Cobalt-Catalyzed Decarbonylation of Aromatic Acylsilanes via the Cleavage of Carbon-Silicon Bonds.

The catalytic decarbonylation of acylsilanes provides a unique entry to arylsilanes through C─Si bond activation. Here we describe a cobalt-catalyzed protocol that enables this transformation. A range of benzoylsilanes bearing trimethylsilyl, triethylsilyl, or dimethylphenylsilyl groups were converted into the corresponding arylsilanes, while functional groups such as esters, nitriles, ethers, and acetals were tolerated. Control experiments using mixed acylsilanes revealed that the cobalt catalyst operates without generating crossover products, suggesting a pathway distinct from that of rhodium catalysts and mechanistically closer to nickel. Comparative studies further demonstrated that the cobalt system exhibits higher activity than the nickel counterpart. In addition, the method allows post-modification of acylsilane directing groups, as illustrated by the sequential ortho-C─H functionalization and subsequent cobalt-catalyzed decarbonylation.