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Protocols for the synthesis of cage-substituted 1-vinylsilatranes have been developed and updated. The 1-vinylsilatranes with organic substituents attached to silatrane cage were functionalized in ruthenium-catalyzed trans-silylation with olefins, leading to novel styrylsilatranes in high yields. [ABSTRACT FROM AUTHOR]

Bifunctional silsesquioxanes create an attractive group of compounds with a wide range of potential applications, and recently they have gained much interest. They are known to be obtained mainly via hydrosilylation, but we disclose novel synthetic protocols based on different but complementary reactions, i.e., cross-metathesis (CM) and silylative coupling (SC). A series of cubic T8 type silsesquioxane derivatives with a broad scope of styryl substituents were synthesized in a one-pot procedure and characterized by spectroscopic and spectrometric methods. All of the new compounds can be obtained in a one-pot manner, which has an attractive impact on the synthetic procedure, as it is economic in terms of the isolation of intermediate products. Additionally, the methodology disclosed here enables the (E)-stereoselective introduction of styrenes derivative to the cubic T8 type core. The presented compounds can be interesting precursors for a further functionalization that may significantly increase the possibility of their application in the design and synthesis of new functional materials.

Oxide-supported rhodium catalysts with excellent activity in silylative coupling reactions have been developed. Reductive pretreatment of the catalysts in the presence of 0.5 equiv triphenylphosphine under a hydrogen atmosphere enhanced and stabilized the catalytic activity. Of the catalysts examined, ceria-supported rhodium had the highest activity in the homo-coupling of vinylsilanes to bis(silyl)ethenes at 170 °C. A zirconia-supported catalyst selectively gave E-1-aryl-2-silylethenes by cross-coupling of vinylsilanes with styrenes at 130 °C, and a high turnover frequency of >8200 h was achieved at 170 °C. Spectroscopic studies revealed that well-dispersed surface rhodium(I) species predominantly formed on ceria or zirconia were transformed into rhodium hydride species, which are believed to be responsible for the high activity. These catalysts were recyclable without loss of activity, and leaching of rhodium species from the catalysts was not observed. [ABSTRACT FROM AUTHOR]

( E)-β-Iodoenamides and ( E)-β-iodoenimides can be easily obtained from N-vinyl derivatives ( N-vinylamides and N-vinylimides) by ruthenium-catalysed silylative coupling with vinyltrimethylsilane (Marciniec coupling) and subsequent stereospecific silicon-iodine exchange. Bromodesilylation of ( E)-β-silylenimides affords ( E)-β-bromoenimides, while the analogous reactions involving ( E)-β-silylenamides lead to decomposition of substrates. N-Halosuccinimides have been found as the most effective halogenating agents in the step under mild conditions. The ruthenium-catalysed silylation/halodesilylation sequence can be performed in a . Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new versatile one-pot protocol for preparation of functionalized 1,4-disubstituted-1,3-diynes via a highly selective catalytic silylative coupling of vinylsilanes and terminal alkynes occurring via [Ru] catalyzed reaction and/or [Ir] catalyzed reaction of iodosilanes with alkynes followed by desilylative homocoupling sequence is presented. Contrary to existing stoichiometric systems, the catalytic conditions for the copper salt mediated homocoupling of trimethylsilylalkyne were elaborated that are very tolerant to various functional groups. [ABSTRACT FROM AUTHOR]

A series of functionalized dialkenylsilsesquioxanes were obtained by efficient and highly stereoselective silylative coupling and cross-metathesis of divinylsubstituted double-decker silsesquioxanes ( DDSQ-2SiVi) with substituted styrenes and other olefins. Both reactions proceed highly stereoselectively and lead to nearly quantitative formation of E isomers. The optimized reaction conditions for styrene were adopted for successful silylative coupling polycondensation of DDSQ-2SiVi with 1,4-divinylbenzene yielding stereoregular cooligomer containing double-decker (silsesquioxyl-silylene)-vinylene-phenylene units. [ABSTRACT FROM AUTHOR]

Abstract: This work describes very precise and controlled catalytic transformations as useful tools for the synthesis of new trans-π-conjugated molecular and macromolecular organosilicon compounds. Several distyryl-arenes were obtained efficiently via silylative coupling in high yields and with excellent selectivity for new E,E-bis(silyl)arenes. [Copyright &y& Elsevier]

Abstract: Novel trans-stereoregular silylene–carbazolylene–vinylene derivatives (13–15) were synthesized via silylative coupling reaction of 3,6-bis(dimethylvinylsilyl)-N-alkylcarbazole (7–9) catalyzed by ruthenium–hydride complex RuHCl(CO)(PCy3)2 (1). All products were isolated, fully characterized by spectroscopic methods and GPC analyses and their absorption and fluorescence properties were determined. [Copyright &y& Elsevier]

