Cobalt-Catalyzed Dehydrogenative C−H Silylation of Alkynylsilanes

Herein, we report that a cobalt catalyst permits the general synthesis of substituted alkynylsilanes through dehydrogenative coupling of alkynylsilanes and hydrosilanes. Several silylated alkynes, including di‐ and trisubstituted ones, were prepared in a one‐step procedure. Thirty‐seven compounds were synthesized for the first time by applying our catalyst system. The alkynylsilanes bearing hydrosilyl moieties provide an opportunity for further functionalization (e. g., hydrosilylation). The use of primary silanes as substrates and precatalyst activators permits the use of inexpensive and easily accessible 3d metal precatalysts, and avoids the presence of additional activators

Iridium Catalyzed Synthesis of Tetrahydro-1H-Indoles by Dehydrogenative Condensation

Novel synthetic routes to the commonly encountered indole motif are highly sought after. Tetrahydro-1H-indoles were synthesized for the first time from secondary alcohols and 2-aminocyclohexanol in the presence of a well-established iridium catalyst using a modified synthetic procedure recently developed for the synthesis of hydrocarbazoles. The catalyst is stabilized by an inexpensive and easy-to-synthesize triazine based PN5P pincer ligand. The reaction proceeds through acceptorless dehydrogenative condensation (ADC) and yields the title compound, dihydrogen, and water and can thus be classified as sustainable synthesis. Overall, five examples, three of which were previously unknown compounds, were prepared. The propitious isolated yields and the mild reaction conditions show the synthetic value of this approach. These tetrahydroindoles can be quantitatively dehydrogenated over a heterogeneous Pd catalyst to yield the corresponding indoles

One- and two-electron reductions of a bulky BODIPY compound

The redox reaction between a bulky BODIPY and a magnesium(I) reducing agent leads to the formal one-electron reduction of the BODIPY, initially generating a dipyrromethene-centred radical compound that dimerises via C–C bond formation. In contrast, reduction with magnesium anthracene leads to the formal two-electron reduction of the BODIPY, resulting in the formation of the corresponding anion