Metal‐Free Twofold Electrochemical C−H Amination of Activated Arenes: Application to Medicinally Relevant Precursor Synthesis

Abstract The efficient production of many medicinally or synthetically important starting materials suffers from wasteful or toxic precursors for the synthesis. In particular, the aromatic non‐protected primary amine function represents a versatile synthetic precursor, but its synthesis typically requires toxic oxidizing agents and transition metal catalysts. The twofold electrochemical amination of activated benzene derivatives via Zincke intermediates provides an alternative sustainable strategy for the formation of new C−N bonds of high synthetic value. As a proof of concept, we use our approach to generate a benzoxazinone scaffold that gained attention as a starting structure against ca…

New Approach to 1,4-Benzoxazin-3-ones by Electrochemical C-H Amination.

1,4-Benzoxazin-3-ones are important structural motifs in natural products and bioactive compounds. Usually the synthesis of benzoxazinones requires transition metal catalysts and pre-functionalized substrates, e.g. aryl halides. However, the anodic C,H amination of phenoxy acetates offers a very efficient and sustainable access to these heterocycles. The herein presented electrochemical protocol can be applied to a broad scope of alkylated substrates. Even tert-butyl moieties or halogen substituents are compatible with this versatile method.

Charged Tags for the Identification of Oxidative Drug Metabolites Based on Electrochemistry and Mass Spectrometry

Abstract Most of the active pharmaceutical ingredients like Metoprolol are oxidatively metabolized by liver enzymes, such as Cytochrome P450 monooxygenases into oxygenates and therefore hydrophilic products. It is of utmost importance to identify the metabolites and to gain knowledge on their toxic impacts. By using electrochemistry, it is possible to mimic enzymatic transformations and to identify metabolic hot spots. By introducing charged‐tags into the intermediate, it is possible to detect and isolate metabolic products. The identification and synthesis of initially oxidized metabolites are important to understand possible toxic activities. The gained knowledge about the metabolism will…

Cover Feature: New Approach to 1,4-Benzoxazin-3-ones by Electrochemical C−H Amination (Chem. Eur. J. 50/2017)