455-86-7Relevant articles and documents
New method for non-metal catalytic oxidation synthesis of substituted benzoic acid compound
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Paragraph 0059; 0060; 0061; 0062, (2018/01/11)
The invention discloses a method for synthesis of a substituted benzoic acid compound, a Wittig reagent and hydrogen peroxide as raw materials are reacted by heating in an organic solvent at reaction temperature of room temperature or 50 DEG C, the reaction formula is as shown in the specification, in the formula, Ar is an aromatic ring substituent, X is an unsaturated ester substituent or an aromatic ring substituent. The method has the following beneficial effects: (1) the method has the advantages of simple operation, wide substrate application range, high yield, friendliness to the environment; (2) the Wittig reagent is simple in preparation, the raw materials are cheap, the Wittig reagent which is not participated in the reaction can also be recycled by recrystallization; (3) the reaction conditions of the Wittig reagent and the hydrogen peroxide are mild, and the post treatment is simple, the method is green and environmentally-friendly and is suitable for industrial enlargement; and (4) by-product triphenylphosphine oxide is also recyclable, is an important chemical raw material and can be applied as organic synthesis intermediates, pharmaceutical intermediates, catalysts and extractants.
Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information, p. 8986 - 8998,13 (2012/12/12)
Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
Kinetic and chemical characterization of aldehyde oxidation by fungal aryl-alcohol oxidase
Ferreira, Patricia,Hernandez-Ortega, Aitor,Herguedas, Beatriz,Rencoret, Jorge,Gutierrez, Ana,Martinez, Maria Jesus,Jimenez-Barbero, Jesus,Medina, Milagros,Martinez, Angel T.
scheme or table, p. 585 - 593 (2011/02/24)
Fungal AAO (aryl-alcohol oxidase) provides H2O2 for lignin biodegradation. AAO is active on benzyl alcohols that are oxidized to aldehydes. However, during oxidation of some alcohols, AAO forms more than a stoichiometric number of H2O2 molecules with respect to the amount of aldehyde detected due to a double reaction that involves aryl-aldehyde oxidase activity. The latter reactionwas investigated using different benzylic aldehydes, whose oxidation to acids was demonstrated by GC-MS. The steady- and presteady state kinetic constants, together with the chromatographic results, revealed that the presence of substrate electron-withdrawing or electron-donating substituents had a strong influence on activity; the highest activity was with p-nitrobenzaldehyde and halogenated aldehydes and the lowest with methoxylated aldehydes. Moreover, activity was correlated to the aldehyde hydration rates estimated by 1H-NMR. These findings, together with the absence in the AAO active site of a residue able to drive oxidation via an aldehyde thiohemiacetal, suggested that oxidation mainly proceeds via the gem-diol species. The reaction mechanism (with a solvent isotope effect, 2H2O kred, of approx. 1.5)would be analogous to that described for alcohols, the reductive half-reaction involving concerted hydride transfer from the a-carbon and proton abstraction from one of the gem-diol hydroxy groups by a base. The existence of two steps of opposite polar requirements (hydration and hydride transfer) explains some aspects of aldehyde oxidation by AAO. Site-directed mutagenesis identified two histidine residues strongly involved in gem-diol oxidation and, unexpectedly, suggested that an active-site tyrosine residue could facilitate the oxidation of some aldehydes that show no detectable hydration. Double alcohol and aldehyde oxidase activities of AAO would contribute to H2O2 supply by the enzyme. The Authors Journal compilation
