Aerobic oxidation of thiols is efficiently catalyzed by diaryl tellurides such as bis(4-methoxyphenyl) telluride under photosensitized conditions to give the corresponding disulfides in good to excellent yields. In this catalytic system, the tellurone oligomer, produced by the reaction of a telluride with singlet oxygen, is assumed to be the active species and is capable of oxidizing 4 equiv of a thiol.

Efficient access to highly enantioselective isotope-labeled serine, cysteine, and alanine for stereoarray isotope labeling (SAIL) is described.

Diorganotellurides efficiently catalyze the aerobic oxidation of organosilanes under photosensitized conditions to afford the corresponding silanols in excellent yield.

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Aerobic oxygenation of diaryl tellurides under photosensitized conditions is investigated. Unlike Ph(2)S and Ph(2)Se, reaction of diaryl tellurides with singlet oxygen proceeds smoothly to yield diaryl telluroxides and the corresponding tellurones. The product distribution is largely affected by the substrate and the reaction conditions. In particular, the photooxygenation of bulky diaryl tellurides principally produces tellurones. The results of a series of trapping experiments suggest that the diaryl telluroxides can capture transient intermediates such as Me(2)S(+)OO(-) and Ar(2)Te(+)OO(-), generated in the singlet oxygen oxidation of chalcogenides, to yield diaryl tellurones, and therefore it may be the most potent precursors of the tellurones.

Bis(2,4,6-triisopropylphenyl) tellurone (Tip(2)TeO(2)) was prepared, fully characterized by spectroscopic and X-ray crystallographic analyses, as well as theoretical calculations, and found to be an effective oxidizing agent that was capable of converting alcohols into carbonyl compounds under mild reaction conditions.

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