β-Amino- and Alkoxy-Substituted Disilanides

Abstract

Our recent study on formal halide adducts of disilenes led to the investigation of the synthesis and properties of β-fluoro- and chlorodisilanides. The reaction of the functionalized neopentasilanes (Me3Si)3SiSiPh2NEt2 and (Me3Si)3SiSiMe2OMe with KOtBu in the presence of 18-crown-6 provided access to structurally related β-alkoxy- and amino-substituted disilanides. The obtained Et2NPh2Si(Me3Si)2SiK·18-crown-6 was converted to a magnesium silanide and further on to Et2NPh2Si(Me3Si)2Si-substituted ziroconocene and hafnocene chlorides. In addition, an example of a silanide containing both Et2NPh2Si and FPh2Si groups was prepared with moderate selectivity. Also, the analogous germanide Et2NPh2Si(Me3Si)2GeK·18-crown-6 could be obtained.

Synthesis and Characterization of Methoxylated Oligosilyl Group 4 Metallocenes

“…NMR data are consistent with the proposed structures, exhibiting one resonance line in the 29 Si NMR spectrum for the three trimethoxysilyl groups and one signal for the quaternary silicon atom (compare Table 1). The quaternary silicon signal for compound 2 shows a significant low-field shift when compared to 3 and 4, whereas the signals for the −Si(OMe) 3 groups adopt only a slight change in the shifts.…”

“…Compound 5 was characterized Table 3. 29 Si NMR Data for 8−11 via EPR spectroscopy and X-ray crystallography. By comparing the crystal structure of 2 and 5, changes in bond lengths and angles were observable.…”

“…The quaternary silicon signal for compound 2 shows a significant low-field shift when compared to 3 and 4, whereas the signals for the −Si(OMe) 3 groups adopt only a slight change in the shifts. By comparison of the 29 Si NMR signals of compounds 1c 34 and 2−4, we found a significant high-field shift for central silicon For 2−4, single crystals suitable for X-ray structure analysis could be grown in n-pentane at −30 °C. The structure of 2 is depicted in Figure 1.…”

“… , In contrast to this, a wide range of oligosilyl-substituted zircono- and hafnocenes are known. Tilley, as well as Marschner and co-workers, have extensively studied these compounds. ,,− …”

Synthesis of Alkoxy‐Substituted Oligosilanes using [β‐(Alkoxy)disilanyl]lithium

“…Oligosilane frameworks were characterized using 29 Si NMR spectroscopy with inverse gated 1 H decoupling mode, and the data are listed in Table 1 [20c,27a,32] . Silicon atom (Si a ) bearing a tert ‐butoxy group resonates at approximately −10 ppm, while the internal silicon atoms (Si b , Si c ) show chemical shifts at approximately −40 ppm.…”