Iron‐Catalyzed Regioselective C(sp 2 )H Alkylation and Heteroannulation of Hydroxyarenes With 2‐Aryl Aziridines

Iron(III)‐catalyzed chemoselective ring opening of 2‐aryl aziridines with unprotected phenols and 2‐naphthols is achieved at room temperature. Here, the phenol acts as a C ‐nucleophile to selectively attack the more substituted ring carbon of the aziridine to form a C ‐alkylated product. Interestingly, in the case of 2‐naphthol, dehydrative heteroannulation occurs after the C ‐alkylation to deliver benzoindolines at room temperature. Mechanistic experiments suggest that the reaction proceeds via a Lewis acid‐assisted formation of a carbocation intermediate, followed by dehydrative cyclization to give benzoindolines by the reaction of 2‐naphthols and 2‐aryl aziridines.