Studies on Optically Active Amino Acids. V. Synthesis of Optically Active α-Aminoalcohols by the Reduction of α-Amino Acid Esters with Sodium Borohydride
A facile reduction of optically active α-amino acid esters and their hydrochlorides took place with sodium borohydride in ethanol or aqueous ethanol to give the corresponding optically active α-aminoalcohols in fair yields. The reaction conditions were investigated.
作者:Stefan Velikogne、Willem B. Breukelaar、Florian Hamm、Ronald A. Glabonjat、Wolfgang Kroutil
DOI:10.1021/acscatal.0c03755
日期:2020.11.20
Although enzymes have been found for many reactions, there are still transformations for which no enzyme is known. For instance, not a single defined enzyme has been described for the reduction of the C═Nbond of an oxime, only whole organisms. Such an enzymatic reduction of an oxime may give access to (chiral) amines. By serendipity, we found that the oxime moiety adjacent to a ketone as well as an ester
Oligonucleotides containing abasic threoninol-terpyridine residues as potential artificial ribonucleases
作者:William C. Putnam、James K. Bashkin
DOI:10.1016/j.jinorgbio.2022.111831
日期:2022.7
Artificial ribonucleases, also known as synthetic ribozymes, were synthesized with an internal, stereochemically-pure, abasic threoninol backbone-residue to which the RNA transesterification catalyst copper (II) terpyridine was covalentlylinked. These oligonucleotide conjugates were constructed to determine if the stereochemistry of the abasic threoninol backbone residue influences the transesterification
人工核糖核酸酶,也称为合成核酶,是用内部立体化学纯的脱碱基苏氨醇骨架残基合成的,RNA 酯交换催化剂铜 (II) 三联吡啶共价连接到该骨架残基上。构建这些寡核苷酸缀合物以确定无碱基苏氨醇骨架残基的立体化学是否影响互补RNA寡核苷酸的酯交换速率。合成后,这些化合物与互补的 28-mer 和 159-mer RNA 底物反应,并测定了它们的相对酯交换效率。酯交换动力学也与之前合成的寡核苷酸进行了比较,这些寡核苷酸通过丝氨醇残基掺入了铜 (II) 三联吡啶。2S,3S )-苏氨醇骨架在 RNA 酯交换中比它们的 ( 2R,3R )-立体异构体对应物更有效。
Mechanistic Insights into the Ene-Reductase-Catalyzed Promiscuous Reduction of Oximes to Amines
作者:Willem B. Breukelaar、Nakia Polidori、Amit Singh、Bastian Daniel、Silvia M. Glueck、Karl Gruber、Wolfgang Kroutil
DOI:10.1021/acscatal.2c06137
日期:2023.2.17
transforming α-oximo β-keto esters. However, the reaction pathway of this two-step reduction remained elusive. By studying the crystal structures of enzyme oxime complexes, analyzing molecular dynamics simulations, and investigating biocatalytic cascades and possible intermediates, we obtained evidence that the reaction proceeds via an imine intermediate and not via the hydroxylamine intermediate. The