Palladium Catalyzed Denitrative Heck Reactions Of Olefins With Nitrobenzenes

Palladium-catalyzed Heck reaction is a kind of coupling reaction to construct new C-C bonds,and it is also an important method for alkenylation of halogenated aromatic hydrocarbons.In recent years,Heck reaction has become one of the research hotspots in the field of catalysis and organic synthetic chemistry,and good research results have been achieved.A series of stilbene derivatives synthesized through the Heck reaction are widely used in the fields of medicine,fluorescent whitening agents,fluorescent probes,and optoelectronic materials.The activation of other aryl C-X bonds has been studied very maturely,and the activation of aryl sp2 NO₂has not been broken!Regarding the activation of C-NO₂bond,it has always been difficult,and no suitable catalytic system has been found.In this thesis,under the condition of using catalytic amount of palladium,the coupling reaction of nitro compound and styrene to denitrate is realized,and then the scope of transition metal-catalyzed C-NO₂bond activation reaction is expanded.Regarding the reaction conditions,we found that the use of Pd/Brett Phos system catalysis can break the C-NO₂bond,which in turn enables our Heck reaction to proceed successfully.In this process,we have selected a variety of We have expanded some substrates,including electron withdrawing groups,electron donating groups and heterocyclic substrates,and found that the reaction has a good compatibility with various functional groups.The reaction system has the characteristics of mild reaction conditions,high yield and simple operation.The use of transition metal palladium as a catalyst realizes the rare problem of C-NO₂bond activation and also ensures the smooth progress of the Heck reaction.