The first ruthenium-silsesquioxyl complexes – synthesis, structure and mechanistic implications in silylative coupling
D. Frąckowiak, J. Walkowiak, G. Hreczycho, B. Marciniec, Eur. J. Inorg. Chem. 2014, 20, 3216-3220
The first ruthenium-silsesquioxyl complexes have been synthesised and characterized via spectroscopic and X-ray methods. Mechanistic studies were performed and the complexes obtained were proved to be intermediates in the catalytic cycle of silylative coupling of olefins with vinylsilsesquioxane. Moreover, a mechanism for silylative coupling of styrene with vinylsilsesquioxanes was proposed.
A new catalytic approach to germasiloxanes
G. Hreczycho, D. Frąckowiak, P. Pawluć, B. Marciniec, Tetrahedron Lett. 2011, 52 , 74-76
A new ruthenium(0) complex catalyzed coupling reaction of silanols with vinylgermanes leading to Si-O-Ge bond formation with the evolution of ethylene is described. Under optimum conditions the catalytic O-germylation of silanols gives exclusively germasiloxanes.
Ru(0) catalyzed coupling of vinylboronates with silanols, disilanols and disiloxanediols– selective route to borasiloxanes
D. Frąckowiak, J. Walkowiak, G. Hreczycho, B. Marciniec, Eur. J. Inorg. Chem. 2014, 20, 3216-3220
A new highly selective method for the synthesis of borasiloxanes through the O-borylation of silanols, disilanols, and disiloxanediols with vinylboronates in the presence of Ru(0) complexes (mainly Ru3CO12) is described. The method leads to the formation of special compounds with a B–O–Si inorganic framework. When Ru(0) complexes are used as a catalyst, no vinylboronate homocoupling is observed. A mechanism for this transformation is proposed on the basis of stoichiometric reactions of Ru(0) with triethylsilanol and vinylboronate.
New vinylgermanium derivatives of silsesquioxanes and their ruthenium complexes – synthesis, structure and reactivity
D. Frąckowiak, P.Żak, G. Spólnik, M. Pyziak, B. Marciniec, Organometallics, 2015, 34, 3950–3958
New vinylgermanium cubic derivatives of silsesquioxanes (i.e., monovinylhepta(alkyl, phenyl)germasilsesqiuoxanes and (dimethylvinylgermoxy)heptaisobutylsilsesquioxanes) were synthesized and characterized by spectroscopic methods. The first ruthenium–germasilsesquioxyl complexes were also prepared via stoichiometric reaction of RuHCl(CO)(PPh3)3 with the above-mentioned vinylgermanium derivatives of silsesquioxanes, and their structures were determined by spectroscopic and X-ray analyses. The initial ruthenium complex as well as the above-mentioned Ge–Ru complexes were tested as catalysts, in the germylative coupling with olefins, and proved to be active in the case of (dimethylvinyl)germoxyheptaisobutylsilsesquioxane but showed no activity toward vinylgermasilsesquioxanes. A general mechanism for the germylative coupling of the two vinylgermanium derivatives of silsesquioxanes is presented.
New Arylene−Germylene−Vinylene Compounds: Stereoselective Synthesis, Characterization, and Photophysical Properties
M. Ludwiczak, M. Bayda, M. Dutkiewicz, D. Frąckowiak, M. Majchrzak, B. Marciniak, B. Marciniec, Organometallics, 2016, 35, 2454–2461
The stereoselective route toward new molecular and macromolecular compounds containing arylene−germy-lene−vinylene units is described. The reagents for germylative coupling reaction were 1,4-bis(dimethylvinylgermyl)benzene and vinyl- and divinylarenes with ruthenium complexes as catalysts. NMR characterization of all isolated products, results of MS and elemental analysis for molecular compounds, and GPC for oligomers are presented. Absorption and luminescence properties of the synthesized compounds are discussed and compared with those of model chromophores.
Olefin Metathesis of Vinylgermanium Derivatives as Method for the Synthesis of Functionalized Cubic and Double-Decker Germasilsesquioxanes
P. Żak, D. Frąckowiak, M. Grzelak, M. Bołt, M. Kubicki, B. Marciniec, Adv. Synth. Cat. 2016, 358, 3265–3276
For the first time, olefin cross metathesis has been developed for vinylgermanium compounds. This paper also marks the first case of transition metal-catalyzed functionalization of heterosilsesquioxanes, which in our case are cubic vinylgermasilsesquioxanes and newly synthesized di(vinylgermyl)-substituted doubledecker silsesquioxane. These processes lead to a series of new molecular, unsaturated mono and divinyl-substituted germasilsesquioxanes, which can be potentially applied as precursors for optoelectronics and for the synthesis of new advanced materials. Additionally, preliminary tests of metathetic copolymerization of divinylsubstituted double-decker digermasilsesquioxanes (DDSQ-2ViGe) with selected diolefins proved to be very promising and resulted in the synthesis of novel stereoregular trans-germasilsesquioxyl-vinylene-phenyl-ene macromolecular derivatives. All newly obtained compounds were isolated and characterized by mass and spectroscopic methods.
