Benzenetellurinic anhydride

Mixed anhydrides such as benzenetellurinyl acetate (PhTe(O)OAc), benzenetellurinyl trifluoroacetate (PhTe(0)OCOCF3) and benzenetellurinyl trifluoromethanesulphonate (PhTe(0)0S02CF3), prepared by reacting benzenetellurinic anhydride with acetic anhydride, trifluoroacetic anhydride and trifluoromethane-sulphonic anhydride, respectively, have been recognized as valuable oxidizing reagents, in some cases superior to the parent benzenetellurinic anhydrides. ... 

Olefins are diacetoxylated by benzenetellurinic anhydride in boiling acetic acid. ... 

Diacetoxylation of olefins with benzenetellurinic anhydride (typical procedure) To a solution of (PhTe0)20 (0.95 g, 2.1 mmol) in dry HOAc (15 mL) is added styrene (0.208 g, 2.0 mmol) in HOAc (4 mL) and 98% H2SO4 (0.020 g, 0.2 mmol) in HOAc (1 mL). The mixture is gently refluxed for 24 h, which turns red with deposition of a small amount of elemental tellurium. After removal of tellurium (0.071 g, 0.56 mmol) by fdtration, the solvent is evaporated, the residue extracted with ether and the ether extract dried (MgS04). Chromatography on Si02 gives the v/c-diacetate (0.363 g (82%)) and 1-phenylethyl acetate (0.029 g (9%)). 

Cyclotelluroetherification of allylphenol (typicalprocedure) To a solution of phenyltel-lurinyl acetate (1.1 mmol) (prepared in situ by treatment of benzenetellurinic anhydride (0.252 g, 0.55 mmol) with AC2O (0.056 g, 0.55 mmol) in CHCI3 (6 mL) under reflux for 30 min) is added, after cooling, 2-aUylphenol (0.134 g, 1.0 mmol) in CHCI3 (2 mL) and... 

Benzenetellurinyl trifluoroacetate, QFFTeOCOCF, (1), is prepared by reaction of benzenetellurinic anhydride with trifluoroacetic anhydride.1... 

Benzenetellurinyl Acetate5 To a suspension of 0.457 g (1.0 mmol) of benzenetellurinic anhydride in 10 ml chloroform are added 0.112 g (1.1 mmol) of acetic anhydride under an atmosphere of nitrogen. The mixture is refluxed for 30 min. When all the solid has disappeared, the solution is concentrated under reduced pressure. The residue is recrystallized from benzene/hexane. The colorless, hygroscopic crystals melted at 150-152" in a sealed tube yield 100%. 

Phenyl tellurium tribromide was quantitatively transformed to benzenetellurinic anhydride upon treatment with 10% aqueous sodium hydroxide in tetrahydrofuran at 20° for 12 hours3. 

Benzenetellurinic Anhydride A mixture of 2.04 g (5.0 mmol) of diphenyl ditellurium, 0.15 g 2HT—75 (mixture of dialkyldimethylammonium chlorides), 38 ml tetrahydrofuran, and 38 ml 50% aqueous sodium hydroxide is vigorously stirred in an open beaker. After 3 h of stirring, the initially dark-red mixture has... 

BF3-etherate followed by allyltrimethylsilane in 1,2-dichloroethane added to a soln. of benzenetellurinyl trifluoroacetate (generated from benzenetellurinic anhydride and trifluoroacetic anhydride) in the same solvent, the mixture stirred at room temp, for 1 h, treated with p-chloroaniline, then stirring continued at 65° for 6 h N-allyl-p-... 

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