- Synthesis of multinuclear Rh(I) complexes bearing triazolylidenes and their application in C-C and c-Si bond forming reactions
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Multidentate carbene ligands are valuable frameworks for the preparation of carbene complexes displaying higher nuclearity. In the present work, we report the synthesis of a series of mono- to tetra-[Rh(COD)I] complexes (3a- d) supported by mesoionic triazol-5-ylidenes. The general synthetic procedure involves the one step reaction of the appropriate triazolium (2a-d) salt in the presence of KHMDS and stoiquiometric amounts of the rhodium(I) precursor. Treatment of complexes 3a-d with an excess of carbon monoxide allows for the quantitative preparation of complexes 4a-d featuring a [Rh(CO)2I] fragment used for the detemination of the donor properties of the new triazolylidene ligands. All complexes have been fully characterized by means of 1H and 13C NMR spectroscopy, melting point, elemental analysis, and in the case of complex 3a, by X-ray crystallography. Comparison of the catalytic activity of the new rhodium complexes in C-C and C-Si bond forming processes demonstrate the enhanced performance of the tetranuclear species suggesting the possibility of strong cooperative effects in these multinuclear complexes.
- Mendoza-Espinosa, Daniel,Rendón-Nava, David,Vásquez-Pérez, Jose M.,Sandoval-Chávez, Cesar I.,Alvarez-Hernández, Alejandro
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p. 3961 - 3971
(2020/12/01)
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- Cycloaddition of a Cyclic (Alkyl)(amino)silylene and a Disilyne Providing a 3-Aminocyclotrisilene
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Despite the notable progress in the chemistry of cycloaddition reactions of silylenes toward unsaturated bonds, such reactions toward a SiSi triple bond remain unknown. Herein, we report [1 + 2] cycloaddition of a cyclic (alkyl)(amino)silylene (1) and a dialkyldisilyne (2) to form a 3-aminocyclotrisilene (3). Cyclotrisilene 3 adopts a slightly cis-bent geometry with a relatively long Si=Si double bond in the solid state, suggesting a π(Si=Si)-σ*(Si-N) interaction. Thermolysis of 3 regenerated silylene 1, which was trapped as Et3SiH and toluene adducts at high temperatures.
- Koike, Taichi,Honda, Shunya,Ishida, Shintaro,Iwamoto, Takeaki
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supporting information
p. 4149 - 4152
(2020/01/31)
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- Method for synthesizing trimethyl(1-(trimethylsilyl)vinyl)silane
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A method for synthesizing trimethyl(1-(trimethylsilyl)vinyl)silane belongs to the technical field of battery additives. The method comprises the following steps: 1, adding lithium methide to tris(trimethylsilyl)methane used as a raw material, introducing a formaldehyde gas, and carrying out a reaction at a temperature of 0-50 DEG C under a 1-5 kg formaldehyde pressure to obtain crude trimethyl(1-(trimethylsilyl)vinyl)silane; and 2, adding the crude trimethyl(1-(trimethylsilyl)vinyl)silane into a polymerization inhibitor, and carrying out molecular distillation at a temperature of 50-85 DEG C under a vacuum degree of 0.5-0.7 Pa to obtain refined trimethyl(1-(trimethylsilyl)vinyl)silane. The method has the advantages of simplicity, mild and stable reaction conditions, and high yield and highpurity of the product.
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Paragraph 0023-0026; 0027-0030; 0031-0038; 0039-0042
(2018/06/15)
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- New catalytic route to (E)-β-silyl-α,β-unsaturated ketones
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(E)-β-(Silyl)-α,β-unsaturated ketones have been efficiently synthesized via one-pot sequential ruthenium-catalyzed silylative homo-coupling of dimethylphenylvinylsilane or trimethylvinylsilane (Marciniec coupling) and rhodium-catalyzed selective desilylative acylation (Narasaka coupling) of (E)-1,2-bis(silyl)ethenes with acid anhydrides. Synthetic strategy relies on the selective mono-substitution of the bis(silyl)ethene intermediate.
- Pawlu?, Piotr
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body text
p. 10 - 13
(2012/06/04)
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- A new selective approach to 1,1-bis(silyl)-2-arylethenes and 1,1-bis(silyl)-1,3-butadienes via sequential silylative coupling-heck coupling reactions
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A novel selective route to 1,1-bis(silyl)-1-alkenes has been developed. Sequential one-pot silylative coupling exo-cyclization of 1,2- bis(dimethylvinylsiloxy)ethane followed by the reaction with Grignard reagents leads to the desired 1,1-bis(silyl)ethene
- Pawluc, Piotr,Hreczycho, Grzegorz,Marciniec, Bogdan
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p. 8676 - 8679
(2007/10/03)
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- A facile synthesis of 1,1-bis(silyl)ethenes
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(Chemical Equation Presented). Symmetrical 1,1-bis(silyl)ethenes have been easily prepared via ruthenium complex-catalyzed silylative coupling cyclization of 1,2-bis(dimethylvinylsiloxy)ethane to give 2,2,4,4-tetramethyl-3-methylene-1, 5-dioxa-2,4-disilac
- Pawluc, Piotr,Marciniec, Bogdan,Hreczycho, Grzegorz,Gaczewska, Beata,Itami, Yujiro
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p. 370 - 372
(2007/10/03)
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- Reactions of gem-dibromo compounds with trialkylmagnesate reagents to yield alkylated organomagnesium compounds
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The reaction of gem-dibromocyclopropanes 5 with nBu3MgLi affords butylated cyclopropylmagnesium species that can be trapped with various electrophiles. The reaction of dibromomethylsilanes 12 requires the addition of a catalytic amount of CuCN · 2 LiCl for smooth migration of the alkyl groups. The resultant α-silylpentylmagnesium compounds 16 react with electrophiles, such as acyl chlorides or α, β-unsaturated ketones to afford α- or γ-silyl ketones, respectively. Treatment of dibromodisilylmethanes with Me3MgLi yields 1-bromo- 1,1-disilylethanes 25 that can be converted into 1,1-disilylethenes 29 by dehydrobromination.
