Preparation Of Novel Photo/electrocatalysts And Their Preliminary Application Studies

Visible-light-catalytic and electrocatalytic organic synthesis has been obtained a great deal of attention and a series of milestones achievement have been achieved in recent years.The catalytic efficiencies are often dependent on the photocatalyst or electrocatalyst redox performances for the photocatalyst organic synthesis.Consequently,a variety of metal complexes or organic dye as photocatalyst or electrocatalyst have been successfully fabricated for a variety of organic transformations.However,a series of key scientific bottlenecks remain in the present field of photocatalytic and electrocatalytic organic synthesis,such as fewer kinds of photocatalysts,high cost,cumbersome synthesis route,and narrow absorption range.Therefore,the development of efficient,cheap and readily available,wide absorption range,easy-to-separation of the new photocatalysts is highly desirable.In this thesis,on the one hand,two kinds of photocatalysts have been successfully designed and applied to the sulfonations of alkenes with sulfonic acid to access the β-ketosulfones with some important biological activities.On the other hand,the “electron” has been used as the “green redox reagent” for the C-3pyridylation of quinolinone-2(1H)-ones with cyanopyridines,aiming to obtain the bidentate nitrogen ligands under mild electrochemical conditions.This thesis mainly consist the following parts:(1)Biomimetic photocatalysis as an important organic transformation strategy has received increasing attention,with the performances of biomimetic catalysts largely depending on their designs.This protocol has been initially used to fabricate a biomimetic photocatalyst of single-atom iron site through coupling carbon nitride with hemin(CNH)for the visible light-promoted sulfonation of alkenes to produce β-ketosulfones with up to 94% yield.The experimental results show that the role of CN in CNH is concentrated on enhancing the separation ability of photogenerated electron pairs and holes to improve the photocatalysts activity and stability.Moreover,prepared photocatalyst of single atom iron can be irradiated under the near-infrared light with a satisfactory yield.The feasibility for the sulfonation reactions of androstenones has also been demonstrated.Importantly,this biomimetic catalysis-based synthesis system has some merits,such as high catalysis efficiency,favorable recyclability,high turnover number,and excellent functional group tolerance,making it promising for extensive applications in organic transformations for the synthesis of various bioactive drugs.(2)The development of facile,efficient,cost-effective,and visible light-driven photocatalysts for organic synthetic chemistry has received increasing attention.This protocol has initially synthesized a naphthalimide-based ND-O-EAc visible light photocatalyst for the sulfonation of alkenes to produce β-ketosulfones.Compared with the current photosynthetic strategies,the newly developed catalytic system has some advantages like high efficiency,no metal contamination,wide substrate scope,green terminal oxidant of air,and gram-scale preparation of low-cost photocatalyst.Moreover,the prepared photocatalyst of ND-O-EAc is feasible for the sulfonation reactions of androstenones.Importantly,such a photocatalysis strategy can easily realize the scale-up synthesis for β-ketosulfone drugs under the mild conditionse up to 90% yield.(3)The construction of functional N-containing active biomolecules and bidentate nitrogen ligand by electrocatalytic pyridylation reduction of N-heteroaromatic has been being a hot research area in the green synthesis field.A simple and practical electroreductive-induced C-3pyridylation of quinoxalin-2(1H)-ones with readily available cyanopyridine is reported.More than 36 examples are supplied and performed in greater than 95% yield.The present protocol provides a convenient,efficient,and gram-scale synthesis strategy for a series of new types of potential bidentate nitrogen ligand.