29488-90-2Relevant academic research and scientific papers
Metal-free oxidation of aromatic carbon-hydrogen bonds through a reverse-rebound mechanism
Yuan, Changxia,Liang, Yong,Hernandez, Taylor,Berriochoa, Adrian,Houk, Kendall N.,Siegel, Dionicio
, p. 192 - 196 (2013/08/23)
Methods for carbon-hydrogen (C-H) bond oxidation have a fundamental role in synthetic organic chemistry, providing functionality that is required in the final target molecule or facilitating subsequent chemical transformations. Several approaches to oxidizing aliphatic C-H bonds have been described, drastically simplifying the synthesis of complex molecules. However, the selective oxidation of aromatic C-H bonds under mild conditions, especially in the context of substituted arenes with diverse functional groups, remains a challenge. The direct hydroxylation of arenes was initially achieved through the use of strong Bronsted or Lewis acids to mediate electrophilic aromatic substitution reactions with super-stoichiometric equivalents of oxidants, significantly limiting the scope of the reaction. Because the products of these reactions are more reactive than the starting materials, over-oxidation is frequently a competitive process. Transition-metal-catalysed C-H oxidation of arenes with or without directing groups has been developed, improving on the acid-mediated process; however, precious metals are required. Here we demonstrate that phthaloyl peroxide functions as a selective oxidant for the transformation of arenes to phenols under mild conditions. Although the reaction proceeds through a radical mechanism, aromatic C-H bonds are selectively oxidized in preference to activated-H bonds. Notably, a wide array of functional groups are compatible with this reaction, and this method is therefore well suited for late-stage transformations of advanced synthetic intermediates. Quantum mechanical calculations indicate that this transformation proceeds through a novel addition-abstraction mechanism, a kind of 'reverse-rebound' mechanism as distinct from the common oxygen-rebound mechanism observed for metal-oxo oxidants. These calculations also identify the origins of the experimentally observed aryl selectivity.
Synthesis and characterization of the luminescent lanthanide complexes with two similar benzoic acids
Liu, Tonghuan,Duan, Guojian,Zhang, Yaping,Fang, Jian,Zeng, Zhengzhi
experimental part, p. 843 - 848 (2010/03/30)
2-((4-Methoxyphenoxy) carbonyl) benzoic acid, 2-(1-methoxyvinyl) benzoic acid and their rare earth complexes LnL2(OH)·3H2O (Ln = La, Eu, Tb) were synthesized and characterized by means of elemental analysis, FTIR, 1H NMR, UV and luminescence spectroscopy. The FTIR and 1H NMR results show that the carboxylic groups in the complexes coordinated to the rare earth ions in the form of one dentate, and the ester carboxylic groups have taken part in the coordination. Among these complexes, Eu(III) complexes and Tb(III) complexes exhibit characteristic fluorescence with comparatively high brightness and good monochromaticity, which indicated that the ligands of HLI and HLII are good organic chromophore to absorb and transfer energy to metal ions.
Synthesis and Structure - Activity Relationships of Sweet 2-Benzoylbenzoic Acid Derivatives
Arnoldi, Anna,Bassoli, Angela,Borgonovo, Gigliola,Merlini, Lucio,Morini, Gabriella
, p. 2047 - 2054 (2007/10/03)
Twenty-four analogues of the sweet compound 2-(4-methoxybenzoyl)benzoic acid 1 were synthesized and tasted. The structure-sweet taste relationships were studied by means of principal component analysis and by comparison with the existing sweet receptor models. Three possible glucophores were identified, which could correspond to the sites B, E1, and E2 of the Tinti - Nofre model. Some similarities between this class of compounds and isovanillic sweeteners were found.
