Organotelluriums reactions with

Reaction of organotellurium compounds with quinones (typical procedure, 2-benzyl-l, 4-benzoquinone) A solution of benzyl p-methylphenyl telluride (111 mg, 0.36 mmol) and 1,4-benzoquinone (78.0 mg, 0.72 mmol) in benzene (0.6 mL) in a Pyrex tube was irradiated with a 200 W high-pressure mercury lamp at 100°C for 1 h. After the solvent was removed under reduced pressure, the crude mixture was purified by flash chromatography (silica gel 6.4 g elution with 5% ethyl acetate in hexane) to give the product in 57% yield. 

The most synthetically useful reaction of nucleophilic tellurium consists in the reaction of organotellurium halides with organometallics. This reaction was systematically studied for the first time by Petragnani several years ago.80 In recent years, it has been used to prepare a number of tellurium-containing organic substrates. The general route is shown in Scheme 57. 

Xenon halides reactions with organic radicals 5.9 organoboranes 5.9 organotelluriums 5.9... 

The reactions of organotellurium compound with organolithium compounds give the ate complex as shown in eq. (3.34). 

Dimethoxybiphenyl (247) has been rnade by the reaction with Raney nickel of an organotellurium complex (248) obtained by heating anisole with tellurium chloride. 

It is worth mentioning that z ncate-da could also take part in tellurium-zinc exchange [12]. Transmetalation is an important synthetic application of organotellurium compoxmds. When n-butyl 2-pyridyl-telluride 24 was treated with Li2ZnMe4 in THF at 0°C and then with benzaldehyde, the corresponding alcohol could be obtained in 81% yield (Eq. 14), while the reaction with LiZnMe3 did not proceed at all even xmder harsher conditions. 

Organotellurium(IV) azides with two or three azido groups attached to tellurium, R2Te(N3)2 (R=alkyl, Ph, C6F5) and RTe(N3)3 (R=alkyl, 2,4,6-Me3C6H2), are prepared by the reaction of organotellurium(IV) fluorides with trimethylsilyl azide.188... 

Several new types of Ge-O-bonded species have appeared and some new methods for the formation of such bonds have been described. Germoxanes can be obtained via reaction of triorganobromogermanes with oxygen in the presence of organotellurium compounds (Equation (127)).164 The germapropadiene 4 reacts with alcohols to provide alkoxides 70 (Equation (128)) or benzaldehyde to yield a 1,2-oxagermetane 71 via a [2 + 2]-addition (Equation (129)), which exhibits unusual thermal stability for an unencumbered oxagermetane.16... 

Organochalcogen(II) compounds, 100-102 Organochalcogen(IV) compounds, 100-102 Organoselenium compounds dehalogenation reactions, 96 electrochemical reduction, 113-117 haloperoxidase-like activity, 108-113 with odd number of ligands, 100-102 one-electron oxidation, 117-118 oxidation of thiols, 102-106 redox reactions, 79-80 thioperoxidase-like activity, 108-113 Organotellurium compounds... 

In 1996, Detty and coworkers reported on the oxidation of sodium halides to positive halogens with hydrogen peroxide in two-phase systems of dichloromethane and pH 6 phosphate buffer, catalyzed by organotellurium catalysts 237 (Scheme 181)545. Mixtures of 1,2-dihalocyclohexane (238) and 2-halocyclohexanol (239) were formed upon reaction of the positive halogens formed with cyclohexene. From the three tellurium catalysts... 

Reaction of tellurium tetrachloride with substrates bearing an internal nucleophile 20 gives rise to cyclic products.66,67 In some cases, the organotellurium trichlorides 21 obtained in this way are reduced to the corresponding organotellurolates 22 followed by alkylation to give tellurides 23 (Scheme 6).47... 

The reaction of tellurium tetrachloride with olefins as a route to organotellurium trichlorides is, however, not general. In some cases, the yields are very poor or unidentified products are formed.5... 

The transformation of a carbon-tellurium bond into a carbon-halogen bond can be performed with several types of organotellurium trihalide or diorganotellurium dihalide compounds, in which the organic group is an alkyl, an alkenyl or an aryl substituent. A variety of reaction conditions have been described to realize these transformations, which belong to three main types ... 

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