Study On The Synthesis Of Quinolines Based On Palladium-catalyzed Activation Of C(sp~2)-H Bond

Nitrogen-containing heterocyclic compounds are core structures of many natural products,pharmaceuticals and bioactive molecules.In addition,nitrogen-containing heterocyclic skeletons gradually appear in the ancillary ligands of catalysts.The quinoline skeleton is one of the most important motif of nitrogen-containing compounds.Therefore,how to efficiently construct quinolineframeworks has always been an important research project in the field of synthetic chemistry.Compared to the traditional synthetic methods,the access to quinoline via transition-metal catalyzed C(sp2)-H bond activation strategy has unique advantages,and received considerable attention.On the basis of previous work,we developed a palladium-catalyzed selective 1,1-bifunctionalization reaction of the alkenyl on 2-vinylaniline to construct quinolines The innovation of this strategy is that sequentially selective difunctionalization the terminal vinyl group of 2-vinylanilines.The transformation is suggested to encompass the consecutive formation of two C(sp2)-C(sp2)and one C(sp3)-N bonds,1,2-migration of an aryl group,and elimination of a tosyl group in a single step under identical reaction conditions.This article mainly includes two parts:The first chapter summarizes the synthesis and application of quinoline compounds,including classical methods and modified synthetic methods,and newly emerged methods based on transition-metal catalysis.The accesses to quinolines from 2-vinylanilines was especially introduced.From atom economic point view,these methods provide new opportunities for the synthesis of quinoline compounds.In chapter 2,A novel domino oxidative annulation of 2-vinylanilines with internal alkynes was developed to constitute a rare class of cyclopentaquinoline derivatives.This transformation encompasses four σ bonds formation,one quaternary carbon center construction and pyridination steps in one port under identical conditions,which fascinatingly increases the molecular complexity from easily available starting materials.This transformation has good tolerance woth to 2-vinylaniline substrates,while is very sensitive to alkyne substrates,only compatible with electron-rich diaryl alkynes.In addition,we also did investigation on the reaction mechanism,and got preliminary insights on the tranformation.The discovery of the selective 1,1-bifunctionalization ofthe alkenyl on 2-vinylanilines provides a new platform for exploring new transformations of 2-vinylanilines or their analogues to valuable nitrogen-containing heterocycles.