We envisioned that electrochemistry could offer a solution to these limitations by eliminating the need for additional chemical reductants while enabling the selective transformation of diverse and complex organic substrates. Furthermore, flow chemistry has recently emerged as a transformative technology in electrosynthesis. By utilizing a standardized electrochemical flow cell, we anticipated addressing challenges such as ohmic drop, mass transfer limitations, scalability, and procedural robustness. Despite these technological advances and the promising foundations laid by early electrochemical studies, electrochemical cyclopropanation remains surprisingly underexplored in the literature. Leveraging the electrochemical flow cell developed in our laboratory, we report herein the development of a flow electroreductive nickel-catalyzed protocol that enables a mild, broadly applicable and scalable cyclopropanation of alkenes using bulk chemical dichloromethane and other widely available gem-dichloroalkanes as methylene precursors (Scheme 1D). We began our investigation by selecting coumarin (1a) as a model substrate for optimization studies. Initially, electrochemical cyclopropanation of 1a was carried out in an undivided batch electrochemical cell using a Ni-PyBOX complex, achieving a 67% yield of 1b (Table ). Encouragingly, thorough optimization allowed us to rapidly adapt the reaction conditions to a continuous-flow setup (Table ). This transition eliminated the need for an inert atmosphere, enhancing the practicality of the protocol. Additionally, the improved mass transfer in the flow cell significantly increased the throughput, from 13 µmol•h -1 in batch to 112 µmol•h -1 in flow (Table , entry 1). The reduced inter-electrode distance in the electrochemical flow cell also enabled us to omit the supporting electrolyte without compromising the yield (Table , entry 2). Control experiments confirmed the electrochemical nature of the reaction, as no product was obtained in the absence of an electrical current, with only the starting material recovered (Table , entry 3). However, reducing the catalyst loading led to a decrease in yield to 50% (Table , entry 4). Similarly, decreasing the residence time, and thus reducing the total number of electrons exchanged, lowered the yield of 1b (Table ). An extensive ligand screening identified i Pr-PyBOX as a cost-effective and optimal ligand for the reaction (Table , entry 6, Table ). Increasing the volumetric proportion of dichloromethane resulted in a slight decrease in product formation (Table ). Altering the sacrificial anode and cathode materials did not improve the yield of 1b (Table , entries 8-9, Tables ). Notably, when the optimized flow conditions were applied to a batch setup, significant degradation of the starting material occurred, resulting in a yield of only 8% for 1b (Table ). This highlights the advantages of the continuous-flow setup for our cyclopropanation conditions. Table . Optimization of reaction conditions. Entry Variation from optimal conditions Yield (%) 1 None 87 (84 ) 10 Batch, 0.9 mA•cm -2 , 8nF, 42.8 h 8 [a] Standard conditions: reaction performed on a 30 µmol scale (see Supplementary Information for experimental details). Yields determined by NMR analysis of the crude reaction mixture using 1-3-5-trimethoxybenzene as an external standard.