Isolable Diaryl Bismuthides: Access to Acyl Bismuthanes and Visible-Light-Induced Reversible Carbon Monoxide Extrusion/Insertion

Carbon monoxide (CO) is one of the simplest and most fundamental molecules that has fascinated chemists ever since. Early-on, chemists have recognized and exploited its favorable properties as a key reagent in large-scale metallurgical processes, productions of base- and fine chemicals, and (more recently) potential medical applications. Most of these transformations rely on reactions that proceed in the coordination sphere of transition metals. Recent endeavors have brought main group elements on the stage of carbonyl chemistry (carbonyl = metal-bound CO). Reversible elementary reactions commonly generate a promising basis for the development of catalytic transformations, insertion/extrusion reactions being of paramount importance in carbonyl chemistry. In main group chemistry, very rare reversible and thermally-driven reactions of this kind have been realized. We report here the innovative access to acyl- bismuth compounds, a peerless class of compounds, enabling the first visible-light-driven reversible CO insertion/extrusion processes in the coordination sphere of a main group metal.