A novel and facile regioselective synthetic method for polyfunctionalized furans involving rhodium (III)-catalyzed pyrazole-or indazole-directed dual CÀ H functionalization with diazodicarbonyls has been developed. This strategy provides rapid access to diverse tetrasubstituted furans bearing various pyrazoles or indazoles. This unprecedented one-pot protocol proceeds via cascade CÀ H activation, metal-carbene formation, migratory insertion, intramolecular cyclization, and deprotonation. Ethyl 4-((1H-pyrazol-1-yl)methyl)-2-(4-methoxyphenyl)-5phenylfuran-3-carboxylate (3 j). Yellow liquid; yield -69 mg; HRMS (EI + ): m/z: calcd for C 24 H 22 N 2 O 4 : 402.1580, Found: 402.1581.Ethyl 4-((1H-pyrazol-1-yl)methyl)-2-(4-nitrophenyl)-5-phenylfuran-3-carboxylate (3 k). Yellow solid; yield -69 mg; 83%; mp 99-100°C; IR (KBr): v˜= H NMR (600 MHz, CDCl 3 ): δ = 8.27 (d, J = 9.6 Hz, 2H), 8.06 (d, J = 9.6 Hz, 2H), 7.78 (d, J = 7.2 Hz, 2H), 7.57 (d, J = 1.2 Hz, 1H),

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A novel b-cyclodextrin-SO3H carbon based solid acid catalyst was prepared and proved highly efficient in solvent free esterification of carboxylic acids with alcohols. The catalyst was easily recovered and reused without any impact on the yields.

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Indium(III)/silver(I)-catalyzed [2 + 2 + 1] annulation of arylhydrazine hydrochlorides with β-enamino esters via multicomponent reactions for the construction of diverse and multisubstituted N-arylpyrazoles has been demonstrated. The oxidative cycloaddition proceeds via a cascade triple Michael addition/elimination/air oxidation. This novel protocol provides a rapid and efficient synthetic route to various 3,4-diester-substituted N-arylpyrazoles. The synthesized compounds are further utilized for various synthetic transformations.

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Sustainable metal-encased (Ni–Co/Fe/Cu)@N-doped-C catalysts were prepared from bio-waste and used for the oxidative dehydrogenation reaction.

An efficient approach to regio‐ and stereoselective synthesis of (Z)‐vinylsulfonylated quinoxalin‐2‐ones has been developed. This oxidative reaction involves copper‐catalyzed vinylsulfonylation of quinoxalin‐2(1H)‐ones with alkynes and sulfonyl hydrazides. Various functionalized vinylsulfonylated quinoxalin‐2(1H)‐one derivatives have been synthesized in excellent yields. The reaction proceeds via sulfonyl radicals generated from sulfonyl hydrazides.