The Synthesis Of Nitrogen Heterocyclic Compounds And Functionalization Of Allenes

Nitrogen heterocyclic compounds are widely found in the structure of natural products and often serve as the core skeletons of pharmaceutical active molecules.They are widely used in medicine,pesticide,biological chemistry,and organic functional materials.Among them,polysubstituted indole,quinoline compounds and pyrrolo[1,2-a]quinoxaline compounds are very important organic compounds,which have aroused great interest of scholars.Allene is often used as a crucial unsaturated synthetic block in the field of asymmetric synthesis of organic chemistry.This structure exists in a variety of natural products,and its own axial chirality can promote the generation of target products.Therefore,the functionalization of allene has become one of the hot topics for organic chemists.Organic nitrogen heterocyclic compounds and the functionalization of allenes have been widely concerned and a series of new synthesis strategies have been reported in recent years.This paper is based on our previous research about heterocyclic chemistry and related methodologies.The synthesis methods of TfOH catalyzed multi-substituted 2-ester indole and quinoline compounds,the synthesis methods of a novel spiro pyrrolo[1,2-a]quinoxaline compounds and the synthesis methods for functionalization of allenes were mainly introduced,including the following three parts:Part?:Metal-free synthesis of C2-Substituted Quinolines and Indoles from 2-vinylanilines and alkynoatesWe use 2-vinylanilines and dimethyl acetylenedicarboxylate synthesize multi-substituted2-ester indole and quinoline compounds by Michael addition and intramolecular cyclization.In this reaction,trifluoromethanesulfonic acid and palladium acetate were used as catalysts to regulate the cleavage of C=C bond and C?C bond,so as to obtain corresponding target products,which had high yield and substrate compatibility.Part?:Synthesis of spiro pyrrolo[1,2-a]quinoxaline derivativesPyrrole[1,2-a]quinoxaline is an important organic compound,which is widely used in organic synthesis,pharmaceutical chemistry and functional materials and other fields.In this reaction,we report on a 1-?2-aminophenyl?pyrrole and benzoquinone or cyclic ketone as the substrate,through imide intermediates,nucleophilic substitution process to synthesize novel spiro pyrrolo[1,2-a]qui-noxaline compound method.Part?:Synthesis of allylic triflones from allenes and triflyl chloridesWe use allenes and trifluoromethanesulfonyl chloride to synthesize allylic triflone compounds.The reaction has the advantages of no catalyst addition and easy to obtain substrates.The reaction was verified to be a free radical process by TEMPO and BHT capture agent.At present,the synthesis of related compounds by free radical pathway in the system of CF₃SO₂Cl/?EtO?₂P?O?H has not been reported.The reaction has good compatibility and high yields.