- Inoue, Atsushi,Kondo, Junichi,Shinokubo, Hiroshi,Oshima, Koichiro
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p. 1730 - 1740
(2007/10/03)
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- A facile synthesis of 1,1-disilylethenes via Me3MgLi-induced monomethylation of dibromodisilylmethanes
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Lithium trimethylmagnesate (Me3MgLi) induces monomethylation of dibromodisilylmethanes in excellent yields. Subsequent dehydrobromination of the resulting 1-bromo-1,1-disilylethanes with DBU affords 1,1-disilylethenes in good yields.
- Inoue, Atsushi,Kondo, Junichi,Shinokubo, Hiroshi,Oshima, Koichiro
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p. 956 - 957
(2007/10/03)
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- Synthesis of bis(trimethylsilyl) ketone and reactions with organometallic compounds
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Bis(trimethylsilyl) ketone (1) has been prepared by hydrolysis of the α-chloro ether 3a on silica gel. Reaction of ketone 1 with organoaluminium, organomagnesium and organolithium compounds gave addition products and/or bis(trimethylsilyl)methanol (5). Acta Chemica Scandinavica 1998.
- Pan, Ming,Benneche, Tore
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p. 1141 - 1143
(2007/10/03)
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- Ruthenium-catalyzed ring-closing reaction of α,ω-bis(vinylsilyl) compounds via a silyl transfer mechanism
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Compounds having a vinyldimethylsilyl group at both terminals have been successfully cyclized by ruthenium hydride catalysts to give selectively disilacycles of various ring sizes via a metathetical reaction, i.e. ethene elimination from the two terminal vinyl groups, not involving metallocarbene-metallacyclobutane type intermediates.
- Mise, Takaya,Takaguchi, Yutaka,Umemiya, Takeshi,Shimizu, Shoichi,Wakatsuki, Yasuo
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p. 699 - 700
(2007/10/03)
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- Insertion of Vinylsilane into the Ruthenium-Silicon-Bond - Direct Evidence for the Non-metallacarbene Mechanism of Silylalkene Disproportionation
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The reversible insertion of the vinylsilane molecule into the Ru-Si bond occurs in two different ways to give E-1,2-bis(silyl)ethene and 1,1-bis(silyl)ethene which, in combination with the previous experiments by Wakatsuki et al., provides convincing evidence for a non-metallacarbene mechanism of silylalkene disproportionation.
- Marciniec, Bogdan,Pietraszuk, Cezary
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p. 2003 - 2004
(2007/10/02)
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- Metathesis of silicon-containing olefins. X. Metathesis of vinyltrimethylsilane catalyzed by ruthenium complexes
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Self metathesis of vinyltrimethylsilane in the presence of an oxygenated benzene solution of RuCl2(PPh3)3 and RuH2(PPh3)4 follows an unusual course and yields two products, 1,2-bis(silyl)ethene (E) and 1,1-bis(silyl)ethene, with products of dimerization, namely 1,4-bis(silyl)butenes-2 (E + Z) and butenylsilanes as well as hexamethyldisiloxane.Gaseous ethylene and traces of ethane were also detected.It is proposed that vinylsilane is inserted into the Ru-Si bond (via ortho-metallation of the ruthenium triphenylphosphine complex) in competition with pathways involving metal-carbene species.Complexes of ruthenium containing no phenylphosphine give stereoselectively only the (E)-product of metathesis (even in the absence of oxygen and hydrosilane co-catalysts) accompanied by traces of the same by-products. Key words: Silicon; Ruthenium; Metathesis; Olefin
- Marciniec, Bogdan,Pietraszuk, Cezary,Foltynowicz, Zenon
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- Anionic rearrangement of the germyl and silyl groups in dimethylammonium N-methylide and related compounds
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The reaction of - and trimethylammonium iodides (3a and 3c) with n-butyllithium gives N-- and N-dimethylamines (5a and 5b), respectively.A mixture of 5a and 5b is obtained from the reaction of trimethylammonium iodide (3b).Use of lithium diisopropylamide in place of n-butyllithium gives the corresponding 1,1-bis(trimethylelemento)ethylenes (8a, 8b, and 8c) as the main products.
- Inoue, Sumie,Urayama, Shin'ichi,Sugiura, Hiroyo,Sato, Yoshiro
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- The Reactions of Tris(trimethylsilyl)methyl-lithium with Some Carbon Electrophiles
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Tris(trimethylsilyl)methyl-lithium (1) reacts with non-enolisable aldehydes, ketones, and acid chlorides, and with some epoxides, with the formation of carbon-carbon bonds.This method of preparing functionalized silanes is limited by the readiness with which (1) abstracts a proton, if one is available, rather than attack at carbon.In the reaction with epoxides, the product alkoxide can transfer a silyl group from carbon to oxygen, and in one case the intermediate so formed reacts to give a cyclopropane (32) in what is a homologue of the Peterson reaction.The 1,4-transfer of a silyl group occurs in other systems when the resulting carbanion is stabilised by such groups as phenylthio and diphenylphosphinoyl.
- Fleming, Ian,Floyd, Christopher D.
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p. 969 - 976
(2007/10/02)
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