Cobaloxime-Based Metalloradical Catalysis: A Versatile Strategy for the Synthesis of Cyclopropenes and Oxazoles

Metalloradical catalysis (MRC), predominantly exemplified by metalloporphyrin complexes, has emerged as a promising strategy for regulating radical reactions and broadening their synthetic applications. Here, an efficient catalytic method has been devised for the radical [2 + 1] cyclopropenation of alkynes and radical [3 + 2] oxazolation of nitriles using α-aryldiazoacetates via MRC. Cobaloxime proves effective in facilitating the metalloradical [2 + 1] cyclopropenation of alkynes and radical [3 + 2] oxazolation cycloaddition reaction under mild conditions. The reactions demonstrate broad substrate tolerance, accommodating gram-scale transformations and the synthesis of pharmaceutical compounds. Our findings highlight the significant potential of cobaloxime-catalyzed cycloaddition as a valuable tool in organic synthesis and broaden the scope of metalloradical systems in catalysis.