Merging Transition Metal Catalysis With Photoredox Catalysis In Organic Reactions

Due to the advantages of simple reaction conditions,broad substrate scope and good selectivity,C–H bond activation plays an irreplaceable role in the field of organic synthesis.Along with the proposal of the green chemistry,how to activate C–H bond more environment-friendly and economic was put forward by chemists.In recent years,the rapid development of visible light induced organic synthesis has become one of the hot topics in organic chemistry.Based on the above two points,this thesis mainly focuses on the organic reactions by combining transition metal catalysis with photoredox catalysis.Accordingly,the research work could be divided into two parts:(1)An efficient acetanilides with ?-oxocarboxylic acids has been developed by combining palladium catalysis and visible-light photoredox catalysis at room temperature under 3 W green LED irradiation.A dual catalytic system for the ortho-acylation of acetanilides has been developed.It is important to note that eosin Y used as photoredox catalyst makes this system both environmentally and avoids high loading of external oxidant.Based on the control experiments and electron paramagnetic resonance spectrometer studies,a plausible mechanism was proposed.This dual catalytic reaction shows a broad substrate scope and good functional group tolerance.(2)A direct synthesis of urea derivatives from N-methoxybenzamides was developed by a combination of palladium catalysis and visible-light photoredox catalysis at room temperature under 3 W blue LED irradiation.The reaction proceeded smoothly under mild conditions and the desired products afforded in good yields with good tolerance of functional groups.