With hydrogen telluride

Hydrogen telluride, H2Te, generated in situ by the hydrolysis of aluminium telluride, reduces aldehydes and ketones to the corresponding alcohols. In the presence of deuterium oxide, deuterated derivatives are formed. 

Reduction ofbenzaldehyde with Al2Te/D20 (typicalprocedure) DgO (0.22 mL, 12 mmol) is added at -78°C to a suspension of AlgToj (0.876 g, 2 mmol) in THF (10 mL) containing benzaldehyde (0.106 g, 1 mmol) with vigorous stirring. The temperature is raised to 0°C 

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In the reduction of imines and enamines with hydrogen telluride and sodium hydrogen telluride, hydrolysis leading to primary amines and carbonyl compounds is frequently competitive with the reduction. This undesired side reaction is minimized by the addition of triethylamine, in the case of hydrogen telluride. ... 

Digermylcarbodiimides reacted at 20° with hydrogen telluride forming digermyl tellurium compounds5. 

An alternative route to telluronocarboxylic acid amides starts with thionoamides that are converted by methyl iodide to (methylthio)organomethyleneiminium iodides. The iminium iodides react with hydrogen telluride at below — 40° to give telluronoamides. 

Sodium hydrogen telluride, (NaTeH), prepared in situ from the reaction of tellurium powder with an aqueous ethanol solution of sodium borohydride, is an effective reducing reagent for many functionalities, such as azide, sulfoxide, disulfide, activated C=C bonds, nitroxide, and so forth. Water is a convenient solvent for these transformations.28 A variety of functional groups including aldehydes, ketones, olefins, nitroxides, and azides are also reduced by sodium hypophosphite buffer solution.29... 

With Teflarfum.—When tellurium is heated to 400° C. in hydrogen, the elements combine, forming hydrogen telluride —... 

Sodium hydrogen telluride is prepared by reduction of tellurium with NaBH4 under several conditions. The original procedure uses ethanol as the solvent, adding, after complete reduction of the tellurium, an appropriate amount of acetic acid (see Section 4.1.2, ref. 10 Section 4.1.7, ref. 29). 

The title reagent (prepared by the reaction of sodium hydrogen telluride with chlorotriph-enylstannane) reacts easily with the more active halides such as benzyl bromides whereas common halides need to be activated by cesium fluoride. 

Organyl tellurols are very unstable compounds owing to their extreme sensitivity to oxygen, giving the corresponding ditellurides. The first short-chain alkyltellurols (C1-C4) have been isolated as yellow liquids with an obnoxious odour, from the reaction of aluminium telluride and hydrogen telluride, respectively, with alcohols and aUcyl bromides. Aryltellurols seem not to have been isolated. As shown in Sections 3.1.3.2 and 3.2.2, aryl tellurolates are... 

Control of the pH to within the 6-7 range has been shown to be important in the reduction of imines with sodium hydrogen telluride. At a higher pH (10-11) no reduction occurs. ... 

Good yields of secondary amines are achieved using both the methods in the reactions of aromatic and aliphatic aldehydes as well as of diaUcyl ketones and cycloalkanones with aliphatic and alicyclic amines (and ammonia). Anilines give low yields, but when 2 equiv is used in the sodium hydrogen telluride method, the yields are improved. In the reaction of ammonia with aldehydes, symmetrical secondary amines are obtained, whereas glu-taraldehyde and amines lead to N-substituted piperidines. 

The reducing power of sodium hydrogen telluride towards nitro compounds is dependent on their structure. Unhindered nitrobenzenes are reduced to azoxybenzenes whereas sterically hindered nitrobenzenes are reduced to anilines by simple stirring with 5 mol equiv of the reagent at room temperature for 1 h. 

The reduction of nitro- and dinitroalkanes with sodium hydrogen telluride gives, respectively, diazenes (dimers of nitrosoalkenes) and olefins.- ... 

Reductive opening of oxiranes with sodium hydrogen telluride and sodium telluride... 

Sodium hydrogen telluride reacts with epoxides, in accordance with an S 2 displacement, giving rise to telluro-alcohols. These products are useful intermediates since they are easily converted into the corresponding alcohols and ketones by treatment with nickel boride followed by oxidation (reaction (a)) or to alkenes via the corresponding tosylates (reaction b)). ... 

Otherwise, the same products can be obtained by a Knovenagel-type reaction between )3-cyanosulphones and aromatic aldehydes in the presence of sodium telluride (behaving as a base). This result is consistent with the above-formulated desulphonylation of an intermediate a-alkylidene )3-cyanosulphone at the expense of the sodium hydrogen telluride formed during the reaction. 

By treating a quaternary a-nitrosulphone with sodium hydrogen telluride, the sulphonyl group is displaced preferentially to the nitro group, as illustrated in the example. ... 

Common esters such as alkyl and benzyl carboxylates are easily dealkylated by sodium hydrogen telluride, sodium telluride and sodium ditelluride in DMF. In accordance with a typical S 2 displacement at the aUcoxy group carbon, methyl, ethyl and benzyl esters react smoothly. The nucleophilicity of the reagents is enhanced by the polar aprotic solvent, and the reactivity decreases with higher alkoxy chains due to steric hindrance (e.g. 

Phenacyl esters, easily prepared from carboxylic salts and phenacyl bromide nnder phase transfer catalysis, regenerate the original carboxylic acid by treatment with sodinm hydrogen telluride in DMF. ... 

The allyl group, a less familiar protective group for carboxylic acids, can be easily removed from esters by treatment with sodium hydrogen telluride. In contrast to the preceding methods, ethanol has been employed as the solvent. 

Hydrogen telluride is prepared by the reaction of aluminum telluride, Al2Te3 with hydrochloric acid ... 

These compounds have only been studied on the trace scale. An ether soluble polonium dibenzyl is reported (80, 118) to be formed by the action of dimethylphenylbenzy 1-ammonium chloride on sodium polonide/telluride mixtures in water saturated with hydrogen. The dimethyl was prepared in the same way, but with dimethyl sulfate (118) and may also be formed in... 

Metal tellurides for semiconductors are made by direct melting, melting with excess tellurium and volatilizing the excess under reduced pressure, passing tellurium vapor in an inert gas carrier over a heated metal, and high temperature reduction of oxy compounds with hydrogen or ammonia. 

Elemental tellurium and the stable tellurides of heavy nonferrous metals are relatively inert and do not represent a significant health hazard (43—47). Other, more reactive tellurides, including soluble and volatile tellurium compounds such as hydrogen telluride [7783-09-7] > tellurium hexafluoride [7783-80-4], and alkyl tellurides, should be handled with caution. Some of these materials can enter the body by absorption through the skin or by inhalation and ingestion of dust or fumes. No serious consequences or deaths have been reported in workers exposed to tellurium and its compounds in industry (48). 

At high temperatures tellurium combines directly, but only to a small extent, with hydrogen, forming hydrogen telluride.1... 

The method of Bruylants and Desmet 8 was similar to the foregoing. Tellurium prepared from hydrogen telluride was treated with nitric acid and the resulting dioxide separated by evaporation, calcined, and... 

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