2020-...

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Grinding the Cubes—Multigram Solid-State Synthesis of Silsesquioxane
Amic Acids

B. Kaczmarek, M. Szołyga, D. Frąckowiak, ACS Sustainable Chem. Eng. 2021

For the first time, ball milling is used in the functionalization of silsesquioxanes. The solid-state nucleophilic addition of aminopropylisobutyl POSS to cyclic anhydrides leads to silsesquioxane amic acids in virtually quantitative yields without the use of a solvent. The reactions are easily scalable and can be adopted to multigram quantities.

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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. 202037, 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).

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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.

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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.

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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.