An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite(K_(2)S_(2)O_(5))as a connector is developed for the synthesis of various lactam-substi...An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite(K_(2)S_(2)O_(5))as a connector is developed for the synthesis of various lactam-substituted alkyl sulfones.Notably,this process does not require a metal catalyst or metal powder reductant,highlighting its environmentally friendly features.The reaction demonstrates outstanding substrate adaptability and a high tolerance towards diverse functional groups.Furthermore,the biologically active molecules and commercially available drugs with a late-stage modification are also highly compatible with this transformation.Mechanistic studies revealed that the reaction proceeds through a single-step process involving intramolecular radical cyclization,"SO_(2)"insertion,and external alkyl incorporation.展开更多
Catalytic reduction of nitrate in groundwater by sodium formate over the catalyst was investigated.Pd-Cu/c-Al2O3 catalyst was prepared by impregnation and charac-terized by brunauer-emmett-teller(BET),inductive couple...Catalytic reduction of nitrate in groundwater by sodium formate over the catalyst was investigated.Pd-Cu/c-Al2O3 catalyst was prepared by impregnation and charac-terized by brunauer-emmett-teller(BET),inductive coupled plasma(ICP),X-ray diffraction(XRD),transmission electron microscopy(TEM)and energy dispersive X-ray(EDX).It was found that total nitrogen was effectively removed from the nitrate solution(100 mg/L)and the removal efficiency was 87%.The catalytic activity was affected by pH,catalyst amount used,concentration of sodium formate,and initial concentration of nitrate.As sodium formate was used as reductant,precise control in the initial pH was needed.Exces-sively high or low initial pH(7.0 or 3.0)reduced catalytic activity.At initial pH of 4.5,catalytic activity was enhanced by reducing the amount of catalyst,while concentrations of sodium formate increased with a considerable decrease in N2 selectivity.In which case,catalytic reduction followed the first order kinetics.展开更多
基金the Scientific Research Fund of Hunan Provincial Education Department(21B0262 and 22B1094)the Natural Science Foundation of Hunan Province(2022JJ40857)the Hunan Provincial Innovation Foundation For Postgraduate(CX20230757)forfinancial support.
文摘An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite(K_(2)S_(2)O_(5))as a connector is developed for the synthesis of various lactam-substituted alkyl sulfones.Notably,this process does not require a metal catalyst or metal powder reductant,highlighting its environmentally friendly features.The reaction demonstrates outstanding substrate adaptability and a high tolerance towards diverse functional groups.Furthermore,the biologically active molecules and commercially available drugs with a late-stage modification are also highly compatible with this transformation.Mechanistic studies revealed that the reaction proceeds through a single-step process involving intramolecular radical cyclization,"SO_(2)"insertion,and external alkyl incorporation.
基金This study was supported by the Science and Technology Cooperation Foundation between Nankai University and Tianjin University of Ministry of Education of China.
文摘Catalytic reduction of nitrate in groundwater by sodium formate over the catalyst was investigated.Pd-Cu/c-Al2O3 catalyst was prepared by impregnation and charac-terized by brunauer-emmett-teller(BET),inductive coupled plasma(ICP),X-ray diffraction(XRD),transmission electron microscopy(TEM)and energy dispersive X-ray(EDX).It was found that total nitrogen was effectively removed from the nitrate solution(100 mg/L)and the removal efficiency was 87%.The catalytic activity was affected by pH,catalyst amount used,concentration of sodium formate,and initial concentration of nitrate.As sodium formate was used as reductant,precise control in the initial pH was needed.Exces-sively high or low initial pH(7.0 or 3.0)reduced catalytic activity.At initial pH of 4.5,catalytic activity was enhanced by reducing the amount of catalyst,while concentrations of sodium formate increased with a considerable decrease in N2 selectivity.In which case,catalytic reduction followed the first order kinetics.
