Base Promoted Cycloisomerization For The Synthesis Of Indolizine

This thesis studies the synthesis of indolizine derivatives via the cesium carbonate mediated 5-exo-dig type cyclization reaction of homopropargyl pyridines.A variety of indolizine derivatives could be obtained in moderate to good isolated yields by treatment of homopropargyl pryidines with cesium carbonate in DMSO at 100 ?.This strategy could also be adapted to the synthesis of pyrrolo[1,2-a]quinolines and pyrrolo[1,2-a]pyrimidines from the corresponding homopropargylquinolines and homopropargylpyrimidines,and can be used for the synthesis of furan derivatives.The mechanism involves ? C-H deprotonation,5-exo-dig cyclization,and isomerization of the exocyclic double bond to provide the scaffold of indolizine.The transformation does not require the aid of transition metal catalysts,and is thus environmentally friendly.