In this study, a multicomponent reaction involving carbohydrates, β-dicarbonyl compounds, and malononitrile was disclosed to synthesize a new class of polyhydroxy compounds incorporating pyrano[2,3- d ]pyrimidine, pyrido[2,3- d ]pyrimidine and chromene heterocycles under mild conditions. For the synthesis of this class of compounds, glucose, galactose, arabinose, maltose, and lactose were used as aldehyde component in the reaction with barbituric acid and malononitrile to produce pyrano[2,3- d ]pyrimidine derivatives. By use of 1,3-cyclohexanedione instead of barbituric acid, chromene derivatives incorporating carbohydrate moieties were obtained. Also, the four-component condensation reaction between d -glucosamine, aldehyde, malononitrile, and barbituric acid was efficiently provided polyhydroxy-substituted pyrido[2,3- d ]pyrimidine derivatives. This new combinatorial approach gave a range of carbohydrate-derived heterocycles in good to excellent yields with high potential biological applications. The antioxidant activities were evaluated using 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant measuring system, and the data were expressed as Trolox equivalent antioxidant capacity. All of these compounds display significant antioxidant activity. The maximum and minimum antioxidant activities were observed for 4j and 6b , respectively. Our results indicated encouraging perspectives for the improvement and usage of this type of synthetic compounds, indicating significant levels of antioxidant activity.

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In this study, graphene oxide (GO) was modified with N-methyl-4-pyridinamine in order to synthesize a novel nitrogencontaining graphene-based material for application as heterogeneous catalyst in organic transformations. To prepare this catalyst system, first, chlorine-functionalized graphene (CFG) was synthesized using reaction of GO and thionyl chloride (SOCl 2 ) and then it was reacted with N-methyl-4-pyridinamine. As a result, aminopyridine fragments connected to the graphene surface covalently via a CÀN linker and form graphene grafted N-methyl-4-pyridinamine (G-NMPA) catalyst. The G-NMPA material was characterized using some different techniques and used as a heterogeneous catalyst in acetylation of alcohols. Results of catalyst activity evaluation demonstrate that G-NMPA has high activity in acetylation of alcohols. Furthermore, the catalyst system was reusable at least for 8 times without remarkable decreasing in its catalytic activity.[a] Dr.

A new DMAP-based magnetic nano-organocatalyst was developed for efficient one-pot synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives in water as a green solvent.