Reactions of organocyclopropanes and spirocycles with metal atoms

Interest in the reactions of metal atoms with organocyclopropanes arises from the possibility of realizing direct metallocyclobutane generation¹ (eq i) and the wealth of chemistry which has been observed between metal complexes and organocyclopropanes under homogeneous conditions.² We report in this communication an extensive study which precisely delineates the substrate features required to observe metal atom -organocyclopropane reactions. Furthermore, this investigation has also resulted in a new and potentially general metallocene synthesis: the cocondensation of iron atoms with spirocyclic precursors affords entry into a number of novel, difficultly accessible substituted ferrocenes.