- Synthesis of a Fluorescent-Labeled Bisbenzamidine Containing the Central (6,7-Dimethoxy-4-coumaryl)Alanine Building Block
-
The synthesis of an amino acid amide is reported, which contains two benzamidine cores, one placed in the amide part the other one within the sulfonyl N-capping group. The amino acid side chain bears the 6,7-dimethoxycoumarin fluorophore. The fluorescent amino acid was prepared by using the von-Pechmann reaction. The two corresponding nitrile groups of a precursor molecule were simultaneously converted to the amidine moieties by the Pinner reaction. The fluorescent properties of the final compound were determined.
- H?ussler, Daniela,Gütschow, Michael
-
-
Read Online
- Catalyst-free rapid conversion of arylboronic acids to phenols under green condition
-
A catalyst-free and solvent-free method for the oxidative hydroxylation of aryl boronic acids to corresponding phenols with hydrogen peroxide as the oxidizing agent was developed. The reactions could be performed under green condition at room temperature within very short reaction time. 99% yield of phenol could be achieved in only 1 min. A series of different arenes substituted aryl boronic acids were further carried out in the hydroxylation reaction with excellent yield. It was worth nothing that the reaction could completed within 1 min in all cases in the presence of ethanol as co-solvent.
- Dong, Zhenhua,Liu, Mengmeng,Pan, Hongguo
-
-
- The graphite-catalyzed: ipso -functionalization of arylboronic acids in an aqueous medium: metal-free access to phenols, anilines, nitroarenes, and haloarenes
-
An efficient, metal-free, and sustainable strategy has been described for the ipso-functionalization of phenylboronic acids using air as an oxidant in an aqueous medium. A range of carbon materials has been tested as carbocatalysts. To our surprise, graphite was found to be the best catalyst in terms of the turnover frequency. A broad range of valuable substituted aromatic compounds, i.e., phenols, anilines, nitroarenes, and haloarenes, has been prepared via the functionalization of the C-B bond into C-N, C-O, and many other C-X bonds. The vital role of the aromatic π-conjugation system of graphite in this protocol has been established and was observed via numerous analytic techniques. The heterogeneous nature of graphite facilitates the high recyclability of the carbocatalyst. This effective and easy system provides a multipurpose approach for the production of valuable substituted aromatic compounds without using any metals, ligands, bases, or harsh oxidants.
- Badgoti, Ranveer Singh,Dandia, Anshu,Parewa, Vijay,Rathore, Kuldeep S.,Saini, Pratibha,Sharma, Ruchi
-
p. 18040 - 18049
(2021/05/29)
-
- Oxidation of Electron-Rich Arenes Using HFIP-UHP System
-
The straightforward oxidation of electron-rich arenes, namely, phenols, naphthols, and anisole derivatives, under mild reaction conditions, is described by means of the use of an environmentally benign HFIP-UHP system. The corresponding quinones or hydroxylated arenes were obtained in moderate to good yields.
- Llopis, Natalia,Baeza, Alejandro
-
p. 6159 - 6164
(2020/05/20)
-
- Development of a Cross-Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)-ABX
-
The cross-conjugated vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94 %, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully achieved in a concise 7-step sequence with an overall yield of about 20 %.
- Huang, Jing-Kai,Shia, Kak-Shan
-
supporting information
p. 6540 - 6545
(2020/03/03)
-
- Method for preparing alcohol and phenol through aerobic hydroxylation reaction of boric acid derivative in absence of photocatalyst
-
The invention discloses a method for preparing alcohol and phenol through aerobic hydroxylation reaction of a boric acid derivative in the absence of a photocatalyst, wherein the boric acid derivativeis aryl boronic acid or alkyl boronic acid, and the corresponding target compounds are respectively a phenol-based compound and an alcohol-based compound. According to the method, by using a boric acid derivative as a reaction substrate, an additive is added under a solvent condition, and a hydroxylation reaction is performed under aerobic and illumination conditions to obtain a corresponding target compound. According to the invention, the new strategy is provided for the synthesis of phenols through aerobic hydroxylation of aryl boronic acid without a photocatalyst; the catalyst-free aerobic hydroxylation method for photocatalysis of aryl boronic acid or alkyl boronic acid by using triethylamine as an additive is firstly disclosed; and the new method has advantages of photocatalyst-freecondition, wide substrate range and good functional group compatibility.
- -
-
Paragraph 0025-0028; 0030-0032
(2020/01/25)
-
- Structural features and antioxidant activities of Chinese quince (Chaenomeles sinensis) fruits lignin during auto-catalyzed ethanol organosolv pretreatment
-
Chinese quince fruits (Chaenomeles sinensis) have an abundance of lignins with antioxidant activities. To facilitate the utilization of Chinese quince fruits, lignin was isolated from it by auto-catalyzed ethanol organosolv pretreatment. The effects of three processing conditions (temperature, time, and ethanol concentration) on yield, structural features and antioxidant activities of the auto-catalyzed ethanol organosolv lignin samples were assessed individually. Results showed the pretreatment temperature was the most significant factor; it affected the molecular weight, S/G ratio, number of β-O-4′ linkages, thermal stability, and antioxidant activities of lignin samples. According to the GPC analyses, the molecular weight of lignin samples had a negative correlation with pretreatment temperature. 2D-HSQC NMR and Py-GC/MS results revealed that the S/G ratios of lignin samples increased with temperature, while total phenolic hydroxyl content of lignin samples decreased. The structural characterization clearly indicated that the various pretreatment conditions affected the structures of organosolv lignin, which further resulted in differences in the antioxidant activities of the lignin samples. These results can be helpful for controlling and optimizing delignification during auto-catalyzed ethanol organosolv pretreatment, and they provide theoretical support for the potential applications of Chinese quince fruits lignin as a natural antioxidant in the food industry.
