0000000000390713
AUTHOR
Manuel Breiner
About the selectivity and reactivity of active nickel electrodes in C–C coupling reactions
Active anodes which are operating in highly stable protic media such as 1,1,1,3,3,3-hexafluoroisopropanol are rare. Nickel forms, within this unique solvent, a non-sacrificial active anode at constant current conditions, which is superior to the reported powerful molybdenum system. The reactivity for dehydrogenative coupling reactions of this novel active anode increases when the electrolyte is not stirred during electrolysis. Besides the aryl-aryl coupling, a dehydrogenative arylation reaction of benzylic nitriles was found while stirring the mixture providing quick access to synthetically useful building blocks.
Comprehensive valorisation of technically relevant organosolv lignins via anodic oxidation
Lignin represents the largest renewable feedstock of aromatic moieties in nature. However, its valorisation towards organic chemicals poses a challenging task. We herein report the selective electrochemical depolymerisation of several technically relevant organosolv lignins to aromatic fine chemicals with a simple two-electrode arrangement using caustic soda as electrolyte. Vanillin, syringaldehyde, the corresponding ketones and guaiacol were obtained with a combined maximum of 7.8 wt% isolated yield. Deeper insight in the process was provided by FT-IR, HSQC NMR and 31P NMR analyses of the lignins.
High-Temperature Electrolysis of Kraft Lignin for Selective Vanillin Formation
Lignin represents the largest renewable resource of aromatic moieties on earth and harbors a huge potential as a sustainable feedstock for the synthesis of biobased aromatic fine chemicals. Due to the complex, heterogeneous, and robust chemical structure of the biopolymer, the valorization is associated with significant challenges. Unfortunately, technical lignins, which are a large side stream of the pulp and paper industries, are mainly thermally exploited. In this study, technical Kraft lignin was selectively electrochemically depolymerized to the aroma chemical vanillin. Using electricity, toxic and/or expensive oxidizers could be replaced. The electrodegradation of Kraft lignin was per…
CCDC 1976461: Experimental Crystal Structure Determination
Related Article: Sebastian B. Beil, Manuel Breiner, Lara Schulz, Aaron Schüll, Timo Müller, Dieter Schollmeyer, Alexander Bomm, Michael Holtkamp, Uwe Karst, Wolfgang Schade, Siegfried R. Waldvogel|2020|RSC Advances|10|14249|doi:10.1039/D0RA02673E