Electrochemical synthesis is the use of electrical energy to drive chemical change; using electricity to replace toxic and costly chemical reagents. This allows cleaner and cheaper syntheses with greater production efficiency and at reduced cost.
In electroorganic synthesis, redox chemistry is carried out by interaction of the starting materials with the electrodes of the electrochemical cell. As electrons are essentially the reagent utilized for the redox process, the use of large amounts of often hazardous oxidizing or reducing reagents can be avoided. Reactive intermediates can be generated under relatively mild conditions (often room temperature) without producing any additional waste. Electrochemical reactions are therefore considered safe and provide some of the greenest and cost efficient synthetic strategies.
Organic electrochemistry deals with the synthesis of organic compounds by electrochemical redox reactions. Its origin can be seen in the Kolbe-electrolysis in 1849. Electrochemical synthesis methods have the outstanding advantage to allow reactions without "substantive" reagents, which otherwise would have to be separated in their used form from the reaction products. Because of the large oxidative and reductive potential range being directly accessible by electrochemical methods, they are in particular of great interest for industry for the production of organic compounds. Prominent examples are the production of adiponitrile, sebacic acid or esters thereof, hydroquinone, benzaldehyde, 4-aminophenol, piperidine, 2,5-dimethoxydihydrofuran, glyoxylic acid and organic fluorine compounds.
Advantages of Electrochemistry
Alternative to traditional reduction/oxidation reagents that are toxic, expensive and not environmentally friendly
Access to chemical transformations not traditionally available through typical chemistries
Reactivity can be “dialed-in” to achieve improved chemoselectivity
Acceleration of redox steps in a complex catalytic cycle possible
The microfluidic electrochemical reactor has the characteristics of short electrode distance and continuous reaction. The feature of short electrode distance can bring advantages of low voltage, less amount of electrolyte or no electrolyte; continuous reaction can bring the advantage of no backflow of materials, so as to realize the product is not excessively redox and improve the product yield. In addition, the microchannel electrochemical reactor has the characteristics of accurate temperature control and fast mass transfer. Under the condition of extremely small electrode distance, special redox coupling reactions can also be realized.
(1) Long residence time, which can realize continuous synthesis or processing;
(2) The temperature of the reactor can be controlled;
(3) There is a wide choice of electrode types, and the electrode distance can be adjusted;
(4) It can be carried out with or without diaphragm.