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

Reported herein is the development of an intramolecular oxidative cyclization of ketoximes with alkenes for the preparation of isoquinoline -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 -heterocyclic products, including aryl/heteroaryl-fused pyridine -oxides, isoindole -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.