Iridium and Rhodium Complexes Containing Enantiopure Primary Amine-Tethered <i>N</i>-Heterocyclic Carbenes: Synthesis, Characterization, Reactivity, and Catalytic Asymmetric Hydrogenation of Ketones
作者:Kai Y. Wan、Florian Roelfes、Alan J. Lough、F. Ekkehardt Hahn、Robert H. Morris
DOI:10.1021/acs.organomet.7b00915
日期:2018.2.12
a bimetallic iridium compound with (S,S)-11 as the bridging ligand. This compound contains interesting NH···Cl and NH···Ir noncovalent intramolecular interactions. Salt (S,S)-12·HPF6 reacts with silver oxide to yield [Ag2((S,S)-12)2](PF6)2 (20). Reagent 20 serves as an efficient transmetalation reagent to deliver to each rhodium in [RhCl(cod)]2 1 equiv of (S,S)-12 as a bidentate ligand to give [Rh(cod)((S
Use of diamines containing the α-phenylethyl group as chiral ligands in the asymmetric hydrosilylation of prochiral ketones
作者:Virginia M. Mastranzo、Leticia Quintero、Cecilia Anaya de Parrodi、Eusebio Juaristi、Patrick J. Walsh
DOI:10.1016/j.tet.2003.12.039
日期:2004.2
Chiral diamines 1–7 were used in the enantioselective hydrosilylation of prochiral aromatic and aliphatic ketones. Some of these ligands combine chiral backbones and chiral N,N′-α-phenylethyl substituents that give rise to synergistic effects between these two groups and lead to catalysts that exhibit high enantioselectivity.
A new class of structurally rigid tricyclic chiralligands based on the hexahydropyrrolo[2,3‐b]indole skeleton has been rationally designed and the catalytic abilities in asymmetric catalysis have been shown in the enantioselective borane reduction of prochiralketones to afford the chiralalcohols in excellent yields and high enantioselectivities (up to 97% ee).
合理设计了基于六氢吡咯并[2,3- b ]吲哚骨架的一类新型结构刚性的三环手性配体,在不对称催化的前手性甲硼烷的对映选择性硼烷还原反应中显示出不对称催化的催化能力,从而得到了手性醇。优异的收率和高对映选择性(高达97%ee)。
Asymmetric Iron-Catalyzed Hydrosilane Reduction of Ketones: Effect of Zinc Metal upon the Absolute Configuration
Just a little bit: The 1/FeCl2 complex was activated in the presence of Zn and exhibited catalytic activity for the hydrosilanereduction of ketones to give the S‐configured alcohol. In contrast, the mixed‐catalyst system of 1 and Fe(OAc)2 provides the R enantiomer. This approach provides both enantiomers from a single chiral source by the addition of a small amount of Zn.
Copper-Catalyzed Asymmetric Hydrogenation of Aryl and Heteroaryl Ketones
作者:Scott W. Krabbe、Mark A. Hatcher、Roy K. Bowman、Mark B. Mitchell、Michael S. McClure、Jeffrey S. Johnson
DOI:10.1021/ol4021223
日期:2013.9.6
High throughput screening enabled the development of a Cu-based catalyst system for the asymmetric hydrogenation of prochiral aryl and heteroarylketones that operates at H2 pressures as low as 5 bar. A ligand combination of (R,S)-N-Me-3,5-xylyl-BoPhoz and tris(3,5-xylyl)phosphine provided benzylic alcohols in good yields and enantioselectivities. The electronic and steric characteristics of the ancillary