- Regioselective Synthesis of 2-Amino-5-(or 3-)arylazo-Substituted Pyridines and Pyrazines from Pyridinium N-Aminides
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Differently modified 2-aminopyridines and pyrazines bearing an arylazo group at the 3- or 5-position have been generated from pyridinium N-aminides in a regioselective fashion. The detailed chemistry starts with attack of the N-aminide on a diazonium salt, to form the arylazo derivative. N-alkylation on the exocyclic nitrogen and reduction to break the N-N bond then affords the final compounds, as an extension of the broad synthetic uses of the pyridinium N-aminides.
- Gala, Elena,Reyes, M. José,Alvarez-Builla, Julio,Izquierdo, M. Luisa
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Read Online
- Selective Carbon-Carbon Bond Amination with Redox-Active Aminating Reagents: A Direct Approach to Anilines?
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Amines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt-type rearrangement using redox-active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.
- Qiu, Xu,Wang, Yachong,Su, Lingyu,Jin, Rui,Song, Song,Qin, Qixue,Li, Junhua,Zong, Baoning,Jiao, Ning
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p. 3011 - 3016
(2021/09/13)
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- Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
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The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.
- Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
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supporting information
p. 2742 - 2747
(2021/05/05)
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- Biorenewable carbon-supported Ru catalyst for: N -alkylation of amines with alcohols and selective hydrogenation of nitroarenes
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Herein, we developed a renewable carbon-supported Ru catalyst (Ru/PNC-700), which was facilely prepared via simple impregnation followed by the pyrolysis process. The prepared Ru/PNC-700 catalyst demonstrated remarkable catalytic activity in terms of conversion and selectivity towards N-alkylation of anilines with benzyl alcohol and chemoselective hydrogenation of aromatic nitro compounds. In addition, local anesthetic pharmaceutical agents (e.g., butamben and benzocaine), including key drug intermediates, were synthesized in excellent yields under mild conditions and in the presence of water as a green solvent. Moreover, the prepared Ru/PNC-700 catalyst could be easily recovered and reused up to five times without any apparent loss in activity and selectivity.
- Goyal, Vishakha,Narani, Anand,Natte, Kishore,Poddar, Mukesh Kumar,Ray, Anjan,Sarki, Naina,Tripathi, Deependra
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p. 14687 - 14694
(2021/08/23)
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- Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
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Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
- Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
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supporting information
p. 1618 - 1629
(2021/01/25)
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- One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols
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Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.
- Akai, Shuji,Ikawa, Takashi,Masuda, Shigeaki
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- C-H Amination of Arenes with Hydroxylamine
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This Letter describes the development of a TiIII-mediated reaction for the C-H amination of arenes with hydroxylamine. This reaction is applied to a variety of electron-rich (hetero)arene substrates, including a series of natural products and pharmaceuticals. It offers the advantages of mild conditions (room temperature), fast reaction rates (30 min), compatibility with ambient moisture and air, scalability, and the use of inexpensive commercial reagents.
- See, Yi Yang,Sanford, Melanie S.
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supporting information
p. 2931 - 2934
(2020/04/09)
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- Oxalic amide ligands, and uses thereof in copper-catalyzed coupling reaction of aryl halides
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The present invention provides oxalic amide ligands and uses thereof in copper-catalyzed coupling reaction of aryl halides. Specifically, the present invention provides a use of a compound represented by formula I, wherein definitions of each group are described in the specification. The compound represented by formula I can be used as a ligand in copper-catalyzed coupling reaction of aryl halides for the formation of C—N, C—O and C—S bonds.
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Page/Page column 89-90
(2020/01/09)
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- HETEROCYCLIC CARBOXYLIC ACID AMIDE LIGAND AND APPLICATIONS THEREOF IN COPPER CATALYZED COUPLING REACTION OF ARYL HALOGENO SUBSTITUTE
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Provided are a heterocyclic carboxylic acid amide ligand and applications thereof in a copper catalyzed coupling reaction. Specifically, provided are uses of a compound represented by formula (I), definitions of radical groups being described in the specifications. The compound represented by formula (I) can be used as the ligand in the copper catalyzed coupling reaction of the aryl halogeno substitute, and is used or catalyzing the coupling reaction for forming the aryl halogeno substitute having C—N, C—O, C—S and other bonds.
