Iron-Catalyzed Intramolecular C(sp3)-H Lactonization of Hydroxamate Derivatives Promoted by a 1,5-HAT

An iron-catalyzed lactonization reaction via intramolecular C(sp3)-H functionalization is described. The process employs easily accessible hydroxamate derivatives from which the noncommon insertion of the oxygen occurred through a 1,5-hydrogen atom transfer. A mixture of water and hexafluoroisopropanol as solvent appeared to be the key parameter of this transformation to reach a high selectivity and efficiency.