New Catalytic Route to Alkynylgermanes

Access to Unsaturated Organogermanes via (De)Hydrosilylation Mediated by Cobalt Complexes

The functionalization of alkynylgermanes using hydrosilanes was accomplished by employing cobalt catalysis. Depending on the reactants used, the reaction can proceed via dehydrogenative coupling or hydrosilylation. Importantly, the presented method is characterized by mild reaction conditions, allowing rapid access to a wide range of organogermanes.

Access to germasiloxanes and alkynylgermanes mediated by earth-abundant species

The reactions between silanols or terminal acetylenes with alkynylgermanes have been accomplished using potassium bis(trimethylsilyl)amide as the catalyst. This strategy has provided an entry point into various organogermanes including germasiloxanes and alkynylgermanes. Remarkably, not only KHMDS but also simple bases such as KOH can serve as efficient catalysts in this process.

Direct C-H Dehydrogenative Germylation of Terminal Alkynes with Hydrogermanes

A direct C(sp)-H germylation of terminal alkynes with triethyl germanium hydride is reported. The method is operationally simple and makes use of B(C₆F₅)₃ catalysis in combination with 2,6-lutidine as an organic base. Exclusive selectivity for dehydrogenative germylation of the alkyne over the competing hydrogermylation is observed.

Inorganometallics (Transition Metal-Metalloid Complexes) and Catalysis

While the formation and breaking of transition metal (TM)-carbon bonds plays a pivotal role in the catalysis of organic compounds, the reactivity of inorganometallic species, that is, those involving the transition metal (TM)-metalloid (E) bond, is of key importance in most conversions of metalloid derivatives catalyzed by TM complexes. This Review presents the background of inorganometallic catalysis and its development over the last 15 years. The results of mechanistic studies presented in the Review are related to the occurrence of TM-E and TM-H compounds as reactive intermediates in the catalytic transformations of selected metalloids (E = B, Si, Ge, Sn, As, Sb, or Te). The Review illustrates the significance of inorganometallics in catalysis of the following processes: addition of metalloid-hydrogen and metalloid-metalloid bonds to unsaturated compounds; activation and functionalization of C-H bonds and C-X bonds with hydrometalloids and bismetalloids; activation and functionalization of C-H bonds with vinylmetalloids, metalloid halides, and sulfonates; and dehydrocoupling of hydrometalloids. This first Review on inorganometallic catalysis sums up the developments in the catalytic methods for the synthesis of organometalloid compounds and their applications in advanced organic synthesis as a part of tandem reactions.

Synthesis of a new class of silsesquioxanes with alkynyl and germyl functionality

Although there are a variety of functional compounds in the vast family of silsesquioxanes (POSS), the number of protocols describing specific monosubstituted silsesquioxanes is limited. There are even fewer reports on alkynyl and/or germyl functionalities appearing together with the POSS compounds. Here, a series of novel kinds of cubic monosubstituted POSS bearing alkynyl and germyl functionality in one molecule are reported. These compounds were synthesized by effective germylative coupling of terminal alkynes with vinylgermanes in the presence of a Ru-H complex. The structures of the products were determined. Moreover, stoichiometric reactions of a complex possessing Ru-Ge were also performed to propose the general mechanistic scheme of this reaction.

Ruthenium-catalyzed dealkenative N-silylation of amines by substituted vinylsilanes

The [RuHCl(CO)(PCy₃)₂]-catalyzed N-silylation of primary and secondary amines with substituted vinylsilanes leads to the formation of a Si–N bond with the evolution of olefin.