Bismuth in Dynamic Covalent Chemistry: Access to a Bowl-Type Macrocycle and a Barrel-Type Heptanuclear Complex Cation

Dynamic covalent chemistry (DCvC) is a powerful and widely applied tool in modern synthetic chemistry, which is based on the reversible cleavage and formation of covalent bonds. One of the inherent strengths of this approach is the perspective to reversibly generate in an operationally simple approach novel structural motifs that are difficult or impossible to access with more traditional methods and require multiple bond cleaving and bond forming steps. To date, these fundamentally important synthetic and conceptual challenges in the context of DCvC have predominantly been tackled by exploiting compounds of lighter p-block elements, even though heavier p-block elements show low bond dissociation energies and appear to be ideally suited for this approach. Here we show that a dinuclear organometallic bismuth compound, containing BiMe2 groups that are connected by a thioxanthene linker, readily undergoes selective and reversible cleavage of its Bi-C bonds upon exposure to external stimuli. The exploitation of DCvC in the field of organometallic heavy p-block chemistry grants access to unprecedented macrocyclic and barrel-type oligonuclear compounds. The Bi-C bonds in a dinuclear organometallic bismuth(III) compound with a thioxanthene linker are highly susceptible to transformations in the realm of dynamic covalent chemistry. Control of the reactions is obtained through template strategies, solvent effects, and the utilization of catalysts. This grants access to novel macrocyclic and barrel-type compounds, including a well-defined heptanuclear cationic complex.image

Automated summary

Dynamic covalent chemistry is a powerful tool in synthetic chemistry, allowing for reversible generation of novel structural motifs. This study demonstrates the application of dynamic covalent chemistry to heavy p-block elements, expanding the range of compounds that can be accessed using this approach.