Synthesis and Application of [Zr-UiO-66-PDC-SO3H]Cl MOFs at The Preparation of Dicyanomethylene Pyridines via Chemical and Electrochemical Methods
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چکیده
Abstract A metal-organic frameworks (MOFs) with sulfonic acid tags as a novel mesoporous catalyst was synthesized. The precursor of Zr-UiO-66-PDC was synthesized both via chemical and electrochemical methods. Then, zirconium based mesoporous metal-organic framework [Zr-UiO-66-PDC-SO3H]Cl was prepared by reaction of Zr-UiO-66-PDC and SO3HCl. The structure of [Zr-UiO-66-PDC-SO3H]Cl was confirmed by FE-SEM and TEM. This mesoporous [Zr-UiO-66-PDC-SO3H]Cl was successfully applied for synthesis of dicyanomethylene pyridine derivatives via condensation of various aldehyde, 2-aminoprop-1-ene-1,1,3-tricarbonitrile and malononitrile. At the electrochemical section, a green electrochemical method has successfully employed for rapid synthesis of the zirconium based mesoporous metal-organic framework UiO-66-PDC at room temperature and atmospheric pressure. The synthesized UiO-66-PDC has a uniform cauliflower-like structure with 13.5 nm mean pore diameter and 181.6 m2 g-1 surface area. The described catalyst [Zr-UiO-66-PDC-SO3H]Cl was also employed for the convergent paired electrochemical synthesis of dihydropyridine derivatives as an environmental friendly technique under constant current at 1.0 mA cm-2 in an undivided cell. The proposed method proceeds with moderate to good yields for the model via a cooperative vinylogous anomeric based oxidation.