Short Survey of the Chemical Reduction Behavior of the Base-Stabilized Iron Dichloroboryl Complexes [(η5‑C5Me5)Fe(CO)2BCl2(LB)]

Stable boryl radicals are rare and often reactive species, usually requiring steric and/or electronic stabilization for their isolation. In this paper we describe attempts to use a sterically bulky and electron-rich metal fragment as a stabilizing group toward this end, using alternatively a phosphine, an N-heterocyclic carbene, and 3,5-lutidine as additional Lewis basic stabilization. Reduction of these complexes did not provide a stable radical as hoped, leading instead to decomposition or no reaction in the first two cases. For lutidine, an unusual dinuclear bis­(boryl) product was obtained resulting from C–C coupling of the lutidine bases, suggesting the intermediacy of a reactive radical based partially on the lutidine ring. This possibility was explored computationally.