[1,2,5]Selenadiazolo[3,4-b]pyrazines: Synthesis from 3,4-Diamino-1,2,5-selena­diazole and Generation of Persistent Radical Anions

• Published in: European journal of organic chemistry 2015-09, Vol.2015 (25), p.5585-5593
• Main Authors: Konstantinova, Lidia S., Bobkova, Irina E., Nelyubina, Yulia V., Chulanova, Elena A., Irtegova, Irina G., Vasilieva, Nadezhda V., Camacho, Paula S., Ashbrook, Sharon E., Hua, Guoxiong, Slawin, Alexandra M. Z., Woollins, J. Derek, Zibarev, Andrey V., Rakitin, Oleg A.
• Format: Article
• Language: English
• Subjects: Cyclovoltammetry; DFT calculations; EPR spectroscopy; Nitrogen heterocycles; Radical anions; Selenium heterocycles; Synthetic methods
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201500742

Previously unknown 3,4‐diamino‐1,2,5‐selenadiazole (6) was prepared by hydrolysis of [1,2,5]selenadiazolo[3,4‐c][1,2,5]selenadiazole (7b) and used in synthesis of novel 1,2,5‐selenadiazolo[3,4‐b]pyrazines by the Koerner–Hinsberg reaction covering the parent compound 4 and its substituted derivatives 5a–g. The compounds synthesized were characterized by solution and solid‐state 77Se NMR, and 6, 5‐Ph and 5,6‐Me2[1,2,5]selenadiazolo[3,4‐b]pyrazines (5a, g, respectively) by X‐ray diffraction. Electrochemical reduction of 5,6‐R2[1,2,5]selenadiazolo[3,4‐b]pyrazines 5c, g (R = Ph, Me) into novel persistent radical anions (RAs) was studied by cyclic voltammetry and the RAs [5c]– and [5g]– were characterized by EPR spectroscopy combined with DFT calculations. 3,4‐Diamino‐1,2,5‐selenadiazole was synthesized and used for preparing novel [1,2,5]selenadiazolo[3,4‐b]pyrazines. Electrochemical reduction of the latter into persistent radical anions (RAs) was studied by CV and the RAs were characterized by EPR combined with DFT calculations.