Mechanochemical Synthesis of ß-Sulfenylated Ketones and Esters.

For the first time, ball milling has been employed in the solvent-free synthesis of sulfur-functionalized materials from thiols and α,ß-unsaturated ketones and esters, using potassium carbonate as a transition metal-free catalyst. This environmentally friendly protocol makes use of easily accessible reagents to prepare ß-sulfenylated carbonyl compounds with yields exceeding 91% under ambient air and solvent-free conditions. Additionally, this innovative synthetic strategy enables the modification of  chalcones, compounds with significant medicinal and synthetic potential. The reactions are efficient and easily scalable to gram quantities, offering substantial benefits for practical applications.

Ball-Milling toward Nickel(II) Diphosphine Complexes for Direct Use in Catalysis.

Mechanochemistry turned out to be a powerful synthetic tool enabling the first efficient synthesis of nickel(II) complexes with diphosphines. It has been demonstrated that solventless ball-milling of nickel(II) halides with diphosphines leads to the [NiX2(diphosphine)] type compounds, which can be directly used in catalysis without any purification. Moreover, it was confirmed that despite the presence of impurities in the resulting complexes, their catalytic activity remains identical to those obtained via traditional solvent-based methods.

New Ceramics Precursors Containing Si and Ge Atoms-Cubic Germasilsesquioxanes-Synthesis, Thermal Decomposition and Spectroscopic Analysis.

Compounds of the silsesquioxane type are attractive material precursors. High molecular weights and well-defined structures predestine them to create ceramics with a controlled composition at the molecular level. New molecular precursors of ceramic materials with the ratio of Si:Ge = 7:1 atoms were obtained. The influence of organic substituents on the thermal decomposition processes of germasilsesquioxanes was investigated. Some of the structures obtained are characterized by a high non-volatile residue after the thermal decomposition process. The introduction of the germanium atom to the structure of the silsesquioxane molecular cage reduces the thermal stability of the obtained structures.

Introduction of organogermyl functionalities to cage silsesquioxanes.

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 between vinylsilanes and vinylgermanes showed a higher reactivity of germanium compounds in the hydrosilylation reaction. To the best of our knowledge, this is the first literature example of the functionalization of silsesquioxanes and spherosilicates with these types of germanium derivatives. The reaction parameters and kinetics were determined by in situ FT-IR. In addition, our research is supported by extensive data obtained from NMR measurements.

Dialkenylgermanes as Precursors of Silsesquioxane-based Macromolecular Structures.

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.

Highly selective synthesis of substituted (E)-alkenylsilatranes via catalytic trans-silylation and mechanistic implications.

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.

The first ruthenium-silsesquioxyl complexes--synthesis, structure and mechanistic implications in silylative coupling.

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.