Rapid Alternating Polarity as a Unique Tool for Synthetic Electrochemistry

Electrosynthesis, driven by renewable energy, is a powerful method for accessing useful chemical reactivity in a sustainable fashion. Typically, electrochemical reactions have been carried out using direct current (DC), where electrons flow in a single direction. In contrast, utilization of alternating current (AC) has been largely unexplored in synthetic electrochemistry despite its wide applications in our daily life. This could stem from a historical perception regarding the lack of unique reactivity/selectivity that would result from using such a waveform, as well as the absence of readily available instrumentation to remove the engineering barrier for mass adoption. A breakthrough in this area is the introduction of rapid alternating polarity (rAP), which alternates the polarity of an electrode in the millisecond timescale. This mode of current delivery, now implemented in the widely employed potentiostat, ElectraSyn2.0, enables access to unique reactivity and selectivity in organic synthesis that are challenging or currently impossible to achieve by any known method (chemical or electrochemical). The remarkable chemoselectivity and simplicity of rAP open new vistas in modern synthetic electrochemistry.