Current Organic Chemistry - Volume 28, Issue 18, 2024

Nowadays palladium-catalyzed C-H bond activation is a useful approach for the synthetic transformation of organic compounds due to step economy, the use of non-prefunctionalized substrates and reduced chemical wastes. Among the various synthetic strategies, palladium catalyzed intra and inter-molecular C-H bond activation has recently drawn a lot of interest to synthesize the decorated π-conjugated polycyclic aromatic hydrocarbon. In this review, we have focused on recent progress along with previous strategies to synthesize various polynuclear aromatic hydrocarbons (PAHs) by the use of Pd-catalyzed C-H bond activation. We have also discussed the mechanistic details of the reaction intra and inter-molecular C-H bond activation.

Nitrogen-positioned radicals are chemical entities that have a lengthier history than carbon ones and their high reactivity makes them invaluable. But, despite its power, much of its chemistry is still uncharted. Currently, developed methodologies to access nitrogen-positioned radicals, such as transition metal catalysis or visible-light photoredox methods through a single-electron transfer process, avoiding the use of harmful or toxic reagents, excess raw materials, solvents as well as pre-functionalization steps or extensive synthetic routes are in continuous progress. This revision aims to depict the recent advances in the field of iminyl-radicals' syntheses, a special class of radicals placed on nitrogen, catalyzed by transition metals or photoredox techniques for the construction of C-N bonds and their synthetic applications. This work serves as a comprehensive guide for the scope of synthetic applications that this kind of radicals could have.

Bioactive glass (BG) shows great potential as a biomaterial for bone regeneration. Chitosan enhances the biological characteristics of BG. Chitosan is the sole commonly utilized natural polysaccharide that may be chemically altered for various purposes and roles. Composite materials formed by combining chitosan bioactive glass (BG) nanoparticles and microparticles are used in this context. Integrating bioactive glasses enhances the mechanical characteristics, bioactivity, and regenerative capacity of the end product. Research indicates that chitosan/BG composites enhance angiogenesis, cell adhesion, and proliferation. Bioglass improves biomineralization and boosts bone extracellular matrix formation by osteoblasts. The current findings demonstrate that the chitosan-glass nanofiber composites can enhance both antibacterial capabilities and bone conductivity. This review examines novel techniques for creating chitosan-based materials for engineering purposes, as well as upcoming difficulties and outlooks.

Nonsteroidal anti-inflammatory drugs account for a sizeable fraction of the drugs prescribed worldwide. If consumed for a long time, they can cause ulcers and lifethreatening side effects. Since the acidic group present in NSAIDs is mainly responsible for these side effects, the scientists try to synthesize polymer drug conjugates that avoid these side effects but still retain the potency of the parent drug. Macromolecular drug conjugates of aceclofenac were prepared by employing pectin, β cyclodextrin, deacetylated chitin (chitosan) and albumin (egg and bovine serum). The prepared conjugates were characterized and tested for their anti-inflammatory, antinociceptive and antiulcerogenic activity. Further experimentation was undertaken to analyze the behavior of compounds and their stability in hydrolytic conditions. Test compound A1, a pectin conjugate of aceclofenac, exhibited significant antinociceptive and anti-inflammatory activity with a significant decrease in ulcer index (4.45±0.24) as against aceclofenac (8.61±0.40) or vehicle (12.39±0.44) treated group. A novel and safer polymer drug conjugate of aceclofenac has been synthesized and evaluated.

In this study, a series of novel pyrazole-based compounds were synthesized starting from the precursor ethyl 3-(4-amino-1-phenyl-3-((4-sulfamoylphenyl)carbamoyl)-1Hpyrazol- 5-yl)-3-oxopropanoate (2). Various synthetic routes were used to obtain pyrazolylpyrazolone 3, tricyclic dipyrazolopyridine 4a-c, thiazolyl-bipyrazoles 5 & 6, pyrazolo[4,3- b]pyridines 7 & 9, and tricyclic pyranopyrazolopyridine 10a-c. These compounds were screened for their antibacterial activity against four bacterial strains. The promising candidates 4a, 4b, 4c, 7, 9, and 10c exhibited minimum inhibitory concentrations ranging from 0.98 to 31.25 μg/mL. The in silico ADME properties for the active compounds exhibited similar physiochemical properties, with compound 9 demonstrating the best likeness and no inhibition effect on the popular drug metabolism enzyme CYP. Molecular docking simulations highlighted compounds 9 and 10c as potent antibacterial agents via DNA-gyrase inhibition