Visible-Light-Driven C-H Bond Oxidation And Dual Catalyzed C-C Bond Formation

Unsaturated functional groups,such as carbonyl and cyano groups,exist in many natural products,medicines,pesticides and material molecules.They also play an important role in organic synthetic chemistry.Therefore,the development of efficient methods for constructing or introducing these groups under mild conditions has been a long-term research topic for chemists.In recent years,visible-light-induced C-C bond formation reactions and C-H bond aerobic oxygenation reactions have emerged to synthesize ketones,nitriles,carboxylic acids and esters.We introduced related research results in this dissertation.Furthermore,revolving around the synthesis of ketones,nitriles,carboxylic acids and ester compounds,copper and chromium metallaphotoredox catalyzed C-C bond formation and photocatalyzed oxidation of C-H bonds were investigated.First,we have reported a ring-opening cyanation reaction of cyclopropyl ketones by merging Lewis acid catalysis with copper catalysis and photoredox catalysis,affording a wide range of y-cyanoketones with high functional group tolerance,which could be translated into piperidine and dihydropyridin-2(1H)-one products.Moreover,we proposed a possible triple catalytic cycle based on cyclic voltammetry experiments and quantum yield determination.Then,we have achieved an photoredox-enabled Cr-catalyzed alkene diacylation using α-keto acids as the acylating agent,giving access to valuable 1,4-diones,1,6-diones and 1,7-diones under mild conditions.Moreover,the synthetic utility of this methodology was proven by converting to diverse furan,pyrrole and dihydropyridazine heterocycles.Furthermore,we proposed a possible mechanism based on control experiments,UV absorption and quantum yield determination.Next,in the absence of transition metals,bases and additional sources of hydrogen,we have achieved an photocatalytic hydrotrifluoromethylation of alkynols via a tandem radical addition/1,5 or 1,6-hydrogen atom translocation/oxidation process to prepare a series of ketones containing vinyl-CF3 motif in good yields.Furthermore,we proposed a possible mechanism based on control experiments and deuterium labeling experiment.Finally,we have developed an aerobic oxidation of alkyl aromatics to carboxylic acids through decatungstate photocatalysis under mild and green conditions.Xylenes are suitable substrates in this reaction and carrying out the catalysis in a gram scale afforded terephthalic acid in excellent yield with high atomic economy and industrial application significance.