Kinetic study of asymmetric hydrogenation of methyl levulinate using the (COD)Ru(2-methylallyl)2–BINAP–HCl catalytic system

The kinetics of asymmetric hydrogenation of methyl levulinate in the presence of the (COD)Ru(2-methylallyl)2–BINAP–HCl catalytic system was studied. The kinetic order in H2, as well as in the catalyst, was found to be equal to 1, whereas the kinetic order for the substrate and HCl falled from 1 to 0 with their increasing starting concentration. The kinetic and 31P NMR data testify that the mechanism of the reaction under consideration, most likely, involves the hydride transfer to the protonated substrate in the dinuclear ruthenium complex as the rate-limiting step of the catalytic cycle.

The kinetics of asymmetric hydrogenation of methyl levulinate in the presence of the (COD)Ru(2-methylallyl)2–BINAP–HCl catalytic system was studied. The kinetic order in H2, as well as in the catalyst, was found to be equal to 1, whereas the kinetic order in the substrate and HCl falled from 1 to 0 with increasing their starting concentration. Based on the kinetic and 31P NMR data, the most probable mechanism of ruthenium-catalyzed hydrogenation of γ-ketoesters has been suggested.Figure optionsDownload as PowerPoint slide