Asymmetric Hydrogenation of β-Aryl Alkylidene Malonate Esters: Installing an Ester Group Significantly Increases the Efficiency

Herein, we report a practical method for efficient asymmetric hydrogenation of beta-aryl alkylidene malonates. With a site-specifically tailored chiral spiro iridium catalyst, a series of beta-aryl alkylidene malonate esters were hydrogenated to afford chiral malonate esters with good to excellent enantioselectivities (up to 99% ee) and high turnover numbers (up to 19000). The results showed that installing an ester group in alpha,beta-unsaturated carboxylic esters significantly increased the efficiency of their asymmetric hydrogenation reactions.

Automated summary

A practical method for efficient asymmetric hydrogenation of beta-aryl alkylidene malonates was reported. By using a site-specifically tailored chiral spiro iridium catalyst, a series of chiral malonate esters were successfully synthesized with good to excellent enantioselectivities (up to 99% ee) and high turnover numbers (up to 19000). The results demonstrated that incorporating an ester group in alpha,beta-unsaturated carboxylic esters significantly enhanced the efficiency of their asymmetric hydrogenation reactions.