79-50-5Relevant articles and documents
Adsorption and stability of chiral modifiers based on 1-(1-naphthyl)-ethylamine for Pt catalysed heterogeneous asymmetric hydrogenations
Meemken, Fabian,Steiger, Titian,Holland, Mareike C.,Gilmour, Ryan,Hungerbühler, Konrad,Baiker, Alfons
, p. 705 - 715 (2015)
Synthetic chiral modifiers suitable for modular build-up are highly desirable for tuning the efficiency and extending the versatility of asymmetric hydrogenations on chirally-modified metal catalysts. Adsorptive anchoring and structural stability of the simple chiral modifier (R)-1-(1-naphthyl)-ethylamine [(R)-NEA] and the upgraded, secondary amine chiral modifier (R,S)-pantoylnaphthylethylamine [(R,S)-PNEA] have been investigated under catalytic hydrogenation conditions. Using attenuated total reflection-infrared (ATR-IR) spectroscopy the adsorption modes of (R)-NEA and (R,S)-PNEA at the solid-liquid interface of a technical 5 wt% Pt/Al2O3 catalyst were investigated. In addition to the naphthalene group, (R,S)-PNEA is also anchored to Pt through its pantoyl moiety providing both enhanced anchoring and also a better defined chiral surface site for the asymmetric hydrogenation of ketopantolactone (KPL). Factors influencing the stability of NEA-based chiral modifiers are discussed. The recently discovered chiral fragmentation product of (R,S)-PNEA, (S)-amino-4,4-dimethyl-dihydrofuran-2-one [(S)-AF] is shown to play no role in conferring enantioselectivity in the asymmetric hydrogenation of KPL.
Preparation method of DL-pantoic acid lactone
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Paragraph 0042; 0046-0048; 0052-0054; 0058-0064, (2021/02/06)
The invention discloses a preparation method of DL-pantoic acid lactone, which comprises the following steps: reacting formaldehyde with isobutyraldehyde in the presence of a basic catalyst, slowly dropwise adding the reaction solution into sodium cyanide, adding an acid solution after the reaction is finished, and carrying out esterification reaction to obtain the DLpantoic acid lactone. The reaction is carried out in a water system, high-temperature and high-pressure reaction conditions are not needed, the process safety performance is high, the energy-saving and consumption-reducing effectsare obvious, and a high-content target product is obtained at a high yield, so that the production cost is reduced, and the method is a safe and simple DL-pantoic acid lactone production method.
Preparation method of hydroxyaldehyde and method for resolving optical isomer by using electrodialysis technology
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Paragraph 0265-0267, (2020/12/15)
The present invention provides a process for preparing hydroxyaldehydes using an immobilized catalyst, wherein the immobilized catalyst comprises a solid support and a tertiary amine-based functionalgroup. The invention also provides a method for preparing a polyhydroxy alcohol compound and a polyhydroxy acid compound. The invention further provides a method for splitting the optical isomer fromthe raceme through electrodialysis.