Cooperative chalcogen bonding interactions in confined sites activate aziridines

The activation of aziridines typically involves the use of strong Lewis acids or transition metals, and methods relying on weak interactions are rare. Herein, we report that cooperative chalcogen bonding interactions in confined sites can activate sulfonyl-protected aziridines. Among the several possible distinct bonding modes, our experiments and computational studies suggest that an activation mode involving the cooperative Se center dot center dot center dot O and Se center dot center dot center dot N interactions is in operation. The catalytic reactions between weakly bonded supramolecular species and nonactivated alkenes are considered as unfavorable approaches. However, here we show that the activation of aziridines by cooperative Se center dot center dot center dot O and Se center dot center dot center dot N interactions enables the cycloaddition of weakly bonded aziridine-selenide complex with nonactivated alkenes in a catalytic manner. Thus, weak interactions can indeed enable these transformations and are an alternative to methods relying on strong Lewis acids. The activation of aziridines is typically achieved via reaction with strong Lewis acids or transition metals. Here, the authors report that cooperative Se center dot center dot center dot O and Se center dot center dot center dot N noncovalent interactions can activate sulfonyl-protected aziridines, which enables their use in cycloaddition reactions with nonactivated alkenes.

Automated summary

This study reports a new method for activating aziridines by cooperative sulfur-arsenic bonding interactions, enabling their use in cycloaddition reactions with nonactivated alkenes.