Chiral Rhodium Complexes Derived From Electron-Rich Phosphine-Phosphites as Asymmetric Hydrogenation Catalysts
作者:Pablo Etayo、José L. Núñez-Rico、Anton Vidal-Ferran
DOI:10.1021/om200933b
日期:2011.12.26
Two new chiral cationic rhodium(I) complexes derived from electron-rich dicyclohexylphosphine-phosphite ligands were prepared from enantiopure Sharpless epoxy ethers. The best-performing catalyst system, which bears a less bulky methyl ether moiety, exhibited remarkably high enantioselectivity (up to 99% ee) and reactivity (up to >2500 TON) in asymmetric hydrogenation reactions of various functionalized
P-Stereogenic <i>N</i>-Phosphine–Phosphite Ligands for the Rh-Catalyzed Hydrogenation of Olefins
作者:Maria Biosca、Pol de la Cruz-Sánchez、Oscar Pàmies、Montserrat Diéguez
DOI:10.1021/acs.joc.9b03508
日期:2020.4.3
We have identified a successful family of simple P-stereogenic N-phosphine-phosphite ligands for the Rh-catalyzed asymmetric hydrogenation of olefins. These catalysts show excellent enantiocontrol for alpha-dehydroamino acid derivatives and aenamides (ee's up to >99%) and promising results for the more challenging beta-analogues (ee's up to 80%). The usefulness of these catalytic systems was further demonstrated with the synthesis of several valuable precursors for pharmacologically active compounds, with ee's at least as high as the best ones reported previously (up to >99%).