The Construction Of Indole-containing Heterocyclic Skeletons Via One-pot Multicomponent Reactions

Multicomponent reactions (MCRs) have attracted increasing attention by virtue of their convergence, productivity, ease of execution and generally high yields of products. As a result, it has become a powerful tool for generating libraries of molecules for the discovery and structural optimization of biologically active leads and potential drug candidates. In addition, indole derivatives have long been the focus of considerable attention due to their abundant existence in numerous nature products as well as their extensive applications in biological and pharmacological area.In this dissertation, our attention mainly focuses on the construction of indole-containg heterocyclic skeletons via one-pot multicomponent reactions.Part I: A new series of indole-containing pyridine derivatives represented by 6-(1H-indol-3-yl)-4-aryl-2,2'-bipyridine-5-carbonitriles were synthesized via one-pot multicomponent reactions of 3-cyanoacetylindoles, aldehydes, heterocyclic ketones and ammonium acetate. Particularly valuable features of this method include high yields of products, broad substrates scope and straightforward procedure.Part II: A regioseletive synthesis to a new series of indole-containing dihydropyrido[2,3-d]Pyrimidine derivatives via the one-pot multicomponent cyclocondensation of 3-cyanoacetyl indoles, aldehydes, and 6-aminopyrimidine-2, 4(1H,3H)-dione has been disclosed, it is noteworthy to point out that the reaction proceeds smoothly in a chemo- and regioselective way and gives the anticipated products in good yields without the formation of any other isomers.Part III: A facile and efficient entry into highly functionalized 3-spiropyrrolidine oxindoles, 3-spiropyrrolizidine oxindoles, and 3-spiropyrrolidine acenaphthenones via one-pot four-component [3+2] cycloaddition of 3-cyanoacetylindoles, aldehydes, isatin/ acenaphthylene-1,2-dione and amino acid has been disclosed. Particularly fascinating characteristics of this protocol include excellent regio- and stereoselectivity, broad substrates scope and straightforward procedure. Plausible mechanism of the reaction is also presented.