Microbial deracemisation of N-(1-hydroxy-1-phenylethyl)benzamide
摘要:
Microbial deracemisation of racemic N-(1-hydroxy-1-phenylethyl)benzamide to give the (R)-enantiomer is described using whole cells of Cunninghamella echinulata NRRL 1384. The deracemisation involves fast highly (S)-selective oxidation followed by slower partially (S)-selective reduction of the intermediate ketone. The yield and ee of (R)-N-(1-hydroxy-1-phenylethyl)benzamide were optimised (82%, 98% ee) by removal of a competing extracellular amidase/protease activity by using static cells at pH 5. Use of the protease inhibitor PMSF with growing cells leads to a slower deracemisation (82% ee) but a very high (98%) overall recovery of alcohol and ketone. (C) 2003 Elsevier Ltd. All rights reserved.
Enantioselective Aminohydroxylation of Styrenyl Olefins Catalyzed by an Engineered Hemoprotein
作者:Inha Cho、Christopher K. Prier、Zhi‐Jun Jia、Ruijie K. Zhang、Tamás Görbe、Frances H. Arnold
DOI:10.1002/anie.201812968
日期:2019.3.4
Chiral 1,2‐aminoalcohols are widely represented in biologically active compounds from neurotransmitters to antivirals. While many synthetic methods have been developed for accessing aminoalcohols, the direct aminohydroxylation of alkenes to unprotected, enantioenriched aminoalcohols remains a challenge. Using directed evolution, we have engineered a hemoprotein biocatalyst based on a thermostable
A Convenient Synthesis of 2-Oxazolines and 2-Benoxazoles with PPh3-DDQ as the Dehydrating Reagent
作者:Quancai Xu、Zhengning Li、Huiying Chen
DOI:10.1002/cjoc.201190190
日期:2011.5
2‐benoxazoles were synthesized in high yields from acylamino alcohols and acylamino‐ phenols, respectively, with triphenylphosphine‐2,3‐dichloro‐5,6‐dicyanobenzoquinone (PPh3‐DDQ) as the dehydrating and activating reagent. The synthesis was accomplished under neutral conditions.
Efficient P-Chiral Biaryl Bisphosphorus Ligands for Palladium-Catalyzed Asymmetric Hydrogenation
作者:Wenhao Jiang、Qing Zhao、Wenjun Tang
DOI:10.1002/cjoc.201700645
日期:2018.2
A series of structurally novel P‐chiral biaryl bisphosphorus ligands L1‐L5 (BABIBOPs) are developed, providing high efficiency for the first time in palladium‐catalyzedasymmetrichydrogenation of β‐aryl and β‐alkyl substituted β‐keto esters. With the Pd‐L3 (iPr‐BABIBOP) catalyst, a series of chiral β‐hydroxyl carboxylic esters are formed in excellent enantioselectivities (up to>99% ee) and yields
Exploration of the Fluoride Reactivity of Aryltrifluoroborate on Selective Cleavage of Diphenylmethylsilyl Groups
作者:Katsumasa Fujiki、Katsunori Tanaka
DOI:10.1002/ejoc.202000707
日期:2020.8.9
substituents on the benzene ring. The fluorine on trifluoroborate interacts with silicon and activates the Si–O bond to enable selective desilylation of the diphenylmethylsilyl group. Selective desilylation of a primary silylether in the presence of a secondary silylether by the trifluoroborate was also successful.
Palladium-Catalyzed Asymmetric Hydrogenation of Functionalized Ketones
作者:You-Qing Wang、Sheng-Mei Lu、Yong-Gui Zhou
DOI:10.1021/ol051007u
日期:2005.7.1
[reaction: see text]. A novel catalytic system for asymmetrichydrogenation of functionalized ketones has been developed using a Pd/bisphosphine complex as the catalyst in 2,2,2-trifluoroethanol. The reaction exhibits high enantioselectivity, and up to 92.2% ee was obtained.