65886-47-7Relevant articles and documents
Evidence for Electron Transfer in Reactions of Thianthrene Cation Radical with Dialkylmercurials
Lochynski, Stanislaw,Shine, Henry J.,Soroka, Miroslaw,Venkatachalam, T. Krishnan
, p. 2702 - 2713 (1990)
Reactions of dialkylmercurials (R2Hg) with thianthrene cation radical perchlorate (Th.+ClO4-) in acetonitrile solution have been studied in quantitative detail.Evidence was obtained from reactions of MeHgR (R = Et, i-Pr, tBu) that reaction begins with electron transfer rather than with electrophilic cleavage of an alkyl-mercury bond.That is, each reaction gave MeHg+ and R., diagnostic of the formation and decomposition of MeHgR.+, rather than 5-methylthianthreniumyl perchlorate (1a), which would have been diagnostic of electrophilic displacement of the least hindered group (Me).The radicals R. either were trapped at the sulfur atom of Th.+ to form a 5-alkylthianthreniumyl perchlorate (Et., 1b) and at the ring positions of Th.+ to form 1- and 2-alkylthianthrenes (Et., i-Pr.) or were oxidized to the cations R+ (Et., i-Pr., and t-Bu.).Products of R+ were obtained, after workup with 4 M aqueous LiCl, as alkene, ROH, RNHCOCH3 and RCl.These reactions had the stoichiometric ratio of reactants 2Th.+ClO4-/MeHgR.Reactions of symmetrical R2Hg sometimes followed this stoichiometry (R = Me, Et, Bu) and led to RHg+ and 5-R-thianthreniumyl perchlorates (1a,b,e).Other R2Hg (R = t-Bu, benzyl, allyl) underwent oxidation by 4 equiv of Th.+ClO4-.Di-tert-butyl- and dibenzylmercury gave products derived entirely from the respective cation, R+.Diallylmercury gave some of the sulfonium product, 5-allylthianthreniumyl perchlorate (1g).None of the reactions with R = i-Pr, t-Bu, and benzyl led to the isolation of a thianthreniumyl perchlorate (i.e., 1c,d,f).Oxidations at the 4:1 molar ratio produced Hg(ClO4)2, which formed a partly insoluble complex (2) with thianthrene having the composition Th3Hg(ClO4)2.This product could be isolated if removed before workup treatment with aqueous 4 M LiCl, which, otherwise caused its decomposition into its components.The complex 2 was also prepared directly from reaction of Th with Hg(ClO4)2 in acetonitrile.Oxidation of benzylmercuric chloride by Th.+ClO4- in methylene chloride solution also occurred quantitatively, giving benzyl chloride, 1- and 2-benzylthianthrene, and a mixture of dibenzylthianthrenes.Oxidation of t-BuHgCl in acetonitrile solution led to a quantitative mixture of isobutene, t-BuOH, and t-BuNHAc.Th.+ClO4- also oxidized metallic Hg to either Hg+ or Hg2+, depending on the amount of oxidant used.
