A Convenient One-Pot Synthesis of Pyrano[3,2-c]quinolin-2,5(6H)-dione and 2H,5H-Pyrano[3,2-c]chromene-2,5-dione Derivatives P y r a n o [ 3 , 2 -c ] q u i n o l i n -2 , 5 ( 6 H ) -d i o n e / 2 H , 5 H -P y r a n o [ 3 , 2 -c ] c h r o m e n e -2 , 5 -d i o n e s Abstract: The preparation of novel pyrano[3,2-c]quinolin-2,5(6H)-dione and 2H,5H-pyrano[3,2-c]chromene-2,5-dione derivatives starting from 4-hydroxyquinolin-2(1H)-ones and 4-hydroxy-2H-chromene-2-one with chlorocarbonyl ketenes is described. This method provides a new route to produce fused pyrano derivatives in good to excellent yields in a short experimental time.

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In the present work, ruthenium nanoparticles were synthesized on functionalized reduced graphene oxide (rGO). First, the surface of rGO was modified with two para‐arsanilic acid and dithiooxamide promoters to create the rGO with scattered hydrophilic positions. The ruthenium nanoparticles were synthesized and immobilized simultaneously in small hydrophilic micro‐reactors under mild conditions. Characterization of the synthesized nanocatalyst was confirmed with different techniques, such as transmission electron microscopy (TEM), X‐ray diffraction, Fourier transform‐infrared and scanning electron microscopy. TEM images of the synthesized catalyst show the Ru nanoparticles have diameters less than 6 nm. The designed nanocatalyst was investigated for the selective liquid phase oxidation of cyclohexene with molecular oxygen in an autoclave under solvent‐free conditions, which obtained a maximum of 91% conversion and 90% selectivity under optimized conditions. The catalytic activity over rGO‐AO‐TO/Ru recycled catalyst remained at a satisfactory state after at least five runs.

Cover image © Mohaddeseh Shahabi Nejad, Soheila Behzadi and Hassan Sheibani Images The cover image is based on the Full Paper Multilayer‐Functionalized Reduced Graphene Oxide Decorated with Gold Nanoparticles as a Designed Nanonanocatalyst for the Selective Oxidation of Cyclohexene by Molecular Oxygen in a Solvent‐Free System by Mohaddeseh Shahabi Nejad et al., https://doi.org/10.1002/aoc.5166.

A series of novel tetracoumarin derivatives (3a-f) were prepared using the reaction of ether functionalized dibenzaldehyde with 4-hydroxycoumarin in the presence of sodium acetate. The structure of compounds was validated by IR, NMR, and CHN analyzes. Antimicrobial (antibacterial and antifungal) activity was studied on the basis of the minimum bactericidal concentration, minimum inhibitory concentration and inhibitory zone diameter. Favorable biological activity was found in compound 3f.