Study On The Selective Dimerizations Of 2-alkynylamines And Their Appliations In The Synthesis Of Nitrogen-containing Fused Heterocyclic Compounds

As important nitrogen-containing fused heterocyclic compounds,polysubstituted quinolines and 2,2-disubstituted indolinolines not only exist widely in nature,but also have significant biological activity and medicinal value.Therefore,the development of simple and efficient new methods for their synthesis is an important topic in the field of synthetic chemistry.On the other hand,2-alkynylarylamines have been frequently used as building blocks in the construction of fused heterocyclic skeletons,and the corresponding synthetic strategies usually have the advantages of high efficiency and good atom-economy.Based on the above mentioned background,this thesis aims to explore and establish some new methods for the selective synthesis of different fused heterocyclic scaffolds by using the easily obtainable 2-alkynylarylamines as substrates.It mainly includes the following two parts:1.The dimerization reactions of 2-alkynylarylamines under the catalysis of Rh(III)complex were studied.First,the optimal reaction conditions leading to the selective formation of indoloquinoline or 3-(2-aminophenyl)quinoline derivatives were established through systematically study on the effect of different solvents,temperature,reaction period,and reaction atmosphere.Next,the substrate scope was investigated under the optimum conditions.The results thus obtained showed that diversely substituted 2-alkynylarylamines could effectively participate in these reactions to generate the corresponding products with high efficiency,thus providing simple,economic and effective methods for the synthesis of indoloquinolines and 3-(2-aminophenyl)quinolines.It is worth to note that this is the first example in which two types of important fused heterocyclic compounds were efficiently synthesized from the same substrates through simply adjusting the reaction conditions.2.The dimerization reaction of 2-alkynylarylamine under the catalysis of Cu(II)or Bi(III)salt was studied.First,the optimum reaction conditions for the selective synthesis of 2-(2-aminophenyl)quinolines and 2,2-substituted indolin-3-ones were established through systematically screening different solvents,additives,reaction atmosphere and other factors.Next,the substrate scope was explored under the optimum conditions.The results showed that diversely substituted 2-alkynylarylamines could smoothly participate in these reactions to generate the corresponding products,thus providing operationally simple and atom-economical approaches leading to 2-(2-aminophenyl)quinolines and 2,2-substituted indolin-3-ones.Meanwhile,it is worth noting that this is the first example in which internal alkynes with steric hindrance and low reactivity could undergo dimerization to afford 2-(2-aminophenyl)quinolines.In summary,some novel methods for the selective synthesis of indoloquinolines,3-(2-aminophenyl)quinolines,2-(2-aminophenyl)quinolines and 2,2-substituted indolin-3-ones through the selective dimerization of 2-alkynylarylamines have been establised.Compared with literature methods,the new protocols developed in this thesis have notable features such as easily obtainable starting materials,excellent selectivity,mild reaction conditions,high atom-economy and environmental benigncy.