JOURNAL OF ORGANIC CHEMISTRY
·
2025
·
IF 3.6
Zelin Zhao,Wenping Li,Qiujie Shan,David J. Young,Zhi-Gang Ren,Hong-Xi Li
We herein disclose a visible-light-induced synthesis of O-aryl esters through the cross-dehydrogenative coupling of aldehydes with phenols using BrCCl3, in which phenolate functions as both a substrate and a photosensitizer. This transition-metal- and photocatalyst-free visible-light-induced esterification is suitable for a wide range of substrates and gives moderate to excellent yields (up to 95%). Mechanistic studies provided evidence of a self-propagating radical reaction involving homolytic cleavage of the aldehydic C–H bond and the formation of acyl bromides. BrCCl3 serves as an oxidant and a hydrogen atom transfer (HAT) agent.
研究领域:
有机化学
·
光化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2013
·
IF 0.596
Bin Liu,Xiaofang Li,Jie Zhang,Liyun Du,Rongjin Zeng
The reaction of 6,7-dihydroindolizin-8(5H)-one and an aromatic aldehyde yielded (E)-7-(arylmethylene)-6,7-dihydroindolizin-8(5H)-ones which underwent addition of bromoform in the presence of magnesium under N2 to give a novel series of 3-aryl-2,2-dibromo-5′H-spiro[cyclopropane-1,7′-indolizin]-8′(6′H)-one derivatives. The structures of the products were established by 1H NMR, 13C NMR, IR spectroscopy and mass spectra.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Weiping Xie,Wei Dong,Deyang Kong,Yuefei Ji,Junhe Lu,Xiaoming Yin
Sulfate radicals (SO 4 − ) generated by activation of peroxymonosulfate (PMS) and persulfate (PS) are highly oxidative and applied to degrade various organic pollutants. This research was designed to investigate formation of halogenated by-products in Co 2+ activated PMS process in the presence of halides and natural organic matter (NOM). It was revealed that no halogenated by-products were detected in the presence of Cl − while 189 μg/L bromoform and 100.7 μg/L dibromoacetic acid (DBAA) were found after 120 h when 2 mg/L NOM, 0.1 mM Br − , 1.0 mM PMS, and 5 μL Co 2+ were present initially. These products are known as disinfection by-products (DBPs) since they are formed in water disinfection processes. Formation of DBPs was even more significant in the absence of Co 2+ . The data indicate that both PMS and SO 4 − can transform Br − to reactive bromine species which react with NOM to form halogenated by-products. Less DBP formation in Co 2+ -PMS systems was due to the further destruction of DBPs by SO 4 − . More DBPs species including chlorinated ones were detected in the presence of both Cl − and Br − . However, more brominated species produced than chlorinate ones generally. The total DBP yield decreased with the increase of Cl − content when total halides kept constant. This is one of the few studies that demonstrate the formation of halogenated DBPs in Co 2+ /PMS reaction systems, which should be taken into consideration in the application of SO 4 − based oxidation technologies .
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 28
·期 1
·259
·
IF 4.927
Ximiao Zhu,Chenhui Hao,Mengze Zhang,Bingyan Lan
This paper selected microplastic polyethylene terephthalate (PET), commonly found in water/wastewater plant effluent, to investigate the changes of PET oxidized under ozonation (designated as ozonized PET), followed by sodium hypochlorite oxidation (designated as ozonized-chlorinated PET) and studied their influence on the adsorption of the disinfection by-product bromoform (TBM). Fragmentation and cracks appeared on the oxidized PET surface. As the oxidation degree increased, the contact angle decreased from 137° to 128.90° and 128.50°, suggesting hydrophilicity was enhanced. FTIR and XPS analyses suggested that carbonyl groups increased on the surface of ozonized PET and ozonized-chlorinated PET, while the formation of intermolecular halogen bonds was possible when PET experienced dual oxidation. These physiochemical changes enhanced the adsorption of TBM. The adsorption capacity of TBM followed the order of ozonized-chlorinated PET (2.64 × 10−6μg/μg) > ozonized PET (2.58 × 10−6μg/μg) > pristine PET (2.43 × 10−6μg/μg). The impact of raw water characteristics on the adsorption of TBM onto PETs, such as the pH, and the coexistence of inorganic ions and macromolecules (humic acid, surfactant, and bovine serum albumin) were studied. A different predominant adsorption mechanism between TBM and pristine PET or oxidized PETs was proposed.Keywords:polyethylene terephthalate;oxidation process;water/wastewater treatment plant;disinfection by-products;bromoform
研究领域:
环境科学
·
水/废水处理
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Lu Wang,Yaqun Yu,Guoqiang Liu,Junhe Lu
Tetrabromobisphenol S (TBBPS), an emerging brominated flame retardant , can cause neurotoxic and cytotoxic effects to human physiology . In this study, the degradation of TBBPS in Co 2+ activated peroxymonosulfate (PMS) oxidation process was explored. In particular, brominated by-products formed during the degradation of the TBBPS were examined. It was found that TBBPS could be effectively removed in the Co 2+ /PMS oxidation process. The pseudo-first-order rate constants were 0.13 min −1 at 0.2 mM PMS and 0.5 μM Co 2+ initially. It appeared that TBBPS degradation occurred via and HO attacks, but played a dominant role. The presence of natural organic matter (NOM) greatly inhibited the transformation of the TBBPS, which can be explained by the scavenging of the radical species. β-Scission, debromination, and cross-coupling were identified as the main reaction pathways of TBBPS degradation in the Co 2+ /PMS system. Further oxidation and ring-opening of the intermediates generated brominated by-products including bromoform, monobromoacetic acid, and dibromoacetic acid. The formation of the brominated by-products increased gradually in approximately 48 h. But, the presence of NOM reduced the yields of the brominated -by-products. The findings of this study indicate that organic bromine contaminants can be effectively removed but lead to brominated by-products in the activated PMS oxidation process, which should be taken into consideration when -based oxidation technology is applied.
