Addition of Thianthrene Cation Radical to Cycloalkenes. An Unexpected Monoadduct
journal contributionposted on 10.12.1999, 00:00 by Wang Keun Lee, Bo Liu, Chan Won Park, Henry J. Shine, Kenton H. Whitmire
Whereas the addition of thianthrene cation radical perchlorate (Th•+ClO4-) to cyclohexene gives a bisadduct, namely, trans-1,2-bis(5-thianthreniumyl)cyclohexane diperchlorate (1), and additon to other alkenes and alkynes also gives trans-bisadducts, addition to cyclooctene gave only a cis-monoadduct, namely, 1,2-(5,10-thianthreniumdiyl)cyclooctane diperchlorate (2a). Similar monoadducts 2b−d were obtained from the addition of Th•+BF4-, Th•+SbF6-, and Th•+PF6- to cyclooctene. The structure of the monoadduct was deduced from its 1H and 13C NMR spectra, from the stoichiometry of its formation, and from the stoichiometry of its reaction with NaSPh, which gave equimolar amounts of cyclooctene, thianthrene, and diphenyl disulfide. The structure was confirmed with X-ray crystallography. Addition of Th•+ salts to cyclopentene and cycloheptene gave mixtures of mono- and bisadducts. The bisadduct of Th•+SbF6- to cyclopentene, separated from the small amount of monoadduct by crystallization, was shown with X-ray crystallography to have the trans configuration.