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Paragraph 0266-0267
(2019/05/15)
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- Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage
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The Br?nsted acid-catalyzed synthesis of primary amines from acetyl arenes and alkanes with C-C bond cleavage is described. Although the conversion from an acetyl group to amine has traditionally required multiple steps, the method described herein, which uses an oxime reagent as an amino group source, achieves the transformation directly via domino transoximation/Beckmann rearrangement/Pinner reaction. The method was also applied to the synthesis of γ-aminobutyric acids, such as baclophen and rolipram.
- Hyodo, Kengo,Hasegawa, Genna,Maki, Hiroya,Uchida, Kingo
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supporting information
p. 2818 - 2822
(2019/04/25)
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- Catalytic Transfer Hydrodebenzylation with Low Palladium Loading
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A highly-efficient catalytic system for hydrodebenzylation reaction is described. The cleavage of O-benzyl and N-benzyl protecting groups was performed using an uncommonly low palladium loading (0.02–0.3 mol%; TON up to 5000) in a relatively short reaction time. The approach was used for a variety of substrates including pharmaceutically important precursors, and gram-scale deprotection reaction was shown. Transfer conditions together with easy-to-make Pd/C catalyst are the key features of this debenzylation scheme. (Figure presented.).
- Yakukhnov, Sergey A.,Ananikov, Valentine P.
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p. 4781 - 4789
(2019/09/16)
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- AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
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In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
- -
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Paragraph 0098; 0134; 0135; 0202
(2018/03/25)
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- Development of a novel protocol for chemoselective deprotection of N/O-benzyloxycarbonyl (Cbz) at ambient temperature
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Abstract: A novel protocol for the deprotection of N-benzyloxycarbonyl and O-benzyloxycarbonyl groups by nickel boride generated in situ from NaBH4 and NiCl2·6H2O in methanol at room temperature has been developed to give the corresponding amines and phenols. This protocol is chemoselective as groups like chloro, bromo, amide, ester, pyridine, and tert-butyloxycarbonyl moiety are unaffected under these conditions. The deprotection has also been validated in gram scale reactions, to establish the wider appropriateness of this protocol. Graphical abstract: [Figure not available: see fulltext.].
- Saroha, Mohit,Aggarwal, Komal,Bartwal, Gaurav,Khurana, Jitender M.
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p. 2231 - 2235
(2018/10/02)
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- Discovery of N-(Naphthalen-1-yl)-N′-alkyl Oxalamide Ligands Enables Cu-Catalyzed Aryl Amination with High Turnovers
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A class of N-(naphthalen-1-yl)-N′-alkyl oxalamides have been proven to be powerful ligands, making a coupling reaction of (hetero)aryl iodides with primary amines proceed at 50 °C with only 0.01 mol % of Cu2O and ligand as well as a coupling reaction of (hetero)aryl bromides with primary amines and ammonia at 80 °C with only 0.1 mol % of Cu2O and ligand. A wide range of coupling partners work well under these conditions, thereby providing an easy to operate method for preparing (hetero)aryl amines.
- Gao, Jie,Bhunia, Subhajit,Wang, Kailiang,Gan, Lu,Xia, Shanghua,Ma, Dawei
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supporting information
p. 2809 - 2812
(2017/06/07)
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- Rapid heteroatom transfer to arylmetals utilizing multifunctional reagent scaffolds
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Arylmetals are highly valuable carbon nucleophiles that are readily and inexpensively prepared from aryl halides or arenes and widely used on both laboratory and industrial scales to react directly with a wide range of electrophiles. Although C-C bond formation has been a staple of organic synthesis, the direct transfer of primary amino (-NH2) and hydroxyl (-OH) groups to arylmetals in a scalable and environmentally friendly fashion remains a formidable synthetic challenge because of the absence of suitable heteroatom-transfer reagents. Here, we demonstrate the use of bench-stable N-H and N-alkyl oxaziridines derived from readily available terpenoid scaffolds as efficient multifunctional reagents for the direct primary amination and hydroxylation of structurally diverse aryl- and heteroarylmetals. This practical and scalable method provides one-step synthetic access to primary anilines and phenols at low temperature and avoids the use of transition-metal catalysts, ligands and additives, nitrogen-protecting groups, excess reagents and harsh workup conditions.
