Oxidative Flow Electrochemistry: A Platform for Generating Reactive Intermediates and Reaction Control.

Oxidative electrochemistry provides direct access to highly reactive intermediates under mild and sustainable conditions, yet controlling reactivity remains a central challenge in synthesis. In batch electrochemical systems, short-lived radicals, electrophilic oxidants, and cationic intermediates often undergo overoxidation, decomposition, or competing side reactions because of inefficient mass transfer and poor thermal control. Continuous-flow electrochemistry addresses many of these limitations by enabling rapid intermediate generation, efficient mass transport, precise residence-time control, and intensified reaction environments. In this Account, we describe how oxidative flow electrochemistry can serve as a platform for controlling reactive intermediates through selective generation and interception under continuous-flow conditions. Emphasis is placed on oxygen-centered radicals and reactive oxygen species, selenium electrophiles and radicals, electrophilic halogen and hypervalent iodine intermediates, heteroatom-centered oxidative coupling processes, and stereoselective electrochemical transformations through memory of chirality. Across these studies, a common principle emerges in which reaction selectivity is governed not only by the nature of the intermediate itself, but also by how fast and precisely it is generated, transported, and trapped within the flow reactor. Mechanistic investigations, automation strategies, online analysis, and scalable electrochemical platforms further demonstrate how flow electrochemistry enables a transition from empirical oxidative synthesis toward controllable and predictable reactive intermediate chemistry. Collectively, these studies establish oxidative flow electrochemistry as a versatile platform for reaction control and highlight its future potential in sustainable synthesis, asymmetric electrosynthesis, and automated reaction development.