340-06-7Relevant articles and documents
Co-immobilized Phosphorylated Cofactors and Enzymes as Self-Sufficient Heterogeneous Biocatalysts for Chemical Processes
Velasco-Lozano, Susana,Benítez-Mateos, Ana I.,López-Gallego, Fernando
, p. 771 - 775 (2017)
Enzyme cofactors play a major role in biocatalysis, as many enzymes require them to catalyze highly valuable reactions in organic synthesis. However, the cofactor recycling is often a hurdle to implement enzymes at the industrial level. The fabrication of heterogeneous biocatalysts co-immobilizing phosphorylated cofactors (PLP, FAD+, and NAD+) and enzymes onto the same solid material is reported to perform chemical reactions without exogeneous addition of cofactors in aqueous media. In these self-sufficient heterogeneous biocatalysts, the immobilized enzymes are catalytically active and the immobilized cofactors catalytically available and retained into the solid phase for several reaction cycles. Finally, we have applied a NAD+-dependent heterogeneous biocatalyst to continuous flow asymmetric reduction of prochiral ketones, thus demonstrating the robustness of this approach for large scale biotransformations.
Assessment of headspace solid-phase microextraction (HS-SPME) for control of asymmetric bioreduction of ketones by Alternaria alternata
Ogórek, Rafa?,Jarosz, Bogdan
, p. 75 - 80 (2019/11/03)
The aim of this study was to assess the effectiveness of headspace solid-phase microextraction (HS-SPME) compared to liquid–liquid extractions using with methylene chloride (CH2Cl2) for control of fungal biotransformation of ketones of varying volatility. The proposed method was successfully applied. The best way to extract all the components of the mixture (alcohols, aldehydes) in quantities similar to the extraction of methylene chloride was the use of fibres coated with a combination of nonpolar material. SPME fibre assembly polydimethylsiloxane/divinylbenzene (PDMS/DVB) was most suitable for the extraction of the products mixture obtained after biotransformation of acetylcyclohexane and acetophenone. On the other hand, the best results were obtained for 2-acetylthiophene, α,α,α-trifluoroacetophenone and their derivatives using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibre. In addition, our study showed that Alternaria alternata is a good biocatalyst for bioreduction of ketones to alcohols according to Prelog's rule.
C1-Symmetric PNP Ligands for Manganese-Catalyzed Enantioselective Hydrogenation of Ketones: Reaction Scope and Enantioinduction Model
Zeng, Liyao,Yang, Huaxin,Zhao, Menglong,Wen, Jialin,Tucker, James H. R.,Zhang, Xumu
, p. 13794 - 13799 (2020/11/30)
A family of ferrocene-based chiral PNP ligands is reported. These tridentate ligands were successfully applied in Mn-catalyzed asymmetric hydrogenation of ketones, giving high enantioselectivities (92%～99% ee for aryl alkyl ketones) as well as high efficiencies (TON up to 2000). In addition, dialkyl ketones could also be hydrogenated smoothly. Manganese intermediates that might be involved in the catalytic cycle were analyzed. DFT calculation was carried out to help understand the chiral induction model. The Mn/PNP catalyst could discriminate two groups with different steric properties by deformation of the phosphine moiety in the flexible 5-membered ring.
Asymmetric Catalytic Meerwein-Ponndorf-Verley Reduction of Ketones with Aluminum(III)-VANOL Catalysts
Guan, Yong,Mohammadlou, Aliakbar,Staples, Richard,Sullivan, Ryan P.,Wulff, William D.,Yin, Xiaopeng,Zheng, Li
, p. 7188 - 7194 (2020/07/21)
We report herein an efficient aluminum-catalyzed asymmetric MPV reduction of ketones with broad substrate scope and excellent yields and enantiomeric inductions. A variety of aromatic (both electron-poor and electron-rich) and aliphatic ketones were converted to chiral alcohols in good yields with high enantioselectivities (26 examples, 70-98percent yield and 82-99percent ee). This method operates under mild conditions (-10 °C) and low catalyst loading (1-5 mol percent). Furthermore, this process is catalyzed by the earth-abundant main-group element aluminum and employs 2-propanol as the hydride source.
