During the optimization process, severe reproducibility issues were observed, which affected the development of our experimental protocol. Even when brand-new RVC electrodes were used, dramatically inconsistent results were recorded, ranging from ~60% yield to traces of 4a (Figure ). We decided to investigate this uncommon behavior, and after a few experiments it was evident that this outcome could be attributed to the electrodes (Figure , see 3 Supporting Information for further details). Analysis of the electrodes via Scanning Electron Microscopy (SEM) revealed that some new electrodes had particles deposited on the carbon surface, and we hypothesized that these particles could be attributed to polymeric residues. Under this assumption, a thorough pretreatment to employ clean electrodes was developed, that involved washing the electrodes in acetone or pentane under sonication and subsequent drying at 100°C for 12 hours (Figure ). By applying this method, the irreproducibility problem was overcome, and consistent data could be obtained across different batches of RVC electrodes. This set of experiments moved our curiosity on the evaluation of the electrodes at the end of the electrolysis. Interestingly, SEM analysis demonstrated the presence of solid deposits on the surface of the electrodes (Figure ). The analysis of a used electrode with Energy Dispersive X-Ray (EDX) showed that these solid particles contained Ni and Br, which were present in solution as the catalyst and the supporting electrolyte, respectively (see Supporting Information for further details). With all the valuable information in hand, we proceeded to evaluate the translation of the reaction to a flow setting. Instead of RVC, graphite felt electrodes were installed in the flow electrolysis cell, as it is an easy-to-handle and cost effective material, more suitable for the utilization of large quantities. However, felt materials are very porous and absorb a consistent amount of the reaction mixture, compromising the solution stream at low flow rates and affecting reaction reproducibility. For these reasons, we employed a reactor design that could allow the use of felt electrodes both in a single-pass and recirculation manner to ensure prompt scalability of the nickel electrocatalyzed reaction (Figure ). The flow reactor consisted in a parallel "plate and frame" type design, in which two rhombus-shape graphite felt electrodes (3 mm thickness, Figure ) were separated by a stack of 4 PTFE mesh sheets (thickness: 150-180 µm each) to avoid short circuit, without affecting the flow of the mixture across the apparatus. The electrical connection to the felts was accomplished using graphite plates as current collectors, (Figure ) each of them connected to the power supply by a pogo pin (Figure ). With this reactor design, the optimization of the flow transformation was carried out (Figure ). Preliminary attempts of running reactions in single pass mode did not lead to the formation of considerable amounts of the desired product. These results were attributed to the low flow rates that did not allow sufficient mass transfer, especially in a setup where the reaction mixture was flowing through a porous carbon felt material (Entry 1, see Supporting Information for further details). These results indicated that higher flow rates would be necessary to guarantee an efficient electrochemical reaction. To validate this hypothesis the reactor was used in recirculation mode employing a peristaltic pump, and promising formation of the desired product 4a was observed, in contrast to the results obtained with the single pass approach (Entry 2). Surveying different electrode materials did not show any relevant formation of the desired product (Entry 3), while increasing the flow rate to 10 mL/min led to further improvement of the process (22%, Entry 4). solution, therefore it was decided to keep the reaction mixture inert by bubbling argon through the reaction mixture during the electrolysis time. This adjustment was sufficient to enhance the product formation (46%, Entry 5). Finally, a further increase in the flow rate to 40 mL/min led to a formation of 4a in similar yields to those observed in batch, even by using a higher reaction mixture concentration (Entry 6-7). During the optimization, the reactor showed consistent results for 2 consecutive runs without the need of opening the reactor, and after that the electrodes could be regenerated using a treatment protocol similar to that developed for the batch cell electrodes (see Supporting Information for further details). This new flow protocol opened new opportunities for the scale-up of this electrocatalytic method, where the experimental procedure for the preparation of the reaction mixture does not differ from the optimized batch one except for the inert atmosphere ensured by inert gas bubbling instead of positive pressure on the vessel headspace. After optimization, the developed flow protocol was then tested on different substrates to validate its robustness (Figure ). Regarding the alcohol coupling partner, the reaction displayed good yields with primary and secondary alcohols (4a-4f). In particular, the reaction could be efficiently employed in the presence of functional groups such as ethers (4b), extended alkyl chains (4c), protected amines (4a, 4d), alkenes (4e), and esters (4f). Other aryl bromides have also been tested, showing moderate compatibility of the method towards different arenes and heteroarenes (4g-4k). Electron poor (4g) and electron rich (4h) aryl bromides could be employed as competent partners in the coupling. Furthermore, heteroarenes like thiophenes (4i) and substituted pyridines (4j-4k), provided the desired products with acceptable yields (up to 43%). Finally, the flow protocol was adopted for the scale-up synthesis of delamanid intermediate 1. For this reaction, the two commodity chemicals 2a and 3a have been employed as coupling partners, and the reaction has been conducted at 10 mmol scale. The Boc-protected intermediate 4a was extracted and then subjected to mild deprotection to obtain compound 1, which could be isolated without column chromatography by simple work-up in 63% yield.