- Transition metal-catalyzed hydrosilylation of polybutadiene – The effect of substituents at silicon on efficiency of silylfunctionalization process
-
Herein we present the results of our studies on the hydrosilylation of polybutadiene with alkyl, aryl and alkoxysilanes in the presence of platinum and rhodium complexes. In order to select the most efficient catalytic system, which, under optimal conditions, would smoothly promote incorporation of the above-mentioned organosilicon modifiers into polybutadienes of various structures via hydrosilylation, the real-time in-situ FT-IR spectroscopy was used. The silyl-functionalized polymeric products were characterized by NMR analysis and gel permeation chromatography (GPC). It was demonstrated that the stereo-electronic properties of substituents directly bonded to the HSi moiety play a crucial role in formation of desired products, as well as affect the time required for total conversion of organosilicon reagents. Partially modified polymers containing pendant alkoxy groups can be applied as additives to rubber compounds to enhance dispersion of inorganic particles in the polymer matrix, as well as to promote formation of organic-inorganic hybrid materials.
- Januszewski, Rafa?,Kownacki, Ireneusz,Maciejewski, Hieronim,Marciniec, Bogdan
-
-
Read Online
- Strontium Hydride Cations Supported by a Large NNNNN Type Macrocycle: Synthesis, Structure, and Hydrofunctionalization Catalysis
-
The use of the 15-membered NNNNN macrocyclic ligand Me5PACP (Me5PACP = 1,4,7,10,13-pentamethyl-1,4,7,10,13-pentaazacyclopentadecane) allowed the isolation of two cationic strontium hydride complexes by hydrogenolysis of benzyl precursors. Treatment of sparingly soluble [(Me5PACP)Sr(CH2Ph)2] with dihydrogen gave free Me5PACP, toluene, and oligomeric strontium hydride [SrH2]n, while hydrogenolysis in the presence of 1 equiv of the benzyl cation [(Me5PACP)Sr(CH2Ph)][B(C6H3-3,5-Me2)4] enabled isolation of the thermally unstable trihydride cation [(Me5PACP)2Sr2(μ-H)3][B(C6H3-3,5-Me2)4]. When the benzyl cation [(Me5PACP)Sr(CH2Ph)][BAr4]2 (Ar = C6H3-3,5-Me2 or C6H4-4-nBu) was reacted with dihydrogen or n-octylsilane, dihydride complexes [(Me5PACP)2Sr2(μ-H)2][BAr4]2 containing a dinuclear core bridged by two hydride ligands were obtained. The soluble dihydride complex [(Me5PACP)2Sr2(μ-H)2][B(C6H4-4-nBu)4]2 was tested in olefin hydrogenation and hydrosilylation catalysis. Kinetic analyses for [(Me5PACP)2Sr2(μ-H)2]2+ showed lower catalytic activity as compared to that of the isostructural calcium homologue [(Me5PACP)2Ca2(μ-H)2]2+. This is explained by a shift in the monomer-dimer equilibrium which precedes the catalytic cycle.
- Carpentier, Ambre,H?llerhage, Thomas,Maron, Laurent,Okuda, Jun,Spaniol, Thomas P.
-
p. 3309 - 3316
(2022/02/23)
-
- PROCESS FOR FUNCTIONALIZATION OF ORGANO-METAL COMPOUNDS WITH SILYL-BASED FUNCTIONALIZATION AGENTS AND SILYL-FUNCTIONALIZED COMPOUNDS PREPARED THEREBY
-
A process to functionalized organo-metal compounds with silyl-based electrophiles. The process includes combining an organo-metal compound, a silyl-based functionalization agent, and an optional solvent. Functionalized silanes and silyl-terminated polyolefins can be prepared by this process.
- -
-
Paragraph 0070; 0072
(2019/10/15)
-
- Catalytic Reduction of Alkoxysilanes with Borane Using a Metallocene-Type Yttrium Complex
-
The catalytic reduction of alkoxysilanes with the borane HBpin (pin = pinacolato) was achieved using a metallocene-type yttrium complex as a catalyst precursor. Mechanistic study supported the pivotal role of the rigid metallocene structure of the catalyst, which bears two bulky n5-C5Me4SiMe3 ligands, in suppressing the coordination of the side product MeOBpin that is generated during the reaction.
