Organo tellurides

A different approach to unsymmetrical diorganyl tellurides, in which an electrophilic tellurium species is used, involves the nucleophilic attack of organomagnesium or organo-lithium reagents to diorganyl ditellurides. 

Sodium telluride reacts with 1-organo- and l,4-diorgano-l,3-butadyines (prepared in situ by the treatment of the corresponding l,4-dichloro-but-2-yines with NaOH in methanol) to give tellurophenes. ... 

Includes bibliographical references and indexes. Contents v. 1. Primary, secondary, and tertiary phosphines, polyphosphines, and heterocyclic organo-phosphorus(III) compounds—v. 2. Phosphine oxides, sulphides, selenides, and tellurides—v. 3. Phosphonium salts, ylides, and phosphoranes. 

The vinylic substitution by tellurolate anions has not been extensively investigated. It is, however, an efficient method for synthesizing vinylic tellurides of defined stereochemistry. (E)-/3-bromostyrene 79 reacts with organo-tellurolate anions to give ( )-vinylic tellurides 80 (Scheme 49).34,144... 

If unusual vinylic tellurides or vinylic tellurides of defined stereochemistry are required, other vinyl organo-metallics are employed. In recent years, a number of methods of preparing vinylic derivatives of tellurium using organotellurium halides have been developed. 

For methods to prepare acyl organo tellurium compounds from disodium telluride, carboxylic acid chlorides, and alkyl halides, see p. 500. 

Phenylacetylene and sodium telluride combine to produce bis[(Z)-2-phenylethenyl] tellurium3, while phenylacetylene and sodium butanetellurolate3 or sodium benzenetel-lurolate4 yields organo (Z)-2-phenylethenyl telluriums. These vinyl telluriums are cleaved by butyl lithium in tetrahydrofuran at -78° to (Z)-2-phcnylcthenyl lithiums. 

Sodium hydrogen telluride, prepared from tellurium and sodium borohydride in ethanol/acetic acid, reacted with organyloxy-(/m.-butyl )-methylenedimethy1iminium chloride, obtained from A,A-2,2-tetramethylpropionamide and phosgene, to form organo... 

Lithium telluride, prepared from tellurium and lithium triethylborohydride in tetrahydrofuran2, and sodium telluride, obtained from sodium and tellurium in a dipolar, aprotic solvent or from tellurium2,5 and Rongalite in aqueous sodium hydroxide2, reacted with aliphatic2,3,6 and aromatic5 dihalides to produce polymeric organo tellurium compounds. 

Disodium telluride and diacetylenes react in methanol to give tellurophenes. With 1,3-butadiyne, tellurophene is obtained. 1 -Organo-l,3-butadiynes yield 2-organotellurophenes. l,4-Diorgano-l,3-butadiynes produce 2,5-diorganotellurophenes. The yields of these reactions generally do not exceed 50%. 

The reaction between dialkynyl(organo)phosphine oxides and disodium telluride in dimethylformamide/water produced 2,6-dialky l-4-organo-4-oxo-4//-1,4-telluraphos-phorins2. 

Te-Esters of tellurocarboxylic acids were prepared from tellurolates and carboxylic acid chlorides or anhydrides, and from sodium telluride and aroyl chlorides". The following types of 7e-organo tellurocarboxylates have thus far been synthesized ... 

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