Addition of thianthrene cation radical to non-conjugated dienes—Part I: Addition to one double bond

Abstract

Reaction of thianthrene cation radical tetrafluoroborate and hexafluorophosphate with an excess of 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene and 1,9-decadiene gave, in each case, a mixture of bis- and monoadduct from addition to one of the diene’s double bonds. Addition to both double bonds did not occur. The monoadduct of each diene and the bisadduct (7a) of 1,5-hexadiene were isolated. All monoadducts and 7a were characterized with ¹H and ¹³C NMR spectroscopy. By reaction on activated alumina adducts were converted into (E)- and (Z)-(5-thianthreniumyl)dienes, all of which were characterized with ¹H and ¹³C NMR spectroscopy. The monoadduct (6a) of 1,4-hexadiene and the bisadduct 7a were characterized with X-ray crystallography.

Keywords:

• Thianthrene cation radical
• Adducts of dienes
• NMR

Acknowledgements

H.J.S. thanks the Welch Foundation for support (Grant D-0028). K.H.W. thanks the Welch Foundation for support (Grant C-0976) and for the purchase of the CCD, and the National Science Foundation for support (Grant CHE-9983352). We thank Mr. David Purkiss (TTU) for the 500 MHz NMR spectroscopy.