Arylation at nitrogen

Carboline stmcture was constructed by one-pot reaction, which involves the three-component indole formation and nucleophilic cycUzation by the addition of t-BuOK or MsOH. This is the first example of multi-component synthesis of carbolines, except for those using the Pictet-Spengler type reaction. Utilizing the three-component indole formation, indole-fused 1,4-diazepines were also synthesized through deprotection/iV-arylation at nitrogen atom of indole by one-pot addition of MeONa after the formation of indole. These reactions form four bonds in a single reaction vessel, which involves two C-C bonds/two C—N bonds or one C-C bond/three C-N bonds. 

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