Electroorganic Synthesis under Flow Conditions.

Despite the long history of electroorganic synthesis, it did not participate in the mainstream of chemical research for a long time. This is probably due to the lack of equipment and standardized protocols. However, nowadays organic electrochemistry is witnessing a renaissance, and a wide range of interesting electrochemical transformations and methodologies have been developed, not only for academic purposes but also for large scale industrial production. Depending on the source of electricity, electrochemical methods can be inherently green and environmentally benign and can be easily controlled to achieve high levels of selectivity. In addition, the generation and consumption of reactive or unstable intermediates and hazardous reagents can be achieved in a safe way. Limitations of traditional batch-type electrochemical methods such as the restricted electrode surface, the necessity of supporting electrolytes, and the difficulties in scaling up can be alleviated using electrochemical flow cells. Microreactors offer high surface-to-volume ratios and enable precise control over temperature, residence time, flow rate, and pressure. In addition, efficient mixing, enhanced mass and heat transfer, and handling of small volumes lead to simpler scaling-up protocols and minimize safety concerns. Electrolysis under flow conditions reduces the possibility of overoxidation as the reaction mixture is flown continuously out of the reactor in contrast to traditional batch-type electrolysis cells. In this Account, we highlight our contributions in the area of electroorganic synthesis under flow conditions over the past decade. We have designed and manufactured different generations of electrochemical flow cells. The first-generation reactor was effectively used in developing a simple one-step synthesis of diaryliodonium salts and used in proof-of-concept reactions such as the trifluoromethylation of electron-deficient alkenes via Kolbe electrolysis of trifluoroacetic acid in addition to the selective deprotection of the isonicotinyloxycarbonyl (