Alkaline-Metal Salts Mediated Tandem Reactions Of Sulphonyl Azides And Terminal Alkynes Toward Hetreocycle Synthesis By Transition M Etal Catalysis

Tandem reaction is one of the most versatile and powerful methods for the construction of complicated molecules and heterocyclic compounds.In this thesis,recent development of transition metal-catalyzed tandem alkyne participated cyclization reactions involving Carbon-hetero bond formation as well as Cu-catalyzed azide-alkyne multicomponent reactions via ketenimine intermediate for the synthesis of heterocyclic compounds are initially reviewed.Encouraged by our previous researches on the ynamido-lithium chemistry,we present herein three CuI-catalyzed azide-alkyne tandem reactions and their application in Pd-catalyzed cyclization reactions to deliver a variety of heterocyclic products,such as triazole compounds,dihydropyrans and furo[2,3-b]pyridines.The details are summarized as following:1.A distinct CuI-catalyzed cascade reaction of terminal alkynes,double sulfonyl azides,and haloalkanes,has been successfully developed for the construction of multi-substituted triazole compounds.Unlike the traditional Cu-catalyzed azide-alkyne cycloaddition reaction,2,5-disubstituted-4-amino-2H-1,2,3-triazole derivatives were prepared via a cascade transformation of intermediates involved reaction of CuAAC triazole-Cu complexes and sulfonyl azides.2.An intramolecular CuI-catalyzed tandem reaction of terminal alkynes derived from 2-OH/NH2 benzaldehyde,and sulfonvl azides has been developed and deliverd to a variety of dihydropyran and dihydroquinoline compounds.Based on our previous work,a proposal mechanism revealed that the ynamido-cesium intermediates in suit generated from terminal alkynes and sulfonyl azides underwent an intramolecular[2+2]cyclization reaction with carbonyl group,followed by the ring opening reaction of 2-sulfonyl-iminooxetane intermediates led to the corresponding product.3.The convergent synthesis of a class of dieneyneimides via a CuI-catalyzed three component reaction of diynes,sulfonyl azides,and acrolein derivatives,as well as their palladium-catalyzed aerobic tandem cyclizations,leading to a set of polysubstituted furo[2,3-b]pyridines are presented.