Current Organic Chemistry - Volume 29, Issue 6, 2025

This review summarizes the recent trends in the transition-metal-catalyzed C-H bond functionalization approach to access C-branched (hetero)aryl/alkenyl/alkyl glycosides with reaction characteristics and proposed mechanisms. Recently, the transition-metal-catalyzed C-H functionalization has arisen as a groundbreaking and versatile method for producing potent C-branched glycosides feasibly and efficiently. Nowadays, site-selective functionalization of C-H bonds in carbohydrate chemistry is highly demanded, owing to the intricate and highly stable nature of C-H bonds. In this context, we systematically summarize the C-H glycosylation of arenes, C-H arylation of glycoside, and Cattelani-strategy with mechanistic investigation. Also, the applications of transition-metal-catalyzed C-glycosylation for the formation of biologically active molecules are discussed.

The development of effective therapeutics to control the infections of drug-resistant bacterial strains is the thrust area in medicinal chemistry. The glycoconjugate containing O-antigenic oligosaccharide and a carrier protein linked through a linker can develop an antigen against gram-negative bacteria like Escherichia coli (E. coli), Shigella, Providencia, and Salmonella. Therefore, the chemical synthesis of glycoconjugate vaccine candidates against these bacterial strains is a growing demand of modern-day research. The synthesis of carbohydrate parts that are oligosaccharides is the most challenging. Significant developments in oligosaccharide synthesis have occurred over the past few decades. This review will focus on the chemical synthesis of different complex oligosaccharides related to different strains of E. coli. This review concludes with a summary of synthetic developments and prospects.

Chemistry is confronted with the pressing issues of depleting non-renewable fossil resources and the imperative to combat environmental pollution, which is crucial for a sustainable future. Biomass stands out as the sole organic carbon source in nature among the array of sustainable resources available, positioning it as a prime substitute for fossil-derived chemicals and fuels. Extensive research has been conducted on the abundant lignocelluloses as a potential source for biofuels, bioenergy, and various valuable products, wherein, the incorporation of various processes in biomass fractionation to separate biopolymers (such as lignin, cellulose, and hemicellulose) has the potential to enhance the overall value of the process. However, industrial demonstration of biomass utilization for commercial products has been limited due to the challenges posed by the recalcitrance and complexity of biomass. Therefore, there is a need for efficient reaction processes to enable the production of bio-chemicals and fuels from renewable lignocellulose. This review focuses on the latest chemical methods developed for producing value-added chemicals from biomass-derived cellulose as a renewable feedstock.

Bioorthogonal chemistry represents a collection of chemical techniques employing unique functional groups to probe and comprehend biological processes within living organisms. This tool has unparalleled selectivity, exceptional biocompatibility, and moreover, the versatility which all together make it a very powerful protocol for the studying of biological processes and developing new therapeutics. This review offers a comprehensive overview of the sophisticated reactions employed in bioorthogonal chemistry, as well as potential methodologies for conducting these reactions. Additionally, it delves into bioorthogonal-based chemical strategies for incorporating 'bioorthogonal handles' into biomolecules. The review extensively covers the recent advancements in bioorthogonal click chemistry, from its inception to its notable applications in live cell imaging, biomolecule characterization, and glycome imaging. Furthermore, it discusses the future potential of click chemistry for synergistic integration of chemistry and biology, highlighting its versatility and promise in advancing various emerging fields in drug discovery and development.