New Polysulfur‐Nitrogen Heterocycles by Thermolysis of 1,3λ⁴δ²,2,4‐Benzodithiadiazines in the Hydrocarbon and Fluorocarbon Series

Abstract

In contrast to thermolysis of 1,3λ4δ2,2,4‐benzodithiadiazine (1) and its 5,6,7,8‐tetrafluoro derivative 2 in dilute (10–3 M) hydrocarbon solutions, which leads to persistent 1,2,3‐benzodithiazolyls in nearly quantitative yields, the thermolysis of 1 and 2 (the 6‐6 bicyclic system) in concentrated (0.5 M) solutions at 150–170 °C results in complex mixtures of various polysulfur‐nitrogen heterocycles, in particular differently fused 5‐5‐6, 5‐6‐7 and 5‐6‐6‐6 polycyclic systems that were previously unknown. The products were isolated by column chromatography, and the structures of the 5‐5‐6 (11, 12), 5‐6‐7 (5, 13), and 5‐6‐6‐6 (6, 14, 15) polycyclic systems, as well as the 6‐7 (4) and 5‐6 (16) bicyclic derivatives, confirmed by X‐ray diffraction. The crystal packing of 6 and 11–16 is discussed with special emphasis on π‐stacking interactions. The fluorescent properties of the 5‐6‐6‐6 systems synthesized are reported. An alternative approach to the linear 5‐6‐6‐6 system 15 based on self‐condensation of an R–N=PPh3 precursor (R = 4,5,6,7‐tetrafluoro‐1,2,3‐benzodithiazol‐2‐yl) is described, and the free‐radical character of this new reaction is proved. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Novel applications of functionalized 2,1,3-benzothiadiazoles for coordination chemistry and crystal engineering

“…For crystal engineering, these compounds are promising due to unlike charges on their S and N atoms, causing intermolecular S/N contacts in the solid state 11 together with extended p-systems capable of p-p interactions in the same state. 12 As a result, multidimensional networks can be formed, which are believed to cause non-trivial chemical and physical properties of this type of compounds. [13][14][15][16][17] At the same time, the coordination chemistry of compounds under discussion is not well-developed, and only a limited number of structurally characterized transition metal complexes, including those of Ag, Cd, Co, Cu, Pd, Ru and trimeric peruoro-ortho-phenylenemercury (anti-crown compound), are known.…”

Recent Developments in the Synthesis and Applications of 1,2,5-Thia- and Selenadiazoles. A Review

“…97 The authors concluded that the transformation of 12π -electron anti-aromatic dithiadiazines 108 and 109 into aromatic thiadiazoles 1 and 110 is thermodynamically favored. …”

Benzo[1,2,3]dithiazole Compounds: A History of Synthesis and Their Renewed Applicability in Materials and Synthetic Chemistry, Originating from the Herz Reaction

“…Mayer, Zhivonitko, Marakov and co-workers have reported on the formation of phenothiazines from self-condensation of benzodithiazoyl radicals [50]. Two self-condensation isomer products, each from an intermediate unsubstituted and fluoro-substituted 1,2,3-benzodithiazoyl radical (26d), were synthesised [92]. These crystalline compounds were isolated in very low yield from a reaction mixture (for which the 1,2,3-benzodithiazoyl radical 26b was detected as a minor intermediate), but also in higher (30%) yield by slowly reacting the fluorinated 2-triphenylphosphoranimine-substituted benzodithiazole (26a) at ambient temperature in chloroform (Scheme 27).…”