Divergent Catalytic Approach from Cyclic Oxime Esters to Nitrogen-Containing Heterocycles with Group 9 Metal Catalysts

We report the divergent catalytic transformation of alkene-tethered isoxazol-5­(4H)-ones by using rhodium and cobalt catalysts to afford 2H-pyrroles (with Rh catalyst) and azabicyclic cyclopropanes (with Co catalyst). The rhodium-catalyzed 2H-pyrrole formation involving hydrogen shift is supported by deuterium-labeling experiments. The control experiments in the cobalt-catalyzed reaction indicate that the bicyclic aziridines as the primary product undergo a skeletal rearrangement assisted by metal iodide salts.