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.

Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.

Benzotriazole has been established as an efficient ligand in Cu-catalyzed cross-coupling of terminal alkynes to form 1,3-dialkynes using CuI as the catalyst and K 2 CO 3 as the base at room temperature in an open round-bottom flask. The established protocol has the following notable advantages: simple to handle, easy work-up, mild reaction condition, high substrate scope, requirement of less quantity of ligand and also Cu-catalyst, less expensive, and high reaction yield.

Dedicated to the late Prof. Alan R Katritzky for his excellent contributions to benzotriazole chemistryReceived 04-07-2017Accepted 06-28-2017 Published on line 07-21-2017 AbstractA facile and economic path for an easy access of diverse N-acylbenzotriazoles from carboxylic acid has been devised using NBS/PPh3 in anhydrous dichloromethane. High yield of product was obtained at room temperature in one hour reaction time under mild reaction conditions.

the upsurge of multidrug resistant bacterial infections with declining pipeline of newer antibiotics has made it imperative to develop newer molecules or tailor the existing molecules for more effective antimicrobial therapies. Since antiquity, the use of curcumin, in the form of Curcuma longa paste, to treat infectious lesions is unperturbed despite its grave limitations like instability and aqueous insolubility. Here, we utilized "click" chemistry to address both the issues along with improvisation of its antibacterial and antibiofilm profile. We show that soluble curcumin disrupts several bacterial cellular processes leading to the fenton's chemistry mediated increased production of reactive oxygen species and increased membrane permeability of both Gram-positive and Gram-negative bacteria. We here report that its ability to induce oxidative stress can be harnessed to potentiate activities of ciprofloxacin, meropenem, and vancomycin. In addition, we demonstrated that the soluble curcumin reported herein even sensitizes resistant Gram-negative clinical isolates to the Gram-positive specific antibiotic vancomycin, thereby expanding the antibacterial spectrum of this drug. This work shows that the soluble curcumin can be used to enhance the action of existing antimicrobials against both Gram-positive and Gram-negative bacteria thus strengthening the antibiotic arsenal for fighting resistant bacterial infections for many years to come. There is a coercing need to find new drug alternatives for the treatment of multidrug resistant (MDR) bacterial infections, which presently affects almost 180 million people across the globe and is anticipated to increase up to 225 million by 2030 1,2. A number of drugs, which has been introduced in last 2 decades for the treatment of MDR infections helped only for short term in managing infections due to acquisition and dissemination of the newer resistance 3. As per the recent data mining, the current assessment of the pipeline shows about 42 new antibiotics in development among which 11 are in Phase I clinical trials, 13 in Phase II, 13 in Phase III, four have submitted marketing authorization applications, and only one drug has received a complete response letter. However, given the irrevocability that some of these "in development" antibiotics will be declined for approval, and that resistance will eventually develop with time to those that will be consented for use, it is unblemished that we will have too few drugs to meet current and anticipated patient needs 4. The global menace of resistance can be understood with the fact that we are helpless against carbapenem-resistant/extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Methicillin resistant Staphylococcus aureus as they are resistant to all or nearly all of the antibiotics available today whom the World Health Organization considers critical threats 5. The studies indicate that the upsurge of resistant strains can only