Vanishing aromaticity: A chiral ruthenium complex catalyzes the hydrogenation of 2,6‐ or 2,7‐disubstituted naphthalenes to give chiral tetralins with up to 92 % ee. The chiral catalyst is applicable to the regio‐ and enantioselective reduction of 6‐substituted 2‐alkoxynaphthalenes and preferentially hydrogenates the alkoxy‐substituted arene rings.
Ketoreductase activity for reduction of substituted-β-tetralones utilizing aqueous-organic systems and β-cyclodextrin derivatives
作者:Galina A. Petkova、Vladimír Král
DOI:10.3109/10242422.2012.662960
日期:2012.3
Ketoreductases (KREDs) were employed for enantioselective reduction of 7-hydroxy-2-tetralone 1a and adduct 7-methoxy-2-tetralonbisulfite 2a to their corresponding (S)-/(R)-alcohols. In addition, the effect of additives such as organic solvents and beta-cyclodextrin derivatives on the enzyme reductions was investigated. The changes in enzyme activity as a function of additives were correlated to structural alterations of the KREDs using circular dichroism and fluorescence spectrophotometric measurements. The effects of both the organic solvents and beta-cyclodextrin derivatives on substrate solubility and equilibrium binding constants (log K) of beta-cyclodextrin-substrate complexes were determined.
Tetrahydroxynaphthalene Reductase: Catalytic Properties of an Enzyme Involved in Reductive Asymmetric Naphthol Dearomatization
作者:Michael A. Schätzle、Stephan Flemming、Syed Masood Husain、Michael Richter、Stefan Günther、Michael Müller
DOI:10.1002/anie.201107695
日期:2012.3.12
In reduced circumstances: Tetrahydroxynaphthalenereductase shows a broad substrate range including alternate phenolic compounds and cyclic ketones. Structural modeling reveals major enzyme–substrate interactions; C‐terminal truncation of the enzyme causes an altered substrate preference, in accordance with stabilization of the substrate by the C‐terminal carboxylate (see picture). This effect allows