A series of ruthenium complexes (RuCl3 × 3H2O, [C5H5Ru(CH3CN)3]+[PF6]−, [RuCl2(PPh3)3], [RuHCl(CO)(PPh3)3], [RuHCl(CO)(PCy3)2]) immobilized in [bmim][Tf2N] were tested in homocoupling of vinylsilanes (H2C=CHSi(OEt)3, H2C=CHSi(Oi Pr)3, H2C=CHSi(OSiMe3)3, H2C=CHSiMe(OSiMe3)2, and H2C=CHSiPh(OSiMe3)2) performed in a biphasic system. The highest catalytic activity and selectivity of homocoupling product was observed for [RuHCl(CO)(PCy3)2]. The complex [RuHCl(CO)(PCy3)2] immobilized in a variety ionic liquids ([bmim][PF6], [bmim][BF4], [bmim][Tf2N], [bmim][TfO], [bmim][HSO4], [bmim][Cl], [trimim][MeSO4], [NBu3Me][MeSO4], [PBu4][Cl], [bpy][PF6], [bpy][BF4], [bpy][Cl]) exhibits high catalytic activity in homocoupling of H2C=CHSiMe2Ph, H2C=CHSi(OEt)3 and H2C=CHSiMe(OSiMe3)2 and enables high-yield stereoselective synthesis of the corresponding E-1,2-bis(silyl)ethenes. The immobilized complex can be easily recycled up to 12 times in the homocoupling of H2C=CHSiMe2Ph and up to 10 times in the homocoupling of H2C=CHSiMe(OSiMe3)2 without a significant drop in activity and selectivity. Results of a split test indicate that the source of catalytic activity is the catalyst immobilized in ionic liquid phase. [Copyright &y& Elsevier]

Abstract: (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. [Copyright &y& Elsevier]

Abstract: A new regio- and stereoselective synthesis of (E)-N-(2-arylvinyl)phthalimides as well as phthalimide-containing (E,E)-buta-1,3-dienes and (E)-but-1-en-3-ynes has been developed. The one-pot ruthenium-catalyzed silylative coupling/iododesilylation sequence provides (E)-N-(2-iodovinyl)phthalimide 1, which undergoes palladium-catalyzed Suzuki–Miyaura or Sonogashira cross-coupling to afford stereodefined highly π-conjugated phthalimides and functionalized dienimides containing phthalimide groups. [Copyright &y& Elsevier]

Abstract: Novel stereoregular molecular compounds 8–13 containing thiophenylene-silylene-vinylene-phenylene units have been synthesised via highly effective silylative coupling of styrene and 1,4-divinylbenzene (7) with respective vinylsilylthiophenes (3, 4) and bis(vinylsilyl)thiophenes (5, 6) catalyzed by RuHClCO(PCy3)2. Respective copolymers (14, 15) were produced via silylative copolycondensation of 5 and 6 with 7. All products were isolated and characterised by NMR, MS, HRMS and two of them 10 and 11 by X-ray method. Catalytic study as well as stoichiometric reactions of Ru–H (1) with 2-(vinylsilyl)thiophene (3) and Ru–Si (16) with styrene confirmed the mechanism of the silylative coupling olefins with vinylsilicon compounds. [Copyright &y& Elsevier]

Abstract: Efficient silylative coupling of linear vinyl-substituted oligo- and polysiloxanes with styrene in the presence of [RuHCl(CO)(PPh3)3] (1) and particularly [RuHCl(CO)(PCy3)2] (2) combined with copper(I) chloride is described. Treatment of styrene, with terminal or side vinyl group at siloxane skeleton catalyzed by [RuHCl(CO)(PCy3)2]/CuCl results in the quantitative and selective formation of respective silylative coupling products. [Copyright &y& Elsevier]

Abstract: An effective selective silylative coupling functionalization of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane with olefins catalyzed by ruthenium-hydride complex [RuHCl(CO)(PCy3)2] has been described. We have obtained numerous unsaturated derivatives of cyclosiloxane possessing a SiCHents (where X=alkyl, aryl, silyl, alkoxy, amine and amide groups). One of the products synthesized (1,3,5,7-tetramethyl-1,3,5,7-tetra-(E)-4-bromostyrylcyclotetrasiloxane) has been efficiently coupled with aryl iodides in the presence of palladium(0) catalyst to yield substituted 4-bromostilbenes. [Copyright &y& Elsevier]

