66291-23-4

Upstream product

• 16914-16-2 α-methylstyrene-methyl-d₃ 
• 108-24-7 acetic anhydride 
• 98-86-2 acetophenone 
• 98-83-9 isopropenylbenzene 

Downstream Products

• 5670-65-5 1-nitro-2-phenylpropene 
• 98-86-2 acetophenone 
• 109757-73-5 1-nitro-2-phenylpropane 
• 59647-78-8 2-phenylpropanal oxime 
• 63278-04-6 Methyl-4-nitro-2-methoxycarbonyl-3-methyl-3-phenylbutyrat 
• 63278-06-8 4-Amino-3-methyl-3-phenylbuttersaeure 
• 7796-75-0 (+)-(R)-1-nitro-2-phenylpropane 
• 5670-65-5 (E)-1-nitro-2-phenyl-1-propene 
• 58502-68-4 1-(1-nitroprop-2-en-2-yl)benzene 

Relevant academic research and scientific papers

Asymmetric bioreduction of C=C bonds using enoate reductases OPR1, OPR3 and YqjM: Enzyme-based stereocontrol

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.

Substrate Scope Evaluation of the Enantioselective Reduction of β-Alkyl-β-arylnitroalkenes by Old Yellow Enzymes 1-3 for Organic Synthesis Applications

The substrate scope of the old yellow enzyme catalyzed reduction of β-alkyl-β-arylnitroalkenes is investigated. Compounds bearing either alkyl chains of increasing length at the carbon atom in position β to the nitro group or different substituents on the aromatic ring are prepared and submitted 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 Meyer reaction. An "explosion" of chiral products can be observed by combining the highly enantioselective ene-reductase-mediated reduction of nitroalkenes with the chemical versatility of the nitro group.

Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA)

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.

The flavoprotein-catalyzed reduction of aliphatic nitro-compounds represents a biocatalytic equivalent to the Nef-reaction

The bioreduction of aliphatic sec-nitro compounds catalyzed by purified flavoproteins from the old-yellow-enzyme family unexpectedly furnished the corresponding carbonyl compounds instead of the expected amines and thus represents a biocatalytic equivalent to the Nef-reaction. The pathway was shown to proceed via initial reduction of the nitro-group to yield the nitroso-derivative, which spontaneously tautomerized to yield the more stable oxime, which was enzymatically reduced in a second step to furnish a hydrolytically unstable imine-species, which spontaneously hydrolyzed to finally give a carbonyl compound and ammonia.

Diastereo- and enantioselective Aza-MBH-type reaction of nitroalkenes to N-tosylimines catalyzed by bifunctional organocatalysts

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).

Highly enantioselective reduction of β,β-disubstituted aromatic nitroalkenes catalyzed by Clostridium sporogenes

(Chemical Equation Presented) 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 3a was a poor substrate, yielding (S)-4a in low yield (10-20%), and the ee (30-70% ee) depended on NADH concentration. An efficient synthesis of a library of nitroalkenes 1 is described.

Asymmetric bioreduction of activated C=C bonds using Zymomonas mobilis NCR enoate reductase and old yellow enzymes OYE 1-3 from yeasts

The asymmetric bioreduction of C=C-bonds bearing an electron-withdrawing group, such as an aldehyde, ketone, imide, nitro, carboxylic acid, or ester moiety by a novel enoate reductase from Zymomonas mobilis and Old Yellow Enzymes OYE 1-3 from yeasts furnished the corresponding saturated products in up to >99%ee. Depending on the substrate type, stereocontrol was achieved by variation of the substrate structure, by switching the (E/Z) geometry of the alkene or by choice of the appropriate enzyme. This substrate- or enzyme-based stereocontrol allowed access to the opposite enantiomeric products. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Organocatalytic asymmetric transfer hydrogenation of nitroolefins

We describe a highly efficient and highly enantioselective Hantzsch ester mediated conjugate transfer hydrogenation of β,β-disubstituted nitroolefins that is catalyzed by a Jacobsen-type thiourea catalyst. Copyright

Asymmetric bioreduction of activated alkenes using cloned 12-oxophytodienoate reductase isoenzymes OPR-1 and OPR-3 from Lycopersicon esculentum (tomato): A striking change of stereoselectivity

(Chemical Equation Presented) Tomato source: 12-Oxophytodienoate reductase isoenzymes OPR1 and OPR3 from tomato possess a broad substrate spectrum for the asymmetric bioreduction of α,β-unsaturated enals, enones, dicarboxylic acids, and N-substituted male-imides (see scheme). Stereocomplementary behavior of both isoenzymes was observed in the reduction of a nitroalkene that led to the formation of opposite stereoisomers in high enantiomeric excess.

Enantioselective synthesis of nitroalkanes bearing all-carbon quaternary stereogenic centers through Cu-catalyzed asymmetric conjugate additions

The first examples of catalytic asymmetric conjugate addition (ACA) of alkylzinc reagents to trisubstituted nitroalkenes, leading to the formation of nitroalkanes bearing a quaternary carbon stereogenic center, are reported. Reactions are promoted in the