Hydrogenation reactions were performed in 25 and 75 mL stainless steel autoclaves equipped with an overhead magnetic stirrer, a pressure indicator and a thermocouple for temperature registration. The autoclaves were equipped with an electrical heating/cooling system to control the temperature inside the vessel. The hydrogenation active catalyst substrate/Ru-complex was prepared in situ, once the Ru-complexes used were pre-catalysts. The autoclave was charged with Ru-complex (0.013, 0.015 or 0.026 mmol), substrate (1.5 or 6.9 mmol), MeOH (20 or 6 mL). The system was flushed three times with H2. Then, the autoclave was pressurized with H2 (15, 50 or 100 bar) and heated to a temperature of 80 or 160 °C, for 15 or 24 h. After the reaction, the homogeneous reaction mixture was cooled down in an ice bath to room temperature, and the upper organic layer was analyzed by GC-FID and GC-MS.