Visible Light-induced C1-coupling Reaction Of N-arylhydroisoquinolines With Alkylboronic Acids And Silver-catalyzed Decarboxylation Coupling Reaction Of 2-benzylidene Malononitrile With ?-oxocarboxylic Acids

The development of mild and efficient methods for the construction of carbon-carbon and carbon-heterobonds is the core task of synthetic organic chemistry.Transition metal-catalyzed cross-coupling reactions and organic small molecule-catalyzed coupling and tandem reactions are important methods for carbon-carbon bond construction.In recent years,visible light-promoted organic synthesis reactions have become one of the current research hotspots in organic synthesis chemistry.Compared with traditional synthetic methods,the organic synthesis methodology initiated by visible light has many significant advantages and meets the requirements of green chemistry.Based on the previous work in the laboratory,this paper mainly carried out the research on the coupling reaction promoted by visible light or catalyzed by transition metals.The specific work includes the following two parts:(1)A visible-light-promoted C1-coupling reaction of N-arylhydroisoquinolines with alkylboronic acids was developed without external photocatalysts.The reaction was successfully completed by using dichloromethane(DCM)as a solvent and irradiating with blue LEDs(450–455 nm)for 6 hours at room temperature without metals.Under optimized reaction conditions,a series of C1 alkylated N-arylhydroisoquinoline derivatives were synthesized.Through control experiments and detection of intermediates,it was determined that the reaction underwent a free radical reaction process.The reaction conditions are mild,the yield is high,and the broad spectrum of reaction substrates is good.(2)A silver-catalyzed decarboxylation coupling reaction of 2-benzylidene malononitrile with?-oxocarboxylic acids was developed.Using silver nitrate(Ag NO₃)as a catalyst,potassium persulfate(K₂S₂O₈)as an oxidant,and acetonitrile(CH₃CN)as a solvent,the reaction was carried out at 80°C for 12 hours,and the corresponding target product could be obtained in good yield.When investigating the scope of geminal dicyanoalkene substrates,it is found that the substituent electrons and steric effects on the aromatic ring have little effect on the reaction,and the expansion of ketoacid substrates has not yet been carried out.The reaction conditions are mild and the operation is simple,which provides an effective method for the preparation of polysubstituted olefins.