas of glycoscience, including the synthesis of triazole appended carbohydrate-containing molecular architectures (mainly glycohybrids, glycoconjugates, glycopolymers, glycopeptides, glycoproteins, glycolipids, glycoclusters, and glycodendrimers through regioselective triazole forming modular and bio-orthogonal coupling protocols). It discusses the widespread applications of these glycoproducts as enzyme inhibitors in drug discovery and development, sensing, gelation, chelation, glycosylation, and catalysis. This review also covers the impact of click chemistry and provides future perspectives on its role in various emerging disciplines of science and technology.

Cu(I)-Catalyzed Click Chemistry in Glycoscience and Their Diverse Applications.

The importance of glycosidase inhibitors and especially the bicyclic molecules has led to design and assessment of many analogs of naturally occurring molecules. This review focuses on the synthesis and enzyme inhibitions of a few selected (synthetic or non-naturally occurring) molecules that have been reported in the last decade, which allow one to draw some connection between varying the structural features and their effect on glycosidase inhibitions. It is expected that further improvements based on these features could lead to improved inhibitors.

Recent developments in design and synthesis of bicyclic azasugars, carbasugars and related molecules as glycosidase inhibitors

Azidation of 1,2-anhydro sugars with NaN3 in CH3CN by using a catalytic amount of ceric ammonium nitrate has been accomplished in a regio- and stereoselective manner. Various 1,2-anhydro sugars produced 2-hydroxy-1-azido sugars in good yields which, in turn, were converted to structurally diverse sugar-derived morpholine triazoles and sugar oxazin-2-ones. These sugar derivatives were tested against various commercially available glycosidases, and two of them were found to be active in the micromolar range.

Ceric Ammonium Nitrate-Catalyzed Azidation of 1,2-Anhydro Sugars: Application in the Synthesis of Structurally Diverse Sugar-Derived Morpholine 1,2,3-Triazoles and 1,4-Oxazin-2-ones

Synthesis of hybrids of D-glucose and D-galactose with pyrrolidine-based iminosugars as glycosidase inhibitors

Total synthesis of (+)-pericosine B and (+)-pericosine C and their enantiomers by using the Baylis–Hillman reaction and ring-closing metathesis as key steps

A. P. John Pal

Papers

Ceric Ammonium Nitrate-Catalyzed Azidation of 1,2-Anhydro Sugars: Application in the Synthesis of Structurally Diverse Sugar-Derived Morpholine 1,2,3-Triazoles and 1,4-Oxazin-2-ones

Synthesis of hybrids of D-glucose and D-galactose with pyrrolidine-based iminosugars as glycosidase inhibitors

Total synthesis of (+)-pericosine B and (+)-pericosine C and their enantiomers by using the Baylis–Hillman reaction and ring-closing metathesis as key steps

Synthesis of aminocyclitols and trihydroxylated indolizidinone from a D-mannitol-derived common building block

Azidation of anomeric nitro sugars: application in the synthesis of spiroaminals as glycosidase inhibitors