Iron(II)-Catalyzed Oxidation of sp3 C−H Bonds Adjacent to a Nitrogen Atom of Unprotected Arylureas with tert-Butyl Hydroperoxide in Water

With a FeSO(4)/TBHP system in water, direct oxidation of sp(3) C-H bonds adjacent to nitrogen of arylureas to give both unprecedented tert-butoxylated and hydroxylated products 2 was revealed. Under elevated temperatures, either 2-oxo-N-arylpyrrolidine-1-carboxamides 3 or 1,3-diarylureas 4 were attained, depending on the aliphatic ring size of the arylurea substrates.