Ruthenium-Catalyzed Asymmetric trans-Selective Hydrogenation of 2,3-Disubstituted Quinoxaline Derivatives.

The asymmetric trans-selective hydrogenation of arenes has long been a significant challenge. In this work, we were able to control the trans/cis selectivity in ruthenium-catalyzed asymmetric hydrogenation of 2,3-disubstituted quinoxalines by varying the catalyst counteranion. Using density functional theory calculations, we investigated the weak interactions─such as CH/π and hydrogen bonding─among the counteranion, the catalyst framework, and the substrate, elucidating the fundamental influence of counteranions on trans/cis selectivity in the asymmetric hydrogenation of quinoxalines.