The Synthetic Study Of Metal-catalyzed N~2-benzyl/N~1-isopropenyl Substituted 1,2,3-triazoles

1,2,3-triazole is a kind of important five-membered nitrogen heterocyclic compound with excellent stability,in which the core contains two carbon atoms and three continue nitrogen atoms.1,2,3-triazole is widely used in the fields of organic synthesis,medicinal chemistry,chemical biology and material science because of their unique structure and properties.Up to now,however,1,2,3-triazole has not been isolated from natural products,and its production relies entirely on artificial synthesis.At present,the synthesis method of 1,2,3-triazole has limitations such as cumbersome steps,poor regional selectivity,and narrow substrate range.Therefore,it is particularly important to develop a synthetie method of 1,2,3-triazole with high efficiency,novelty,selectivity,simple operation and wide substrate range.The main research contents of this thesis are as follows:(1)Silver-catalyzed three-component reaction:Synthesis of N2-substituted-1,2,3-triazoles via direct benzylic amination.A Ag(I)-catalyzed click reaction and benzyl C(sp3)-H/NH amination strategy for N2-substituted 1,2,3-triazoles through three-component reaction in one-pot is described,in which reagent were alkyne,sodium azide and trisubstituted phenol.The reaction achieves simple operation,good regional selectivity,no influence by air,good functional group tolerance,and a wide range of substrates.This strategy provides a new idea for the synthesis of N2-substituted-1,2,3-triazole.(2)Pd/Cu-catalysed cascade reaction for efficient synthesis of N-isopropenyl-1,2,3-triazoles via in situ generated 2-azidopropenes.We have disclosed a Pd/Cu-catalyzed tandem reaction for synthesis of diverse N1-isopropenyl substituted 1,2,3-triazoles with alkynes,alkenyl azides and nucleophiles.This reaction involves in situ formation of explosive 2-azidopropene and its derivatives via C(sp3)-OAr bond cleavage under mild conditions,which subsequently participate in the click reaction for the unique 1,2,3-triazole skeleton by dispensing with tedious isolation.This one-pot reaction strategy achieves a wide range of substrates,good functional group tolerance and readily costeffective substrates.