Selective Hydrogenation of Lignin-derived Aromatics to Give Cyclohexanes with a Rhodium-Pincer Precatalyst

Catalytic hydrogenation of aromatic rings represents an essential industrial chemical process for the synthesis of commodity chemicals and intermediates in pharmaceuticals, polymers, and fine chemicals. Herein, we report an air-stable rhodium complex bearing a pincer bis(oxazolinyl)phenyl ligand that shows good catalytic activity for the hydrogenation of lignin-derived acetophenones, benzoic acids as well as other functionalised aromatics to the corresponding alicyclic products by reducing the aryl groups. The rhodium complex is a precatalyst, offering easy access to active rhodium species, which appears to be heterogeneous in the hydrogenation.