Construction Of Photothermal Co-catalysis System And Its Application In One-pot Organic Synthesis

In recent decades,photoredox catalysis has become a powerful tool for the synthesis of organic chemistry,providing a practical strategy for the preparation of large quantities of fine chemicals under mild conditions.When photocatalysis is combined with other non-photochemical catalytic strategies,a very feasible synergistic effect appears.In these two-catalyst systems,one catalyst is used to absorb light and activate the organic matrix,and a separate catalyst is used to further manipulate the reactivity of the intermediates generated by light.This strategy overcomes the weak interaction between organic substrates and light,and generally can promote the conversion of visible light to chemical energy under abnormal mild conditions with the help of readily available metal pyridine complexes as photocatalysts.In addition,due to the use of Lewis acid in the process of organic synthesis can activate organic molecules containing heteroatoms,so Lewis acid and photosensitizer synergistic catalytic system have been widely studied and explored.In view of the importance of reducing cost and pollution by immobilized precious metals,we chose UIO-67（Zr）with strong acid and water resistance,ligand modification and high specific surface area as the carrier of photothermal synergistic catalysis system and carried out the study of one-pot catalytic organic synthesis reaction.In this thesis,a novel photothermal system of Browns acid or Lewis acid and photocatalyst was constructed to catalyze heterocyclic organic reactions by one-pot method.Firstly,the catalytic activity of p-chlorobenzene sulfonic acid as Browns acid and fac-Ir（ppy）3 as photocatalyst for the synthesis of phenanthrene and biphenylcyanide from biphenyl aldehyde in one step was investigated,and the effect was good after adjusting the conditions.Besides,a bifunctional catalyst with Lewis acid and photosensitizer supported on MOF was designed,and then multiphase photocatalysis of the cycloaddition reaction of chalconone[2+2]was carried out to achieve the purpose of efficient catalysis of organic reactions and recycling and reuse of the catalyst at the same time,which was in line with the concept of green chemistry.The main research contents of this paper are as follows:1.A one-step photocatalytic reaction of biphenyl aldehyde and DPH to phenanthrene and 2-biphenylnitrile is envisaged with the cooperation of photocatalyst and Browns acid.Feasibility through contrast experiment found that assumption is higher at the same time to avoid the organic alkali,acid brown and electron donor before not catalytic consumed each other,we first explore the acyloxime first step from the reactants to the intermediate oxygen reaction Brown sville,acid needed for optimum dosage,and then explores the oxygen from the intermediate acyl oxime to the final product 2-biphenyl nitrile anthracene and the second step reaction required the best electron donor organic alkali dosage,finally use the response time plus alkali strategy incorporating the best condition of two-step reaction,modulation reaction conditions at the same time,finally can completely into a product of reactants,The yield of the main product,2-biphenylnitrile,reached 81.8%,and the catalytic activity was good,which indicated that the catalytic strategy had certain adaptability.2.The functionalized UIO-67 supported by photocatalyst UIO-67（10%[Ir（ppy）₂（dcbpy）]Cl）（Ir-L）was used,and then the Lewis acid Sm₂O₃ NPs was supported by light reduction.We adjusted the synthesis conditions of the support and confirmed that the best performance of UIO-67（10%（Ir-L））catalyst was obtained under the conditions of the ratio of zirconium source to ligand is 1:1,the auxiliary acid is benzoic acid,the ratio of benzoic acid to zirconium source is 26:1,and the reaction temperature is 120℃ for 48 h.Determine the optimal synthetic conditions after further Sm₂O₃ NPs load on the carrier,at the same time,the dosage of the modulation of iridium ligand and load of Sm₂O₃ NPs,and successfully got both crystallinity,morphology,specific surface area,iridium and samarium metal load or light absorption ability,optical properties,such as reducing power the best catalyst 0.34%Sm₂O₃ NPs@UIO-67（1.65%（Ir-L））,and the catalytic activity of the verification performance.Use to check your ketone reducing[2+2]cycloaddition as probe reaction of catalyst,and then through modulation experiments of reaction conditions including the dosage of the catalyst,the type and dosage of solvents,the variety and dosage of power supply daughter,etc.,finally the catalyst to check you in 6 hours ketone cyclization reaction conversion rate could reach 100%,the yield can reach 76.8%.It illustrates the bifunctional catalyst for such reaction catalytic effect is good,has a certain application prospect.