Twofold Electrochemical Amination of Naphthalene and Related Arenes

The twofold, electrochemical amination reaction of polycyclic arenes, e.g. naphthalene (4), via Zincke intermediates is demonstrated for the first time. The installation of the nitrogen functionalities occurs regioselectively in positions 1 and 5 of naphthalene (4). The key for this electro-conversion is boron-doped diamond as anode material. The method of the multi-amination reaction is expanded to other aromatic substrates. A detailed study is provided, covering electrolysis parameters, e.g. anode material, electrolyte system, current density, separator, etc. Despite the moderate yields, this approach offers the first direct electro-synthetic access to diaminated products.

Electrochemical Amination of Less-Activated Alkylated Arenes Using Boron-Doped Diamond Anodes

The anodic C–H amination of aromatic compounds is a powerful and versatile method for the synthesis of aniline derivatives. By using boron-doped diamond (BDD) anodes, a method initially described by Yoshida et al. for electron-rich arenes was expanded to less-activated aromatic systems e.g., simple alkylated benzene derivatives. Anodes based on sp3 carbon seem to be the key for the electrochemical amination reaction. The corresponding primary anilines are obtained in good yields. Despite the cationic intermediates of the electrolytic reaction tert-butyl moieties are tolerated.

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.

ChemInform Abstract: Electrochemical Amination of Less-Activated Alkylated Arenes Using Boron-Doped Diamond Anodes.

Anodic Formation of Aryl Mesylates through Dehydrogenative Coupling Reaction

Applicability of a Polymerized Ionic Liquid/Carbon Nanoparticle Composite Electrolyte to Reductive Cyclization and Dimerization Reactions

Abstract Recently, a reusable polymerized ionic liquid/carbon nanoparticle composite electrolyte was developed and effectively applied to a variety of oxidative transformations. The efficient recovery of the composite material and its application in subsequent electroorganic conversions without sacrificing yield adds to the sustainability of the protocol. Herein, we describe our efforts to expand the operational window of the composite electrolyte to include cathodically initiated processes occurring at potentials up to −2.6 V. The results indicate that the composite electrolyte is applicable to reductive processes, but the scope of transformations appears to be limited.

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

CCDC 1545585: Experimental Crystal Structure Determination

Related Article: Sabine Möhle, Sebastian Herold, Frank Richter, Hartmut Nefzger, Siegfried R. Waldvogel|2017|ChemElectroChem|4|2196|doi:10.1002/celc.201700476