Ion radicals. 39. Reactions of 10-methyl- and 10-phenylphenothiazine cation radical perchlorates with ketones

Ion radicals. 43. Addition of thianthrene and phenoxathiin cation radicals to alkenes and alkynes

“…These follow, for example, eq 10, and although the mechanism of reaction has not been established, it is thought that the cation radical adds to the enolic form of the ketone (eq 11). 16 Loss of a proton from the adduct 13 is thought to occur either before, after, or during the electron transfer step from which the parent sulfide (eq 10) is obtained. The adducts 11 and 13 then are similar in form but enjoy different fates.…”

Electron Transfer Initiated Reactions: Bond Formation and Bond Dissociation

“…While the reaction leads to the formation of keto-thianthrenium salts in the presence of methyl ketones, in the presence of alkenes dithianthrenium salts form as a result of the addition of a thianthreniun radical cation to each side of the double bond. The thianthrene radical cation is readily formed through oxidation either homogeneously in solution [153][154][155][156][157][158][159][160][161][162][163][164][165][166][167][168] or electrochemically. 169 Thianthrenium salts have been obtained using both methods, 162,163,165 although bisulfonium salts were only isolated through electrolysis.…”

Adducts of Thianthrene- and Phenoxathiin Cation Radical Tetrafluoroborates to 1-Alkynes. Structures and Formation of 1-(5-Thianthreniumyl)- and 1-(10-Phenoxathiiniumyl)alkynes on Alumina Leading to α-Ketoylides and α-Ketols

“…Confirmation of the nature of 2b was also obtained by protonation with HBF 4 -etherate, which converted 2b into 5-[(2-keto)hexyl]thianthrenium tetrafluoroborate ( 2d ), eq 1. The formation of 5-[(β-keto)alkyl]thianthrenium perchlorates by reactions of ketones with Th •+ ClO 4 - was reported from this laboratory about 30 years ago. − Reactions were deduced then and later to occur by addition of Th •+ to the enolic form of the ketone. In those cases, reactions with methyl ketones, MeC(O)R, in which the group R had an enolizable H atom, e.g., 2-butanone, occurred necessarily at that enolizable position rather than at the methyl group.…”