Mechanistic Understanding of the Heterogeneous, Rhodium-Cyclic (Alkyl)(Amino)Carbene-Catalyzed (Fluoro-)Arene Hydrogenation

Daniel Moock; Mario P Wiesenfeldt; Matthias Freitag; Satoshi Muratsugu; Satoru Ikemoto; Robert Knitsch; Jacob Schneidewind; Wolfgang Baumann; Andreas H Schäfer; Alexander Timmer; Mizuki Tada; Michael Ryan Hansen; Frank Glorius

doi:10.1021/acscatal.0c01074

Mechanistic Understanding of the Heterogeneous, Rhodium-Cyclic (Alkyl)(Amino)Carbene-Catalyzed (Fluoro-)Arene Hydrogenation

ACS Catal. 2020 Jun 5;10(11):6309-6317. doi: 10.1021/acscatal.0c01074. Epub 2020 May 5.

Affiliations

¹ Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
² Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Aichi, Japan.
³ Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany.
⁴ Leibniz-Institut für Katalyse e. V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany.
⁵ nanoAnalytics GmbH, Heisenbergstrasse 11, 48149 Münster, Germany.
⁶ Research Center for Materials Science (RCMS) and Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Aichi, Japan.

Abstract

Recently, chemoselective methods for the hydrogenation of fluorinated, silylated, and borylated arenes have been developed providing direct access to previously unattainable, valuable products. Herein, a comprehensive study on the employed rhodium-cyclic (alkyl)(amino)carbene (CAAC) catalyst precursor is disclosed. Mechanistic experiments, kinetic studies, and surface-spectroscopic methods revealed supported rhodium(0) nanoparticles (NP) as the active catalytic species. Further studies suggest that CAAC-derived modifiers play a key role in determining the chemoselectivity of the hydrogenation of fluorinated arenes, thus offering an avenue for further tuning of the catalytic properties.