Asymmetric hydrogenation of the C–C double bond of 1- and 1,2-methylated maleimides with cultured suspension cells of Marchantia polymorpha
摘要:
Suspension cultured cells of Marchantia polymorpha have the potential to hydrogenate the C-C double bonds of 2-methyl- and 2,3-dimethylmaleimide derivatives to give enantiomerically pure (2R)-2-methyl- and (2R, 3R)-2, 3-dimethylsuccinimide derivatives, respectively. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis of Aliphatic Carboxamides Mediated by Nickel NN<sub>2</sub>
-Pincer Complexes and Adaptation to Carbon-Isotope Labeling
作者:Karoline T. Neumann、Aske S. Donslund、Thomas L. Andersen、Dennis U. Nielsen、Troels Skrydstrup
DOI:10.1002/chem.201804077
日期:2018.10.9
reagents, stoichiometric carbonmonoxide and amines is described for the first time, which can be adapted to late‐stage carbon‐isotope labeling. This work expands the scope of the highly established palladium‐promoted version of the reaction, by allowing carbon‐sp3 fragments to take part in the three‐component reaction. Finally, the results obtained show a remarkable effect of the pincer ligand for
首次介绍了使用NN 2钳形镍配合物,烷基锌试剂,化学计量一氧化碳和胺开发镍介导的氨基羰基化反应的方法,该方法可用于后期碳同位素标记。通过允许碳sp 3片段参与三组分反应,这项工作扩展了高度确立的钯促进反应的范围。最后,获得的结果显示了钳型配体在用胺进行的还原消除步骤中的显着效果,随后进行了13 C NMR光谱研究。
Asymmetric bioreduction of activated carbon–carbon double bonds using Shewanella yellow enzyme (SYE-4) as novel enoate reductase
作者:Naseem Iqbal、Florian Rudroff、Ann Brigé、Jozef Van Beeumen、Marko D. Mihovilovic
DOI:10.1016/j.tet.2012.05.092
日期:2012.9
Shewanella yellow enzyme (SYE-4), a novel recombinant enoate reductase, was screened against a variety of different substrates bearing an activated double bond, such as unsaturated cyclic ketones, diesters, and substituted imides. Dimethyl- and ethyl esters of 2-methylmaleic acid were selectively reduced to (R)-configured succinic acid derivatives and various N-substituted maleimides furnished the desired (R)-products in up to >99% enantiomeric excess. Naturally occurring (+)-carvone was selectively reduced to (-)-cis-dihydrocarvone and (-)-carvone was converted to the diastereomeric product, respectively. Overall SYE-4 proved to be a useful biocatalyst for the selective reduction of activated C=C double bonds and complements the pool of synthetic valuable enoate reductases. (C) 2012 Elsevier Ltd. All rights reserved.
Selective ammonolysis and aminolysis of dimethyl succinate. Synthesis of optically active N-alkylsuccinimides
Candida antarctica lipase catalyzes the selective monoammonolysis and aminolysis of dimethyl succinate with ammonia and aliphatic amines, respectively, in dioxane as solvent. This enzyme shows a high enatioselectivity when racemic amines are used. Optically active amidoesters are also obtained in the reaction of dimethyl succinate with racemic alpha-methylalkylamines in hexane as solvent. In this medium, the enzyme catalyzes the formation of N-alkylsuccinimides or optically active N-alkyl-alpha-methylsuccinimides from dimethyl succinate or alpha-methylsuccinate and amines.
Efficient asymmetric hydrogenation of the C–C double bond of 2-methyl- and 2,3-dimethyl-N-phenylalkylmaleimides by Aspergillus fumigatus
作者:Maximiliano Sortino、Susana Alicia Zacchino
DOI:10.1016/j.tetasy.2010.02.017
日期:2010.3
Eight N-phenylalkylmaleimides (four 2-methyl-N-phenylalkylmaleimides and four 2,3-dimethyl-N-phenylalkylmaleimides with an alkyl chain (CH(2))(n) (n = 1-4) between the imide N and the benzene ring) were subjected to biotransformation using the fungal strain Aspergillus fumigatus ATCC 26934. All compounds were reduced enantioselectively to their respective succinimides: (R)-2-methyl-N-phenylalkylsuccinimides and (2R,3R)-2,3-dimethyl-N-phenylalkylsuccinimides, with satisfactory conversion rates and high stereoisomeric excesses. NMR analysis using the chiral shift reagent Eu(hfc)(3) showed that enantiomeric excesses were >99%. (C) 2010 Elsevier Ltd. All rights reserved.