- A novel route to pentacoordinated organylsilanes and -germanes
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New convenient methods of sila- and germatranes synthesis from ethoxy- and tetraorganylsilanes and -germanes have been elaborated. The reaction of ethoxysilanes with boratrane in the presence of catalytic amounts of metal alcoholates has been investigated. Dimethylformamide (DMF) as a solvent and NaOEt as a catalyst used instead of xylene and Al(Oi-Pr)3 were found to give better yields. The possibility of using alkoxy-, aminosilanes, tetraethoxygermane and even tetraorganylsilanes in this reaction leading to the corresponding atranes with good yields has been demonstrated. Triethanolamine in the presence of catalytic amounts of base or CsF easily substitutes furyl-, dihydrofuryl-, dihydropyranyl- and thienyl groups in tris- and tetraheterylsilanes, leading to organylsilatranes with good to excellent yields.
- Gevorgyan, Vladimir,Borisova, Larisa,Vyater, Armand,Ryabova, Victoria,Lukevics, Edmunds
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p. 149 - 155
(2007/10/03)
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- MEDIUM-SIZED SILICON-CONTAINING RINGS. IV. SILOCANE-SILATRANE TRANSFORMATIONS
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We have discovered an intramolecular condensation of trimethylsilyl ethers of silocines with a phenyl substituent on the silicon atom that leads to the corresponding silatranes.For the preparation of N-(hydroxyethy) derivatives of silocines we have, for the first time, used the cyclosilylation of triethanolamine with a bis(dialkylamino)silane.It was found that in the exothermic reaction of trialkoxyalkylsilanes with N-(hydroxyethyl) derivatives of silocines and their trimethylsilyl ethers the yield of silatranes is only slighthly dependent on the nature of the substituent both in the silocines and in the alkoxysilanes.
- D'yakov, V. M.,Makarov, A. F.
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p. 291 - 294
(2007/10/02)
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- DIRECT TRANSFER OF ALIPHATIC AND AROMATIC SUBSTITUENTS FROM ORGANOSILATRANES TO MERCURY(II) SPECIES
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The relative reaction rates of several silatranes (derivatives of 2,8,9-trioxa-5-aza-1-silatricyclo1,5>undecane) and HgCl2 in acetone-d6 to yield the corresponding organomercury compound are of the order of e.g., 5 * 10-1 1 mol-1 sec-1 or slightly less, a rate that is unexpectedly high compared to the essentially inert parent organotrialkoxysilanes.Thus, the apical Si-C bond of the silatrane is extraordinarily susceptible to direct electrophilic attack by mercury(II).The rates decrease in the order CH2=CH, C6H5, p-ClC6H4 > CH3 > CH3CH2, CH3CH2CH2 > C6H11, ClCH2, Cl2CH, CH3CH2O.The effects of varying the solvent and the counterions are noted, and the probable mechanism is discussed.
- Nies, J. Dirk,Bellama, Jon M.,Ben-Zvi, Nava
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p. 315 - 320
(2007/10/02)
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