- Cheng, Xi-Chuang,Guo, Xin-Ran,Liu, Hua-Min,Liu, Yu-Lan,Qin, Zhao,Wang, Xue-De
-
p. 4348 - 4358
(2020/09/22)
-
- Nickel-catalyzed oxidative hydroxylation of arylboronic acid: Ni(HBTC)BPY MOF as an efficient and ligand-free catalyst to access phenolic motifs
-
A straightforward and mild oxidative ipso-hydroxylation of arylboronic acids has been achieved using a simple and non-noble metal, nickel-based reusable heterogeneous catalyst Ni(HBTC)BPY MOF (HBTC = benzene-1,3,5-tricarboxylate, BPY = 4,4′-bipyridine) in the presence of benign hydrogen peroxide as an oxidant under ambient reaction condition. The Ni(HBTC)BPY MOF exhibits excellent catalytic activity towards the formation of phenols from diverse arylboronic acids within short time and can be reused up to five times without any notable loss in its activity as well as shown high functional group tolerance even in the presence of sensitive functionalities and useful to achieve hydroxyl group in heterocycles.
- Latha, Ganesapandian,Devarajan, Nainamalai,Karthik, Murugan,Suresh, Palaniswamy
-
-
- Phthalocyanine Zinc-catalyzed Hydroxylation of Aryl Boronic Acids under Visible Light
-
A visible-light-promoted aerobic oxidative hydroxylation of boronic acids using phthalocyanine zinc as an easily available photosensitizer has been developed. It provided a direct access to synthesize aliphatic alcohols and phenols from boronic acids. The advantages of this approach included the low catalyst loading (0.5 mol%), high efficient, the use of O2 as an oxygen source, wide substrate range, the simple operational process, and mild conditions. (Figure presented.).
- Luo, Dong-Ping,Huang, Yang-Feng,Hong, Xiao-Yi,Chen, Dingben,Li, Guo-Xing,Huang, Xiao-Bo,Gao, Wen-Xia,Liu, Miao-Chang,Zhou, Yun-Bing,Wu, Hua-Yue
-
supporting information
p. 961 - 964
(2019/01/25)
-
- Room-Temperature Ionic Liquids (RTILs) as Green Media for Metal- and Base-Free ipso -Hydroxylation of Arylboronic Acids
-
The oxidative hydroxylation of arylboronic acids to the corresponding phenolic compounds under metal- and base-free aerobic conditions is successfully demonstrated on a greener media. Hydrogen peroxide, as an eco-friendly oxidant, is compatible with green mediates room-temperature ionic liquids (RTIL)s, providing hydroxylation products of arylboronic acids in an efficient manner. The RTIL support is particularly interesting for its reusability.
- Kim, Seung-Hoi,Kwon, Gyu-Tae,Shin, Eun-Jae
-
supporting information
p. 1815 - 1819
(2019/09/09)
-
- Heterogeneous Palladium–Chitosan–CNT Core–Shell Nanohybrid Composite for Ipso-hydroxylation of Arylboronic Acids
-
Abstract: A novel palladium-nanohybrid (Pd–Chitosan–CNT) catalytic composite has been developed using CNT–chitosan nanocomposite and palladium nitrate. The prepared catalytic platform displays excellent catalytic reactivity for the ipso-hydroxylation of various arylboronic acids with a mild oxidant aqueous H2O2 at room temperature, affording the corresponding phenols in excellent yields. Significantly, the easy recovery and reusability by simple manipulation demonstrate the green credentials of this catalytic platform. Graphical Abstract: [Figure not available: see fulltext.]
- Shin, Eun-Jae,Kim, Han-Sem,Joo, Seong-Ryu,Shin, Ueon Sang,Kim, Seung-Hoi
-
-
- Photoinduced hydroxylation of arylboronic acids with molecular oxygen under photocatalyst-free conditions
-
Photoinduced hydroxylation of boronic acids with molecular oxygen under photocatalyst-free conditions is reported, providing a green entry to a variety of phenols and aliphatic alcohols in a highly concise fashion. This new protocol features photocatalyst-free conditions, wide substrate scope and excellent functional group compatibility.
- Xu, Yu-Ting,Li, Chen-Yuan,Huang, Xiao-Bo,Gao, Wen-Xia,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
-
supporting information
p. 4971 - 4975
(2019/09/30)
-
- First total synthesis of medicinally important 3,4,7-trimethoxy-9,10-dihydrophenanthrene-1,5-diol
-
The first total synthesis was successfully achieved for biologically active 9,10-dihydrophenanthrene-1,5-diol. The key features of our synthetic approach are Perkin condensation, followed by bromination, palladium mediated intramolecular C-C bond coupling, and selective isopropyl ether cleavage. Synthesized compounds were purified and characterized by IR, 1HNMR, 13CNMR and HRMS/LC-MS.
