623-04-1

The catalytic reduction of 4-aldehyde nitrobenzene to 4-Aminobenzyl alcohol by a semi-sandwich ruthenium complex 2a is as follows: Synthesis of the semi-sandwich ruthenium complex with a 2,6-dithionone-substituted pyridine coordination compound 2a: At 25 °C, 0.05 mmol of [(CymeneRuCl2)2] and 0.1 mmol of 2,6-dimethylimidazolium-substituted pyridine were weighed into a Schlenk reaction tube, followed by the addition of 5 mL of DCM. The mixture was stirred for 16 hours under nitrogen protection. After the reaction was complete, the solution was filtered, the solvent was removed by rotary evaporation, 2 mL of CH3OH was added to dissolve the solid, and then an aqueous solution of saturated KPF6 (containing 0.25 mmol of KPF6) was added. A solid was immediately produced. The solid was washed with a small amount of water and diethyl ether to give 58 mg of a yellow-brown solid, with a yield of 71%.