Dialkyl selenides

Tetraalkylammonium borohydrides react with elemental selenium and tellurium to form the symmetrical dialkyl selenides and tellurides [44]. Diphenyl selenide yields the alkyl phenyl selenides. 

The dialkyl selenides are colourless strongly refractive oils of obnoxious odour and low boiling-point. In the presence of moisture they tend... 

Complex Compounds of Platinum and Palladium Halides with Dialkyl Selenides.6... 

When dialkyl selenides are treated with nitric acid they are converted into dialkyl selenium dinitrates, R2Se(N03)2, and these with hydrochloric and hydrobromic acids give dichlorides and dibromides, respectively, potassium iodide forming the di-iodide. The dimethyl compounds crystallise well, but the diethyl derivatives are all described as liquids. When selenium and methyl iodide are heated together at 180° C., the di-iodide of trimethyl selenium iodide results. Combination takes place directly between diethyl selenide and ethyl iodide, giving triethyl selenium iodide, which is stable in air, and converted by moist silver oxide into the hydroxide, which is a powerful base, giving salts on treatment with acids. 

The production of selenophene via the thermolysis of dialkyl selenides in the presence of acetylene was explored <2004RJ0290>. Thermal reactions leading to selenophenes and thiophenes have also been reviewed <2000CHE1>. 

Reduction of elemental selenium with Sml2 leads to the selective formation of Se and Se depending on the reaction stoichiometry, similar to the reduction with NaBH4 and hydrazine (Sects. 2.2.2 and 2.2.3). These inorganic dianions react with alkyl bromides to produce dialkyl selenides and diselenides, respectively, in excellent yields (Scheme 15) [17a]. 

Yanada et al. synthesized a new selenide exchange resin 78 by treatment of borohydride exchange resin (BER) with selenium. The subsequent reaction with alkyl halides or tosylates gives dialkyl selenides 79 selectively in a high yield (Scheme 50) [95]. 

Alkyl aryl and dialkyl selenides, aside from the parent compounds methyl phenyl selenide (Scheme 13, a) and trifluoromethylphenyl methyl selenide (Scheme 13, b), cannot be easily metallated. It was expected that the extra stabilization provided by the cyclopropyl group would be sufficient to permit the metallation of cyclopropyl selenides, but that proved not to be the case. ... 

Carbodiimides. Selcni oxidation completes the synth Dialkyl selenides. Wli methanol at room temperaiur RSeR are obtained (6 exampii or foul-smelling RSeH. 

Dialkyl selenides. When Se is reduced with borohydride exchange resin in methanol at room temperature and addition of alkyl halides or tosylates, good yields of RSeR are obtained (6 examples, 84-98%). This procedure avoids formation of toxic I Se or foul-smelling RSeH. 

Dialkyl selenides. The reaction of trialkylboranes with an equimolar amount of selenium dioxide suspended in THF leads to dialkyl selenides as the major... 

Dialkyl selemdes dialkyi diselenides. Reaction of selenium with 2.1 equiv. of this hydride in THF gives a suspension of milky white lithium selenide. On addition of alkyl halides dialkyl selenides are formed in 60-95% yield (equation I). 

Dialkyl diselenides, 310 Di-f-alkyl ethers, 441 Dialkyl selenides, 310... 

Reductions. Elemental selenium can be reduced using sodium hydride. The resulting sodium diselenide (Na2Se2) can be used to prepare dialkyl selenides (eq 55). Similarly, elemental sulfur can be reduced to diatomic sulfur by sodium hydride in the presence of a phase transfer catalyst,... 

The formation of t-butoxy-dialkylselenonium chlorides from dialkyl selenides and Bu OCI has been studied. ... 

A number of halogenated methanes and 2,2,2-trifluoroethanol have been found to exert solvent effects up to 48 Hz on the Se chemical shifts of some dialkyl selenides and diselenides (R-Se-R and R-Se-Se-R R = Me, Et and Pf) these were interpreted in terms of an intermolecular polarizability concept (88Lut). 

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