Synthesis Of Polycyclic Indole Compounds Via Tandem Reaction Of Indole-derived Isonitriles And Azide

This thesis focuses on the efficient construction of three types of polycyclic fused indole derivatives through the tandem reactions of N-arylisocyanindoles with aryl azides or aryl sulfonyl azides.The details are as follows:Firstly,we developed a Pd₂（dba）₃catalyzed tandem reaction of N-isocyanoaryl-tethered indoles-with aryl azides in CH₃CN or THF at 80 ^oC,which led to the formation of a series of structurally diverse N1,C2,and C3-fused polycyclic indole derivatives with a yield of up to94%.In this work,the indole C2 position serving as a nucleophile and C3 position as an electrophilic center.The umpolung reactivity of indole provides a new strategy for the construction of polycyclic indole derivatives.Sencondly,we developed a Co Br₂·H₂O catalyzed tandem reaction of N-isocyanoaryl-tethered indoles with aryl sulfonyl azides,affording a series of tetracyclic indole derivatives in 35-72%yield.In this work,the in-situ generated indole-derived carbodiimide intermediate exhibited a different reactivity,in which the electrophilic carbodiimide central carbon atom was trapped by the nucleophilic indole C2 position and followed by aromatization to give the desired tetracyclic indole derivatives.Thirdly,we achieved the efficient construction of guanidines containing bisindole moieties through a[Rh Cp*Cl₂]₂catalyzed cross-coupling/nucleophilic addition tandem reaction of N-isocyanoaryl-tethered indoles with sulfonyl azides.Such guanidine compounds could be acted as a versatile building block.For example,they can react with the electrophilic halogenating reagent NIS via bicyclization reactions to provide polycyclic indole derivatives.