Fully Borylated Methane and Ethane by Ruthenium-Mediated Cleavage and Coupling of CO

Many transition‐metal complexes and some metal‐free compounds are able to bind carbon monoxide, a molecule which has the strongest chemical bond in nature. However, very few of them have been shown to induce the cleavage of its C−O bond and even fewer are those that are able to transform CO into organic reagents with potential in organic synthesis. This work shows that bis(pinacolato)diboron, B2pin2, reacts with ruthenium carbonyl to give metallic complexes containing borylmethylidyne (CBpin) and diborylethyne (pinBC≡CBpin) ligands and also metal‐free perborylated C1 and C2 products, such as C(Bpin)4 and C2(Bpin)6, respectively, which have great potential as building blocks for Suzuki–Miyaura cross‐coupling and other reactions. The use of 13CO‐enriched ruthenium carbonyl has demonstrated that the boron‐bound carbon atoms of all of these reaction products arise from CO ligands. Piñacolato: The C−O bond of coordinated carbon monoxide can be cleaved by a diborane(4) compound. A combination of bis(pinacolato)diboron, B2pin2, with ruthenium carbonyl promotes the cleavage and reductive coupling of coordinated CO to give not only metallic complexes containing either CBpin or C2(Bpin)2 ligands but also metal‐free highly borylated organic molecules, such as C(Bpin)4 and C2(Bpin)6.