Enzyme-catalysed asymmetric reduction of ketones is an attractive tool for the production of chiral building blocks or precursors for the synthesis of bioactive compounds. Expression of robust ketoreductase (KRED) from Hansenula polymorpha was upscaled and applied for the asymmetric reduction of 31 prochiral carbonyl compounds (aliphatic and aromaticketones, diketones and β-keto esters) to the corresponding
The direct proline-catalyzedasymmetric α-aminoxylation of aldehydes and ketones has been developed using nitrosobenzene as an oxygen source, affording α-anilinoxy-aldehydes and -ketones with excellent enantioselectivity. Reaction conditions have been optimized, and low temperature (−20 °C) was found to be a key for the successful α-aminoxylation of aldehydes, while slow addition of nitrosobenzene
Preparation of monoacetylated diols via cyclic ketene acetals
作者:Peter C. Zhu、Jinyan Lin、Charles U. Pittman
DOI:10.1021/jo00122a075
日期:1995.9
Intermediates for preparing optically active carboxylic acids
申请人:Zambon spa
公开号:US04861903A1
公开(公告)日:1989-08-29
A process is described for preparing optically active alpha-arylalkanoic acids consisting of rearranging an optically active ketal of formula ##STR1## in which the substituents have the meaning given in the description of the invention.
Highly efficient and recyclable chiral Pt nanoparticle catalyst for enantioselective hydrogenation of activated ketones
作者:Xiuru Xue、Pu Chen、Peng Xu、Yanhua Wang
DOI:10.1016/j.catcom.2018.03.012
日期:2018.5
phase-separable chiral Pt nanoparticle catalyst exhibited excellent ee (>99%) in the enantioselectivehydrogenation of activated ketones for preparing chiral α-hydroxy acetals and chiral 1,2-diols. More importantly, the chiral catalyst could be easily separated by phase separation and directly reused in the next cycle without any loss in catalytic activity and enantioselectivity, even in the gram-scale reaction