Synthesis And Modification Of Nitrogen-containing Heterocyclic Compounds Via Transition Metals Catalyzed Reactions

As a powerful means of synthesis,transition metal catalyzed coupling reactions and C-H activation reactions have been well investigated.Due to the special structures and bioactivities of nitrogen-containing heterocyclic compounds,the synthesis and modification of them via transition metals catalyzed reactions have been paid more and more attention.In this context,the synthesis of pyrazolothiazine derivatives,isoquinoline derivatives and indole derivatives of the derivatives have been studied and the results are as follows:An efficient method has been developed for the synthesis of benzo[e]pyrazolo[1,5-c][1,3]thiazines via one-pot two-step reactions of readily available substituted 1-(2-halophenyl)-3-akylprop-2-yn-1-ones,hydrazine hydrochloride and β-oxodithioesters under mild conditions,and the corresponding benzo[e]pyrazolo[1,5-c][1,3]thiazines were obtained in good to excellent yields.The novel method affords a new strategy for the construction of diverse and useful poly N,S-heterocyclic compounds.We report herein a tandem Ir(Ⅲ)-catalyzed C-H activation and annulation reaction for the synthesis of isoquinolines by using readily available substituted benzimidates and a-diazocarbonyl compounds under mild conditions.The catalytic reaction exhibits excellent tolerance to different functional groups and the corresponding isoquinolines were obtained in good to excellent yields.This novel method affords an alternative strategy for the construction of diverse and useful isoquinoline derivatives.An efficient and practical method for the C-7 amination of indolines via Rh(III)-catalyzed C-H activation has been reported.This reaction affords various C-7aminated indolines in good to excellent yields by using readily available anthranils as the aminating agents.The corresponding indolines with an amino and a carbonylgroup together provide an opportunity for the construction and modification of diverse indoles and indolines in the pharmaceutical industry.We have developed a facile and practical method for the synthesis of valuable N-fused heterocycles via Rh(III)-catalyzed sequential C–H activation and annulation by using arylazoles and α-diazocarbonyl compounds as the substrates.In this protocol,pyrazoles,benzimidazoles and one 1,2,4-triazole were obtained,and most of pyrazoles were synthesized smoothly and efficiently under mild conditions.Additionally,the comparison of the reactivity for other arylazoles was conducted.It provides a new and alternative way for the construction of diverse and potential bioactive N-fused heterocycles in drug candidates screening.