Sulfonamides are among the most important chemical motifs in pharmaceuticals and agrochemicals. However, there is no methodology to directly introduce the sulfonamide group to a non‐prefunctionalized aromatic compound. Herein, we present the first dehydrogenative electrochemical sulfonamide synthesis protocol by exploiting the inherent reactivity of (hetero)arenes in a highly convergent reaction with SO2 and amines via amidosulfinate intermediate. The amidosulfinate serves a dual role as reactant and supporting electrolyte. Direct anodic oxidation of the aromatic compound triggers the reaction, followed by nucleophilic attack of the amidosulfinate. Boron‐doped diamond (BDD) electrodes and a HFIP–MeCN solvent mixture enable selective formation of the sulfonamides. In total, 36 examples are demonstrated with yields up to 85 %.
Scheme 1. Selected approved drugs containing nitro functionalities.Scheme 2. Traditional approach (electrophilic aromatic substitution) in comparison to the electrochemical nitration with nitrite (this work); C gr = graphite.
zu finden. 2020 Die Autoren. Angewandte Chemie verçffentlicht von Wiley-VCH GmbH. Dieser Open Access Beitrag steht unter den Bedingungen der Creative Commons Attribution Non-Commercial NoDerivs License, die eine Nutzung und Verbreitung in allen Medien gestattet, sofern der ursprüngliche Beitrag ordnungsgemäß zitiert und nicht für kommerzielle Zwecke genutzt wird und keine ¾nderungen und Anpassungen vorgenommen werden.
Electrochemical Synthesis In their Communication on page 5056, Siegfried R. Waldvogel et al. report the metal‐free electrochemical synthesis of sulfonamides directly from (hetero)arenes, SO2, and amines.
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