Reductive detelluration of tellurides by triphenyltin hydride

Phenyl aUcyl tellurides are reduced by triphenyltin hydride under mild conditions, giving the corresponding hydrocarbons in high yields. An excess of the reagent is necessary (2-2.8 equiv), but a radical initiator need not be employed. 

The corresponding tellurium dichlorides can also be employed as starting materials, and although a greater excess of the reagent is needed (3.5 equiv) the reactions are faster. These reductive cleavages can be rationalized through a radical mechanism. 

Since the starting tellurides are easily prepared from alkyl hahdes or epoxides by displacement with tellurolate anions (see Section 3.1.3.2), the overall sequence constitutes a mild reduction of these substrates and is advantageous over the analogous reductions of selenides, which require more severe conditions (a temperature of 120°C is necessary). 

The example in sequence, where a carbonyl function remains untouched, clearly demonstrates the value of this method. 

In a typical experiment, n-dodecyl phenyl telluride (0.160 g, 0.42 mmol) in benzene (1 mL) is treated with PhjSnH (0.361 g, 1.03 mmol) during 5 h at room temperature, furnishing n-dodecane (0.080 g (87%)). 

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