NOVEL PROCESS FOR PRODUCTION OF HIGHLY PURE POLYMORPH (I) DONEPEZIL HYDROCHLORIDE
申请人:Richter Gedeon Nyrt.
公开号:EP1966136B1
公开(公告)日:2014-02-26
Bidentate NHC-Cobalt Catalysts for the Hydrogenation of Hindered Alkenes
作者:Zeyuan Wei、Yujie Wang、Yibiao Li、Raffaella Ferraccioli、Qiang Liu
DOI:10.1021/acs.organomet.0c00498
日期:2020.9.14
Herein, we report a series of easily accessible bidentate N-heterocyclic carbene (NHC) cobalt catalysts, which enable the hydrogenation of hindered alkenes under mild conditions. The four-coordinated bidentate NHC-Co(II) complexes were characterized by X-ray diffraction, elemental analysis, ESI-HRMS, and magnetic moment measurements, revealing a distorted-tetrahedral geometry and a high-spin configuration
Asymmetric hydrogenation of pyridines and subsequent N-alkylation lead to indolizidines and quinolizidines. The presence of Cl− results in retention of the absolute configuration of the initially formed alcohol. Noncovalent interactions, H-bonding, π-π stacking and electrostatic interactions also play important roles in regulating the stereoselectivity of the reaction process.