Ajesh Vijayan

A series of novel quinoline–pyranocoumarin hybrids incorporating quinoline and coumarin moieties were designed, synthesized, and evaluated as DNA topoisomerase II inhibitors. The key scaffold, 2‐amino‐5‐oxo‐4‐(quinolin‐4‐yl)‐4,5‐dihydropyrano[3,2‐c]chromene‐3‐carbonitrile, was obtained via a one‐pot reaction in 92% yield at room temperature. Ten derivatives ( 4a–4j ) were characterized by ¹ H/ ¹³ C NMR and mass spectrometry. Docking studies against TOPO IIα (PDB ID: 5GWK) revealed compound 4b with the best binding affinity (−8.02 kcal/mol), outperforming doxorubicin. In vitro cytotoxicity on MCF‐7 and K562 cells showed lower IC ₅₀ values for MCF‐7, and cell cycle analysis indicated G ₂ /M arrest consistent with TOPO II inhibition.

Transition metal catalyzed C─H activation is a dynamic synthetic route for coupling reactions in the field of chemistry, which has been developed over the last 20 years. The C─H activation approach for achieving C─C bond cross‐coupling reactions avoids all elements of pre‐functionalized substrates and lengthy synthetic routes. Pyridine‐derived moieties are indispensable in directed C─H bond activation by selective direction of the transition metal catalyst to bind C─H bonds in the phenyl ring. This review focuses on the rhodium(III)‐catalyzed direct functionalization of C─H bonds under oxidative conditions, enabling the formation of C─C, C─N, and C─O bonds of 2‐phenylpyridines to functionalized products with an emphasis on reports from 2009. The efficient creation of C─E bonds (where E═C, N, S, or O) makes Rh(III) catalysis an appealing, step‐efficient method for producing value‐added molecules from readily available starting materials. Focus is given to the significant regioselectivity and functional group tolerance of each reaction mechanism, along with a brief discussion of a few mechanistic pathways. Also demonstrates considerable scientific progress and greater advances, particularly in developing functionalized systems via transition metal‐catalyzed C─H activation with practical applications in the pharmaceutical industries, agrochemical industry, and drug discovery.

This review highlights two decades of progress in palladium-catalyzed ortho -C–H functionalisation of 2-phenyl pyridine, showcasing its regioselectivity, broad scope, and relevance in pharmaceuticals, agrochemicals, and material science.

We report a facile, expeditious, user‐friendly, and convenient metal‐free synthesis employing base catalysis in a one‐pot procedure to construct 11 H ‐dipyrido[1,2‐ a : 3′,2′‐d]pyrimidin‐11‐imine derivatives. This protocol involves a domino process leading to the formation of double C−N bonds utilising KO ^t Bu as the base and DMAc as the superior solvent at 25 °C for 2 h. The versatility of this methodology was demonstrated by its successful application to substrates with both electron‐withdrawing and electron‐donating functional groups, yielding novel functionalized stable 11 H ‐dipyrido[1,2‐ a : 3′,2′‐d]pyrimidin‐11‐imine derivatives in good to excellent yields. Additionally, we have discussed a plausible reaction pathway for the synthesis.

A novel palladium functionalised magnetic nanocatalyst (Fe₃O₄@SiO₂–FA–Pd) was prepared using silica-coated iron oxide and furaldehyde Schiff base as a supported material. FT-IR, VSM, TEM, FESEM, XPS, EDAX and TGA were used to analyse the morphological structure and chemical composition of Fe₃O₄@SiO₂–FA–Pd NPs. Thus, the prepared Fe₃O₄@SiO₂–FA–Pd NPs as a magnetic nanocatalyst were used in the Mizoroki–Heck reaction of arylbromide and terminal alkenes, exhibiting effective catalysis with good yields. The magnetic nanocatalyst can be reused up to 6 times without significantly losing catalytic activity and is easily separable from the reaction mixture. This new catalytic system has significant and potentially useful applications in the pharmaceutical industry.

A facile and effectual regioselective one‐pot synthesis protocol has been developed for the construction of pyrido[1,2‐a]benzimidazole and its derivatives using Copper(I) bromide as the catalyst, 1,10‐phenanthroline as ligand, and K ₃ PO ₄ (Tripotassium phosphate) as the base in Dimethyl sulfoxide as solvent at 110 °C for 12 h. The reaction conditions were optimized by screening various copper catalysts, ligands, solvents, and bases. The substrate scope of the reaction was also carried out with electron‐withdrawing and donating functional groups to prepare novel functionalized regioselective benzimidazole compounds in good to excellent yields. All the isolated compounds were characterized by ¹ H, ¹³ C, and ¹⁹ F NMR.

The Fe ₃ O ₄ @SiO ₂ -TCT-Gua-Pd catalyst anchored with guanidine moiety on Fe ₃ O ₄ nanoparticles was synthesised for Suzuki–Miyaura cross coupling reaction.

An efficient rhodium(III)‐catalyzed C−H activation approach for the construction of fused heterocyclic motifs with urea‐derived bicyclic olefins has been demonstrated. A rhodium‐catalyzed reaction of O‐acetyl ketoximes with these bicyclic motifs furnished isoquinoline derivatives, whereas isoquinolone‐fused bicyclic olefins were obtained with the reaction of N‐methoxybenzamides.