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Geometrical isomers of thione S-imides

Geometrical isomers of thione S-imides

Authors :
Binne Zwanenburg
A. Tangerman
Source :
Recueil des Travaux Chimiques des Pays-Bas. 98:127-132
Publication Year :
2010
Publisher :
Wiley, 2010.

Abstract

Reaction of highly substituted dithiobenzoates 1 (a-e) with chloramine-T in methanol at 20°C gives, in high yields, thione S-imides 2 (a-e) to which the E-geometry was assigned. Heating of these compounds in methanol for 1 hr causes thermodynamic isomerization to the Z-isomers 3 (a-e). Similarly, 2,4,6-trimethyl-thiobenzophenone gives the corresponding E- and Z-S-tosylimides 6 and 7. Irradiation of thione S-imides 2, 3, 6 and 7 leads to extrusion of sulfur yielding N-tosylimines 4 and 8. The geometrical configurations were based on ASIS experiments. From the 1H-NMR spectra of 2 and 3 the preferred conformation of the thione S-imides have been deduced (S-trans conformation for the E-isomer 2 and a folded S-cis conformation for the Z-isomer 3). It will be shown that in order to obtain stable thione S-tosylimides from dithiobenzoates and thiobenzophenones, steric hindrance in the direct environment of the thiono function is a prerequisite.

Details

ISSN :
01650513
Volume :
98
Database :
OpenAIRE
Journal :
Recueil des Travaux Chimiques des Pays-Bas
Accession number :
edsair.doi...........5d9727587a6a0d1d0b0f15debd724fc2
Full Text :
https://doi.org/10.1002/recl.19790980321