Convincing Catalytic Performance of Oxo-Tethered Ruthenium Complexes for Asymmetric Transfer Hydrogenation of Cyclic α-Halogenated Ketones through Dynamic Kinetic Resolution

A highly efficient dynamic kinetic resolution of cyclic halohydrins was achieved by the asymmetric transfer hydrogenation of racemic alpha-haloketones. Bifunctional oxo-tethered Ru(II) catalysts could promote the reduction without deterioration of halogens. By structural tuning of the catalyst, chiral alcohols having halogen, ester, carboxamide, and sulfone functions were obtained variably with excellent diastereo- and enantioselectivities (up to >99:1 d.r. and >99.9 ee), which provided a concise synthetic approach to a dopamine D3 receptor ligand, (+)-PHNO.

Automated summary

Efficient dynamic kinetic resolution of cyclic halohydrins was achieved by asymmetric transfer hydrogenation of racemic alpha-haloketones using bifunctional oxo-tethered Ru(II) catalysts. The catalyst could produce chiral alcohols with various functional groups with excellent diastereo- and enantioselectivities, providing a concise synthetic approach to a dopamine D3 receptor ligand, (+)-PHNO.