Synthesis of Isoquinoline N-Oxides via Hypervalent Iodine-Mediated Oxidative Cyclization of Ketoximes with Alkenes

High Resolution Image Download MS PowerPoint Slide Reported herein is the development of an intramolecular oxidative cyclization of ketoximes with alkenes for the preparation of isoquinoline N -oxides. The reaction, which utilizes phenyliodine bis(trifluoroacetate) (PIFA) as an oxidant and 2,2,2-trifluoroethanol (TFE) as a solvent, proceeds to afford various N -heterocyclic products, including aryl/heteroaryl-fused pyridine N -oxides, isoindole N -oxides, and 2-benzazepine derivatives. Preliminary experimental and computational mechanistic studies suggest that the ionic pathway is the primary mechanism. The synthetic utility of the developed method was highlighted via several product transformations.