Rh(Ⅲ)-catalyzed Cycloaddition Reactions Of 1,4-Ynamines With Alkynes

In modern organic chemistry, nitrogen-containing heterocyclic compounds are particularly important synthetic intermediates, as well as are the structural skeletons of many natural products and drugs. Accordingly, these heterocyclic compounds and their derivatives have been of great concern by many chemists. Among them, five-membered ring azoles, six-membered ring pyridines and seven-membered heterocyclic compounds have a high value in many fields such as biological medicine, new materials, and pesticides and so on. Therefore, the discovery of new simple and effective methods for constructing such compounds is one hot topics and remains a urgent challenge in organic synthesis.In recent years, transition-metal-catalyzed reactions are growing rapidly. Further, with the rapid development of social economy transition-metal-catalyzed reactions attracted more and more attention from the green chemist and atom-economy concepts. Owing to the lower amount of transition-metal-catalyst and good selectivity, transition-metal-catalyzed reactions have become one of the most straightforward and effective ways to build new chemical bonds. Typical methds include the cycloaddition reaction, which presents excellent selectivity and high atom-economy, and provides an efficient route to the synthesis of heterocyclic compounds and various natural drugs.This dissertation mainly develops two strategies for the construction of nitrogen-containing heterocyclic compounds through the transition-metal-catalyzed cycloaddition reactions and tandem reactions using alkynes and 4-arylbut-3-yn-1-amines as the reaction partners. The dissertation is divided into three parts:In the first chapter, recent advances in transition-metal-catalyzed cycloaddition reactions for the synthesis of heterocyclic compounds and their applications in modern organic synthesis are dicussed.In the secondary chapter, a Rh(Ⅲ)-catalyzed oxidative bicyclization reaction between 4-arylbut-3-yn-1-amines and alkynes has been presented, which allows the synthesis of various ring-fused naphthalenes with excellent functional-group tolerance via a sequence of C(sp2)-H functionalization, cyclodimerization and nucleophilic cyclization.In the third chapter. a new. practical method for the construction of a spirocyclic ring system, which is of great bioactive and medicinal values, has been developed by transition-metal-co-catalyzed the formal [3+2] cycloaddition between 4-arylbut-3-yn-1-amines and alkynes. A screen of the optimal reaction conditions revealed a combination of 5 mol% of [Cp*RhCl2]2,20 mol% of AgSbF6 and 1.0 equiv of Cu(OAc)2 in the medium CH2ClCH2Cl at 80℃ for 18 h as the best choice for this reaction.