- Push-pull azobenzene chromophores with negative halochromism
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This work describes the synthesis and properties of monoazobenzene compounds carrying multiple electron-donating and electron-withdrawing substituents. The donors are methoxy and dialkylamine groups. The acceptors are cyano and nitro groups. The position of these groups has a strong influence on the absorption spectrum. When the nitro and cyano groups are located at the ortho and para positions to the azo bond, respectively, then the absorption maximum (λmax) can be found at 484 nm. However, switching this arrangement leads to a 57 nm red-shift (λmax = 541 nm). This shift can be enhanced further (λmax = 584 and 604 nm) by moving one of the methoxy groups from the ortho to the meta position and by encompassing the nitrogen atom in a five-membered ring. Interestingly, under acidic conditions, a reversible blue-shift (negative halochromism) is observed.
- Eom, Taejun,Khan, Anzar
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- Aza-Matteson Reactions via Controlled Mono-and Double-Methylene Insertions into Nitrogen-Boron Bonds
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Boron-homologation reactions represent an efficient and programmable approach to prepare alkylboronates, which are valuable and versatile synthetic intermediates. The typical boron-homologation reaction, also known as the Matteson reaction, involves formal carbenoid insertions into C-B bonds. Here we report the development of aza-Matteson reactions via carbenoid insertions into the N-B bonds of aminoboranes. By changing the leaving groups of the carbenoids and altering Lewis acid activators, selective mono- and double-methylene insertions can be realized to access various α- and β-boron-substituted tertiary amines, respectively, from common secondary amines. The derivatization of complex amine-containing bioactive molecules, diverse functionalization of the boronate products, and sequential insertions of different carbenoids have also been achieved.
- Xie, Qiqiang,Dong, Guangbin
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supporting information
p. 14422 - 14427
(2021/09/29)
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- Green synthesis of N-(2-hydroxyethyl)anilines by the selective alkylation reaction in H2O
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Based on our previous work, a safer and more sustainable protocol for the synthesis of N-(2-Hydroxyethyl)anilines has been developed. The synthesis included the selective alkylation reaction of aniline with 2-chloroethanol in H2O, eliminating the need for any catalysts and solvents during synthesis. Comparing with our previous work, the salient features of this methodology are eco-friendliness, economic benefit, and the ease of obtaining target compounds. The selective alkylation reaction in H2O is amenable to scale-up for the synthesis of N-(2-Hydroxyethyl)anilines.
- Guo, Hui,Hao, Jia,Sun, Tingting,Wang, Zuoyao,Cao, Jian,Zhang, Guobao
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- Ru-Catalyzed Switchable N-Hydroxyethylation and N-Acetonylation with Crude Glycerol
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Highly efficient Ru-catalyzed selective C?C or C?O bond cleavage of polyols (e.g., crude glycerol) for N-hydroxyethylation or N-acetonylation of amines was achieved through the hydrogen-borrowing approach. A variety of amines were transformed to the desired amino alcohols/ketones in moderate-to-excellent yields, opening up new avenues for generation of oxygenated pharmaceuticals and fine chemicals from renewable raw materials. The use of new redox-active catalysts containing bisphosphine/thienylmethylamine ligands allows this hydrogen-borrowing system to be operated selectively under both basic and acidic conditions.
- Xin, Zhuo,Jia, Le,Huang, Yuxing,Du, Chen-Xia,Li, Yuehui
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p. 2007 - 2011
(2020/03/19)
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- Direct hydroxyethylation of amines by carbohydrates: Via ruthenium catalysis
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An efficient and halogen-free catalytic methodology for the synthesis of β-amino alcohols from aromatic amines and biomass-derived carbohydrates is demonstrated for the first time. The activation of C5/C6 sugars by a ruthenium catalyst selectively generates the C2 alkylating reagent glycolaldehyde. The transformation involves metal-catalyzed hydrogen borrowing for the reduction of the imine intermediate. A series of arylamines bearing various substituents were successfully transformed into the desired products in good to excellent yields.
- Jia, Le,Makha, Mohamed,Du, Chen-Xia,Quan, Zheng-Jun,Wang, Xi-Cun,Li, Yuehui
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supporting information
p. 3127 - 3132
(2019/06/18)
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- A process for preparing N - ethyl - N - hydroxyethyl aniline
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The invention discloses a method for preparing N - ethyl - N - hydroxyethyl aniline. The method in order to N - ethyl aniline, ethylene oxide as the raw material, in the absence of solvent, in the presence of the taurine, program heating heating, direct synthesis N - ethyl - N - hydroxy ethyl aniline, cooling discharging, to obtain the finished product. The method easily available raw materials, good atom economy, mild reaction conditions, environmental protection, simple and efficient, and is suitable for industrial production.
