Synthesis Of Indole-Fused Dihydrothiopyranones And Indole-Fused Dihydropyridinones Through N-Heterocyclic Carbene Catalyzed Annulation

In recent years,N-heterocyclic carbenes(NHCs)as powerful organocatalysts that have attracted widely attention and deeply research with respect to the construction of C-C and carbon-hetero bonds.This thesis mainly focused on the use of indoline-2-thiones and indoline-2-imines as the substrates,derived from indole skeleton,which reacted with ?,?-unsaturated acylazolium intermediates,generated from the complex between bromoenols and NHCs,to construct C-C and C-S/C-N bonds via a one-pot reaction.The first part is a,P-unsaturated acylazolium intermediate and its[3+3]cyclization reaction with indoline-2-thiones,for the efficient synthesis of indolo[2,3-b]dihydrothiopyranones.This kind of compounds is the core motif of many nature products and pharmaceuticals.It worth mentioning that NHC-catalyzed constructions of carbon-hetero bonds,mainly focused on the constructions of C-O and C-N bonds,but few on the construction of C-S bond.The second part is ?,?-unsaturated acylazolium intermediate and its[3+3]cyclization reaction with indoline-2-imines,for the efficient synthesis of indolo[2,3-b]dihydropyridiones.We found that this kind of compounds can be transformed smoothly into bioactive a-carbolines based on appropriate strategies reported before.In contrast to the reported methods,we developed a new synthetic strategy for the synthesis of this kind of a-carbolines that can be not synthesized by using the reported methods,and thereby enriched the synthesis of this kind of compounds.Furthermore,it also provides a synthetic support for the research on their biological and pharmacological activities.