- Gangireddy Venkata, Sivarami Reddy,Narkhede, Umesh C.,Jadhav, Vinod D.,Gangu Naidu, Ch.
-
p. 1670 - 1673
(2018/03/29)
-
- A convenient synthesis of phenols
-
Anilines are rapidly, often within 60 minutes, converted into the corresponding phenols in up to 87% isolated yield. The presented experimentally simple protocol display broad compatibility with a variety of functional groups, and in particular, well suited for the preparation of methyl-substituted phenols. Such phenols are not easily available by other synthetic approaches. The formation of phenolic radical coupling products was not observed even for activated anilines using this open flask method.
- Kristianslund, Renate,Vik, Anders,Hansen, Trond V.
-
supporting information
p. 2809 - 2814
(2018/12/04)
-
- Recyclable CNT-chitosan nanohybrid film utilized in copper-catalyzed aerobic ipso-hydroxylation of arylboronic acids in aqueous media
-
A convenient heterogeneous catalytic system consisting of recyclable and reusable carbon nanotube-chitosan nanohybrid film and copper salt was developed for the aerobic ipso-hydroxylation of arylboronic acids. A variety of arylboronic acids bearing electron-withdrawing or electron-donating groups were smoothly transformed at room temperature in water to afford the corresponding phenols in high yields.
- Kim, Han-Sem,Joo, Sung-Ryu,Shin, Ueon Sang,Kim, Seung-Hoi
-
p. 4597 - 4601
(2018/11/23)
-
- Synthetic method for aurone compounds and anti-inflammatory compounds containing thereof
-
The present invention relates to a synthesis method capable of synthesizing aurone compounds, Rreogoron A (Compound 1a), Gram-flavonoid A (Compound 1b), and derivatives thereof (Compounds 1c to 1o) in a high yield from the disclosed commercially-available products. Also, their anti-inflammatory effects were evaluated in LPS-induced RAW-264.7 macrophages. The aurone compounds do not show cytotoxicity, and weakens or reduces the generation of nitrogen oxide that is induced by LPS at 10 andmu;M, and the IC_50 values of the compounds 1a - 1o are each in the range of 3.39-19.55 andmu;M. Among 15 aurone compounds synthesized in the present invention, the highest inhibitory activities were shown by the following compounds in this order: the compound 1g (63.98%; IC_50= 4.50), the compound 1o (49.07%; IC_50= 4.98) and the Rreogoron A (41.72%; IC_50= 3.39). Among the aurone compounds derived from 5,6-dimethoxybenzofuran-3(2H)-one (Compound 5), the compounds bound to 4-bromophenyl group (Compound 1g), ferrocenyl group (Compound 1o), and 4-hydroxyphenyl group (Compound 1a) were more effective to iNOS-mediated nitrogen oxide inhibitors than other aurone compounds.COPYRIGHT KIPO 2017
- -
-
Paragraph 0053-0054
(2017/10/21)
-
- Convergent Total Synthesis of (±)-Apomorphine via Benzyne Chemistry: Insights into the Mechanisms Involved in the Key Step
-
Convergent total synthesis of (±)-apomorphine hydrochloride was accomplished by an approach that employs in the key step a sequence of transformations involving a [4+2]-cycloaddition reaction followed by a hydrogen migration. Through this sequence of transformations, the desired aporphine core was obtained regioselectively in 75% isolated yield. Since only one regioisomer was produced in the key step of the synthesis, a polar [4+2]-cycloaddition mechanism was proposed. Furthermore, NMR experiments and theoretical calculations were carried out to elucidate the hydrogen migration mechanism. (±)-Apomorphine hydrochloride was achieved after 9 steps in an overall yield of 8% involving benzyne chemistry.
- Muraca, Ana Carolina A.,Perecim, Givago P.,Rodrigues, Alessandro,Raminelli, Cristiano
-
supporting information
p. 3546 - 3557
(2017/08/15)
-
- Aurone Mannich base derivatives as promising multifunctional agents with acetylcholinesterase inhibition, anti-β-amyloid aggragation and neuroprotective properties for the treatment of Alzheimer's disease
-
A series of aurone Mannich base derivatives were designed, synthesized and evaluated as multifunctional agents for the treatment of Alzheimer's disease. In vitro assays demonstrated that most of the derivatives were selective AChE inhibitors with good multifunctional properties. Among them, compound 7d exhibited outstanding inhibitory activity for RatAChE, EeAChE and HuAChE (IC50= 0.00878 ± 0.0002 μM, 0.0212 ± 0.006 μM and 0.0371 ± 0.004 μM, respectively). Moreover, 7d displayed high antioxidant activity and could confer significant neuroprotective effect against H2O2-induced PC-12 cell injury. In addition, 7d also showed biometal chelating abilities, good self- and Cu2+-induced Aβ1-42aggregation inhibitory potency and high BBB permeability. These multifunctional properties highlight 7d as promising candidate for further studies directed to the development of novel drugs against AD.
