Hypervalent Iodine Reagent Mediated Oxidative Heterocyclization of Aldoximes with Heterocyclic Alkenes

An efficient cycloaddition of heterocyclic alkenes with nitrile oxides generated in situ from the corresponding aldoximes using organohypervalent iodine(III) reagent, [hydroxy(tosyloxy)iodo]benzene (Koser's reagent), has been developed. The oxidative cyclization of various aldoximes with 1-propene-1,3-sultone affords the respective isoxazoline-ring-fused heterobicyclic products in moderate to good yields. Furthermore, the reaction of aldoxime with a cyclic phospholene-oxide under similar conditions produces the corresponding heterobicyclic phospholene oxides in moderate yields. The structures of bicyclic phospholene oxide and two sultones were established by single-crystal X-ray crystallography.