Benzenetellurinic Mixed Anhydrides as Mild Oxidizing Agents

Abstract

Three benzenetellurinic mixed anhydrides, i.e., benzenetellurinyl acetate, trifluoroacetate, and trifluoromethanesulfonate, have been found to be mild oxidizing agents for various substrates such as thiol, phosphine, acyloin, α-hydroxy ester, catechol, hydroquinone, thiourea, and thioamide. The reactions towards the last two substrates are highly chemoselective, depending on both the reagent and substrate.

An unexpected synthesis of 3,5-diaryl-1,2,4-thiadiazoles from thiobenzamides and methyl bromocyanoacetate

“…The reported methods for the preparation of 3,5-diaryl-1,2,4-thiadiazoles from the corresponding thioamides include using different oxidants such as hypervalent iodine, 3 dimethyl sulfoxide (DMSO)/2-chloro-1,3-dimethylimidazolinium chloride (DMC), 8 DMSO/haloiminium salt, 9 DMSO/HCl, 7 methanesulfonic acid derivative with benzenetellurinic acid, 10 and telluroxide or selenoxide. 11 Other more complicated methods are also reported: from the corresponding oxathiazolone, 12 benzenecarboximidamide and diethyl azodicarboxylate, 13 or from 1,2,4-oxathiazoles and Lewis acid.…”

Triphenylbismuth Dichloride‐Mediated Conversion of Thioamides to Nitriles

“…It is worth mentioning that the Ph 3 BiCl 2 ‐mediated process is selective as the reaction stopped at the dehydrosulfurization stage with no further reaction towards dimeric thiadiazoles. The latter could have been generated in situ by condensation of the produced nitriles with the starting thioamides, as previously observed by others …”

CuBr-Catalysed Oxidative Desulfurisation of Thiobenzamides

“…From Table 1, CuBr was chosen as the best catalyst. Then a series of solvents were examined (Table 1, entries [12][13][14][15][16]. It was showed that the reaction gave the product with 89% yield when it was performed in ClCH 2 CH 2 Cl (Table 1, entry 7).…”