Screening and dissecting electroorganic synthesis by mass spectrometry decoupling of electrode and homogeneous processes.

Rapid reaction screening and in-depth mechanistic exploration of electroorganic synthesis remain challenging due to low throughput of experimentation and high complexity of electrode and homogenous processes. Here, we report a decoupled electrochemical flow microreactor hyphenated mass spectrometry (namely DEC-FMR-MS) platform for high-throughput reaction screening and intermediate tracking of electrosynthesis. This platform combines in-capillary electrochemical transformation with operando MS interrogation, enabling rapid reactivity survey of a series of electrosynthetic reactions on nanomole scale. Moreover, the spatial decoupling design allows segmented dissection of short-lived intermediates involved pathways in interfacial electrochemical and homogenous chemical events, which are initially interwoven in reaction networks. The utility of this platform is highlighted by 1) discovery and verification of quasi-electrocatalytic pathways in electrooxidative C-H/N-H cross-coupling, 2) kinetic measurements of TEMPOH-mediated dehydrogenation of N-heterocycles, and 3) mapping the landscape of intermediates (alkene radical cation and nitrene) in electrochemical aziridination.