Studies of silicon–nitrogen ring formation from tetrachlorodisilanes

✍ Scribed by John L. Shibley; Robert West; Douglas R. Powell; Claire A. Tessier

• Book ID: 102846594
• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 790 KB
• Volume: 5
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.520050304

✦ Synopsis

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 (RSiCl,), ( R = Mesityl; t-Butyl) in THF at -78°C resulted in higher yields and improved selectivities of cycbdisilazanes tznd azadisilacyclopropanes. The reaction of 2 equiv of MesNDLi with (MesSiClJ, (I) yielded cis-2-chloro-l,2,3,4-tetramesitylcyclodisilazane (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 'H NMR studies from -70°C to 25°C in d8-THF were pevformed 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(mesitylarnino)-l,2,3-trimesitylazadisilacycbpropane 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. Conipound 1 crystallized in the monoclinic spacc group P2,/c, wjth cell parametecs a =