- Li, Yan,Qiang, Xiaoming,Luo, Li,Yang, Xia,Xiao, Ganyuan,Liu, Qi,Ai, Jiachen,Tan, Zhenghuai,Deng, Yong
-
p. 762 - 775
(2016/12/16)
-
- A lignin oxidation into small molecules of aromatic compounds (by machine translation)
-
A lignin oxidation into small molecules of aromatic compounds, which belongs to the technical field of biomass degradation, in particular to a through a non-transition metal catalyzed organic method fracture C - C key, will oxidize lignin into small molecules of aromatic compounds. First will oxidize lignin in the organic solvent is the oxidizing agent, and then the obtained intermediate product at the catalyst under the action of hydrolysis or alcoholysis, to obtain small molecular aromatic compound, such as methoxy substituted benzoic acid, methoxy substituted phenol, methoxy substituted benzoates, chain alcohol and the like. The invention has simple step, mild reaction conditions, high conversion rate (can be up to 100%), without the need of transition metal and the like, to oxidizing lignin a plurality of connection have all played a role, can reach the high selectivity, high-effectively degrade the purpose of lignin, and is favorable for the large-scale industrial application. (by machine translation)
- -
-
Paragraph 0025; 0026; 0029; 0030; 0055; 0062-0064
(2017/08/30)
-
- Highly effective C-C bond cleavage of lignin model compounds
-
A highly effective method is developed for the C-C bond cleavage of lignin model compounds. The inert Cα-Cβ or Cα-Cphenyl bond of oxidized lignin model compounds was successfully converted to an active ester bond through the classic organic name reaction, Baeyer-Villiger (BV) oxidation, and thus acetal esters and aryl esters were produced in high yields (up to 99%) at room temperature. Next, K2CO3 catalyzed the alcoholysis of the resulting ester products at 45 °C, affording various useful chemical platforms in excellent yields (up to 99%), such as phenols and multifunctional esters. This method uses commercially available reagents, is transition-metal free and simple, but highly effective, and involves mild reaction conditions.
- Wang, Yinling,Wang, Qianyi,He, Jianghua,Zhang, Yuetao
-
supporting information
p. 3135 - 3141
(2017/07/24)
-
- Facile synthesis and nitric oxide inhibitory activity of aurones, rugaurone a, gramflavonoid a and their derivatives
-
Facile synthesis of natural aurones, rugaurone A (1a), gramflavonoid A (1b) and their novel derivatives (1c-1o) is accomplished in good to high yields with exceptional Z-selectivity (≥ 97%) from the commercially available starting materials. Herein, practically improved method was developed for the synthesis of common key intermediate, 5,6-dimethoxybenzofuran-3(2H)-one (5). Later, their nitric oxide (NO) production inhibition effects were estimated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages as an indicator of anti-inflammatory activity. All compounds exhibited weak to good strength against NO production in a concentration-dependent manner and none of the compound showed significant cytotoxicity against macrophages at the highest (10 μM) concentration. The IC50 values are showed in the range from 3.39 to 19.55 μM. Among the 15 aurones synthesized in this study, 3 compounds that is compound 1g (63.98%) followed by compound 1o (49.07%) and rugaurone A (1a) (41.72%) showed the maximum inhibitory activity with respective IC50 values of 4.50 μM, 4.98 μM and 3.39 μM compared to L-NMMA (IC50 = 5.19 μM), which was used as a standard NO inhibitor. This study suggests that compounds 1g, 1o and 1a may serve as favorable structures for further development of NO production-targeted anti-inflammatory agents.
- Damodar, Kongara,Kim, Jin-Kyung,Jun, Jong-Gab
-
p. 1091 - 1098
(2016/11/25)
-
- Biomimetic oxidation of acetaminophen prodrugs catalyzed by iron porphyrins: Effect of nitrogen and thiolate axial ligands on drug and metabolite formation
-
Metalloporphyrins (MP) are often employed in biomimetic catalysis due to their structural and functional similarity to the heme prosthetic group of oxygenating enzymes. In these enzymes, the iron porphyrin is primarily protein-bound at the active site by cysteine (cytochrome P450, CYP), histidine (peroxidase), and tyrosine (catalase), acting as axial ligands. The diverse functionality and variable oxidizing power exhibited by different oxygenating enzymes is [in part] attributed to the ligating amino acid, and the relationship between iron and the heteroatom. Attempts to mimic this relationship by developing MP systems that behave similarly to CYP enzymes have mainly focused on incorporating nitrogen (N)-heterocycles. Although it is widely known that different enzyme families favor distinctive products, sulfur is easily oxidized and prone to form disulfide bonds, and as such, thiolates for the most part remain unexplored. Herein, we report our findings from the biomimetic oxidation of phenacetin, methacetin, and acetanilide by meta-chloroperoxybenzoic acid (m-CPBA), catalyzed by hindered iron (III) porphyrins that are chelated by different axial ligands. Nine axial ligands that vary in pKa (2.8-11.2), size, and heteroatomic identity were examined, to more accurately determine the factors that contribute to function and effect. The [three] thiolate ligands afforded the greatest yields of acetaminophen in the majority of cases. Furthermore, nitrogen- and sulfur-containing ligands were observed to promote different reaction pathways, regardless of pKa or ligand size.
