Substrates functionalized nitroalkane

Addition-elimination sequence. Addition of a photochemically generated free radical to an electron-deficient double bond engenders different consequence depending on the structural features of the substrates. Routes to functionalized nitroalkanes" and cycloalkanone oxime ethers demonstrate the versatile method. 

Functionalized nitroalkanes containing an aldehyde or ketone functionality at a convenient position can also be employed as substrates in the reaction with... 

Primary and secondary nitroalkanes, and substrates containing terminal em-dinitroaliphatic functionality, have one or more acidic a-protons, a consequence of inductive and resonance effects imposed by the nitro group. As a result, such compounds can behave like carbanions and participate in a number of addition and condensation reactions which are typical of substrates like ketones, aldehydes, and /S-ketoesters. Such reactions are extremely useful for the synthesis of functionalized polynitroaliphatic compounds which find potential use as explosives, energetic oligomers and plasticizers. 

The use of soluble amine bases failed to give products, whereas the heterogeneous conditions KOH/THF proved optimal in promoting aldoxime formation for a broad range of substrates. Optically active nitroalkanes including aromatic (both electron-rich and electron-deficient), heteroaromatic, branched and unbranched aliphatic substrates, as well as substrates that incorporate unprotected alcohol functionalities were successfully reduced. 

Substrates with doubly bonded nitrogen-atom functionalities, e.g. the C=N-R (imino, oxime) group, are usually cleaved by dioxirane to give the corresponding carbonyl product" . A particular case represents the DMD oxidation of the nitronate ions, generated from nitroalkanes" or nitroarenes. For example, the nitronate anion 16 (equation 13) affords initially the cyclohexadienone on oxidation with DMD, which subsequently tau-tomerizes to the phenol as the final product. An exception is the DMD oxidation of an... 

Synunetrically disubstituted molecules of type II are mostly obtained from bifunctional substrates such as bisphenols, cyclic urcids, etc., or bifiinctional amines such as ethylenediamine or piperazine. Accordingly, the amino group replacement of mono-functional Mannich bases by bifunctional nucleophiles such as nitroalkanes or bisamides gives derivatives of type II, as represented by the heat stabilizer for polymers 496, bearing two antioxidant phenolic moieties per molecule. 

Erythromycin is a substrate for the cytochrome P450 (CYP 450) 3A4 isoenzyme. Once bound to CYP 3A, erythromycin stimulates its own metabolism via demethylation and oxidation to nitroalkane metabolites. These nitroalkane metabolites appear to form stable complexes with the iron of the CYP 3A4 isoenzyme, decreasing its functional capacity. Depending upon the erythromycin dose and duration of therapy, CYP 3A4 activity could be inhibited to undetectable activity and serves as the basis of erythromycin-associated metabolic-based drug-drug interactions. 

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