Gentle generation of nitrileoxide bearing a carbamoyl group was performed. 4-Nitro-3-isoxazolin-5-one was treated with dipolarophiles in the mixed solvent () at room temperature to afford cycloadducts in good yields.
A nitrile oxide containing a carbamoyl group is readily generated upon the treatment of 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with water under mild reaction conditions, even in the absence of special reagents. The obtained nitrile oxide undergoes cycloaddition with dipolarophiles, alkynes and alkenes, to afford the corresponding isoxazol(in)es, which are useful intermediates in the synthesis of polyfunctionalized