Synthesis of 2‐Amino‐3‐arylindoles and their Fused Analogues via Intramolecular C‐Arylation

Abstract

2‐Aminobenzyl cyanide was reacted with nitrobenzenesulfonyl chlorides and alkylated under Mitsunobu or Fukuyama conditions. The resulting intermediates were exposed to basic conditions, which triggered a Truce‐Smiles rearrangement, leading to intramolecular C‐arylation. This reaction was followed by spontaneous cycloaddition, which yielded 2‐aminoindole derivatives. The developed synthetic route represents a simple and metal‐free approach for accessing 1‐substituted 2‐amino‐3‐arylindoles. Furthermore, pyrimido[1,2‐a]indoles and dihydrobenzo[6,7][1,3]diazepino[4,5‐b]indoles were synthesized through the use of functionalized alcohols.