52780-14-0Relevant articles and documents
Mechanochemical, Water-Assisted Asymmetric Transfer Hydrogenation of Ketones Using Ruthenium Catalyst
Kolcsár, Vanessza Judit,Sz?ll?si, Gy?rgy
, (2022/01/04)
Asymmetric catalytic reactions are among the most convenient and environmentally benign methods to obtain optically pure compounds. The aim of this study was to develop a green system for the asymmetric transfer hydrogenation of ketones, applying chiral Ru catalyst in aqueous media and mechanochemical energy transmission. Using a ball mill we have optimized the milling parameters in the transfer hydrogenation of acetophenone followed by reduction of various substituted derivatives. The scope of the method was extended to carbo- and heterocyclic ketones. The scale-up of the developed system was successful, the optically enriched alcohols could be obtained in high yields. The developed mechanochemical system provides TOFs up to 168 h?1. Our present study is the first in which mechanochemically activated enantioselective transfer hydrogenations were carried out, thus, may be a useful guide for the practical synthesis of optically pure chiral secondary alcohols.
Manganese catalyzed asymmetric transfer hydrogenation of ketones
Zhang, Guang-Ya,Ruan, Sun-Hong,Li, Yan-Yun,Gao, Jing-Xing
supporting information, p. 1415 - 1418 (2020/11/20)
The asymmetric transfer hydrogenation (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% of catalyst loading, affording highly valuable chiral alcohols with up to 95% ee.
Asymmetric reduction of prochiral aromatic and hetero aromatic ketones using whole-cell of Lactobacillus senmaizukei biocatalyst
?olak, Nida Sezin,Kalay, Erbay,?ahin, Engin
, p. 2305 - 2315 (2021/05/31)
Asymmetric bioreduction of aromatic and heteroaromatic ketones is an important process in the production of precursors of biologically active molecules. In this study, the bioreduction of aromatic and hetero aromatic prochiral ketones into optically active alcohols was investigated using Lactobacillus senmaizukei as a whole-cell catalyst, since whole-cells are less expensive than pure enzymes. The study indicates enantioselective bioreduction of various substituted aromatic ketones (1–16) to the corresponding (R)-and (S)-chiral secondary alcohols (1a–16a) in low to excellent enantioselectivity (6–94%) with good yields (58–95%). In addition, heteroaromatic prochiral ketones 1-(pyridin-2-yl)ethanone (17) and 1-(furan-2-yl)ethanone (18) were reduced to (R)-17a and (R)-18a in enantiopure form with excellent conversion (>99%) and yields. These findings show that L. senmaizukei is a very important biocatalyst for asymmetric reduction of both 6-membered and 5-member heteroaromatic methyl ketones. This method promising a green synthesis for the synthesis of biologically important secondary chiral alcohols in an environmentally friendly and inexpensive process.
