110. Interaction of alcohols with silicon tetrachloride

Abstract

Octan-Z-ol and silicon tetrachloride formed chlorosilanes and tetra-2octyloxysilane in proportions depending on the proportion of silicon tetrachloride, but none of the chloride, RCl. (+)-1-Phenylethanol formed considerably racemised chloride, RCl, under similar conditions. Whereas hydrogen chloride had no action on tetra-2-octyloxysilane, it rapidly dealkylated the corresponding (+ ) -1-phenylethyl compound, the chloride formed being considerably racemised. In the presence of py-ridine a number of tetraalkyloxysilanes have been obtained in excellent yield. These and other data are now available for comparison with those from a study of phosphorus trichloride-alcohol systems, and provide a contribution to the eventual elucidation of mechanism.

Double role of polyethylene glycol in the microwaves-assisted non-hydrolytic synthesis of nanometric TiO2: oxygen source and stabilizing agent

“…This is usually the main mechanism when the involved species are primary alcohol (as PEG's terminal hydroxyl groups can be considered) and a strong nucleophile as in this case. A comparable behavior was also observed by Gerrard and Woodhead (1951) and Mutin and Vioux (2009) for a similar reaction between alcohols and SiCl 4 . This second mechanism can be schematized as follows: Indeed, the S N 1 mechanism is usually observed for ternary, benzyl, and allyl alcohols (Vioux 1997) that are able to provide stable carbocations.…”

Mechanistic Aspects in the Formation, Growth and Surface Functionalization of Metal Oxide Nanoparticles in Organic Solvents

“…[142][143][144] The reactiono fp rimary and secondary alcohols with SiCl 4 gave tetraalkoxysilanes, while the same reactionw ith tertiary and benzylic alcohols yielded silica and the corresponding alkyl halides. [54,145] Li and co-workers highlightedt he synthesis of TiO 2 , Fe 2 O 3 and ZnO from the corresponding metal chlorides and benzyla lcohol from the perspective of aS N 1r eaction mechanism. [143] The carbon-oxygen bond in benzyl alcohol was easily broken, because the formation of ab enzyl carbocation is favored due to the possibility to effectively distribute the charge onto the benzyl group via p-p conjugation.T he benzyl carbocation then underwent nucleophilic substitution with chloride ions to form benzyl chloride and am etal hydroxide, which further reacted to the metal oxide.T he authors also mentioned an interesting side reaction at high temperatures, namely the polymerization of benzyla lcohol in the presence of metal chlorides.…”

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

“…[42] Amazingly, already these authors proposed an aqueous and nonaqueous route to silica gels, assuming that they might show "different absorptive power". Although many other groups continued to work on this topic, [43][44][45] including peculiar but interesting examples like the conversion of chlorosilanes to oligosiloxanes and of silicon and titanium tetrachloride to the respective oxide by refluxing in dimethylformamide, [46] the reaction of silicon tetrachloride with benzaldehyde [47] and organic ethers, [48] or the synthesis of silica-sodalite from nonaqueous systems, [49] it was only at the beginning of the nineties that these concepts became popular to a larger scientific community. [50,51] Emanating from the preparation of monolithic silica gels from the reaction of silicon tetrachloride with oxygen donors such as alkoxides, aldehydes, and ethers, [52] the Corriu and Vioux groups were particularly active in the field of nonhydrolytic sol-gel chemistry.…”