Telluride-assisted sulphenylation and sulphonylation reactions

These two classes of compounds can be prepared by treating diphenyl disulphide and aryl sulphonyl chlorides with sodium telluride followed, respectively, by a-halocarbonyl compounds and alkyl halides. 

These methods involve the polarity reversal of the formerly electrophilic thio reagents, giving the thiolate and sulphinate anions through an electron transfer from the 

Ar = p-Me, p-BrCgH4, 1-naphthyl, 2-naphthyl RX = alkyl bromide and iodides, PhCH2CI 

0-diethyl phosphorotellurolates can be employed instead of sodium telluride, the alkylation occurring even with a-withdrawing group-substimted halides.  

Alkyl aryl sulphones (typical procedure). Method A. A solution of NajTe (prepared by heating a mixture of Te (0.13 g, 1 mmol), Rongalite (0.79 g, 5 mmol) and aqueous 1 M NaOH (15 mL)) is added dropwise to a stirred solution of TsCl (1 mmol) and BzEtjN+CF (0.022 g, 0.1 mmol) in THF (10 mL) at room temperature under Nj. An instantaneous reaction occurs and the colour of the mixture changes to deep black. After stirring for 5 min. 

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