A revitalization of organic electrosynthesis has incited the organic chemistry community to adopt electrochemistry as a green and cost-efficient method for activating small molecules to replace highly toxic and expensive redox chemicals. However, many of the critical challenges of batch electrosynthesis, especially for organic synthesis, still remain. The combination of continuous flow technology and electrochemistry is a potent means to enable industry to implement large scale electrosynthesis. Indeed, flow electrosynthesis helps overcome problems that mainly arise from macro batch electro-organic systems, such as mass transfer, ohmic drop, and selectivity, but this is still far from being a flawless and generic applicable process. As a result, a notable increase in research on methodology and hardware sophistication has emerged, and many hitherto uncharted chemistries have been achieved. To better help the commercialization of widescale electrification of organic synthesis, we highlight in this perspective the advances made in large-scale flow electrosynthesis and its future trajectory while pointing out the main challenges and key improvements of current methodologies.

We report a new electrochemical supporting-electrolyte-free method for synthesizing ureas, carbamates, and thiocarbamates via the oxidation of oxamic acids. This simple, practical, and phosgene-free route includes the generation of an isocyanate intermediate in situ via anodic decarboxylation of an oxamic acid in the presence of an organic base, followed by the onepot addition of suitable nucleophiles to afford the corresponding ureas, carbamates, and thiocarbamates. This procedure is applicable to different amines, alcohols, and thiols. Furthermore, when single-pass continuous electrochemical flow conditions were used and this reaction was run in a carbon graphite C gr /C gr flow cell, urea compounds could be obtained in high yields within a residence time of 6 min, unlocking access to substrates that were inaccessible under batch conditions while being easily scalable.

The insertion reaction of a broad range of diazo compounds into Si–H bonds was found to be efficiently catalysed by Fe(OTf)2 in an emerging green solvent i.e. dimethyl carbonate (DMC).

An efficient synthesis of 3-trifluoromethyl-3-aryl-cyclopropenes via the cyclopropenation reaction of alkynes with photolytically generated carbenes from diazirine compounds is described. This reaction is performed in continuous flow using readily available LEDs under mild reaction conditions. This new and efficient method describes the synthesis of 25 examples of 3-trifluoromethyl-3-arylcyclopropenes with yields up to 97%, achieved in continuous flow with a 5 min residence time. Control experiments highlighted that diazirines are more efficient than diazo compounds for this transformation.