Study On Annulation Reaction Based On ?-aroyl Hydrazide/?-oxoamides And Sulfur Ylide

Sulfur ylide is a series of dipole molecules with strong nucleophilic properties,which are widely used in organic synthesis as reaction reagents or active intermediates in cyclization,carburization and rearrangement reactions.In recent years,a series of sulfur yelide has been synthesized and used in the synthesis of natural products and drugs.It is also found that sulfur yelide can be involved in the construction of different kinds of heterocyclic compounds,and it has a good application prospect and development prospect in the synthesis methodology of heterocyclic compounds.?-Arylhydrazonoketones and ?-oxoamides have the characteristics of simple preparation and have more reaction sites.It is easy to react with a variety of nucleophilic and electrophilic reagents,and a variety of nitrogen heterocyclic and oxygen heterocyclic compounds can be synthesized.Therefore,it should be a valuable research to study the synthesis and their application of ?-arylhydrazonoketones and ?-oxoamides.Based on the research of the research group,this paper designed and synthesized ?-aroyl hydrazideketones and ?-oxoamides as the reaction precursors,and discussed its reaction with different kinds of sulfur ylide,developing new synthetic methods for heterocyclic compounds and possible mechanisms are proposed.This work mainly includes the following two parts:1.A facile and efficient straightforward synthesis of 4,5-dihydro-1H-pyrazoles and1H-pyrazoles has been developed via a formal [4+1] annulation of varied?-arylhydrazonoketones and dimethyl sulfonium methylides under very mild reaction conditions.The possible mechanisms of nucleophilic substitution reaction,intramolecular cyclization reaction,desulfurization methyl reaction and dehydration reaction were proposed.2.A facile and efficient straightforward synthesis of substituted ?-lactams and furans has been developed via a formal [3+2] annulation from the ?-oxyamides which are easy to be prepared,by controlling the reaction of the substituted groups of the substrate with3-alkyl/arylprop-2-ynyl sulfonium salts and chemoselective C-N or C-O bond formation.The possible mechanism of intramolecular cyclization,elimination and intramolecular isomerization were proposed.