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5-(α-D-Glucosyloxymethyl)furfural, a versatile building block from renewable resources, was prepared from isomaltulose–choline chloride melts by acid catalysis. In this solvent-free process, moderate yields were achieved under mild reaction conditions. 相似文献
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Recombinant Cyanobacteria for the Asymmetric Reduction of C=C Bonds Fueled by the Biocatalytic Oxidation of Water 下载免费PDF全文
Katharina Köninger Dr. Álvaro Gómez Baraibar Dr. Carolin Mügge Dr. Caroline E. Paul Dr. Frank Hollmann Dr. Marc M. Nowaczyk Prof. Dr. Robert Kourist 《Angewandte Chemie (International ed. in English)》2016,55(18):5582-5585
A recombinant enoate reductase was expressed in cyanobacteria and used for the light‐catalyzed, enantioselective reduction of C=C bonds. The coupling of oxidoreductases to natural photosynthesis allows asymmetric syntheses fueled by the oxidation of water. Bypassing the addition of sacrificial cosubstrates as electron donors significantly improves the atom efficiency and avoids the formation of undesired side products. Crucial factors for product formation are the availability of NADPH and the amount of active enzyme in the cells. The efficiency of the reaction is comparable to typical whole‐cell biotransformations in E. coli. Under optimized conditions, a solution of 100 mg prochiral 2‐methylmaleimide was reduced to optically pure 2‐methylsuccinimide (99 % ee, 80 % yield of isolated product). High product yields and excellent optical purities demonstrate the synthetic usefulness of light‐catalyzed whole‐cell biotransformations using recombinant cyanobacteria. 相似文献
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The SBFEM is used to calculate dynamic stiffness matrices of unbounded media. Time–domain respresentations of the associated force–displacement relationship are obtained approximating the latter by rational functions. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献