Lukasz T. Pilarski

Ru-Catalysed C-H Arylation of Indoles and Pyrroles with Boronic Acids : Scope and Mechanistic Studies

The Ru-catalysed C2–H arylation of indoles and pyrroles by using boronic acids under oxidative conditions is reported. This reaction can be applied to tryptophan derivatives and tolerates a wide range of functional groups on both coupling partners, including bromides and iodides, which can be further derivatised selectively. New indole-based ruthenacyclic complexes are described and investigated as possible intermediates in the reaction. Mechanistic studies suggest the on-cycle intermediates do not possess a para-cymene ligand and that the on-cycle metalation occurs through an electrophilic attack by the Ru centre.

Boryl (Hetero)aryne Precursors as Versatile Arylation Reagents: Synthesis through C-H Activation and Orthogonal Reactivity.

(Pinacolato)boryl ortho-silyl(hetero)aryl triflates are presented as a new class of building blocks for arylation. They demonstrate unique versatility by delivering boronate or (hetero)aryne reactivity chemoselectively in a broad range of transformations. This approach enables the unprecedented postfunctionalization of fluoride-activated (hetero)aryne precursors, for example, as substrates in transition-metal catalysis, and offers valuable new possibilities for aryl boronate postfunctionalization without the use of specialized protecting groups.

Crystal structure of aceto­nitrile­[η6-1-methyl-4-(1-methyl­eth­yl)benzene][1-(pyrimidin-2-yl)-3H-indol-1-ium-2-yl-κ2N,C]ruthenium(II) bis­(hexa­fluorido­anti­monate)

Cyclometalated Ru complexes play a major role in catalytic transformation. The Ru cation is coordinated by a pyrimidyl-3H-indole ligand, as well as a para-cymene ligand and one acetonitrile molecule.