Abstract: The utility of acyclic diene metathesis (ADMET) polymerization in the synthesis of silicon–carbon hybrid materials is reviewed. Silicon containing macromolecules are synthesized from organosilicon α,ω-dienes (except those which are divinyl substituted). As an extension of olefin metathesis, ADMET is catalyzed by many transition metal complexes which either initiate the formation of carbene complexes (“ill-defined” catalysts) or by metallacarbene complexes (“well-defined” catalysts). Constant developments of catalytic systems have made this methodology more viable by allowing incorporation of numerous silicon containing functionalities into the polymer''s backbone or pendant to it. Divinyl substituted organosilicon derivatives are inert to ADMET conditions; they undergo silylative coupling (SC) polycondensation catalyzed by ruthenium and rhodium complexes yielding metathesis-like products, although this transformation proceeds via a non-metallacarbene mechanism. [Copyright &y& Elsevier]

Abstract: Cross-metathesis of 4-chlorostyrene with vinylsilanes in the presence of second generation of Grubbs catalyst [Cl2(PCy3)(IMesH2)Ru( silylative coupling in the presence of [RuH(Cl)(CO)(PPh3)3] followed by palladium-catalysed Hiyama coupling have been proved convenient and effective methods for stereoselective synthesis of unsymmetrical stilbenoids. [Copyright &y& Elsevier]

Abstract: Cross-coupling of vinyldisilacyclobutane with a variety of olefins in the presence of [RuH(Cl)(CO)(PCy3)2] leads to stereoselective formation of functionalized vinyldisilacyclobutanes. Analogous homo-coupling of vinyldisilacyclobutane leads to the formation of E- and gem-bis(silyl)ethenes. The reaction offers a new route for synthesis of attractive monomers for ring opening polymerization (ROP). [Copyright &y& Elsevier]

An effective stereoselective synthesis of E-N-2-(silyl)vinylamides via silylative coupling of vinyl amides such as N-vinylpyrrolidinone, N-vinylphthalimide, and N-vinylformamide with vinyltrisubstituted silanes catalyzed by [RuH(Cl)(CO)(PCy3)2] I is described. [Copyright &y& Elsevier]

The first trans-tactic stereo-regular vinylene-siloxylene-p-phenylene copolymer 1 with perfect vinylsiloxane linkage was obtained via acyclic diene metathesis copolymerization of divinyltetraethoxydisiloxane with 1,4-divinylbenzene (DVB) in the presence of Grubbs catalyst. The similar trans-tactic copolymers 2 and 3 but with no consecutive vinylsiloxane linkage was also prepared by silylative coupling copolycondensation of DVB with divinyltetra(methyl,ethoxy)disiloxane catalyzed by [Ru(H)(Cl)(CO)(PCy3)2]. [Copyright &y& Elsevier]

Abstract: The iridium-based catalytic system, [{Ir(μ-Cl)(CO)2}2]/NEt(i-Pr)2, was examined in the coupling reaction of iodotrisubstituted silanes (R3SiI) with various terminal arylalkynes (R1C CH). Under optimum conditions, the process occurs very efficiently (in particular for Me3SiI and Me2PhSiI), giving exclusively the respective C sp -silyl functionalized alkynes (R1C CSiR3). Additionally, this iridium-based catalytic system was successfully used for the preparation of selected bis(phenylethynyl) disubstituted silanes [R2 2Si(C CPh)2] via coupling of phenylacetylene with appropriate diiodo-disubstituted silanes (R2 2SiI2). [Copyright &y& Elsevier]

Abstract: A new ruthenium(0) complex catalyzed coupling reaction of silanols with vinylgermanes leading to SiO–Ge bond formation with the evolution of ethylene is described. Under optimum conditions the catalytic O-germylation of silanols gives exclusively germasiloxanes. [ABSTRACT FROM AUTHOR]

Bifunctional silsesquioxanes create an attractive group of compounds with a wide range of potential applications, and recently they have gained much interest. They are known to be obtained mainly via hydrosilylation, but we disclose novel synthetic protocols based on different but complementary reactions, i.e., cross-metathesis (CM) and silylative coupling (SC). A series of cubic T8 type silsesquioxane derivatives with a broad scope of styryl substituents were synthesized in a one-pot procedure and characterized by spectroscopic and spectrometric methods. All of the new compounds can be obtained in a one-pot manner, which has an attractive impact on the synthetic procedure, as it is economic in terms of the isolation of intermediate products. Additionally, the methodology disclosed here enables the (E)-stereoselective introduction of styrenes derivative to the cubic T8 type core. The presented compounds can be interesting precursors for a further functionalization that may significantly increase the possibility of their application in the design and synthesis of new functional materials. [ABSTRACT FROM AUTHOR]