transfer hydrogenation (ATH) of ketonescatalyzed by Rh-based macrocycles proceeded smoothly in the presence of air with high catalytic activity and enantioselectivity. Even though the S/C ratio (substrate to catalyst molar ratio) was increased up to 2000:1, the ATH of ketone still afforded 92% isolated yield with 92% ee. Notably, the Rh-based macrocycles could be successfully used to catalyze the ATH
preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetrichydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes usecatalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium
手性分子(如醇)对于精细化学品、药物、农用化学品、香料和新型材料的制造至关重要。这些分子需要以高产率和高光学纯度并优先催化生产。在所有的不对称催化反应中,工业上应用最广泛的是与H2(AH)的不对称加氢反应。除了少数例外,这些 AH 工艺使用基于三种关键金属(铑、钌和铱)的催化剂。在本文中,我们描述了一种简单的、工业上可行的铁催化剂,它允许酮的 AH,目前该过程主要由钌和铑催化剂主导。通过将手性 22 元大环配体与廉价、易得的 Fe3(CO)12 结合,多种酮在 50 bar H2 和 45-65 °C 下氢化,提供了非常有价值的手性醇,其对映选择性接近或超过用贵金属催化剂获得的那些。与大多数贵金属催化剂的 AH 相比,铁催化的氢化似乎是非均相的。
Manganese catalyzed asymmetric transfer hydrogenation of ketones
The asymmetrictransferhydrogenation (ATH) of a wide range of ketones catalyzed by manganese complex as well as chiral PxNy-type ligand under mild conditions was investigated. Using 2-propanol as hydrogen source, various ketones could be enantioselectively hydrogenated by combining cheap, readily available [MnBr(CO)5] with chiral, 22-membered macrocyclic ligand (R,R,R',R')-CyP2N4 (L5) with 2 mol%
研究了锰配合物以及手性P x N y型配体在温和条件下催化的多种酮的不对称转移氢化(ATH)。使用2-丙醇作为氢源,可以通过将廉价的,易于获得的[MnBr(CO)5 ]与手性22元大环配体(R,R,R ',R ')-CyP 2 N结合起来,对映异构地氢化各种酮4(L5)具有2 mol%的催化剂负载量,可提供具有高达95%ee的高度有价值的手性醇。
Ruthenium-catalyzed hydrogenation of aromatic ketones using chiral diamine and monodentate achiral phosphine ligands
作者:Mengna Wang、Ling Zhang、Hao Sun、Qian Chen、Jian Jiang、Linlin Li、Lin Zhang、Li Li、Chun Li
DOI:10.1016/j.catcom.2021.106303
日期:2021.6
The Ru-catalyzed asymmetric hydrogenation of ketones with chiral diamine and monodentate achiral phosphine has been developed. A wide range of ketones were hydrogenated to afford the corresponding chiral secondary alcohols in good to excellent enantioselectivities (up to 98.1% ee). In addition, an appropriate mechanism for the asymmetric hydrogenation was proposed and verified by NMR spectroscopy.
A Concise Synthesis of (S)-(+)-Ginnol Based on Catalytic Enantioselective Addition of Commercially Unavailable Di(n-alkyl)zinc to Aldehydes and Ketones
作者:Kazuaki Ishihara、Manabu Hatano、Tomokazu Mizuno
DOI:10.1055/s-0030-1258129
日期:2010.8
Catalytic, enantioselective n-alkyl addition of commercially unavailable di(n-alkyl)zinc reagents, which were prepared by a refined version of Charette's procedure with Grignard reagents, to aldehydes and ketones was developed. To minimize the side reactions in the catalysis by chiral phosphoramide ligand (1) or 3,3'-diphosphoryl-BINOL ligand (2), a preparation of di(n-alkyl)zinc reagents with a 1:2