Design,Synthesis,Diels-Alder Reaction Studies Of Triazenyl Dienes And Investigation Of Multicomponent Reactions For Sulfonyl Fluoropeptides Construction

Since the discovery by Otto Diels and Kurt Alder in 1928,the Diels-Alder(DA)reaction has been one of the most powerful methods for the efficient synthesis of sixmembered ring systems,which is still widely used in organic synthesis,medicinal chemistry and materials science.The design,development of novel dienes and dienophiles can expand the types of DA reactions,enrich the structures of products,and modulate the selectivity of the reactions.In this dissertation,triazene-based dienes were constructed by the hydroalkenylation of alkynyl triazenes.As a new DA reaction diene synthesis module,a classic DA reaction and a DA-HDA cascade reaction were developed,which constructed a series of structurally novel multi-heterocyclic skeletons successfully.Moreover,two types of novel multi-component reactions were developed to construct functional peptidomimetic molecules.Part Ⅰ.Design,synthesis and Diels-Alder reaction studies of triazenyl dienes.Taking advantage of the electron-donating and convertible characteristics of triazenes,we combined them with diene structures to design a class of triazene-based dienes as a new type of DA-reactive dienes,then we developed a new kind of Palladium-catalyzed alkynyl triazenes hydroalkenylation reaction to realize stereoselective synthesis of these structures.Subsequently,we studied the classical DA reaction of triazenyl diene to construct cyclohexene.This reaction has regioselectivity and diastereoselectivity.What’s more,the triazene fragments in the product can be structurally transformed to achieve diversity-oriented synthesis.In addition,the structure of the conjugated diene and nitrogen-nitrogen double bond in the triazenyl diene is similar to that of [3]Dendralene,so the triazenyl diene could participate in the Diene-Transmissive Diels-Alder(DTDA)reaction to construct a series of heterocyclic compounds with an aza-ring structure successfully,which also has regio and diastereoselectivity.These reactions featured broad substrate scope,mild condition as well as scalability.In addition,we proposed plausible transition states of the cascade reaction process.Part Ⅱ.Studies of multicomponent reaction for sulfonyl fluoropeptides construction.Based on the strategies such as reactivity reference and component replacement,we developed two novel multi-component reactions by designing new types of synthesis modules.(1)We constructed a series of new peptidomimetic molecules with the potential of Sulfur(VI)Fluoride Exchange(Su FEx)by Ugi reaction using a novel substrate integrated by sulfonyl fluoride and isocyano group.Furthermore,the application studies revealed its potential value in covalent drug discovery and probe development.(2)Taking advantage of the dual electrophilic and nucleophilic reactivity of ynamides,we developed a Passerini-like three-component reaction involving ynamides,N-hydroxamic acids and aldehydes,which rapidly constructed peptidomimetic compounds β-aminoxy amides with unique conformational characteristics.On the basis of control experiments,we proposed a plausible mechanism.