Diversity-oriented Synthesis Of Polycyclic Indole-fused Frameworks And 1,6-dihydropyridines Using Post-MCR Transformiations Involving Triple Bond

Multicomponent reactions(MCR)are widely used in organic chemistry,heterocyclic chemistry,synthesis of natural products and pharmaceuticals.Furthermore,multicomponent reactions are characterized by mild reaction conditions,simple operation procedures,broad scope,good chemical selectivity,high reaction efficiency and atom economy.Since their discovery,they have played an important role in organic synthesis.In recent years,the application of complex nitrogen-containing heterocyclic compounds in drug discovery process has attracted substantial attention of scientific community.In this regard,multicomponent reactions have been widely recognized for their potential in a diversity-oriented construction of libraries of nitrogen-containing heterocyclic compounds through the use of appropriate post-transformation.Therefore,the assembly of nitrogen-containing heterocycles by means of various multicomponent approaches has become a popular research direction.This thesis consists of two parts and deals with the construction of polycyclic indole-fused frameworks and 1,6-dihydropyridines through the post-MCR transformations involving triple bond.In the first part of this thesis,the Ugi adducts prepared from propiolic acids,propargylamines,indole-2-carbaldehydes,and isocyanides were utilized to assemble polycyclic indole-fused frameworks via two consecutive carbocyclizations involving triple bonds.In general,all steps of the strategy proceeded with moderate to good efficiency,allowing to attain a small set of target products.Depending on the triple bond substitution pattern,two kinds of indole-fused heterocyclic frameworks were generated.The second part focuses on a copper(I)bromide-catalyzed reaction of A3-coupling-derived propargylamines with ethyl buta-2,3-dienoate for the fast assembly of 1,6-dihydropyridine core.The developed protocol was tested on a variety of secondary propargylamines demonstrating high efficiency and operational simplicity.