Ionic liquid-promoted [3+2]-cycloaddition reactions of nitroformonitrile oxide generated by the cycloreversion of dinitrofuroxan

A new approach to the synthesis of 3-nitroisoxazoles and 3-nitroisoxazolines based on the [3+2]-cycloaddition of nitroformonitrile oxide (NFNO), generated by the cycloreversion of dinitrofuroxan (DNFO), to acetylene and ethylene derivatives, under ionic liquid catalysis is developed. The approach is of a general nature and applicable to cycloaddition reactions with other dipolarophiles.