Organocatalytic Biomimetic Reduction of Conjugated Nitroalkenes
作者:Peter Schreiner、Zhiguo Zhang
DOI:10.1055/s-2007-983805
日期:2007.8
A thiourea-catalyzed biomimetic reduction of conjugatednitroalkenes has been developed. Various aromatic and aliphatic conjugatednitroalkenes can be reduced to give the respective nitroalkanes with good yields under mild conditions. This protocol is not only practical, but may also provide insight into the mechanisms of redox transformations in biological systems.
Characterization of xenobiotic reductase A (XenA): study of active site residues, substrate spectrum and stability
作者:Yanto Yanto、Hua-Hsiang Yu、Mélanie Hall、Andreas S. Bommarius
DOI:10.1039/c0cc02354j
日期:——
Xenobiotic reductase A (XenA) has broad catalytic activity and reduces various α,β-unsaturated and nitro compounds with moderate to excellent stereoselectivity. Single mutants C25G and C25V are able to reduce nitrobenzene, a non-active substrate for the wild type, to produce aniline. Total turnover is dominated by chemical rather than thermal instability.
Weak Lewis acid for high nucleophilicity: Hydridoborate derived from B(2,6‐F2C6H3)3 shows significant hydride character. Solid‐state and solution structure analysis revealed a dihydrogen‐bonded aggregate. The new frustratedLewispair was applied in the hydrogenation of nitroolefins and acrylates (see scheme; EWG=electron‐withdrawing group). The decreased Lewis acidity provides higher reactivity and
弱路易斯酸,具有高亲核性:衍生自B(2,6-F 2 C 6 H 3)3的氢硼酸盐显示出显着的氢化物特征。固态和溶液结构分析表明,存在氢键结合的聚集体。新的受阻的路易斯对用于硝基烯烃和丙烯酸酯的氢化反应(参见方案; EWG =吸电子基团)。降低的路易斯酸度可提供更高的反应性和官能团耐受性。
Conjugate Addition of Nitro-Derivatives to α,β-Unsaturated Carbonyl Compounds on Basic Alumina
Conjugate addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of basic alumina without a solvent. Yields are fair to good also with substrates which are acid or base sensitive.
Asymmetric Organocatalytic Sequential Reaction of Structurally Complex Cyclic Hemiacetals and Functionalized Nitro-olefins To Synthesize Diverse Heterocycles
作者:Jun-Ping Pei、Ying-Han Chen、Yan-Kai Liu
DOI:10.1021/acs.orglett.8b01386
日期:2018.6.15
Structurally complex cyclic hemiacetals bearing a racemic tetrasubstituted stereocenter have been prepared in a concise manner and were successfully used in an organocatalytic enantioselective sequence to react with functionalized nitro-olefins, providing bicyclic acetal-containing compounds as two separable epimers with excellent stereoselectivity. The reaction showed broad substrate scope, with respect