- Chapman, Chiara M.,Pruneau, John M.,Laverack, Chloe A.,Dutton, Andrew S.,Jones, Graham B.
-
p. 204 - 215
(2015/12/05)
-
- ANALOGS OF VINAXANTHONE AND XANTHOFULVIN, METHODS OF SYNTHESIS, AND METHODS OF TREATMENTS THEREOF
-
The present invention relates generally to methods of synthesis of vinaxanthone and xanthofulvin, novel analogs, and methods of use thereof.
- -
-
Page/Page column 73; 74
(2015/02/25)
-
- Flying-seed-like liquid crystals. Part 4: A novel series of bulky substituents inducing mesomorphism instead of using long alkyl chains
-
We synthesized a novel series of flying-seed-like derivatives (3a-g) based on phthalocyaninato copper(ii) (abbreviated as PcCu) substituted by bulky groups {PhO (a), (o-C1)PhO (b), (m-C1)PhO (c), (p-C1)PhO (d), [m,p-(C1)2]PhO (e), [m,m′-(C1)2]PhO (f), and [m,p,m′-(C1)3]PhO (g)} instead of using long alkyl chains, in order to investigate their mesomorphism. Their phase transition behaviour and the mesophase structures were established using a polarizing optical microscope, a differential scanning calorimeter, a thermogravimetry analyser and a temperature-dependent small angle X-ray diffractometer. It was demonstrated that (PhO)8PcCu (3a) and [(p-C1)PhO]8PcCu (3d) show no mesophase, whereas [(m-C1)PhO]8PcCu (3c), {[m,p-(C1)2]PhO}8PcCu (3e), {[m,m′-(C1)2]PhO}8PcCu (3f), and {[m,p,m′-(C1)3]PhO}8PcCu (3g) show various kinds of columnar mesophases of Colro(P21/a), Colro(P21/a), Colro(C2/m) and Coltet.o, respectively, while [(o-C1)PhO]8PcCu (3b) shows a monotropic Colro(P2m) mesophase. Thus, we revealed that mesomorphism could be induced by these novel bulky substituents instead of using long alkyl chains, and that the mesophase structures were greatly affected by the number and position of the methoxy groups. In particular, it is very interesting that the derivatives with methoxy group(s) at the meta position(s), namely, 3c, 3e, 3f and 3g, tend to show enantiotropic mesophase(s), whereas neither the derivative with no methoxy group, 3a, nor the derivative with a methoxy group at the para position, 3d, show a mesophase. This journal is
- Yoshioka, Miho,Ohta, Kazuchika,Yasutake, Mikio
-
p. 13828 - 13839
(2015/02/19)
-
- Regioselectivity of the palladium-mediated intramolecular coupling reaction of highly oxygenated phenyl benzoate derivatives and application to the synthesis of altertenuol
-
The regioselectivity of the intramolecular biaryl coupling reaction of 3',4'-dialkoxyphenyl 2,4-dimethoxybenzoates was investigated using a palladium reagent, and transition state models of the reaction are proposed. As an application of this study, a short-step synthesis of altertenuol is also performed.
- Matsukihira, Takuya,Saga, Shumpei,Horino, Yoshikazu,Abe, Hitoshi
-
-
- Acceleration of the Dakin reaction by trifluoroacetic acid
-
An acceleration of the Dakin reaction caused by addition of trifluoroacetic acid is described. The modified protocol converts aromatic aldehydes to the corresponding phenols within 4 hours at room temperature by means of hydrogen peroxide in acidic medium. This acceleration is attributed to the stability of hydrogen peroxide in an acidic medium. This modified protocol provides alternative and easy access to important phenolic precursors that have been used in the synthesis of various natural products.
- Natu, Arun D.,Burde, Ameya S.,Limaye, Rohan A.,Paradkar, Madhusudan V.
-
p. 381 - 382
(2014/07/08)
-
- Fenpropathrin biodegradation pathway in bacillus sp. DG-02 and its potential for bioremediation of pyrethroid-contaminated soils
-
The widely used insecticide fenpropathrin in agriculture has become a public concern because of its heavy environmental contamination and toxic effects on mammals, yet little is known about the kinetic and metabolic behaviors of this pesticide. This study reports the degradation kinetics and metabolic pathway of fenpropathrin in Bacillus sp. DG-02, previously isolated from the pyrethroid-manufacturing wastewater treatment system. Up to 93.3% of 50 mg L-1 fenpropathrin was degraded by Bacillus sp. DG-02 within 72 h, and the degradation rate parameters qmax, Ks, and K i were determined to be 0.05 h-1, 9.0 mg L-1, and 694.8 mg L-1, respectively. Analysis of the degradation products by gas chromatography-mass spectrometry led to identification of seven metabolites of fenpropathrin, which suggest that fenpropathrin could be degraded first by cleavage of its carboxylester linkage and diaryl bond, followed by degradation of the aromatic ring and subsequent metabolism. In addition to degradation of fenpropathrin, this strain was also found to be capable of degrading a wide range of synthetic pyrethroids including deltamethrin, λ-cyhalothrin, β-cypermethrin, β-cyfluthrin, bifenthrin, and permethrin, which are also widely used insecticides with environmental contamination problems with the degradation process following the first-order kinetic model. Bioaugmentation of fenpropathrin-contaminated soils with strain DG-02 significantly enhanced the disappearance rate of fenpropathrin, and its half-life was sharply reduced in the soils. Taken together, these results depict the biodegradation mechanisms of fenpropathrin and also highlight the promising potentials of Bacillus sp. DG-02 in bioremediation of pyrethroid-contaminated soils.
