99-45-6Relevant articles and documents
Visible-Light-Mediated Amination of π-Nucleophiles with N-Aminopyridinium Salts
Goliszewska, Katarzyna,Rybicka-Jasińska, Katarzyna,Szurmak, Jakub,Gryko, Dorota
, p. 15834 - 15844 (2019/11/03)
N-Aminopyridinium salts generate nitrogen-centered radicals by means of photoredox catalysis. Herein, we report that they can be trapped by enol equivalents to give α-amino carbonyl compounds in excellent yields. The broad synthetic utility of this method is demonstrated by functionalization of ketones, aldehydes, esters enol equivalents, vinyl ethers, and 1,3-diketones without the need for prior conversion to enol derivatives. The developed method is easily scalable, offers broad substrate scope, high chemoselectivity.
Purification and characterization of a novel carbonyl reductase involved in oxidoreduction of aromatic β-amino ketones/alcohols
He, Shengbin,Wang, Zhenshou,Zou, Yang,Chen, Shaofang,Xu, Xiaoping
, p. 1107 - 1112 (2014/06/10)
Aromatic β-amino ketones/alcohols such as adrenalone play an important role in some stereoselective synthesis of pharmaceuticals. Unfortunately, the transformation of aromatic β-amino ketones to their chiral alcohols has been carried out chemically as no corresponding biocatalyst has been available. Here, a novel carbonyl reductase responsible for the reduction of adrenalone to (R)-(-)-epinephrine was identified and characterized from Kocuria rhizophila. This enzyme was purified to homogeneity by ammonium sulfate precipitation followed by ion-exchange column chromatography, hydrophobic chromatography and gel chromatography. The purified enzyme yielded pure (R)-enantiomer product with high activity and utilized NADH as the cofactor. The enzyme had special significance by showing selectivity for many aromatic β-amino ketones/alcohols such as 2-amino-acetophenone, 2-amino-4′- hydroxyacetophenone, isoproterenol and ephedrine. The maximum reaction rate (Vmax) and apparent Michaelis-Menten constant (Km) for adrenalone and NADH were 14.62 μmol/(min mg) protein and 0.189 mM, 11.66 μmol/(min mg) protein and 0.204 mM respectively. These properties ensure the enzyme a promising future for industrial application as a replacement of chemical synthesis of aromatic β-amino chiral alcohols.
One-Electron Redox Potentials of Phenols. Hydroxy- and Aminophenols and Related Compounds of Biological Interest
Steenken, S.,Neta, P.
, p. 3661 - 3667 (2007/10/02)
The rate constants for reversible electron transfer between a series of substituted phenolate ions and anilines and various substituted phenoxyl or anilino radicals in aqueous solution were measured by observing the formation or depletion of the radicals involved.Nonequilibrium concentrations of the radicals were produced in the presence of the corresponding phenols or anilines by using the pulse radiolysis technique.The relaxation of the system to equilibrium was monitored by optical detection methods.From the equilibrium constants for one-electron transfer, the one-electron redox potentials (E2) for 38 phenolic or anilino type compounds were determined, many of which are natural products.The redox potentials are strongly influenced by electron-donating or -withdrawing substituents at the aromatic system.
