Modern Electrochemical Aspects for the Synthesis of Value‐Added Organic Products

The use of electricity instead of stoichiometric amounts of oxidizers or reducing agents in synthesis is very appealing for economic and ecological reasons, and represents a major driving force for research efforts in this area. To use electron transfer at the electrode for a successful transformation in organic synthesis, the intermediate radical (cation/anion) has to be stabilized. Its combination with other approaches in organic chemistry or concepts of contemporary synthesis allows the establishment of powerful synthetic methods. The aim in the 21st Century will be to use as little fossil carbon as possible and, for this reason, the use of renewable sources is becoming increasingly impo…

Elektrifizierung der organischen Synthese

Simple and scalable electrochemical synthesis of 2,1-benzisoxazoles and quinoline N-oxides.

Cathodic reduction of the nitro moiety and subsequent intramolecular cyclization affords different substituted 2,1-benzisoxazoles and quinoline N-oxides. This methodology allows the synthesis of two different types of heterocycles from common simple starting materials, using electrons as a sole reagent for this transformation. The electrolysis can be conducted in a very simple undivided electrolysis cell under constant current conditions. This permits working on a larger scale compared to other electrochemical methodologies and represents a significant advantage.

Recent advances in the electrochemical reduction of substrates involving N−O Bonds

Moderne Aspekte der Elektrochemie zur Synthese hochwertiger organischer Produkte

Front Cover: Selective and Scalable Electrosynthesis of 2H ‐2‐(Aryl)‐benzo[ d ]‐1,2,3‐triazoles and Their N‐Oxides by Using Leaded Bronze Cathodes (Chem. Eur. J. 25/2020)

Simple electrochemical reduction of nitrones to amines.

Only electricity is needed for the transformation of nitrones to amines. Such a direct double reduction has not been reported by any sole chemical reagent in a single step process.

A very simple one-pot electrosynthesis of nitrones starting from nitro and aldehyde components

The cathodic treatment of nitroarenes in the presence of aldehydes yields directly and selectively nitrones. Electrolysis can be conducted on a very simple undivided beaker-type cell under constant current conditions. The conversion tolerates multiple bonds, a variety of functional groups and heterocyclic moieties. Competing reductive conversions such as pinacolization are not observed. The green aspects of this electro-conversion are avoidance of metals, an environmentally benign solvent mixture, and stable as well as sustainable carbon electrodes.

Selective and Scalable Electrosynthesis of 2H-2-(Aryl)-benzo[d]-1,2,3-triazoles and Their N-Oxides by Using Leaded Bronze Cathodes.

Abstract Electrosynthesis of 2H‐2‐(aryl)benzo[d]‐1,2,3‐triazoles and their N‐oxides from 2‐nitroazobenzene derivatives is reported. The electrolysis is conducted in a very simple undivided cell under constant current conditions with a leaded bronze cathode and a glassy carbon anode. The product distribution between 2H‐2‐(aryl)benzo[d]‐1,2,3‐triazoles and their N‐oxides can be guided by simply controlling the current density and the amount of the charge applied. The reaction tolerates several sensitive functional groups in reductive electrochemistry. The usefulness and the applicability of the synthetic method is demonstrated by a formal synthesis of an antiviral compound.

Electrifying Organic Synthesis

Abstract The direct synthetic organic use of electricity is currently experiencing a renaissance. More synthetically oriented laboratories working in this area are exploiting both novel and more traditional concepts, paving the way to broader applications of this niche technology. As only electrons serve as reagents, the generation of reagent waste is efficiently avoided. Moreover, stoichiometric reagents can be regenerated and allow a transformation to be conducted in an electrocatalytic fashion. However, the application of electroorganic transformations is more than minimizing the waste footprint, it rather gives rise to inherently safe processes, reduces the number of steps of many synth…