- Synthesis of alkoxybenzylmethylsilanes and polybenzylmethylsiloxane polymers on their basis
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An efficient solvent-free procedure for the preparation of alkoxybenzylmethylsilanes by organomagnesium synthesis was developed. The reaction conditions gave the high yields of the target products. A number of benzylmethylsiloxane polymers was synthesized by polycondensation of alkoxybenzylmethylsilanes in anhydrous acetic acid. The products obtained can become a good alternative to phenylsiloxanes in some practical applications.
- Milenin,Kalinina,Gorodov,Vasilenko,Buzin,Muzafarov
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p. 2498 - 2504
(2016/09/28)
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- Mild partial deoxygenation of esters catalyzed by an oxazolinylborate-coordinated rhodium silylene
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An electrophilic, coordinatively unsaturated rhodium complex supported by borate-linked oxazoline, oxazoline-coordinated silylene, and N-heterocyclic carbene donors [{κ3-N,Si,C-PhB(OxMe2)(OxMe2SiHPh)ImMes}Rh(H)CO][HB(C6F5)3] (2, OxMe2 = 4,4-dimethyl-2-oxazoline; ImMes = 1-mesitylimidazole) is synthesized from the neutral rhodium silyl {PhB(OxMe2)2ImMes}RhH(SiH2Ph)CO (1) and B(C6F5)3. The unusual oxazoline-coordinated silylene structure in 2 is proposed to form by rearrangement of an unobserved isomeric cationic rhodium silylene species [{PhB(OxMe2)2ImMes}RhH(SiHPh)CO][HB(C6F5)3] generated by H abstraction. Complex 2 catalyzes reductions of organic carbonyl compounds with silanes to give hydrosilylation products or deoxygenation products. The pathway to these reactions is primarily influenced by the degree of substitution of the organosilane. Reactions with primary silanes give deoxygenation of esters to ethers, amides to amines, and ketones and aldehydes to hydrocarbons, whereas tertiary silanes react to give 1,2-hydrosilylation of the carbonyl functionality. In contrast, the strong Lewis acid B(C6F5)3 catalyzes the complete deoxygenation of carbonyl compounds to hydrocarbons with PhSiH3 as the reducing agent.
- Xu, Songchen,Boschen, Jeffery S.,Biswas, Abhranil,Kobayashi, Takeshi,Pruski, Marek,Windus, Theresa L.,Sadow, Aaron D.
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p. 15897 - 15904
(2015/09/15)
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- Remarkably robust monomeric alkylperoxyzinc compounds from tris(oxazolinyl)boratozinc alkyls and O2
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Metal alkylperoxides are remarkable, highly effective, yet often thermally unstable, oxidants that may react through a number of possible pathways including O-O homolytic cleavage, M-O homolytic cleavage, nucleophilic O-atom transfer, and electrophilic O-atom transfer. Here we describe a series of zinc alkyl compounds of the type ToMZnR (ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate; R = Et, n-C3H 7, i-C3H7, t-Bu) that react with O2 at 25 °C to form isolable monomeric alkylperoxides ToMZnOOR in quantitative yield. The series of zinc alkylperoxides is crystallographically characterized, and the structures show systematic variations in the Zn-O-O angle and O-O distances. The observed rate law for the reaction of ToMZnEt (2) and O2 is consistent with a radical chain mechanism, where the rate-limiting SH2 step involves the interaction of ?OOR and ToMZnR. In contrast, ToMZnH and ToMZnMe are unchanged even to 120 °C under 100 psi of O 2 and in the presence of active radical chains (e.g., ?OOEt). This class of zinc alkylperoxides is unusually thermally robust, in that the compounds are unchanged after heating at 120 °C in solution for several days. Yet, these compounds are reactive as oxidants with phosphines. Additionally, an unusual alkylperoxy group transfer to organosilanes affords ToMZnH and ROOSiR3'.
- Mukherjee, Debabrata,Ellern, Arkady,Sadow, Aaron D.
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experimental part
p. 13018 - 13026
(2012/10/08)
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- THERMAL REACTIONS OF BENZOSILACYCLOBUTENES WITH ALCOHOLS
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In the thermal reaction with alcohols, benzosilacyclobutenes underwent both benzylsilicon and aryl-silicon bond rupture to yield (dialkyl)alkoxy-o-tolylsilanes and (dialkyl)-alkoxybenzylsilanes, respectively.
- Kang, Kyung-Tae,Seo, Hee-Chan,Kim, Kwang-Nam
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p. 4761 - 4762
(2007/10/02)
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