HYPERVALENT IODINE-CATALYZED CYCLOADDITION OF NITRILE OXIDES TO ALKENES

A new and convenient method for preparation of isoxazolines was developed by a catalytic cycloaddition of nitrile oxides generated in situ from aldoximes to alkenes in the presence of a catalytic amount of iodobenzene. In this protocol, iodobenzene was first oxidized into the hypervalent iodine intermediate by m-chloroperbenzoic acid, which then transformed aldoximes into nitrile oxides, and a 1,3-dipolar cycloaddition of nitrile oxides to alkenes to provide the isoxazolines in moderate to good yields. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for the following free supplemental resource(s): Full experimental and spectral details.]