Access to N-aryl-2,2′-diindole via Fluoroarene-induced One-Pot Bicyclization Strategy with tBuOK

We present a systematic and concise one-pot protocol for synthesizing diversely substituted N-aryl-2,2'-biindoles with tBuOK. The fluoroarene-facilitated dual cycloisomerization of 1,3-diynylaniline enables efficient construction of target compounds under mild conditions. Substrate scope investigation revealed that fluoroarenes bearing electron-deficient substituents exhibited exceptional reactivity, achieving yields up to 99%. Mechanistic studies demonstrated that fluoroarenes selectively react with primary amines to generate N-aryl-substituted secondary amine intermediates, which subsequently undergo spontaneous cycloisomerization to afford the desired products.