First catalytic asymmetric hydrogenation of quinoxaline-2-carboxylates

For the first time, the asymmetric hydrogenation of quinoxaline-2-carboxylates was performed successfully. The best catalysts are based on iridium complexes modified by chiral phosphorous ligands. Accelerated examination of ligands and catalysts has been undertaken by using a Chemspeed workstation, which enables carrying out, in parallel, eight independent catalytic reactions at the laboratory scale. Tetrahydroquinoxaline-2-carboxylates could be obtained with high yields and up to 74% ee.