61912-03-6Relevant articles and documents
CO2-Enabled Cyanohydrin Synthesis and Facile Iterative Homologation Reactions**
Juhl, Martin,Petersen, Allan R.,Lee, Ji-Woong
supporting information, p. 228 - 232 (2020/11/30)
Thermodynamic and kinetic control of a chemical process is the key to access desired products and states. Changes are made when a desired product is not accessible; one may manipulate the reaction with additional reagents, catalysts and/or protecting groups. Here we report the use of carbon dioxide to accelerate cyanohydrin synthesis under neutral conditions with an insoluble cyanide source (KCN) without generating toxic HCN. Under inert atmosphere, the reaction is essentially not operative due to the unfavored equilibrium. The utility of CO2-mediated selective cyanohydrin synthesis was further showcased by broadening Kiliani–Fischer synthesis under neutral conditions. This protocol offers an easy access to a variety of polyols, cyanohydrins, linear alkylnitriles, by simply starting from alkyl- and arylaldehydes, KCN and an atmospheric pressure of CO2.
Immobilized Baliospermum montanum hydroxynitrile lyase catalyzed synthesis of chiral cyanohydrins
Jangir, Nisha,Padhi, Santosh Kumar
, p. 32 - 40 (2018/11/27)
Hydroxynitrile lyase (HNL) catalyzed enantioselective C–C bond formation is an efficient approach to synthesize chiral cyanohydrins which are important building blocks in the synthesis of a number of fine chemicals, agrochemicals and pharmaceuticals. Immobilization of HNL is known to provide robustness, reusability and in some cases also enhances activity and selectivity. We optimized the preparation of immobilization of Baliospermium montanum HNL (BmHNL) by cross linking enzyme aggregate (CLEA) method and characterized it by SEM. Optimization of biocatalytic parameters was performed to obtain highest % conversion and ee of (S)-mandelonitrile from benzaldehyde using CLEA-BmHNL. The optimized reaction parameters were: 20 min of reaction time, 7 U of CLEA-BmHNL, 1.2 mM substrate, and 300 mM citrate buffer pH 4.2, that synthesized (S)-mandelonitrile in ～99% ee and ～60% conversion. Addition of organic solvent in CLEA-BmHNL biocatalysis did not improve in % ee or conversion of product unlike other CLEA-HNLs. CLEA-BmHNL could be successfully reused for eight consecutive cycles without loss of conversion or product formation and five cycles with a little loss in enantioselectivity. Eleven different chiral cyanohydrins were synthesized under optimal biocatalytic conditions in up to 99% ee and 59% conversion, however the % conversion and ee varied for different products. CLEA-BmHNL has improved the enantioselectivity of (S)-mandelonitrile synthesis compared to the use of purified BmHNL. Nine aldehydes not tested earlier with BmHNL were converted into their corresponding (S)-cyanohydrins for the first time using CLEA-BmHNL. Among the eleven (S)-cyanohydrins syntheses reported here, eight of them have not been synthesized by any CLEA-HNL. Overall, this study showed preparation, characterization of a stable, robust and recyclable biocatalyst i.e. CLEA-BmHNL and its biocatalytic application in the synthesis of different (S)-aromatic cyanohydrins.
Aminoalcohol neuraminidase inhibitors, and preparation method thereof
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Paragraph 0031; 0035, (2017/09/01)
The invention discloses aminoalcohol neuraminidase inhibitors, and a preparation method thereof. The method concretely comprises the following steps: 1, reacting cinnamaldehyde, lithium perchlorate LiClO4.3H2O and trimethylsilyl cyanide (TMSCN) to obtain cyan analog; 2, reducing the cyan analog under the action of a reducing agent and an additive in order to obtain hydroxyl-substituted amino compounds; 3, reacting the hydroxyl-substituted amino compounds with acyl chloride under an alkaline condition to obtain one neuraminidase inhibitor; and 4, reacting the hydroxyl-substituted amino compounds with substituted benzyl bromide under an alkaline condition to obtain another one neuraminidase inhibitor with another structure. The compounds synthesized in the invention have novel structures, and have good neuraminidase activity.
