Control of reactive intermediates by electrical current

Scientists are developing an environmentally friendly process for the production of fine chemicals

Scientists from the Johannes Gutenberg University Mainz (JGU) and Evonik Performance Materials GmbH have been able to successfully develop a novel and innovative approach to important fine chemicals. The research results, which were presented in two publications in the journal Angewandte Chemie International Edition this year, show an environmentally friendly strategy for the presentation of these fine chemicals and overcome important hurdles in the field of electrosynthesis for the first time.

In recent years, electrochemistry has undergone a renaissance, and numerous research groups are working on the environmentally friendly production or conversion of molecules. This key technology enables molecules to be reacted without hazardous chemical reagents and thus without reagent waste. Despite the superiority of electrochemistry, its application to various molecules has  been problematic. The electrolysis of such highly reactive substances has so far only led to the formation of high-molecular weight products (polymers). This method of production was sometimes even used on purpose. Two interesting examples are polythiophene and polyaniline (also known as aniline black). The production of both polymers by electrolysis is considered to be textbook examples.

The defined production of fine chemicals based on the same starting materials has been very difficult and only possible through complex synthetic steps. The research group led by Prof. Dr. Siegfried Waldvogel from the Institute of Organic Chemistry at JGU have succeeded in overcoming the problem of electrochemical polymer formation and in developing a sustainable and efficient synthesis strategy for these important products for the first time. However, it is not only the simplicity of this synthesis that is convincing, but also its environmental friendliness. The only "waste" produced is hydrogen, which is known as an environmentally friendly fuel in hydrogen cars. The key to success here is the use of a unique electrolyte system. This is extremely stable and can be reused after electrolysis, which reinforces the green aspect of this method. In addition, this extraordinary electrolyte is also the source of the high selectivity of these reactions. Therefore, a very simple electrolysis setup can be used. For the first time, this development provides an easy, environmentally friendly access to a number of compounds with high pharmaceutical, material science potential and as building blocks for co-catalysts in homogenous catalysis.