66291-23-4Relevant articles and documents
Asymmetric bioreduction of C=C bonds using enoate reductases OPR1, OPR3 and YqjM: Enzyme-based stereocontrol
Hall, Melanie,Stueckler, Clemens,Ehammer, Heidemarie,Pointner, Eva,Oberdorfer, Gustav,Gruber, Karl,Hauer, Bernard,Stuermer, Rainer,Kroutil, Wolfgang,Macheroux, Peter,Faber, Kurt
, p. 411 - 418 (2008)
Three cloned enoate reductases from the "old yellow enzyme" family of flavoproteins were investigated in the asymmetric bioreduction of activated alkenes. 12-Oxophytodienoate reductase isoenzymes 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 reaction proceeded with absolute chemoselectivity-only the conjugated C=C bond was reduced, while isolated olefins and carbonyl groups remained intact-with excellent stereoselectivities (ees up to >99%). Upon reduction of a nitroalkene, the stereochemical outcome could be determined via choice of the appropriate enzyme (OPR1 versus OPR3 or YqjM), which furnished the corresponding enantiomeric nitroalkanes in excellent ee. Molecular modelling suggests that this "enzyme-based stereocontrol" is caused by subtle differences within the active site geometries.
Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA)
Durchschein, Katharina,Fabian, Walter M. F.,MacHeroux, Peter,Zangger, Klaus,Trimmel, Gregor,Faber, Kurt
supporting information; experimental part, p. 3364 - 3369 (2011/06/25)
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.
Diastereo- and enantioselective Aza-MBH-type reaction of nitroalkenes to N-tosylimines catalyzed by bifunctional organocatalysts
Wang, Xiao,Chen, Yong-Fei,Niu, Liang-Feng,Xu, Peng-Fei
supporting information; experimental part, p. 3310 - 3313 (2009/12/05)
The first example of diastereo- and enantioselective aza-MBH-type reaction was accomplished by the asymmetric synthesis of β-nitro-γenamines via a (1R,2R)-diaminocyclohexane thiourea derivative mediated tandem Michael addition and aza-Henry reaction in good yields (up to 95%) and high enantioselectivities (up to 91% ee) and diastereoselectivities (up to 1:99 dr).
