Preparation of the Borane (Fmes)BH2 and its Utilization in the FLP Reduction of Carbon Monoxide and Carbon Dioxide.

Treatment of 1,3,5-tris(trifluoromethyl)benzene with n-BuLi, followed by H3 B⋅SMe2 and subsequent hydride removal gave the (Fmes)BH2 reagent, which was isolated as a SMe2 stabilized monomer or a ligand free (μ-H)2 -bridged dimer. Reaction with Mes2 P(vinyl) gave the respective ethylene-bridged P/B(Fmes)H FLP. It reduced carbon monoxide to the formyl stage and carbon dioxide to the formaldehyde oxidation state. Most new compounds were characterized by X-ray diffraction.