Highly Selective Oxidation of Organosilanes to Silanols with Hydrogen Peroxide Catalyzed by a Lacunary Polyoxotungstate
作者:Ryo Ishimoto、Keigo Kamata、Noritaka Mizuno
DOI:10.1002/anie.200904694
日期:2009.11.9
Silanol synthesis: Divacant lacunary polyoxotungstate (nBu4N+)4[γ‐SiW10O34(H2O)2] (I) is an efficient homogeneous catalyst for highlyselectiveoxidation of organosilanes to silanols with 30–60 % aqueous H2O2. Various kinds of silanes 1 containing aryl, alkyl, alkenyl, alkynyl, and alkoxy groups are chemoselectively converted into the corresponding silanols 2 in high yields with only one equivalent
硅烷醇合成:Divacant缺位polyoxotungstate(Ñ卜4 Ñ +)4 [γ-硅钨酸10 ø 34(H 2 O)2 ](我)是一种有效的均相催化剂用于向硅烷醇的有机硅烷的高度选择性氧化用30-60%含水H 2 O 2。含有芳基,烷基,烯基,炔基和烷氧基的各种硅烷1仅以一当量的H 2 O 2水溶液就可以高选择性地化学选择性转化为相应的硅烷醇2。 相对于基板。
Disiloxane Synthesis Based on Silicon–Hydrogen Bond Activation using Gold and Platinum on Carbon in Water or Heavy Water
that disiloxanes were effectively constructed of hydrosilanes catalyzed by gold on carbon in water as the solvent and oxidant in association with the emission of hydrogen gas at room temperature. The present oxidation could proceed via various reaction pathways, such as the hydration of hydrosilane into silanol, dehydrogenative coupling of hydrosilane into disilane, and the subsequent corresponding
We report here an efficient non-aqueous route to symmetrical disiloxanes from their corresponding organosilanes using Ni(COD)2 with 3,4,7,8-tetramethyl-1,10-phenanthroline in air. Our methodology is very simple and high yielding. The reaction mechanism is also proposed.
Hydroxyapatite-supported goldnanoparticles (AuHAP) can act as highlyefficient and reusable catalysts for the oxidation of diverse silanes into silanols in water; this is the first catalytic methodology for the selective synthesis of aliphatic silanols using water under organic-solvent-free conditions.
NMR spectroscopy has been used in a kinetic study of the cleavage of siloxane bonds by hydrogenchloride in dioxane. The cleavages show an induction period which is associated with the autocatalytic effect of the water formed during the reaction. The kinetic behavior can be expressed in terms of a rate law that includes rate contants for cleavage by both dioxane. HCl (k1) and H2O·HCl(k2). The k′1 (k′1