ISSN:
1042-7163
Schlagwort(e):
Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The addition of n equiv of MesNHLi (n = 1, 2, 3, 4) and m equiv of 12-crown-4 (m = 0.1, 1, 2, 3, 4) to (RsiCl2)2 (R = Mesityl; t-Butyl) in THF at -78°C resulted in higher yields and improved selectivities of cyclodisilazanes and azadisilacyclopropanes. The reaction of 2 equiv of MesNDLi with (MesSiCl2)2 (I) yielded cis-2-chloro-1,2,3,4-tetramestylcyclodisilazane (2a) with 95% Si—H deuteration. 2a was quantitatively chlorinated with retention of stereochemistry by N-chlorosuccinimide to give the cis dichlorocyclodisilazane (3). Variable-temperature 1H NMR studies from -70°C to 25°C in d8-THF were performed on 1, 2a, 2b, and 3. 1 exhibited little variation throughout the temperature range, whereas 2a, 2b, and 3 showed several rotational isomers. trans-2,3-Bis(mesitylamino)-1,2,3-trimesitylazadisilacyclopropane was shown to isomerize to the cis isomer in the presence of n-BuLi or MesNHLi. The molecular structures of 1 and 3 were determined by X-ray crystallography. Compound 1 crystallized in the monoclinic space group P21/c, with cell parameters a = 16.599(2) Å b = 14.633(2) Å, c = 16.945(2) Å, β = 92.044(13)°, V = 4113.1(8) Å3, Z = 8, d (calcd) = 1.409 g/cm3, and R = 6.88%. Compound 3 ° C6H6 crystallized in the orthorhombic space group Pbca, with cell parameters a = 17.906(4) Å, b = 13.918(3) Å, c = 31.700(6) Å, V = 7900(3) Å3, Z = 8, d (calcd) = 1.194 g/cm3, and R = 7.52%.
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hc.520050304
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