- Aoyagi, Keiya,Matsumoto, Kazuhiro,Shimada, Shigeru,Sato, Kazuhiko,Nakajima, Yumiko
-
supporting information
p. 210 - 212
(2019/02/01)
-
- Synthesis of hydrosilanes: Via Lewis-base-catalysed reduction of alkoxy silanes with NaBH4
-
Hydrosilanes were synthesized by reduction of alkoxy silanes with BH3 in the presence of hexamethylphosphoric triamide (HMPA) as a Lewis-base catalyst. The reaction was also achieved using an inexpensive and easily handled hydride source NaBH4, which reacted with EtBr as a sacrificial reagent to form BH3in situ.
- Aoyagi, Keiya,Ohmori, Yu,Inomata, Koya,Matsumoto, Kazuhiro,Shimada, Shigeru,Sato, Kazuhiko,Nakajima, Yumiko
-
supporting information
p. 5859 - 5862
(2019/05/27)
-
- MANUFACTURING METHOD OF HYDROSILANE
-
PROBLEM TO BE SOLVED: To provide a manufacturing method of hydrosilane capable of manufacturing hydrosilane at good efficiency. SOLUTION: Hydrosilane having a structure represented by the following formula (b) can be manufactured at good efficiency by reacting borohydride and hydrocarbon having a halogen atom and 1 to 20 carbon atoms, and/or a metal salt and further reacting the reaction product with alkoxysilane having a structure represented by the following formula (a) in the presence of triamide phosphate. In the formula (a), R represents a hydrocarbon group having 1 to 20 carbon atoms. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
- -
-
Paragraph 0034-0042
(2019/07/13)
-
- Hydrosilane synthesis via catalytic hydrogenolysis of halosilanes using a metal-ligand bifunctional iridium catalyst
-
Hydrogenolysis of various halosilanes was catalysed by iridium amido complexes to produce hydrosilanes. Selective monohydrogenolysis of di- and trichlorosilanes similarly proceeded, resulting in the formation of chlorohydrosilanes (R2SiHCl or RSiHCl2) as synthetically important building blocks for various organosilicon compounds. A mechanistic study supported the in-situ formation of an iridium hydride species as a key intermediate, which could transfer the hydride to the silicon atom through a metal–ligand bifunctional mechanism. One-pot hydrotrimethylsilylation of olefins was achieved via successive hydrogenolysis and hydrosilylation reactions starting from Me3SiCl.
- Beppu, Teruo,Sakamoto, Kei,Nakajima, Yumiko,Matsumoto, Kazuhiro,Sato, Kazuhiko,Shimada, Shigeru
-
-
- METHOD FOR PRODUCING HYDROSILANE USING BORANE REDUCTION
-
PROBLEM TO BE SOLVED: To provide a method for producing hydrosilane that can efficiently produce the hydrosilane. SOLUTION: In the presence of a Lewis base, a silane having a structure represented by a formula (a) reacts with a borane complex or diborane, to efficiently produce hydrosilane (in the formula (a), R1 is a C1 to C20 hydrocarbon group, or a C1 to C10 acyl group). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
- -
-
Paragraph 0021; 0023
(2018/07/28)
-
- METHOD OF PRODUCING ORGANIC SILICON COMPOUND
-
PROBLEM TO BE SOLVED: To provide a method of producing an organic silicon compound efficiently by improving a catalyst for hydrosilylation reactions of alkenes and alkynes. SOLUTION: An organic silicon compound can be produced efficiently by using an iron
- -
-
Paragraph 0045-0046
(2017/03/23)
-
- Hydrosilanes are not always reducing agents for carbonyl compounds but can also induce dehydration: A ruthenium-catalyzed conversion of primary amides to nitriles
-
A practical procedure for production of nitriles is offered by the triruthenium carbonyl cluster catalyzed dehydration of primary carboxamides with hydrosilanes under neutral conditions. This is the first example that a transition-metal-catalyzed activation of Si-H bonds does not lead to the reduction of carbonyl compounds but to dehydration. Possible mechanisms for the dehydration is discussed on the basis of NMR spectroscopic detection of intermediary species. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Hanada, Shiori,Motoyama, Yukihiro,Nagashima, Hideo
-
supporting information; experimental part
p. 4097 - 4100
(2009/04/10)
-