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.