A Study On Novel Reactions Of Vinyl Azides And Nitrones

N-heterocycles is an important class of heterocycles species that are finding many diverse applications.They play important roles in agricultural chemical,pharmaceuticals,and nature products.Therefore,Methodology for the highly efficient construction of N-heterocycle skeletons,such as tandem reactions,and Multicomponent reactions(MCRs)is one of the most important themes in contemporary organic synthesis.As remarkably versatile intermediates in modern organic synthesis,azides participate in a wide range of reactions that construct new carbon-nitrogen or nitrogen-heteroatom bonds.Recently,much attention has been focused toward applying vinyl azides as a pivotal three-atom synthon for the formation of diverse nitrogencontaining heterocycles including indoles,pyridines,pyrroles,isoquinolines,1,2,4-triazolines,pyrrolo[1,2-?]-pyrazines,and pyrazoles,which have been synthesized with the assistance of meal salt,triphenylphosphine,or base.Inspired by these results and with the interest of developing a newtype of[3+3]cycloaddition of vinyl azides,we investigated the reaction of vinyl azides and nitrones.The essential work is listed as follows:1.We have developed a new and efficient strategy to prepare highly substituted imidazoles inmoderate to excellent yields.This reaction was realized through a novel domino process from readily available vinyl azides and nitrones.This reaction proceeded under mild conditions without the assistance of any metal,acid,or base.Additionally,some details about the mechanism were studied,and a tentative mechanism have been proposed.2.The reaction of nitrones,formed in situ by reaction of hydroxylamines and aldehydes,with vinyl azides results in the formation of 1,2,4,5-tetrasubstituted imidazoles has been developed.This three-component reaction allows for the formation of a diverse array of imidazole derivatives with moderate to excellent yields.