Cobalt‐Catalyzed Annulation of Benzimidates or NH‐Benzaldimines with Ynamides: Synthesis of 1‐Alkoxy‐ and 1‐Alkyl‐3‐Aminoisoquinolines

Abstract

Inexpensive cobalt‐catalyzed, pivalic acid‐assisted oxidative C‐H functionalization of benzimidates or NH‐benzaldimines with ynamides is presented, providing an access to 3‐aminoisoquinoline derivatives. The procedure is compatible with various substrates featuring alkyl, alkoxy, acyl or halogen as substituents, heteroaryl structures, and diverse ynamides. The reaction has been scaled up, with subsequent transformation of the yielded products. Control experiments and mechanistic investigations corroborate the regioselectivity of this conversion, positioning the amine group proximal to the nitrogen atom in isoquinolines.