Silicon-hydrogen bond synthesis

Hydrosilylation, the addition of a silicon-hydrogen bond to multiple bonds, is a valuable laboratory and industrial process in the synthesis of organosilicon compounds. The addition to carbon-carbon multiple bonds can be accomplished as a radical process initiated by ultraviolet (UV) light, y irradiation, or peroxides. Since the discovery in the 1950s that chloroplatinic acid is a good catalyst to promote the addition, metal-catalyzed transformations have become the commonly used hydrosi-... 

Certain reactions of silyl—alkali metal compounds, such as coupling of (CH3) (C6H5)3 BSiLi with appropriate chlorosilanes (51) and hydrolysis of [(CH3)3Si]3SiLi (63), lead to the formation of organopolysilanes with the silicon-hydrogen bond. There have been few reports of such synthesis. 

The reaction of tetramethylsilane with fluorine led to the isolation of several, partially fluorine-substituted tetramethylsilanes (see Tables VII-IX), and preservation of over 80% of the silicon-carbon bonds in the initial, tetramethylsilane reactant. The stability of many of the partially fluorinated germanes and silanes (some are stable to over 100°C) is very surprising, for the possibility of elimination of hydrogen fluoride is obvious. Indeed, before the first reported synthesis (12) of... 

The hydrogen bond interaction of OH groups at the surface is determined by the Si-O-Si ring size, and its opening degree, the number of hydroxyls per silicon site, and the surface curvature. The concentration of OH groups at the surface is approximately 2-5 x 1018 OH/m2, and it is found to be almost independent of the synthesis conditions of porous silica [162],... 

Attempts to isolate 204 and 205 provide only the silanols 200 or 32. The sign and magnitude of the Si-NMR chemical shift is indicative of tetracoordinate silicon species [77], yet it does not match any of the previously synthesized tetracoordinate silanes. The possibility that 204 and 205 are oligomers was eliminated by a Si-NMR crossover experiment [30]. Structural possibilities that remained for 204 and 205 required that they be monomeric and tetracoordinate. The tetrabutylam-monium silyloxide salt ( )-206 and a TBAF hydrogen bond complex ( )-205 were proposed (Figure 7.2). The silyloxide salt is ruled out by independent synthesis of the corresponding tetramethylammonium salt, the Si-NMR chemical shift (—26.23 ppm) of which does not correspond to that for 206. Because compound... 

---