Stereoselective sulfur extrusion reaction of syn- and anti-10,20-dibromo-2,3,12,13-tetrathia[4.4]metacyclophanes to the corresponding syn- and anti-dithia[3.3]metacyclophanes
✍ Scribed by Hisashi Fujihara; Jer-Jye Chiu; Naomichi Furukawa
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 393 KB
- Volume
- 4
- Category
- Article
- ISSN
- 1042-7163
No coin nor oath required. For personal study only.
✦ Synopsis
A new cyclophane, 10,20-dibromo-2,3,12,13-tetrathia[4.4]metacyclophane (l), has been synthesized by the oxidative coupling reaction of 2,6bis(mercaptomethy1)-1-bromobenzene with 12. Both syn and anti isomers of 1 can be isolated at room temperature. The thermal sulfur extrusion reaction of anti-1 with (Et2N,13P afforded anti-9,18-dibromo-2,11dithia[3.3]metaqcIophane, while syn-1 gave 9,19-dibromo-2J I ,12-trithia[3.4]metacyclophane. syn-9,18-
Dibromo-2,1l-dithia[3.3]metacyclophane was produced from the photochemical sulfur extrusion of syn-1 with (Me013P.
INTROD UCTIQN
Varieties of cyclophanes have been synthesized, and the structures have been determined by NMR spectroscopy and X-ray crystallographic analysis [ 13. The conformational properties of [2.21metacyclophanes and thia[3.3]metacyclophanes have been extensively studied because, in general, syn and anti conformations can exist [21. In contrast, very few thia[4A]rnetacyclophanes or larger thia-Dedicated to Prof. A. Fava on the occasion of his seventieth