FUEL
·
2021
·
IF 6.609
Guang Miao,Peng Chong,Cuiting Yang,Zewei Liu,Hao Yu,Lei Dong,Guoqing Li,Jing Xiao
The demand for heterocyclic sulfur compounds is increasingly in fine chemical industry, where the thiophenic sulfur impurities in fuels can be a potential recyclable feedstock. In this work, the catalytic upgrading of thiophenic sulfur compounds over a silver-modified MoO 3 catalyst under ambient conditions was reported. Br 2 and H 2 O 2 /HBr were used to convert thiophenic compounds in alkane and alcohol solutions. The conversion of various thiophenic compounds (thiophene, benzothiophene and dibenzothiophene) to the corresponding bromides reached up to 81.6 ~ 99.8%. The bromination path undergoes electrophilic substitution mechanism, and the transformation of mono- to dibromides is identified as the rate-determining step. The introduction of MoAg 2 O 4 phase on MoO 3 is rationalized to boost the conversion of mono-bromothiophene, which results in the selectivity of 2,5-dibromothiophene increased from 10% to over 50%. The optimized silver loading was 10% due to its high thiophene conversion and selectivity of dibromides. Silver modification of MoO 3 rods not only stabilized the textural property of catalysts but also improved its bromination activity compared to the bulk MoO 3 indicated by SEM and FTIR characterization. Density functional theory (DFT) calculation suggested that the formation of 2-bromothiphene and 2,5-dibromothiophene were preferred on the MoO 3 (111) and MoAg 2 O 4 (111) sites, respectively. The catalytic upgrading approach paves the way for the efficient utilization of thiophenic sulfur impurities in fuels to their value-added under mild conditions.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2025
·Vol. 19
·期 4
·1-13
·
IF 6.4
Jiang Linke,Li Yong,Shi Shuiqin,Yan Junmei,Chi Lianbao,Liu Hui,Feng Mingbao
Chlorinating wastewater before it is released into surface water can change the fate of organic pollutants. This transformation is influenced by chlorine residues, bromine-containing wastewater, and solar radiation. Losartan (LOS), one of the earliest sartan antihypertensive drugs produced, is used worldwide and has been found in the environment. However, its transformation mechanisms and environmental risks have not been systematically investigated. This research presents the degradation kinetics, transformation products, and environmental risks of LOS in different scenarios. The results revealed that k app, HClO (LOS) ranged from 0.47 to 8.30 L/(mol·s) at pH 5.0–8.0. The k app, HBrO (LOS) values at pH 5.0–8.0 ranged from 8.38 × 10 3 to 1.55 × 10 5 L/(mol·s), revealing a faster bromination reaction than chlorination. LOS degrades through direct photolysis, carbonate radicals (CO 3 / •− ), and singlet oxygen ( 1 O 2 ) under sunlight exposure. The solar/chlorination process accelerates the reaction rate through radical activity. In addition, chlorination and bromination resulted in halogen addition to the aromatic ring, whereas hydroxylation, hydrogen abstraction, demethylation, ring opening, and hydrolysis reactions were observed across all processes. Some products exhibit high biodegradation resistance and high toxicity, potentially threatening the aquatic environment. This study aims to enhance our understanding of the environmental behavior and resulting risks of LOS by exploring its environmental fate through various transformation processes.
研究领域:
环境科学
·
药理学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 4
·914
·
IF 3.267
Ligeng Wang,Chun Feng,Yan Zhang,Jun Hu
The regioselective mono-bromination of phenols has been successfully developed with KBr and ZnAl–BrO3−–layered double hydroxides (abbreviated as ZnAl–BrO3−–LDHs) as brominating reagents. The para site is much favorable and the ortho site takes the priority if para site is occupied. This reaction featured with excellent regioselectivity, cheap brominating reagents, mild reaction condition, high atom economy, broad substrate scope, and provided an efficient method to synthesize bromophenols.Keywords:phenol;bromination;regioselecitvity
研究领域:
有机化学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Fujun Li,Peihao Cheng,Xinghai Li,Yun Zou,Shengyang Tao
Bromination reactions involving bromine monomers tend to be polybrominated, resulting in poor product selectivity and subsequent separation difficulties. This proposal outlines a multistep cascade for continuous flow synthesis involving photobromination and debromination. The process comprises five units: bromine generation, photobromination, quenching, water/oil separation, and photodebromination. A full-process continuous and efficient synthesis of the trifluorostrolibin intermediate (E)-Methyl-2-(2-broMoMethylphenyl)-2-MethoxyiMinoacetate (MBPA) was achieved. This process converts the byproduct (E)-Methyl-2-(2-dibroMoMethylphenyl)-2-MethoxyiMinoacetate into the target product MBPA. At a total residence time of 12.9 min, the conversion of (E)-Methy-2-(methoxyimino)-2-(o-toly) acetate reached 99.0%, and the total yield of MBPA reached 94.2%. Machine learning and quantum chemical calculations enhance the comprehension of photodebromination mechanisms. Simultaneously, through comprehensive simulations involving sensitivity and scenario analyses, the optimization of photon utilization emerged as a pivotal factor for improving the overall applicability of the production process. This method of synthesizing halogenated products is anticipated to play a crucial role in pharmaceuticals or pesticides.
研究领域:
有机化学
·
农药合成
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC COMMUNICATIONS
·
2019
·
IF 1.439
Bingbing Han,Zubiao Zheng,Dongcheng Zheng,Lei Zhang,Peng Cui,Jianjun Shi,Changjiang Li
The applications of a new supported tribromide reagent based on poly(vinylbenzyltrimethylammonium hydroxide) resin (Amberlite 717) were reported. This supported tribromide resin was used directly in α-bromination and α-bromoacetalization of acetophenones without any other catalyst under mild conditions. The effects of solvents and the amount of the supported tribromide resin on the reactions were investigated. Under the optimal conditions, most of α-bromo and α-bromoacetal of acetophenones were selectively obtained in excellent yields.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）