5575-49-5Relevant articles and documents
Selective Formation of Alkoxychlorosilanes and Organotrialkoxysilane with Four Different Substituents by Intermolecular Exchange Reaction
Komata, Yuma,Yoshikawa, Masashi,Tamura, Yasuhiro,Wada, Hiroaki,Shimojima, Atsushi,Kuroda, Kazuyuki
supporting information, p. 3225 - 3233 (2016/11/29)
Alkoxychlorosilanes are scientifically and industrially important toward preparing silicone and silica as well as preparation of siloxane-based nanomaterials by stepwise reactions of Si?OR (R=alkyl) and Si?Cl groups. Intermolecular exchange of alkoxy and chloro groups between alkoxysilanes and chlorosilanes (functional group exchange reaction) provides an efficient and environmentally benign route to alkoxychlorosilanes. BiCl3 as a Lewis acid catalyst can promote the functional group exchange reactions more efficiently than conventional acid catalysts. Higher reactivity has been observed for chlorosilanes with smaller numbers of Si?CH3 groups and for alkoxysilanes with larger numbers of Si?CH3 groups. The reaction mechanism is proposed and selective syntheses of alkoxychlorosilanes are demonstrated. These findings also enable us to synthesize an organotrialkoxysilane with four different substituents.
N-(DIMETHYLALKOXYSILYLMETHYL)- AND N-(DIMETHYLARYLOXYSILYLMETHYL)LACTAMS
Artamkina, O. B.,Kramarova, E. P.,Shipov, A. G.,Baukov, Yu. I.,Macharashvili, A. A.,et al.
, p. 1590 - 1597 (2007/10/02)
A comparison is made of conditions and preparative possibilities of synthesizing Si-substituted N-(dimethylsilylmethyl)lactams with oxygen-containing substituents (alkoxides, aryloxides, benzoates, and triflates) by several methods: by reactions of N-(dimethylchlorosilylmethyl)lactams with sodium alkoxides and with alcohols in the presence of triethylamine, by exchange reactions with trimethylsilyl derivatives of alcohols, phenols, benzoic and trifluoromethylsulfonic acids, and also by a one-pot technique using lactam, dimethylchloromethylchlorosilane, and triethylamine with subsequent addition to the reaction mixture of the alcohol and triethylamine. In the reaction of N-(dimethylchlorosilylmethyl)lactams with sodium alkoxides, concurrently with the replacement of halogen by an alkoxy group the Si-C bond is split to form N-methyllactams, which can also be prepared by the reaction of the initial chlorides with potassium hydroxide. According to IR spectroscopy, intramolecular O->Si coordination is observed in aryloxy-, benzoyloxy-, and trifluoromethylsulfonyloxy derivatives of N-(dimethylsilylmethyl)lactams, whereas the corresponding alkoxy derivatives lack this interaction. The structure of 1-(dimethylsilylmethyl)-2-pyrrolidone phenoxide and benzoate, 1-(dimethylpentafluorophenoxysilylmethyl)perhydro-2-azepinone, and 1-(dimethyltrifluoromethylsulfonyloxymethyl)-2-piperidone was studied by x-ray structural analysis. The lengths of the axial (C=)O->Si and Si-O bonds are, respectively, 2.367 and 1.711(2) Angstroem for the first, 2.228 and 1.711(2) Angstroem for the second, 2.078 and 1.787(2) Angstroem for the third, and 1.753 and 2.785(2) Angstroem for the fourth compound. Variations in the bond lengths are due to the properties of the Si-substituent and to the size of the lactam rings. The ease of formation of the Si-substituted N-(dimethylsilylmethyl)lactams with oxygen-containing substituents via the exchange reaction of N-(dimethylchloromethyl)lactams with the corresponding trimethylsiloxy derivatives correlates with the strength of the silicon-oxygen coordination in the reaction products.
CLEAVAGE OF THE SILOXANE BOND IN POLY(DIALKYLSILOXANES) BY ALKYL ORTHOTITANATES
Fridman, L. I.,Suvorov, A. L.,Khrustaleva, E. A.,Kodess, M. I.,Abramova, V. I.
, p. 813 - 816 (2007/10/02)
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