Cobalt‐Porphyrin‐Catalyzed Intramolecular Buchner Reaction and Arene Cyclopropanation of In Situ Generated Alkyl Diazomethanes

Cobalt(II)‐porphyrin catalyzed intramolecular Buchner reaction and arene cyclopropanation of alkyl diazomethanes generated in situ from N‐tosylhydrazones gave a range of bicyclic cycloheptatriene fused pyrrolidines and tetracyclic cyclopropane fused pyrrolidines in good to high yields and with high chemo‐ and regioselectivities. The obtained cyclopropane fused pyrrolidines can be readily converted into other N‐heterocycles with potential synthetic and biological interest. magnified image