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Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile via asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal was successfully carried out for the first time. The optimal volume ratio of aqueous to organic phase, buffer pH value and reaction temperature were 15% (v/v), 5.0 and 30°C, respectively, under which both substrate conversion and product enantiomeric excess (ee) were 99%. Silicon atom in the substrate showed great effect on the reaction. Acetyltrimethylsilane was a much better substrate for (R)-hydroxynitrile lyase from Prunus japonica than its carbon analogue. 相似文献
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Synthesis of (R)-2-trimethylsilyl-2-hydroxyl-propionitrile via asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed by (R)-hydroxynitrile lyase from Prunus japonica seed meal was successfully carried out for the first time. The optimal volume ratio of aqueous to organic phase, buffer pH value and reaction temperature were 15% (v/v), 5.0 and 30°C, respectively, under which both substrate conversion and product enantiomeric excess (ee) were 99%. Silicon atom in the substrate showed great effect on the reaction. Acetyltrimethylsilane was a much better substrate for (R)-hydroxynitrile lyase from Prunus japonica than its carbon analogue. 相似文献
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The synthesis of optically active (R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide by asymmetric trans-cyanation of acetyltrimethylsilane with acetone cyanohydrin in a biphasic system was achieved using (R)-oxynitrilase from loquat seed meal. Diisopropyl ether was the most suitable organic phase among the organic solvents examined. The optimal concentration of acetyltrimethylsilane, concentration of crude enzyme, volume ratio of the aqueous to the organic phase, temperature and the buffer pH value were 14 mM, 61.4 U ml-1, 13% (v/v), 30 °C and 4, respectively. The substrate conversion and the product enantiomeric excess were 95% and 98% under the optimized conditions. Acetyltrimethylsilane was a better substrate of the enzyme than its carbon counterpart.
Revisions requested 24 August 2004; Revisions received 12 November 2004 相似文献
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非天然有机硅化合物不但在有机合成及功能材料的制备中发挥重要的作用,且在药物设计和改造中具有广阔的应用前景。近年来,酶催化有机硅化合物的生物合成研究取得了长足的进展。 相似文献
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Kazuhiro Haraguchi Masanori Sumino Hiromichi Tanaka 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):835-839
For the synthesis of 2′,3′ -didehydro-3′ -deoxy-4′ -C-ethynylthymidine (8: 4′ -Ed4T), a recently reported promising anti-HIV agent, a new approach was developed. Since treatment of 1-(2,5-dideoxy-β-l-glycero-pent-4-enofuranosyl)thymine with Pb(OBz)4 allowed the introduction of a 4′-benzoyloxy leaving group, nucleophilic substitution at the 4′ -position became feasible for the first time. Thus, reaction between the 4′-benzoyloxy derivative (11) and Me3SiC ≡ CAl(Et)Cl as a nucleophile led to the isolation of the desired 4′-“down”-ethynyl derivative (15) stereoselectively in 62% yield. 相似文献
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(R)-oxynitrilase-catalysed synthesis of chiral silicon-containing aliphatic (R)-ketone-cyanohydrins 总被引:2,自引:0,他引:2
Optically active 2-trimethylsilyl-2-hydroxyl-ethylcyanide was prepared by enzymatic enantioselective transcyanation of acetyltrimethylsilane with acetone cyanohydrin in a biphasic system at 35°C and pH 5. (R)-Oxynitrilase from apple seed meal was the best among all the enzymes explored and diisopropyl ether was the most suitable organic phase. Acetyltrimethylsilane was a better substrate of the enzyme than its carbon analogue. The substrate conversion and product enantiomeric excess of 2-trimethylsilyl-2-hydroxyl-ethylcyanide were >99% and >99%, respectively. 相似文献
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