Rhodium(III)‐Catalyzed [4+2] Annulation of N‐Hydroxyoximes with Maleate Esters/2‐Chloroacrylates: Synthesis of Isoquinoline‐3,4‐Dicarboxylates and Isoquinoline‐3‐Carboxylates

Abstract A novel Rh(III)‐catalyzed [4+2] annulation of N ‐hydroxyoximes with maleate esters/2‐chloroacrylates is disclosed, in which diverse isoquinoline skeleton compounds were generated in moderate to excellent yields. The protocol exhibits a good compatibility of functional groups and wide scope of substrates without using any external metal oxidants. Gram‐scale and derivatization reactions were performed to show the potential utility of this transformation.