- Chen, Shaohua,Chang, Changqing,Deng, Yinyue,An, Shuwen,Dong, Yi Hu,Zhou, Jianuan,Hu, Meiying,Zhong, Guohua,Zhang, Lian-Hui
-
p. 2147 - 2157
(2014/04/03)
-
- Boron dipyrromethene as a fluorescent caging group for single-photon uncaging with long-wavelength visible light
-
Caged compounds are useful tools for precise spatiotemporal modulation of cell functions, but in most cases uncaging requires ultraviolet (UV) light, which is cytotoxic and has limited tissue penetration. Therefore, caged compounds that can be activated by longer-wavelength light are required. Here we describe a novel photoelimination reaction of 4-aryloxy boron dipyrromethene (BODIPY) derivatives and show that BODIPY can function as a caging group for phenol groups. We developed a novel BODIPY-caged histamine compound, which is photoactivatable with blue-green visible light to stimulate cultured HeLa cells in a spatiotemporally well-controlled manner. This caging strategy is expected to be widely applicable to develop tools for probing various cellular functions. (Chemical Equation Presented).
- Umeda, Nobuhiro,Takahashi, Hironori,Kamiya, Mako,Ueno, Tasuku,Komatsu, Toru,Terai, Takuya,Hanaoka, Kenjiro,Nagano, Tetsuo,Urano, Yasuteru
-
p. 2242 - 2246
(2015/02/19)
-
- Benzoquinone-promoted aerobic oxidative hydroxylation of arylboronic acids in water
-
A general and efficient aerobic oxidative hydroxylation of arylboronic acids promoted by benzoquinone in water was realized, and provided phenols in 72-95% yields for 20 examples. The main advantages of this protocol are the use of water as solvent in the presence of a catalytic amount of benzoquinone, and metal-free conditions. Georg Thieme Verlag KG Stuttgart · New York.
- Cheng, Guolin,Zeng, Xiaobao,Cui, Xiuling
-
p. 295 - 300
(2014/02/14)
-
- Synthesis of fluorinated aromatic compounds by one-pot benzyne generation and nucleophilic fluorination
-
The fluorination of substituted benzenes using fluoride ions under mild reaction conditions has been one of the most important challenges for the synthesis of biologically active fluorinated aromatic compounds; however, only a few synthetically useful methods are known. In this paper, it is reported that the nucleophilic fluorination of benzynes, generated from either 2-(trialkylsilyl)phenyl nonafluorobutanesulfonates or 2-(trialkylsilyl)phenols, meets this challenge. In particular, the fluorination starting from 2-(trialkylsilyl)phenols for fabricating aryl fluorides involves three sequential reactions in one-pot: the nonaflylation of phenols, benzyne generation, and nucleophilic fluorination of the benzynes. The regioselectivities of these reactions are controlled by the substituents at the C3-position of the benzynes. CSIRO 2014.
- Ikawa, Takashi,Masuda, Shigeaki,Nishiyama, Tsuyoshi,Takagi, Akira,Akai, Shuji
-
p. 475 - 480
(2014/04/03)
-
- Continuous-flow synthesis of functionalized phenols by aerobic oxidation of grignard reagents
-
Phenols are important compounds in chemical industry. An economical and green approach to phenol preparation by the direct oxidation of aryl Grignard reagents using compressed air in continuous gas-liquid segmented flow systems is described. The process tolerates a broad range of functional groups, including oxidation-sensitive functionalities such as alkenes, amines, and thioethers. By integrating a benzyne-mediated in-line generation of arylmagnesium intermediates with the aerobic oxidation, a facile three-step, one-flow process, capable of preparing 2-functionalized phenols in a modular fashion, is established. Putting on airs: Aerobic oxidation of (hetero)aryl Grignard reagents using compressed air proceeds with a gas-liquid continuous-flow system, thus enabling preparation of fucntionalized phenols. By integrating an in-line generation of ArMgBr intermediates with the aerobic oxidation, ortho-functionalized phenols can be assembled. The method demonstrates good functional-group (FG) compatibility, mild reaction conditions, and short reaction times.
- He, Zhi,Jamison, Timothy F.
-
supporting information
p. 3353 - 3357
(2014/04/03)
-
- Ortho-and para-selective ruthenium-catalyzed C(sp2)-H oxygenations of phenol derivatives
-
Versatile ruthenium catalysts allowed for efficient direct oxygenations of aryl carbamates under remarkably mild reaction conditions. In addition to chelation-assisted C-H activation, the optimized ruthenium catalyst proved amenable to para-selective hydroxylations of anisoles without Lewis basic directing groups.
- Liu, Weiping,Ackermann, Lutz
-
supporting information
p. 3484 - 3486
(2013/07/26)
-
- Chemical conversion of β-O-4 lignin linkage models through Cu-catalyzed aerobic amide bond formation
-
Methods for conversion of the lignin β-O-4 models into amide derivatives and phenols have been developed, which is achieved via chemo-selective oxidation of the secondary benzylic alcohol and subsequent Cu-catalyzed aerobic amide bond formation.
