124-70-9Relevant articles and documents
Reaction of bis(trifluoromethyl)amino-oxyl with alkylchlorosilanes and allyldichloro(methyl)silane and of perfluoro-2,5-diazahexane 2,5-dioxyl with vinylsilanes and hydrolysis of the products
Tipping, Anthony E.,Yadav, Rajendraprasad B.
, p. 1 - 10 (1994)
Treatment of the silanes MeSiHCl2, Me2SiHCl and EtSiMeCl2 with the oxyl (CF3)2NO(.) (1) gives the substitution products (CF3)2NOSiMeCl2 (4) and (CF3)2NOSiMe2Cl (5), and a mixture of (CF3)2NOCHMeSiMeCl2 (8) and (CF3)2NOCH2CH2SiMeCl2 (9) (ratio 20:37), respectively, while the silane EtSiMe2Cl affords mainly the ester (CF3)2NO2CMe (7).Attack of oxyl 1 on the silane CH2=CHCH2SiMeCl2 results in both allylic substitution and addition to give the compounds CH2=CHCH(SiMeCl2)ON(CF3)2 (14) and (CF3)2NOCH2CH(CH2SiMeCl2)ON(CF3)2 (15) (ratio 56:40).Reaction of the dioxyl (.)ON(CF3)CF2CF2N(CF3)O(.) (2) with the vinylsilanes CH2=CHSiX3 (X3 = Me3, Cl3, MeCl2) gives mainly 1:1 copolymers n (17), although the cyclic 1:1 adduct (18) is also formed in low yield.Hydrolysis of the silanes 15, (CF3)2NOCH2CH(SiMeCl2)ON(CF3)2 (19a) and (CF3)2NOCH2CH(SiCl3)ON(CF3)2 (19b) affords the corresponding polysiloxanes 24 and 25, and the polysilsesquioxane 26, respectively; the polymers 25 and 26 undergo rearrangement of the type -CH(Si)ON(CF3)2 --> -CH(OSi)N(CF3)2 on storage.The 1:1 copolymers 17b (X3 = MeCl2) and 17c (X3 = Cl3) are also hydrolysed to the corresponding siloxane and silsesquioxane polymers.In contrast, hydrolysis of the compounds 4,5 and (CF3)2NOCH2CH(OSiX3)N(CF3)2 (20a; X3 = MeCl2) and (20b; X3 = Cl3) results in Si-O bond cleavage.
SELECTIVE PREPARATION OF VINYL- AND ETHYL-FUNCTIONALIZED CHLOROSILANES
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Paragraph 0094-0096, (2021/06/26)
A method of preparing an organosilicon compound via selective silylation of ethylene is disclosed. The method comprises reacting via silylation (A) a hydridochlorosilane compound and (B) ethylene in the presence of (C) a catalyst, thereby preparing the organosilicon compound. The silylation may be selectively conducted as a dehydrogenative coupling to prepare the organosilicon compound as a vinylchlorosilane compound, or as a hydrosilylation to prepare the organosilicon compound as an ethylchlorosilane compound. The catalyst (C) comprises a Ru(0) complex, and may be recycled for use in subsequent silylation reactions without purification. The organosilicon compound prepared according to the method is also disclosed.
Silyl and σ-silane ruthenium complexes: Chloride substituent effects on the catalysed silylation of ethylene
Lachaize, Sebastien,Vendier, Laure,Sabo-Etienne, Sylviane
experimental part, p. 8492 - 8500 (2011/01/08)
Silylation of ethylene by the chlorosilanes HSiMe2Cl and HSiMeCl2 was catalysed by the bis(dihydrogen) complex RuH 2(η2-H2)2(PCy3) 2 (1). Dehydrogenative silylation leading to the formation of the corresponding vinylsilanes was in competition with hydrosilylation. The rate and selectivity of the reactions were influenced by the number of chloro substituents and the ethylene pressure. A comparative mechanistic study was performed in toluene-d8 with the two chlorosilanes. Reaction of 1 with an excess of HSiMe2Cl (10 equiv.) produced the σ-silane complexes RuH2(η2-H2)(η2- HSiMe2Cl)(PCy3)2 (2Me2Cl), RuH 2(η2-HSiMe2Cl)2(PCy 3)2 (3Me2Cl) and the silyl complex RuCl(SiMe2Cl)(η2-H2)(PCy3) 2 (4Me2Cl), all characterised by multinuclear NMR spectroscopy. Complexes 2Me2Cl and 3Me2Cl adopt a cis configuration for the two bulky phosphine ligands as a result of stabilising SISHA (Secondary Interactions between Silicon and Hydrogen Atoms) interactions. Complex 4Me2Cl resulted from the stoichiometric reaction of HSiMe2Cl with 1 producing RuHCl(η2-H 2)(PCy3)2in situ which further reacted with evolution of H2 and formation of 4Me2Cl. When reacting 1 with 10 equiv. of HSiMeCl2, the corresponding complexes 3MeCl 2 and 4MeCl2 were detected as well as traces of 2MeCl 2. The reactivity toward ethylene was then examined. Under catalytic conditions (excess silane in toluene-d8, ethylene atmosphere) only two compounds could be characterised: free PCy3 and the new (η6-aryl)(disilyl) complexes of the general formula Ru(η6-C6D5CD3)(SiMe 3-nCln)2(PCy3) (6Me 3-nCln-d8, n = 1,2). The X-ray structure of 6MeCl2 was obtained on a single-crystal at 160 K. When only 2 equiv. of HSiMe2Cl were added, the ethylene(silyl) complex RuH(SiMe 2Cl)(C2H4)(PCy3)2 (7Me2Cl) was obtained in addition to the organic products resulting from catalytic hydrogenation, hydrosilylation and dehydrogenative silylation, i.e. C2H6 (major one), C2H3SiMe 2Cl and C2H5SiMe2Cl. In the case of 2 equiv. of HSiMeCl2, upon ethylene addition, 7MeCl2 was formed in minority compared to a new disilyl complex Ru(SiMeCl2) 2(PCy3)2 (8MeCl2) characterised by NMR spectroscopy and X-ray diffraction on a single crystal at 160 K. In 8MeCl2, a formal 14-electron species, stabilisation through two agostic C-H bonds of the cyclohexyl groups was ascertained by DFT calculations.
