Ligand-Controlled Highly Regioselective and Asymmetric Hydrogenation of Quinoxalines

Significance

The research group of Glorius developed a ligand-controlled hydrogenation of quinoxalines. Selecting the right N-heterocyclic carbene ligand facilitates the regioselective hydro-genation of either the heterocyclic or the carbocyclic ring of a substituted quinoxaline. The hydrogenated products were generally obtained in quantitative yields and by employing chiral N-heterocyclic carbene ruthenium complexes, the 5,6,7,8-tetrahydroquinoxalines were furnished with good enantioselectivities.