- Zhang, Jian,Liu, Yu,Chiba, Shunsuke,Loh, Teck-Peng
-
supporting information
p. 11439 - 11441
(2013/12/04)
-
- Reductive cleavage of aryl O-carbamates to phenols by the Schwartz reagent. Expedient link to the directed ortho metalation strategy?
-
A general, mild, and efficient method for the reductive cleavage of aryl O-carbamates to phenols, 1 → 2 using the Schwartz reagent is reported. The method is selective, tolerating a large number of functional groups; may be carried out by direct or by an economical in situ procedure; and, notably, establishes a synthetic connection to the directed ortho metalation strategy (Figure 1) allowing new entries into difficult to prepare contiguously substituted aromatics and heteroaromatics.
- Morin, Justin,Zhao, Yigang,Snieckus, Victor
-
supporting information
p. 4102 - 4105
(2013/09/12)
-
- Chemo- and regioselective direct hydroxylation of arenes with hydrogen peroxide catalyzed by a divanadium-substituted phosphotungstate
-
Peroxide in, phenol out: The catalyst [-PW10O38V 2(μ-OH)2]3- showed high activity in the hydroxylation of various aromatic compounds with aqueous H2O 2. The system was regioselective, producing para-phenols from monosubstituted benzene derivatives. Furthermore, alkylarenes with reactive side-chain Ca spa 3-H bonds could be chemoselectively hydroxylated without significant formation of side-chain oxygenated products. Copyright
- Kamata, Keigo,Yamaura, Taiyo,Mizuno, Noritaka
-
supporting information; experimental part
p. 7275 - 7278
(2012/08/28)
-
- New approach for the construction of the coumarin frame and application in the total synthesis of natural products
-
A new synthetic approach is described for building the coumarin scaffold through the Lewis acid-promoted cyclization of novel aryl 3-(dimethylamino)prop- 2-enoates 2a - 2f. The latter precursors were prepared via aminomethylenation of the corresponding aryl acetates 4a - 4f with the Bredereck reagent. This approach was used for the synthesis of biologically active natural compounds 1a - 1f, through a three-step procedure starting from the corresponding phenols.
- Jerezano, Alberto,Jimenez, Fabiola,Del Carmen Cruz, Maria,Montiel, Luisa E.,Delgado, Francisco,Tamariz, Joaquin
-
p. 185 - 198
(2011/04/17)
-
- Highly efficient synthesis of phenols by copper-catalyzed hydroxylation of aryl iodides, bromides, and chlorides
-
8-Hydroxyquinolin-N-oxide was found to be a very efficient ligand for the copper-catalyzed hydroxylation of aryl iodides, aryl bromides, or aryl chlorides under mild reaction conditions. This methodology provides a direct transformation of aryl halides to phenols and to alkyl aryl ethers. The inexpensive catalytic system showed great functional group tolerance and excellent selectivity.
- Yang, Kai,Li, Zheng,Wang, Zhaoyang,Yao, Zhiyi,Jiang, Sheng
-
supporting information; experimental part
p. 4340 - 4343
(2011/10/08)
-
- Synthesis of 1,2,4-trimethoxybenzene and its selective functionalization at C-3 by directed metalation
-
A new and efficient strategy was developed for the preparation of 1,2,4-trimethoxybenzene (3, a powerful attractant of Euglossini bees) and its C-3 derivatives (7a-j), from vanillin (2) in 56% overall yield.
- Alves, Ana P. L.,Junior, Jose Augusto B. C.,Slana, Glaucia B. A.,Cardoso, Jari N.,Wang, Qiang,Lopes, Rosangela S. C.,Lopes, Claudio C.
-
experimental part
p. 3693 - 3709
(2009/12/06)
-
- Improved solvent-free Dakin oxidation protocol
-
A solvent-free Dakin reaction with mCPBA was accomplished with various aromatic aldehydes, resulting in an easy and improved methodology for the preparation of corresponding phenols. 3,4-Methylenedioxyphenol, 3,4-dimethoxyphenol, 4-methoxyphenol, 4-chlorophenol, and other functionalized phenols were obtained in high yields from the corresponding aromatic aldehydes in a few minutes. This new methodology represents an efficient alternative for this important synthetic conversion. Copyright Taylor & Francis Group, LLC.
- Da Silva, Emerson Teixeira,Camara, Celso Amorim,Antunes,Barreiro, Eliezer J.,Fraga, Carlos A. M.
-
p. 784 - 788
(2008/09/16)
-
- Synthesis of lamellarin U and lamellarin G trimethyl ether by alkylation of a deprotonated α-aminonitrile
-
(Chemical Equation Presented) 1,2,3,4-Tetrahydroisoquinoline-1- carbonitriles can serve as starting materials for the one-pot synthesis of 5,6-dihydropyrrolo[2,1a]isoquinolines and 1-benzyl-3,4-dihydroisoquinolines. The latter compounds were transformed to lamellarin G trimethyl ether and lamellarin U in short reaction sequences. This method allows the introduction of acid-sensitive protecting groups for the phenolic hydroxy functions which would be cleaved under the harsh conditions of the classical Bischler-Napieralski reaction.