研究领域:
环境科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2024
·
IF 6.2
Yemian Zhou,Yun Liu,Tong Wang,Han Li,Jing He,An Xu
Disinfection by-products (DBPs) generated from water treatment have serious adverse effects on human health and natural ecosystems. However, research on the mutagenicity of DBPs with different chemical structures is still limited. In the present study, we compared the mutagenicity of 8 typical DBPs in human-hamster hybrid (A L ) cells and clarified the mechanisms involved. Our data displayed that the rank order for mutagenicity was as follows: iodoacetamide (IAcAm) > iodoacetonitrile (IAN) > iodoacetic acid (IAA) > bromoacetamide (BAcAm) ≈ bromoacetonitrile (BAN) > bromoacetic acid (BAA), which was confirmed by DNA double strand breaks and oxidative DNA damage. In contrast, bromoform (TBM) and iodoform (TIM) had minimal mutagenicity. The mutation spectrum analysis further revealed that IAN, IAcAm, and IAA could induce multilocus deletions in mammalian cells. Interestingly, nitrogenous DBPs (N-DBPs) and IAA were found to cause varying degrees of iron overload and lipid peroxidation, which was mediated by the activation of the Nrf2/HO-1 signaling pathway. Moreover, the presence of deferoxamine (DFO), an iron ion inhibitor, effectively reduced γ-H2AX and 8-OHdG induced by N-DBPs and IAA. These results indicated that the variations in genotoxicity among DBPs with different structures were associated with their ability to disrupt iron homeostasis. This study provided new insights into the mechanisms underlying the structure-dependent toxicity of DBPs and established a foundation for a more comprehensive understanding and intervention of the health risks associated with DBPs.
研究领域:
环境科学
·
毒理学
·
分子生物学
·
细胞生物学
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产品关联
DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2013
·Vol. 41
·期 4
·2345-2352
·
IF 0.88
Liu Bin,Li Xiao Fang,Zhang Jie,Wang Meng Ting,Zeng Rong Jin
The conjugate addition of bromoform with 2-aryliene-2,3-dihydro-1 H -pyrrolizin-1-ones in the presence of magnesium afforded novel 2,2-dibromo-3-arylspiro[cyclopropane-1,2′-pyrrolizin]-1′(3′ H )-ones in moderate yield. The structures of all the products were characterized thoroughly by 1 H NMR, 13 C NMR, infrared spectroscopy, and mass spectrum.
研究领域:
有机化学
·
合成化学
·
光谱学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Ziying Wang,Yisheng Shao,Naiyun Gao,Bin Xu,Na An,Xian Lu
Applying the highly oxidative sulfate radical ( SO 4 - · ) to pollutant degradation may cause it to react with the coexisting bromide (Br − ) to form undesired byproducts. This study investigated the transformation of Br − during the degradation process of a contaminant (diethyl phthalate (DEP)) via heat-activated persulfate (PS). Dibromoacetonitrile and bromoform formed with Br − and natural organic matter (NOM) in the solution, while only bromoform was detected without NOM. The formation of these brominated disinfection byproducts (Br-DBPs) can be ascribed to the reactions between the phenolic groups of DEP degradation intermediates or NOM and reactive bromine species (free bromine and radical bromine) generated through the oxidation of Br − by SO 4 - · . Br-DBPs were degraded by excessive SO 4 - · , which indicates that organic bromine is a temporary phase during the turnover of Br − . The time-dependent formation of organic and inorganic bromines suggests that Br − may have cycled several times between organic and inorganic forms before eventually turning into bromate. The bromate formation showed a lag phase before continuously increasing. Generally, increasing the temperature, PS dosage, and Br − and organic matter (DEP and NOM) concentrations increased the maximum concentration of Br-DBPs. Additionally, these reaction parameters facilitated bromate formation except for organic matter, whose inhibitory effect is probably due to the consumption of reactive species by organic matter and the generated superoxide anion. The total organic carbon concentration of the solution exhibited a relatively quick reduction followed by a slow decrease. These results highlight the potential risks of PS activation technologies and can help prevent such risks in actual practice.
研究领域:
环境科学
·
水处理
·
化学工程
·
污染物降解
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）