3006-96-0Relevant articles and documents
One-step highly selective oxidation of p-xylene to 4-hydroxymethylbenzoic acid over Cu-MOF catalysts under mild conditions
Li, Ying,Wu, Mingzhu,Chen, Daomei,Jiang,He, Jiao,Luo,Wang, Wei,Wang, Jiaqiang
, (2019)
p-Xylene, a cheap industrial raw material, is mainly used to synthesize terephthalic acid. However, p-xylene was oxidized rarely to other oxygen-containing derivatives. On the other hand, current methods for synthesis of 4-hydroxymethylenzoic acid suffer from multistep reactions, long reaction time, high temperature, high pressure, and lower selectivity. In this work, p-xylene was directly oxidized into 4-hydroxymethylbenzoic acid using Cu-MOF as the catalyst, acetonitrile as the solvent, and 30% H2O2 as the oxidant under mild conditions. Very high selectivity (99.2%) of 4-hydroxymethylbenzoic acid and good substrate conversion (85.5%) of p-xylene were achieved at 30 °C for 5 h. Fast hot catalyst filtration experiments proved that Cu-MOF acted as a heterogeneous catalyst. It can be reused three times without losing its activity. Under optimized conditions, the selectivity of 4-hydroxymethyl benzoic acid and the conversion of p-xylene were 97.6% and 84.8% even though the experiment was amplified 15-folds. The efficiency of H2O2 was also up to 92.0%. The reaction mechanism was proposed combined with the analysis of XRD, FT-IR and XPS. All data displayed that Cu-MOF shows great potential as a catalyst for highly selective oxidation of stable C–H to high value-added compounds containing two diverse C–O bands under mild conditions. It also opens a new way to use of p-xylene.
Gram-scale synthesis of carboxylic acids via catalytic acceptorless dehydrogenative coupling of alcohols and hydroxides at an ultralow Ru loading
Chen, Cheng,Cheng, Hua,Verpoort, Francis,Wang, Zhi-Qin,Wu, Zhe,Yuan, Ye,Zheng, Zhong-Hui
, (2021/12/13)
Acceptorless dehydrogenative coupling (ADC) of alcohols and water/hydroxides is an emergent and graceful approach to produce carboxylic acids. Therefore, it is of high demand to develop active and practical catalysts/catalytic systems for this attractive transformation. Herein, we designed and fabricated a series of cyclometallated N-heterocyclic carbene-Ru (NHC-Ru) complexes via ligand tuning of [Ru-1], the superior complex in our previous work. Gratifyingly, gram-scale synthesis of carboxylic acids was efficiently enabled at an ultralow Ru loading (62.5 ppm) in open air. Moreover, effects of distinct ancillary NHC ligands and other parameters on this catalytic process were thoroughly studied, while further systematic studies were carried out to provide rationales for the activity trend of [Ru-1]-[Ru-7]. Finally, determination of quantitative green metrics illustrated that the present work exhibited superiority over representative literature reports. Hopefully, this study could provide valuable input for researchers who are engaging in metal-catalyzed ADC reactions.
KB3H8: An environment-friendly reagent for the selective reduction of aldehydes and ketones to alcohols
Li, Xinying,Mi, Tongge,Guo, Wenjing,Ruan, Zhongrui,Guo, Yu,Ma, Yan-Na,Chen, Xuenian
supporting information, p. 12776 - 12779 (2021/12/10)
Selective reduction of aldehydes and ketones to their corresponding alcohols with KB3H8, an air- and moisture-stable, nontoxic, and easy-to-handle reagent, in water and THF has been explored under an air atmosphere for the first time. Control experiments illustrated the good selectivity of KB3H8 over NaBH4 for the reduction of 4-acetylbenzaldehyde and aromatic keto esters. This journal is
Nitrogen doped carbon for Pd-catalyzed hydropurification of crude terephthalic acid: Roles of nitrogen species
Gao, Huanxin,He, Limin,Liu, Zhicheng,Wang, Yangdong,Xie, Zaiku
, p. 33646 - 33652 (2021/12/07)
The purification of crude terephthalic acid was performed by the hydrogenation of 4-carboxybenzaldehyde (4-CBA) over activated carbon (AC) supported Pd catalysts in industry. However, traditional Pd/AC catalysts usually suffer from low hydrogenation activ