- Liermann, Johannes C.,Opatz, Till
-
p. 4526 - 4531
(2008/09/21)
-
- Process for the preparation of substituted phenols
-
A substituted phenolic compound is prepared by oxidizing a substituted diarylethane compound with oxygen in the presence of a nitrogen-containing cyclic compound, and treating the oxidized product with an acid. The nitrogen-containing cyclic compound includes, as a constituent of its ring, a skeleton represented by following Formula (I): wherein X is oxygen atom or an -OR group, where R is hydrogen atom or a hydroxyl-protecting group. The substituted diarylethane compound is represented by following Formula (1): wherein each of Ring Ar1 and Ring Ar2 is independently a monocyclic or polycyclic aromatic carbocyclic ring; Y1 is an electron-donating group; Y2 is an electron-withdrawing group; "p" is an integer of 1 or more; and "q" is an integer of 0 or more. The substituted phenolic compound is represented by following Formula (2): wherein Ring Ar1, Y1, and "p" are as defined above.
- -
-
Page/Page column 14
(2008/12/08)
-
- Selective one-pot synthesis of various phenols from diarylethanes
-
Various substituted phenols were selectively synthesized by a one-pot reaction through the NHPI-catalyzed aerobic oxidation of 1,1-diarylethanes followed by treatment with dilute sulfuric acid. The Royal Society of Chemistry.
- Nakamura, Ryota,Obora, Yasushi,Ishii, Yasutaka
-
supporting information; experimental part
p. 3417 - 3419
(2009/02/05)
-
- Mild debenzylation of aryl benzyl ether with BCl3 in the presence of pentamethylbenzene as a non-lewis-basic cation scavenger
-
Scope and limitations of the debenzylation conditions for aryl benzyl ether, which was developed during our synthetic studies on yatakemycin, were investigated. The chemoselective debenzylation proceeds at low temperature with a combination of BCl3 and pentamethylbenzene as a cation scavenger in the presence of various functional groups.
- Okano, Kentaro,Okuyama, Kei-Ichiro,Fukuyama, Tohru,Tokuyama, Hidetoshi
-
body text
p. 1977 - 1980
(2009/04/07)
-
- Convenient synthetic route to a dehydrorotenoid via selective intramolecular aldol condensation of 1,2-diaryl diketone
-
Synthesis of dehydrorotenoid (1) was successfully achieved via an intramolecular aldol reaction of the corresponding 1,2-diaryl diketone intermediate. The 1,2-diaryl diketone was prepared using a ruthenium-catalyzed oxidation of the corresponding substituted diaryl acetylene. Treatment of this 1,2-diketone with l-proline induced a selective intramolecular aldol condensation reaction, forming the desired benzopyranone over the alternative benzofuran. Deprotection, cyclization, and dehydration gave the target compound in good overall yield.
- Tummatorn, Jumreang,Khorphueng, Prapas,Petsom, Amorn,Muangsin, Nongnuch,Chaichit, Narongsak,Roengsumran, Sophon
-
p. 11878 - 11885
(2008/03/13)
-
- Oxidation of aromatic aldehydes and ketones by H2O 2/CH3ReO3 in ionic liquids: A catalytic efficient reaction to achieve dihydric phenols
-
A convenient and efficient application of hydrogen peroxide/ methyltrioxorhenium in ionic liquids [bmim]BF4 and [bmim]PF 6 for the oxidation of hydroxylated and methoxylated benzaldehydes and acetophenones to the corresponding phenols is described. Good yields of products were obtained in short reaction times.
- Bernini, Roberta,Coratti, Antonietta,Provenzano, Gianfranco,Fabrizi, Giancarlo,Tofani, Daniela
-
p. 1821 - 1825
(2007/10/03)
-
- Studies toward the total synthesis of angelmicin B (hibarimicin B): Synthesis of a model CD-D′ arylnaphthoquinone
-
(Chemical Equation Presented) A synthesis of arylnaphthoquinone 22 corresponding to the CD-D′ unit of angelmicin B via the Suzuki coupling of the D′ arylboronic acid 15 with the CD bromonaphthoquinone 21 is described. The mild conditions for the Suzuki cross-coupling leading to 22 may prove to be useful for the eventual late-stage coupling of the two highly functionalized halves of angelmicin B.
- Narayan, Sridhar,Roush, William R.
-
p. 3789 - 3792
(2007/10/03)
-
- Process for the synthesis of phenols from arenes
-
A process to synthesize substituted phenols such as those of the general formula RR′R″Ar(OH) wherein R, R′, and R″ are each independently hydrogen or any group which does not interfere in the process for synthesizing the substituted phenol including, but not limited to, halo, alkyl, alkoxy, carboxylic ester, amine, amide; and Ar is any variety of aryl or hetroaryl by means of oxidation of substituted arylboronic esters is described. In particular, a metal-catalyzed C—H activation/borylation reaction is described, which when followed by direct oxidation in a single or separate reaction vessel affords phenols without the need for any intermediate manipulations. More particularly, a process wherein Ir-catalyzed borylation of arenes using pinacolborane (HBPin) followed by oxidation of the intermediate arylboronic ester by OXONE is described.
- -
-
-
