Pd(II)-Catalyzed Synthesis of Carbolines by Iminoannulation of Internal Alkynes via Direct C−H Bond Cleavage Using Dioxygen as Oxidant

Abstract

A palladium-catalyzed iminoannulation of internal alkynes via direct C-H bond cleavage was developed. Dioxygen was employed as a clean oxidant in this kind of catalysis. Carbolines were synthesized from tert-butylimines of N-substituted indole-2-carboxaldehydes or indole-3-carboxaldehydes.