Reaction monitoring for detailed kinetic and mechanistic studies is often carried out using off-line sampling, which is rather time consuming and requires the ability to quench the reaction. Alternatively, reactions are run in situ in an NMR tube under static conditions. Both setups introduce delays and, therefore, do not provide initial kinetic information or access to short-lived intermediates. In situ reaction setups are generally not adaptable to heterogeneous reactions containing solid components that require mixing or illumination. They, furthermore, do not allow reactions to be carried out in non-standard reaction vessels, such as electrochemical cells. Here, we describe several heterogeneous reactions that were investigated using modifications to Bruker’s Insight NMR setup [1]. This system enables operando reaction monitoring by NMR via temperature-controlled flow from a reaction vessel. To the best of our knowledge, this is the first time that the reactions reported here were accessible to NMR investigations which have provided valuable mechanistic and kinetic insights.
