29 shared publications
Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry; Iran University of Science and Technology; P.O. Box 16846-13114 Tehran I. R. Iran
6 shared publications
Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846, Iran
2 shared publications
Catalyst and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran
(2014 - 2019)
Recently considerable attention has been devoted to heterogeneous catalysts. Generally, heterogeneous catalysts offer several advantages such as mild reaction conditions, high throughput and ease of work-up procedures. Among the heterogeneous catalysts investigated, polymeric mesoporous graphitic carbon nitrides (g-C3N4) has attracted much attention recently due to strong van der Waals interactions between the layers, g-C3N4 is chemically stable against acid, base and organic solvents and also thermogravimetric analysis (TGA) reveals that g-C3N4 is thermally stable even in air up to 600 oC, which can be attributed to its aromatic C-N heterocycles. More importantly, g-C3N4 is only composed of two earth-abundant elements: carbon and nitrogen. This not only suggests that it can be easily prepared at low cost, but also its properties can be tuned by simple strategies without significant alteration of the overall composition. The last approach is considered as the most efficient way to design of high-performance heterogeneous catalysts utilizing the g-C3N4 as catalyst support. An interesting phenomenon is that the modification is mainly focused on metal oxides. Zirconia (ZrO2) is a physically rigid material with chemical inertness. It has high resistance against attacks by acids, alkalis, oxidants and reductants. In this study, ZrO2/g-C3N4 hybrid nanocomposite has been shown to be an excellent catalyst for the conversion of alcohols and phenols into their corresponding trimethylsilyl ethers with hexamethyldisilazane (HMDS) under solvent-free condition and for the synthesis of a-aminophosphonates. In addition, the ZrO2/g-C3N4 can be easily recycled after separation from the reaction mixture without considerable loss in catalytic activity.
Nowadays, with increasing environmental concerns, the development of sustainable and friendly heterogeneous catalysts has attracted more and more attention in both the scientific and industrial communities. Hence, the use of nanocatalysts with well-defined structures, environmentally benign, high catalytic activity, and high chemical stability are desirable instead of corrosive and hazardous chemicals. In recent years, polymeric mesoporous graphitic carbon nitride (g-C3N4) has turned out to be a fascinating choice for catalyst or catalyst support due to the special physical and chemical properties, thermal stability, non-toxicity, unique electronic properties, and large surface area. The incorporation of nitrogen atoms in the carbon architecture of the g-C3N4 gives rise to the active chemical sites exposed on the surface. On the other hand, depositing metal nanoparticles onto g-C3N4 is an effective strategy to enhance the catalytic activity of g-C3N4. In the present study, g-C3N/Ni as a recyclable, highly efficient heterogeneous catalyst with a good porous structure have been prepared and its catalytic activity was investigated for the synthesis of quinoxaline derivatives.