Efficient Synthesis of 4,8-Dibromo Derivative of Strong Electron-Deficient Benzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole) and Its SNAr and Cross-Coupling Reactions

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 21; p. 7372
• Main Authors: Chmovzh, Timofey N., Alekhina, Daria A., Kudryashev, Timofey A., Rakitin, Oleg A.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.11.2022; MDPI
• Subjects: aromatic nucleophilic substitution; benzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole); Bromination; Bromine; Chemical reactions; Cross coupling; Nitrogen; Solvents; sulfur–nitrogen heterocycles; Suzuki and Stille cross-coupling reactions; Thermal stability; Thiadiazoles; Thiols; X ray analysis
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27217372

An efficient synthesis of hydrolytically and thermally stable 4,8-dibromobenzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole) by the bromination of its parent heterocycle is reported. The structure of 4,8-dibromobenzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole) was confirmed by X-ray analysis. The conditions for the selective aromatic nucleophilic substitution of one bromine atom in this heterocyclic system by nitrogen nucleophiles are found, whereas thiols formed the bis-derivatives only. Suzuki–Miyaura cross-coupling reactions were found to be an effective method for the selective formation of various mono- and di(het)arylated derivatives of strong electron-deficient benzo[1,2-d:4,5-d’]bis([1,2,3]thiadiazole), and Stille coupling can be employed for the preparation of bis-arylated heterocycles, which can be considered as useful building blocks for the synthesis of DSSCs and OLEDs components.