Electrosynthesis in Laminar Flow Using a Flow Microreactor

Abstract

Electrosynthesis and microflow synthesis have become essential tools in their own rights in modern organic synthesis. In this personal account, we summarize our works on the integrated use of these techniques, i. e., electrosynthesis in a flow microreactor. Our group has developed an electrochemical microflow system composed of a pair of electrodes that face each other to form a micrometer‐scale gap for the flow path, through which solution passes in laminar flow. By the aid of laminar flow, unprecedented chemo‐ and electrochemical selectivity has been observed, which is not achievable with conventional batch‐type electrochemical cells. In addition, we showcase various unique electrochemical systems and reactions achieved with the flow microreactor, including self‐supported electrolysis, efficient paired electrolysis, in situ generation of active species and its flash use, the spaciotemporal control of electropolymerization, and combinatorial screening of the reaction conditions.

Electrogenerated base-promoted cyclopropanation using alkyl 2-chloroacetates

“…Compound 6 in entries 3 and 4 contained an impurity of non-negligible amount, despite of repeated purification by GPC. Compound 6 in entry 2, 10 in entry 5 and 12 in entry 6 contained a small amount of impurities (see 13 C NMR spectra of compounds 6, 10 and 12 in Supporting Information File 1). Values in parentheses in entries 2-6 are estimated yields, calculated from the ratio of isolated compounds and impurities given in the 1 H NMR spectra, because the impurities seem to be the corresponding trialkyl propane-1,2,3-carboxylates (vide infra).…”

“…The generation of an anionic intermediate was indicated. During our study, we discovered that 1,2,3-trisubstituted cyclopropane derivatives could be formed in moderate yields through the electrochemical reduction [13][14][15][16][17][18][19][20][21] of alkyl 2-chloroacetates in a divided cell (Scheme 1, reaction 4). The in Abushanab's study utilized metal lithium is one of the rarest and most expensive metals.…”

Process intensification in continuous flow organic synthesis with enabling and hybrid technologies

“…Electrosynthesis can be carried out via a variety of procedures and technical variations, and portable electrochemical reactors are currently available at a moderate cost. Importantly, electrochemical flow reactors can easily be implemented and/or combined with other techniques, such as US or photochemistry (Folgueiras-Amador et al, 2017;Shida et al, 2021).…”

Local Electric Field and Electrical Conductivity Analysis Using a Glass Microelectrode

“…In recent decades, various functions of microfluidic devices have attracted significant attention. Focusing on transport phenomena in fluids, several applications have been proposed for microelectromechanical systems (MEMS) and micro-total analysis systems (μ-TAS), , for example, flow sensors, , micromixers, and microreactors . Microscale convective heat transfer , and mass transport phenomena , have also been investigated.…”