Electron Acceptor-catalyzed Photoredox Reactions Enabled By Electron Donor-acceptor Complex

Photochemistry of electron donor-acceptor(EDA)complexes have drawn significant attention in the field of organic chemistry in the past decade.Comparing with the traditional photochemical reactions,EDA complex-mediated reactions do not need photosensitizers.At present,in addition to the strategy of bonding between electron donors and acceptors,the photoreactions catalyzed by EDA complexes have also been widely reported,mainly focusing on electron donor catalysis.To date,there are very limited reports on electron acceptor catalysis.Based on the previous work in our group,this dissertation studies the organic photoreactions catalyzed by N-arylphthalimide(NAPI)electron acceptors.N-hydroxyphthalimide carboxylates(NHPI esters)are widely used in EDA complexmediated organic photoreactions.After accepting an electron,the N-O bond of NHPI esters is easy to cleave,making them ideal radical precursors.In this work,we synthesized a series of NAPI derivatives by mimicking the structure of NHPI esters,and established EDA complexcatalyzed photoreactions with NAPI derivatives as stable electron acceptors.The research work of this dissertation includes:(1)Twenty-one NAPI derivatives were synthesized and characterized.The potential donor substrates were screened by colorimetry,and the formation of EDA complexes was confirmed by UV-Vis analysis.(2)Acceptorcatalyzed γ-elimination-addition reaction of 3,3,3-trifluoro-2-arylprop-1-ene,imine radical addition of 4-methyl-N,N-dimethylaniline and olefin bifunctionalization were established.(3)The catalytic performance and structure-activity relationships of the acceptor catalysts were discussed.Cyclic voltammetry and DFT computation were conducted to probe the property of NAPI derivatives.In conclusion,NAPI derivatives were used in establishing several EDA complex acceptorcatalyzed photoreactions.NAPI acceptor catalysts can activate multiple electron rich substrates,suggesting their potential application in synthetic chemistry.