Base-Mediated Synthesis of 2-Bromobenzoheterocycles

Abstract A base-mediated cyclization to synthesize 2-bromobenzoheterocycles is reported. This transformation was demonstrated with 16 examples to access a broad range of brominated benzoheterocycles. Mechanistic studies support the reaction proceeds through a bromoalkyne, and revealed an exchangeable proton at C3 of the indole products.