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 1 H and 13 C NMR spectroscopy. By reaction on activated alumina adducts were converted into (E)-and (Z)-(5-thianthreniumyl)dienes, all of which were characterized with 1 H and 13 C NMR spectroscopy. The monoadduct (6a) of 1,4-hexadiene and the bisadduct 7a were characterized with X-ray crystallography.

Addition of thianthrene cation radical to non-conjugated dienes—Part II: Addition to two double bonds

“…Similar reactions were carried out with 1,4-cyclohexadiene and 1,5-cyclooctadiene, each of which gave only a bisadduct. 16 (X = PF − 6 ) (from Th •+ PF − 6 and 1,4-cyclohexadiene in a ratio of 4:1 or from Th •+ PF − 6 with excess of 1,4-cyclohexadiene), mp 135-136 • C (dec); 1 …”

“…X-Ray crystallography was performed as described in Part I [1]. The CCDC deposition number for 16 is 286931.…”

“…In this context, the additions to only one of a diene's double bonds which we report in Part I [1] are comparatively simple. The additions we report now in Part II, in which a molar excess of Th •+ was used, show that comparatively still uncomplicated additions occur to both double bonds of the α, ω-acyclic but not to the cyclic dienes.…”

“…In the preceding publication (Part I) [1], we have described the addition of thianthrene cation radical (Th •+ ) to one of the double bonds of some non-conjugated dienes. Under the conditions of reaction, namely, a large molar excess of diene over Th •+ or even a molar ratio diene: Th •+ of 1:2, addition occurred to only one of the diene's double bonds.…”

Addition of the Phenoxathiin Cation Radical to Alkenes and Nonconjugated Dienes. Formation of (E)- and (Z)-(10-Phenoxathiiniumyl)alkenes and (E)- and (Z)-(10-Phenoxathiiniumyl)dienes on Basic Alumina

“…Numerous reactions of the thianthrene cation radical (Th •+ ) have been reported since it was first characterized with ESR spectroscopy. − Most of those reactions were with nucleophiles and with electron transfer agents. − With alkynes 8,9 and alkenes, however, additions of Th •+ to the unsaturated bonds occur, among which the detailed characteristics of additions to alkenes and cycloalkenes have been established only in more recent years. − Two types of adducts are formed, namely, a monoadduct ( 2 ) having a cyclic structure, and a bisadduct ( 3 ). They are formed in a way that retains the configuration of the alkene, that is, from a stereospecifically formed cyclic cation radical ( 1 ), as shown in Scheme .…”