Reaktionen von Halogenthiazylen: Darstellung, Strukturen und Eigenschaften von perhalogenierten 1,2‐Thiazinen^[1]

Abstract

Key Words: [4 + 21 Cycloadditions / Thiazyl compounds 1 1,2-Thiazines 1 1,2-Thiazin-l-ium hexafluoroarsenates / lh4,2-Thiazine, 1-chloro-3,3,4,5,6,6-hexafluoro-3,6-dihydro-, crystal structure of Reactions of Halogeno Thiazyls: Preparation, Structures, and Properties of Perhalogenated 1.2-Thiazines Reactions of (XSN), (n = 1,3; X = F, CI) with perfluorobutadiene provide the lh4,2-thiazines 1 a and 1 b. The structure of 1 b was determined by single-crystal X-ray diffraction analysis.From the molecular structure it is evident that a formal [4 + 21 cycloaddition has occured. Fluorination with KF converts 1 b almost quantitatively into 1 a. The lh4,2-thiazine 1 a does not exhibit fluorinating properties towards chloroalkanes but undergoes reaction with CH30H and Me3SiNMe2 to form 1 c and I d , respectively. 1,2-Thiazine oxide 3 is obtained from l a or 1 b and (Me3Si)z0. Treatment of 1 b with AgAsF6 in SOz yields perfluoro-l,2-thiazin-l-ium hexafluoroarsenate (4) as the main product. No reaction is observed between FSN and hexachlorobutadiene. The 1,2-thiazines 5, 6, and 9 are prepared from tetrachlorothiophene dioxide (7) and FSN. Fluorine abstraction reactions of 5 and 6 with formation of the expected 1,2-thiazin-l-ium ions 11 and 13, respectively, provide evidence for the structures of 5 and 6. These cations are very sensitive to hydrolysis and are converted into the correspond-

Fluorinated azines and benzazines containing oxygen or sulfur atoms

“…1b). Angle between the planes N 1 C 1 C 4 /N 1 C 4 S is 33.58 [36]. The S-Cl bond length is 0.2066 nm, and S-N bond length is 0.1544 nm.…”

“…1,2-Thiazines (19, X = F) were found to react with MeOH and Me 3 SiNMe 2 to form 1-methoxy-(21) or 1-dimethylamine derivatives; in particular 1,2-thiazine oxide was obtained from 19 and (Me 3 Si) 2 O [36]. The reaction of 19 (X = Cl) with water leads to trifluoro-1,2-thiazine-3-one-1-oxide 20 (Scheme 9) [35].…”