Visible Light Induced Rhodium(I)-Catalyzed C-H Borylation

Jompol Thongpaen (1, 2) , Romane Manguin (1) , Vincent Dorcet (1) , Thomas Vives (1) , Carine Guyard-Duhayon (2) , Marc Mauduit (1) , Olivier Baslé (1, 2)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 LCC - Laboratoire de chimie de coordination

An efficient visible light induced rhodium(I)-catalyzed regioselective borylation of aromatic C-H bonds is reported. The photocatalytic system is based on a single NHC-Rh complex capable of both harvesting visible light and enabling the bond breaking/forming at room temperature. The chelating nature of the NHC-carboxylate ligand was critical to ensure the stability of the Rh complex and to provide excellent photocatalytic activities. Experimental mechanistic studies evidenced a photooxidative ortho C-H bond addition upon irradiation with blue LEDs, leading to a cyclometalated Rh -hydride intermediate.

Keywords: C−H activation; boron; carbenes; photochemistry; rhodium

Domains: Chemical Sciences

Jompol Thongpaen, Romane Manguin, Vincent Dorcet, Thomas Vives, Carine Guyard-Duhayon, et al.. Visible Light Induced Rhodium(I)-Catalyzed C-H Borylation. Angewandte Chemie International Edition, 2019, 58 (43), pp.15244-15248. ⟨10.1002/anie.201905924⟩. ⟨hal-02307077⟩