Synthesis of Isoxazolines and Isoxazoles via Metal-Free Desulfitative Cyclization

A novel, one-pot reaction for the synthesis of isoxazolines and isoxazoles is developed via a cascade process under metal-free conditions. The approach involves the formation of intramolecular C-N and C-O bonds and intermolecular C-C bonds from aromatic alkenes or alkynes and N -hydroxysulfonamides using hypervalent iodine(VII) and iodine as the oxidant. Activation of C-H and C-C bonds/construction of C-O bonds/elimination of SO (2) /C-N bond formation is achieved in sequence in the reaction system.