Accessing Arenes via the Hydrodeoxygenation of Phenolic Derivatives Enabled by Hydrazine

Hydrodeoxygenation (HDO) is an effective method for converting lignin and its derived phenolic compounds to value-added aromatic chemicals and fuels. Efforts to exploit molecular hydrogen have been made to remove the hydroxyl group in lignin-derived phenolic compounds to make them appealing for the chemical industry. However, these processes rely on high pressure and expensive catalysts, presenting challenges in terms of safety, hydrogen storage, and cost-effectiveness. This highlights the demand for alternatives under more accessible reaction conditions. Herein, we present a methodology for the HDO of phenols and naphthols using Pd/C as a commercial heterogeneous catalyst employing hydrazine as a dual reagent for reducing and hydrazone formation. This paper presents an applicable substrate scope for the HDO of different naphthols and phenols including pharmaceutically relevant molecules such as paracetamol. Additionally, highly challenging steroid derivatives, such as β-estradiol, have been hydrodeoxygenated.