Highly enantioselective synthesis of both tetrahydroquinoxalines and dihydroquinoxalinones via Rh-thiourea catalyzed asymmetric hydrogenation.

ABSTRACT: Chiral tetrahydroquinoxalines and dihydroquinoxalinones represent the core structure of many bioactive molecules. Herein, a simple and efficient Rh-thiourea-catalyzed asymmetric hydrogenation for enantiopure tetrahydroquinoxalines and dihydroquinoxalinones was developed under 1 MPa H₂ pressure at room temperature. The reaction was magnified to the gram scale furnishing the desired products with undamaged yield and enantioselectivity. Application of this methodology was also conducted successfully under continuous flow conditions. In addition, ¹H NMR experiments revealed that the introduction of a strong Brønsted acid, HCl, not only activated the substrate but also established anion binding between the substrate and the ligand. More importantly, the chloride ion facili

SUBMITTER: Xu A 

PROVIDER: S-EPMC10466277 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature