The 9-Borataphenanthrene Anion

Angew Chem Int Ed Engl. 2020 Jul 6;59(28):11470-11476. doi: 10.1002/anie.202002125. Epub 2020 May 7.

Abstract

The 9-borataphenanthrene anion is easily accessed by deprotonation of a 9,10-dihydro-9-boraphenanthrene and its diverse reactivity is investigated. Alkylation occurs at the carbon atom adjacent to boron, and room temperature hydroboration occurs across the B=C bond. The π-manifold of the central BC5 ring coordinates to chromium in an η6 fashion while only the B=C unit binds η2 to gold, indicating versatility of the 9-borataphenanthrene anion as a ligand. Supporting calculations rationalize the reactivity and aromaticity is corroborated by nucleus-independent chemical shift (NICS) indices.

Keywords: borataalkene; boratabenzene; boron; heterocycles; hydroboration.