A highly selective synthesis of new alkenylsilsesquioxanes by hydrosilylation of alkynes
A. Franczyk, K. Stefanowska, M. Dutkiewicz, D. Frąckowiak, B. Marciniec, Dalton Trans. 2017, 46, 158-164
Hydrosilylation of a wide group of mono- and disubstituted (symmetrical and nonsymmetrical) alkynes with 1-dimethylsiloxy-3,5,7,9,11,13,15-heptaisobutylpentacyclo-[184.108.40.206,9.15,15.17,13]octasiloxane [(HSiMe2O)(i-Bu)7Si8O12] in the presence of Karstedt's catalyst (Pt2(dvs)3) has been performed for the first time. A series of new 1,2-(E)-disubstituted and 1,1,2-(E)-trisubstituted ethenes with a silsesquioxane moiety were selectively afforded and fully characterized. On the basis of nuclear magnetic resonance (NMR) and infrared spectroscopy (in situ FT-IR and/or FT-IR), the influence of alkyne structure and reaction conditions on the stereoselectivity as well as on the progress of triple bond hydrosilylation catalyzed by Pt2(dvs)3 was explained. The results of the studies clearly indicated for which reagents the developed procedures lead to alkenylsilsesquioxanes with almost stoichiometric yields in short time, and for which other catalytic systems or methods should be considered.
Highly selective synthesis of substituted (E)-alkenylsilatranes
via catalytic trans-silylation and mechanistic implications
B. Sztorch, D. Frąckowiak, J. Pyziak, A. Czapik, M.Hoffmann, B. Marciniec, Dalton Trans. 2017,46, 4975-4981
A new route for the synthesis of functionalized alkenylsilatranes has been developed based on ruthenium-catalyzed trans-silylation with olefins. This transformation allowed for the synthesis of new (E)-alkenylsilatranes in good yields and excellent selectivity. Experimental studies concerning the reaction mechanism were carried out and the intermediate ruthenium–silatranyl complex was isolated and characterized. Moreover, detailed DFT calculations regarding the mechanism of the silylative coupling catalytic cycle of silatranes catalyzed by [Ru]–H complexes were also performed.
Vinyl functionalized silsesquioxanes and germasilsesquioxanes
M. Grzelak, D. Frąckowiak, B. Marciniec, Eur. J. Inorg. Chem. 2017, 27, 3337–3342
We report herein an efficient procedure for the synthesis of new POSS derivatives, as a multifunctional reagents. This study concerns the incompletely condensed silsesquioxanes and germasilsesqiuoxanes with vinylsubstituted silyl and germyl functional groups which allow to further modification. Furthermore, our experiments have been extended to synthesis new subclass of completely condensed vinylgermasilsesquioxanes. These hybrid building blocks were obtained selectively within a few hours and were isolated with excellent yields.
Highly selective synthesis of novel (E)-styrylsilatranes via ruthenium-catalyzed trans-silylation
B. Sztorch, D. Frąckowiak, B. Marciniec, Synth. Commun. 2018, 48, 3025–3032
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.
Reactivity of 1-allylsilatrane in ruthenium-catalyzed silylative coupling with olefins – mechanistic considerations
B. Sztorch, D. Frąckowiak, B. Marciniec, Heterocycl. Commun. 2020, 26, 33–36
We have developed a new effective route for obtaining (E)-vinyl-substituted silatranes via ruthenium- catalyzed silylative coupling of 1-allylsilatrane with olefins. Experimental research allowed us also to propose the mechanism of the process based on stoichiometric reactions.
Introduction of organogermyl functionalities to the cage silsesquioxanes
M. Grzelak, D. Frąckowiak, R. Januszewski, B. Marciniec, Dalton Trans. 2020, 49, 5055-5063
In this work, we present the first example of highly efficient platinum-catalyzed hydrosilylation of vinyl- and allylgermanes with different types of silsesquioxanes and spherosilicates. This protocol allows the straightforward introduction of organogermyl functionalities with alkyl chains linked to the silsesquioxane core with good yields and excellent selectivity. These derivatives may be applied as precursors for the development of advanced hybrid materials in the future. In addition, a comparison made for vinylsilanes and vinylgermanes showed a higher reactivity of germanium compounds in hydrosilylation reaction. To the best of our knowledge, this is the first literature example of the functionalization of silsesquioxanes and spherosilicates with this type of germanium derivatives. The reaction parameters and kinetics were determined by in situ FT-IR. Additionally, our research is supported by extensive data from NMR measurements.
Dialkenylgermanes as precursors of silsesquioxane‐based macromolecular structures
M. Grzelak, D. Frąckowiak, B. Marciniec, Chem.: Asian J. 2020, 15, 1598-1604
Herein we report a study of highly efficient platinum‐catalyzed hydrosilylation of dialkenylgermanes with silsesquioxanes and spherosilicates. The use of divinyl‐ and diallylgermanes allowed the synthesis of new classes of compounds, i.e., dumbbell type systems, silsesquioxanes with alkenyl pendant group, and oligomeric derivatives. The results are supported by detailed data from in situ FT‐IR and NMR measurements enabling precise monitoring of the reaction progress and determination of regioselectivity of the formed products.
New functionalized borasilsesquioxanes obtained via metathetical transformation of 4-vinylphenylborasilsesquioxanes
M. Frydrych, B. Sztorch, D. Brząkalski, D.Pakuła, D. Frąckowiak, M. Majchrzak, B.Marciniec, Eur. J. Inorg. Chem. 2020, 37, 3532-3611
We report here functionalizing borasilsesquioxanes in a cross-metathesis reaction in the presence of a ruthenium catalyst. The procedure provides new, silsesquioxanes containing boron atoms in their structure, which may find potential application in the preparation of special materials, e.g. flame retardants for polymers, organoboron Lewis acids for catalysts and scavengers, or molecular probes. The most attractive aspect of this study was obtaining hybrid silsesquioxane systems in the metathesis reaction of styrylborasilsesquioxane with mono- and octavinylsilsesquioxanes as well as diborate systems with vinylborate derivatives. Most of the compounds were obtained in good yields (>75%) and were characterized by spectroscopic methods (NMR, MALDI-TOF-MS).