An Efficient One–pot Procedure for the Direct Preparation of 4,5‐Dihydroisoxazoles from Amides

A Mo(CO)6 (molybdenumhexacarbonyl) catalyzed reductive functionalization of amides to afford 5‐amino substituted 4,5‐dihydroisoxazoles is presented. The reduction of amides generates reactive enamines, which upon the addition of hydroximinoyl chlorides and base undergoes a 1,3‐dipolar cycloaddition reaction that gives access to the desired heterocyclic compounds. The transformation of amides is highly chemoselective and tolerates functional groups such as nitro, nitriles, esters, and ketones. Furthermore, a versatile scope of 4,5‐dihydroisoxazoles derived from a variety of hydroximinoyl chlorides and amides is demonstrated.