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Paragraph 0050; 0052; 0054; 0056; 0057; 0058
(2018/06/16)
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- Synthetic technology of hydroxyethylaniline ester (III)
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The invention discloses a synthetic technology of hydroxyethylaniline ester (III). The synthesis process is shown by a chemical equation shown in the description. The technology has the following advantages: 1, the advantage of few instant reaction substances of a micro-channel reactor is used, so the flammable and explosive disadvantages of a hydroxyethylation reaction in a routine kettle are solved, the process safety is increased, and current chemical engineering safety operation requirements are met; and 2, the advantage of high mixing efficiency of the micro-channel reactor is used, the reaction can be carried out under solvent-free conditions when a hydroxyethylation reaction raw material is liquid, and when the excess amount of ethylene oxide is very small, so a reaction solution obtained after the hydroxyethylation reaction ends can be esterified in the micro-channel reactor, serial operation of two-step reactions is realized, and manpower and three wastes are greatly reduced. The technology is a new technology with simplified processes, and accords with environmental protection and safety requirements.
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Paragraph 0042; 0043; 0056; 0057; 0063
(2016/11/02)
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- New "X-type" second-order nonlinear optical (NLO) dendrimers: Fewer chromophore moieties and high NLO effects
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New types of "X-type" NLO dendrimers, C2 and C3, in which the chromophore moieties were arranged in order, were rationally designed. The special topology of the chromophore moieties contributed a great deal to the good NLO performance of C2 and C3: the d33 value of C2 (containing only five chromophore moieties) was 157.4 pm V-1, while that of C3 (containing nine chromophore moieties) achieved 195.2 pm V-1, much larger than that of C1 (74.7 pm V-1, containing three chromophore moieties) and the fifth generation dendrimer (G5) (193.1 pm V-1, bearing 62 pieces of chromophore moieties). Through careful experimental and theoretical analysis, their structure-property relationship was explained, and discussed in detail.
- Tang, Runli,Zhou, Shengmin,Xiang, Wendi,Xie, Yujun,Chen, Hong,Peng, Qian,Yu, Gui,Liu, Binwen,Zeng, Huiyi,Li, Qianqian,Li, Zhen
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p. 4545 - 4552
(2015/05/13)
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- Catalytic N-Alkylation of Amines Using Carboxylic Acids and Molecular Hydrogen
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A convenient, practical and green N-alkylation of amines has been accomplished by applying readily available carboxylic acids in the presence of molecular hydrogen. Applying an in situ formed ruthenium/triphos complex and an organic acid as cocatalyst, a broad range of alkylated secondary and tertiary amines are obtained in good to excellent yields. This novel method is also successfully applied for the synthesis of unsymmetrically substituted N-methyl/alkyl anilines through a direct three-component coupling reaction of the corresponding amines, carboxylic acids, and CO2 as a C1 source.
- Sorribes, Iván,Cabrero-Antonino, Jose R.,Vicent, Cristian,Junge, Kathrin,Beller, Matthias
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supporting information
p. 13580 - 13587
(2015/11/10)
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- Direct catalytic N-alkylation of amines with carboxylic acids
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A straightforward process for the N-alkylation of amines has been developed applying readily available carboxylic acids and silanes as the hydride source. Complementary to known reductive aminations, effective C-N bond construction proceeds under mild conditions and allows obtaining a broad range of alkylated secondary and tertiary amines, including fluoroalkyl-substituted anilines as well as the bioactive compound Cinacalcet HCl.
- Sorribes, Iván,Junge, Kathrin,Beller, Matthias
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p. 14314 - 14319
(2014/12/10)
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- Oxidatively activated DNA-modifying agents for selective cytotoxicity
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DNA-modifying agents are stalwarts of chemotherapeutic cancer treatments, but require significant design improvements to improve selectivity, minimize side effects, and for their widespread use to continue. Herein we present a novel design strategy in which DNA-modifying agents contain an oxidizable leaving group and a nitrogen mustard. The agents form strong electrophiles specifically when oxidized. Activation, measured by hydrolysis, illustrates that oxidants increase reactivity 1700-fold. Reaction in the presence of 2'-deoxyguanosine leads to the formation of lesions. Cytotoxicity measured in HeLa cells showed that low IC50 values require an oxidizable hydroquinone and a nitrogen mustard fragment. Cytotoxicity measurements in 15 cancer cell lines demonstrates that oxidatively activated DNA-modifying agents are highly selective, as the analogue tested has IC50 values less than 10μM for only three of the 15 cell lines; in contrast, cisplatin is highly toxic to 13 of the 15 cell lines. The selective cytotoxicity of oxidatively activated DNA-damaging agents could be useful against kidney cancer cells, as the 786-O cell line model assay resulted in an IC50 value of 5μM. DNA-modifying agents require design improvements to lower side effects. A novel design strategy in which agents that contain oxidizable leaving groups is shown. Oxidation increases reactivity 1700-fold. Reactions occur between the agent and 2'-deoxyguanosine, and compounds in this class selectively target the renal carcinoma model cell line 786-O.
- Li, Guorui,Bell, Tiffany,Merino, Edward J.
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experimental part
p. 869 - 875
(2012/01/06)
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- Omega-quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal antiinflammatory drugs
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Quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal anti-inflammatory drugs (NSAIDs) are disclosed. These esters and thioesters display the anti--inflammatory profile of the parent NSAIDs with greatly reduced gastrointestinal irritancy, providing a more favorable separation of therapeutic activity and toxicological side effects than the parent NSAIDs.
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