High-efficient metal-free aerobic oxidation of aromatic hydrocarbons by N, N-dihydroxypyromellitimide and 1,4-diamino-2,3-dichloroanthraquinone

• Published in: Molecular catalysis 2022-01, Vol.518, p.112078, Article 112078
• Main Authors: Wang, Huibin, Zhang, Qiaohong, Zhu, Zhuwei, Yang, Yuanyuan, Ye, Yicheng, Lv, Zhenguo, Chen, Chen
• Format: Article
• Language: English
• Subjects: DADCAQ; Metal-free; Molecular oxygen; NDHPI; Oxidation of hydrocarbons
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2021.112078

•Efficient catalytic oxidation of hydrocarbon with organic metal-free NDHPI/DADCAQ.•Simultaneously showing good catalytic activity for hydrocarbon and alcohol.•High catalyst consumption problem of the N-hydroxyl system was resolved with only 5 mol%.•High selectivity of ketone could be obtained. Metal-free organic catalytic system combining with N, N-dihydroxypyromellitimide (NDHPI) and 1,4-diamino-2,3-dichloroanthraquinone (DADCAQ) was developed for the selective oxidation of hydrocarbon. Being able to simultaneously show good catalytic activity for the oxidation of hydrocarbon and alcohol, NDHPI/DADCAQ was found to be efficient for the conversion of hydrocarbon to ketone. In addition, due to its specific molecular structure, NDHPI was found to be more stable and could supply a PIDNO (pyromellitimide N, N-dioxyl free radical) during the catalytic process. So, higher catalytic activity could be obtained than the famous NHPI even with only half usage, which resolved the problem of high usage (usually 10 mol%) for the organic N-OH compounds to some extent. With 5 mol% NDHPI and 1.25 mol% DADCAQ being used under the conditions of 110 °C and 0.3 MPa molecular oxygen for 7 h, high conversion of ethylbenzene (89.6%), tetralin (98.8%), indene (96.9%), and inert toluene (50.7%) could be selectively converted to the products of acetophenone (93.4%), α-tetralone (97.3%), 1-indanone (98.9%), and benzoic acid (92.4%), respectively. [Display omitted]