Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA)
作者:Katharina Durchschein、Walter M. F. Fabian、Peter Macheroux、Klaus Zangger、Gregor Trimmel、Kurt Faber
DOI:10.1039/c0ob01216e
日期:——
A novel reductive biotransformation pathway for β,β-disubstituted nitroalkenes catalyzed by flavoproteins from the Old Yellow Enzyme (OYE) family was elucidated. It was shown to proceed via enzymatic reduction of the nitro-moiety to furnish the corresponding nitroso-alkene, which underwent spontaneous (non-enzymatic) electrocyclization to form highly strained 1,2-oxazete derivatives. At elevated temperatures the latter lost HCN via a retro-[2 + 2]-cycloaddition to form the corresponding ketones. This pathway was particularly dominant using xenobiotic reductase A, while pentaerythritol tetranitrate-reductase predominantly catalyzed the biodegradation via the Nef-pathway.
Three cloned enoate reductases from the “old yellow enzyme” family of flavoproteins were investigated in the asymmetricbioreduction of activatedalkenes. 12-Oxophytodienoatereductaseisoenzymes OPR1 and OPR3 from Lycopersicon esculentum (tomato), and YqjM from Bacillus subtilis displayed a remarkably broad substrate spectrum by reducing α,β-unsaturated aldehydes, ketones, maleimides and nitroalkenes
The asymmetricbioreduction of C=C-bonds bearing an electron-withdrawing group, such as an aldehyde, ketone, imide, nitro, carboxylic acid, or ester moiety by a novel enoatereductasefrom Zymomonas mobilis and OldYellowEnzymesOYE1–3fromyeasts furnished the corresponding saturated products in up to >99 % ee. Depending on the substrate type, stereocontrol was achieved by variation of the substrate
Highly Enantioselective Reduction of β,β-Disubstituted Aromatic Nitroalkenes Catalyzed by <i>Clostridium sporogenes</i>
作者:Anna Fryszkowska、Karl Fisher、John M. Gardiner、Gill M. Stephens
DOI:10.1021/jo800124v
日期:2008.6.1
This is the first report of the use of Clostridium sporogenes extracts for enantioselective reduction of C═C double bonds of β,β-disubstituted (1) and α,β-disubstituted nitroalkenes (3). Crude enzyme preparations reduced aryl derivatives 1a−e and 1h, in 35−86% yield with ≥97% ee. Reduction of (E)- and (Z)-isomers of 1c gave the same enantiomer of 2c (≥99% ee). In contrast, α,β-disubstituted nitroalkene
Substrate Scope Evaluation of the Enantioselective Reduction of β-Alkyl-β-arylnitroalkenes by Old Yellow Enzymes 1-3 for Organic Synthesis Applications
作者:Mattia Bertolotti、Elisabetta Brenna、Michele Crotti、Francesco G. Gatti、Daniela Monti、Fabio Parmeggiani、Sara Santangelo
DOI:10.1002/cctc.201500958
日期:2016.2
to bioreduction, to define the synthetic potential of this enantioselective reaction in the preparation of chiral fine chemicals. The versatility of the resulting nitroalkanes as chiral building blocks is shown by reducing the nitro group into a primary amine and by converting it into a carboxylic acid moiety by Meyerreaction.