Cover Feature: Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions? (Eur. J. Org. Chem. 34/2020)

The Cover Feature shows the exceptionally mild hydrogenation of aromatic compounds, including both heteroarenes and arenes, which was accomplished by using catalytic Pd/C with H2-balloon pressure at room temperature. As the representative reaction, pyridine was hydrogenated on 1 mol% Pd/C in AcOH to afford piperidine quantitatively. Substrate scope analysis and DFT calculations indicated that reaction rates are highly dependent on the steric bulkiness of substituents and the HOMO/LUMO states. Moreover, the usefulness and chemo-selectivity of the established reaction were demonstrated by the synthesis of the anti-Alzheimer drug donepezil. More information can be found in the Full Paper by N. Tanaka and T. Usuki.