13393-61-8Relevant articles and documents
Improved Oxidation of Amines with Dibenzoyl Peroxide
Biloski, Alan J.,Ganem, Bruce
, p. 537 - 538 (1983)
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Oxidation of Amines by a 4a-Hydroperoxyflavin
Ball, Sheldon,Bruice, Thomas C.
, p. 6498 - 6503 (1980)
Kinetic and product studies have been carried out for the reaction of 12 tertiary amines, secondary amines, and secondary hydroxylamines with the 4a-hydroperoxide of N5-ethyl-3-methyllumiflavin (4a-FlEtOOH).All reactions were found to be first order in 4a-FlEtOOH and amine in t-BuOH solvent.Transfer from t-BuOH to the aprotic solvent dioxane decreases the second-order rate constant by ca. threefold, but does not change the kinetic order in reactants (i.e., no external proton source is required).The reactions with the secondary and tertiary amines are quantitative, yielding secondary hydroxylamines and tertiary amine oxides along with the flavin pseudobase (4a-FlEtOH).Secondary hydroxylamines yield with 4a-FlEtOOH nitrones and 4a-FlEtOH.The free radical trap 2,6-di-tert-butyl-4-methylphenol does not influence the rate constants or product yields.This finding, along with the observation that rate constants are not related to the stability of cation radicals derived from amine, establishes that free radical processes are not involved in the N-oxidation reactions.The N-oxidation reactions are best explained as occurring through nucleophilic attack of amine nitrogen upon the terminal oxygen of the 4a-FlEtOOH molecule with back donation of the hydroperoxy hydrogen to the internal peroxy oxygen.Comparison of the second-order rate constants ( on the basis of the amine pKa's in H2O) provides the nucleophilic order secondary hydroxylamines > tertiary amines > secondary amines.The disappearance of 4a-FlEtOOH from solution in the presence of primery amines is much slower than with secondary amines and the reaction does not follow a simple rate law nor is 4a-FlEtOH a major product.In t-BuOH the spontaneous first-order rate constant for decomposition of 4a-FlEtOOH exceeds that for the decomposition of H2O2 by more than 400-fold while the second-order rate constant for N-oxidation of N,N-dimethylbenzylamine by 4a-FlEtOOH exceeds that for N-oxidation by H2O2 by 36000-fold (and N-oxidation by t-BuOOH by > 400000).These results are discussed in terms of the involvement of 4a-hydroperoxyflavin cofactor in the metabolism of amines by the hepatic flavoprotein microsomal oxidase.
Nitrones from Addition of Benzyl and Allyl Grignard Reagents to Alkyl Nitro Compounds: Chemo-, Regio-, and Stereoselectivity of the Reaction
Bartoli, Giuseppe,Marcantoni, Enrico,Petrini, Marino
, p. 5834 - 5840 (2007/10/02)
Reaction of allyl and benzyl Grignard reagents with functionalized nitroalkanes afford nitrones in good yield.This process shows considerable chemoselectivity; carbonyl groups and other highly reactive electrophilic functions are unaffected by the reaction conditions (THF, -70 deg C).A mixture of regioisomers 4 and 5 is usually obtained, and the product distribution depends on the nature of the alkyl framework.An intermediate 3 is postulated, and the isomeric pair of nitrones arises, very likely through a selective syn elimination. α-Substituted alkyl chains give mostly conjugated products 4 while unbranched chains afford predominantly the nonconjugated nitrones 5.The 4/5 ratio can be strongly modified by using a proton source of suitable strength; trichloroacetic acid produces 4 exclusively in the reaction of nitroethane with benzyl Grignard, while 2,6-dimethylphenol affords completely the nonconjugated nitrone 5.The stereochemistry of the double bond is affected by the nature of the reagent used.Benzyl Grignard gives only Z nitrones 4 and 5; 2-butenylmagnesium chloride gives nonconjugated Z nitrones and a predominance of E isomer in the conjugated nitrone 5.
Nucleophilic Oxidation with Bis Peroxide: Direct Preparation of O-Phosphinylated Aminating Reagents
Yaouanc, Jean Jacques,Masse, Guy,Sturtz, Georges
, p. 807 - 810 (2007/10/02)
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