Construction Of ?-Lactam And Naphthalene Derivatives Via Cascade Radical Cyclization Of Enyne

As we know,carbocycles and heterocycles are a class of important structural motifs,which can be widely found in numerous biologically active molecules,natural products,drugs and functional organic materials.Among these cyclic compounds,?-lactam and naphthalene derivatives are structural units of great research value,which play an important role in organic chemistry research due to their unique structure and function.Therefore,synthetic organic chemists try to develop efficient,green and simple synthetic methods to access these two types of compounds.In recent years,cascade radical cyclization reaction has become one of the most popular research areas.Among them,the development of efficient method towards the construction of cyclic compounds by using radical cascade cyclization of enynes have attracted considerable attention from synthetic organic chemists.The first chapter of this thesis mainly described the progress of radical cyclization reactions of enyne in recent years.It is classified according to different radical precursors,mainly including sulfonyl radical,acyl radical,aryl radical,nitro radical,alkyl radical and so on.The second chapter of this thesis is the cascade radical cyclization of 1,6-enynes initiated by benzenesulfonyl radicals to synthesize ?-lactams derivatives containing alkenyl C-X bonds.We use tert-butyl hydroperoxide(TBHP)as the radical initiator,arylsulfonyl hydrazide as the benzenesulfonyl radical precursor,and N-iodosuccinimide(NIS)as the iodine source.The reaction occured under mild conditions and afforded the corresponding ?-lactam derivatives in moderate to excellent yields.These reactions are characterized by mild conditions,broad substrate scope,good functional group tolerance,and simple operation.The third chapter of this thesis is the synthesis of naphthalene ring structure by radical addition/cyclization reaction of 2-vinylaniline and alkyne.We have developed an efficient synthetic method by using tetrabutylammonium iodide as a radical initiator,and diazonium salt formed in situ from 2-vinylaniline as an effective aryl radical precursor,then react with phenylacetylene in one-pot to construct naphthalene derivatives.It is worth mentioning that this reaction can be further extended to the construction of anthracene ring and phenanthrene ring structure.Note that,transition-metals are not required to run the process.