Thioketones dissolving metals

There is apparently only one report of the dissolving metal reduction of thioketones thiobenzophe-none (107) has been reduced with excess Na-THF to give dianion (108), which on acidification gave thiol (109). The thiol was not isolated, but was oxidized with iodine to give the corresponding disulfide in 65% overall yield. The mechanism of the reduction is suggested to be the sequential addition of two electrons to the thiocarbonyl, which was confirmed by electron spin resonance spectroscopy studies of the intermediate thioketyl, and trapping dianion (108) with a variety of electrophiles. ... 

Metal Complexes.—Minoura and Tsuboi have studied the reactivity of thiobenzophenone towards alkali metals. When dissolved in THF under an atmosphere of nitrogen, the thioketone reacted with one equivalent of alkali metal to form the rather unreactive radical anion (72). With more than two equivalents of alkali metal, however, the very reactive dianion complex (73) was formed according to the equilibrium (72) -I- Na (73). The structure of (73) was established mainly on the basis of the reactions with electrophilic reagents. Thus the reactivity of (73) closely parallels that of the thiobenzaldehyde dianion (12). ... 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ , ]

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