ISSN:
0009-2940
Keywords:
[4 + 2] Cycloadditions
;
Thiazyl compounds
;
1,2-Thiazines
;
1,2-Thiazin-1-ium hexafluoroarsenates
;
1λ4,2-Thiazine, 1-chloro-3,3,4,5,6,6-hexafluoro-3,6-dihydro-, crystal structure of
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reactions of Halogeno Thiazyls: Preparation, Structures, and Properties of Perhalogenated 1,2-ThiazinesReactions of (XSN)n (n = 1,3; X = F, Cl) with perfluorobutadiene provide the 1λ4,2-thiazines 1a and 1b. 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 + 2] cycloaddition has occured. Fluorination with KF converts 1 b almost quantitatively into 1 a. The 1λ4,2-thiazine 1 a does not exhibit fluorinating properties towards chloroalkanes but undergoes reaction with CH3OH and Me3SiNMe2 to form 1 c and 1 d, respectively. 1,2-Thiazine oxide 3 is obtained from 1 a or 1 b and (Me3Si)2O. Treatment of 1 b with AgAsF6 in SO2 yields perfluoro-1,2-thiazin-1-ium hexafluoroarsenate (4) as the main product. No reaction is observed between FSN and hexa-chlorobutadiene. 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-1-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 corresponding ketones 12 and 14. The very unstable intermediate CF3SSN, formed on treating Me3SiSCF3 or B(SCF3)3 with FSN, decomposes to CF3SxCF3 (X = 2-4), S4N4, S8, and N2. No addition product can be detected when CF3SSN prepared in situ is treated with dienes.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250309
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