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An efficient method is developed for the synthesis of furo[2,3-b]quinoxalines using novel Cu(OTf)2 loaded protonated trititanate nanotube catalysts via A3-coupling followed by 5-endo-dig cyclization from o-phenylenediamines, ethylglyoxalate and phenylacetylenes. This method is beneficial and advantageous as it facilitates high yield in conventional heating and a short reaction time besides offering reusable heterogeneous catalysts. These catalysts can be recovered by centrifugation and their activity remain largely unchanged for five successive runs. On the other side, these catalysts are prepared using simple hydrothermal and wet-impregnation methods and are characterized using XRD, HR-TEM and N2-adsorption–desorption techniques. [ABSTRACT FROM AUTHOR]

CuI catalysts supported on protonated trititanate nanotubes (CuI/HTNT) were prepared and used as catalysts for the synthesis of propargylamines via A3 (aldehyde, amine and acetylene) coupling under solvent-free conditions. The results revealed that the CuI/HTNT with 5 wt % CuI had the best catalytic activity. The protocol provides access to a wide range of propargylamines in excellent yields (up to 98 %). The prepared catalysts were characterized by TEM, XRD, N2-adsorption desorption, EDS and ICP-MS analysis. The catalyst can be recovered by centrifugation and reused in further catalytic reactions, its activity remaining largely unchanged for five successive runs. [ABSTRACT FROM AUTHOR]

In attempt to search for more potent , a series of 7-nitro-1-(piperidin-4-yl)-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinoline-derived sulphonamides were synthesized. Their structures were established by elemental analyses, IR, and NMR (1H and 13C) spectral data. The of the obtained compounds was investigated against different Gram-negative ( Escherichia coli and Pseudomonas aeruginosa) and Gram-positive ( Bacillus subtilis and Staphylococcus aureus) bacteria and antifungal activity against two fungal strains ( Aspergillus niger and Aspergillus clavatus) using disk diffusion method at various concentrations (20, 40, 60, and 80 μg/mL). The study reveals that most of the title compounds showed significant antibacterial and fungal activity when compared with their respective standards streptomycin and griseofulvin. [ABSTRACT FROM AUTHOR]

Title compounds are simply and environmentally friendly synthesized by Kabachnik-Fields reaction using protonated trititanate nanotubes as highly active recyclable catalyst. [ABSTRACT FROM AUTHOR]

Despite the growing importance of volatile functionalized diazoalkanes in organic synthesis, their safe generation and utilization remain a formidable challenge because of their difficult handling along with storage and security issues. In this study, we developed a bench-stable difluoroacetaldehyde N-triftosylhydrazone (DFHZ-Tfs) as an operationally safe diazo surrogate that can release in situ two low-molecular-weight diazoalkanes, diazoacetaldehyde (CHOCHN 2 ) or difluorodiazoethane (CF 2 HCHN 2 ), in a controlled fashion under specific conditions. DFHZ-Tfs has been successfully employed in the Fe-catalyzed cyclopropanation and Doyle-Kirmse reactions, thus highlighting the synthetic utility of DFHZ-Tfs in the efficient construction of molecule frameworks containing CHO or CF 2 H groups. Moreover, the reaction mechanism for the generation of CHOCHN 2 from CF 2 HCHN 2 was elucidated by density functional theory (DFT) calculations., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)