Electro-Oxidative Synthesis of Phenazines

Abstract

We disclose herein electro-oxidative synthesis as the general protocol for procuring phenazines under mild reaction conditions. Using aerial oxygen as an oxidant, inexpensive electrolyte, and electrodes, a diverse range of phenazines have been accessed in good yields via the ring contraction of 10,11-dihydro-5H-dibenzo­[b,e]­[1,4]­diazepines. In addition, the syntheses of phenazines and diamino phenazines via direct electro-oxidation of dihydrophenazines and electro-dimerization of o-phenylenediamines, respectively, have also been accomplished.

Intermediate aminophenol enables hectogram-scale synthesis of highly bright red carbon quantum dots under ambient conditions

“…S2a and c †). According to previous literature, [27][28][29] the peak with an m/z of 211 was attributed to 2,3-diaminophenazine (DAP). However, R-C-dots could not be obtained when using commercial DAP reacted with o-PDA or aminophenol under acidic conditions.…”

Electrochemical Oxidative (4 + 2) Cyclization of Anilines and o-Phenylenediamines for the Synthesis of Phenazines

“…Then, control experiments and CV studies were conducted to investigate the mechanism. When 3 equiv of ascorbic acid were added under the standard conditions, the product 3aa could not be detected, which suggested the involvement of a radical process (Scheme a) . In addition, we detected the C–H amination product 4 in the initial exploration of the conditions.…”

Facile Synthesis of Diazaanthraquinone Dimers as High-Capacity Organic Cathode Materials for Rechargeable Lithium Batteries

“…For example, hexaazatrianthraquinone (HATAQ), 11 oxidized indanthrone (oIDT), 12 and 7,9,16,18tetraazadibenzo[a,l]pentacene-5,6,8,14,15,17-hexaone (TADB-PHO) 13 have exhibited the most excellent comprehensive electrochemical performance among all small-molecule OCMs due to the extended π-conjugated structure in addition to the high theoretical capacity. To construct pyrazine units in these molecules, the most commonly used two synthesis methods are the oxidation condensation of amino-based monomers 14 and the dehydration condensation between ortho-diamine group and ortho-quinone 15 or ortho-hydroxy group 16 (sometimes further oxidation is necessary to convert the formed dihydropyrazine unit into pyrazine). Nevertheless, up to now, such high-performance OCMs are still lacking.…”