- Gao, Hongyin,Zhou, Zhe,Kwon, Doo-Hyun,Coombs, James,Jones, Steven,Behnke, Nicole Erin,Ess, Daniel H.,Kürti, László
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p. 681 - 688
(2017/06/30)
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- Sonication and Microwave-Assisted Primary Amination of Potassium- Aryltrifluoroborates and Phenylboronic Acids under Metal-Free Conditions
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The transition-metal-free generation of a series of primary arylamines from potassium aryltrifluoroborates and phenylboronic acids- is reported. The method uses a mild, inexpensive source of nitrogen (hydroxylamine-O-sulfonic acid) in cooperation with aqueous sodium hydroxide in acetonitrile. Both a sonication and a microwave-assisted method were developed, which are capable of converting ArBF3K functionalities into primary arylamines (ArNH2) in isolated yields of up to 78% (10 examples for each method). This report represents the first general method for the conversion of aryltrifluoroborates into primary arylamines under mild, transition-metal-free conditions in moderate to very good yields. The method is applicable to a wide array of substrates containing electron-donating, electron-neutral, or electron-withdrawing substituents. Both the sonication and microwave methods were also applied to the generation of anilines from phenylboronic acids in isolated yields of up to 96% (12 examples for each method) that were superior to existing room temperature methods in terms of yield, while also offering much shorter reaction times (15 min vs 16 h). In particular, the microwave method is the first to allow for the conversion of arylboronic acids containing strongly electron-withdrawing substituents into the corresponding anilines in good yields, along with electron-donating- substituents in very good to excellent yields.
- Kuik, Dale,McCubbin, J. Adam,Tranmer, Geoffrey K.
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p. 2555 - 2561
(2017/05/22)
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- Nickel-Catalyzed Synthesis of Primary Aryl and Heteroaryl Amines via C-O Bond Cleavage
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A nickel-catalyzed protocol for the conversion of aryl and heteroaryl alcohol derivatives to primary and secondary aromatic amines via C(sp2)-O bond cleavage is described. The new amination protocol can be applied to a range of substrates bearing diverse functional groups and uses readily available benzophenone imines as an effective nitrogen source.
- Yue, Huifeng,Guo, Lin,Liu, Xiangqian,Rueping, Magnus
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p. 1788 - 1791
(2017/04/11)
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- Nickel-Catalyzed Decarbonylative Silylation, Borylation, and Amination of Arylamides via a Deamidative Reaction Pathway
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A nickel-catalyzed decarbonylative silylation, borylation, and amination of amides has been developed. This new methodology allows the direct interconversion of amides to arylsilanes, arylboronates, and arylamines and enables a facile route for carbon-heteroatom bond formations in a straightforward and mild fashion.
- Lee, Shao-Chi,Guo, Lin,Yue, Huifeng,Liao, Hsuan-Hung,Rueping, Magnus
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p. 2594 - 2598
(2017/10/31)
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- Hexafluoro-2-propanol-assisted quick and chemoselective nitro reduction using iron powder as catalyst under mild conditions
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Hexafluoro-2-propanol as the promoter for the quick nitro reduction using a combination of iron powder and 2 N HCl aqueous solution is reported. This methodology has several positive features, as it is of room temperature, remarkably short reaction time. A wide range of substrates including those bearing reducible functional groups such as aldehyde, ketone, acid, ester, amide, nitrile, halogens, even allyl, propargyl and heterocycles are chemoselectively reduced in good to excellent yields, even on gram scale. Notably, the highly selective reduction of 3-nitrophenylboronic acid is achieved quantitatively. The reduction is also tolerant of common protecting groups, and aliphatic nitro compound, 1-nitrooctane can be reduced successfully.
- Chen, Xu-Ling,Ai, Bai-Ru,Dong, Yu,Zhang, Xiao-Mei,Wang, Ji-Yu
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supporting information
p. 3646 - 3649
(2017/08/23)
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- Fe-Catalyzed Amination of (Hetero)Arenes with a Redox-Active Aminating Reagent under Mild Conditions
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A novel and efficient Fe-catalyzed direct C?H amination (NH2) of arenes is reported using a new redox-active aminating reagent. The reaction is simple, and can be performed under air, mild, and redox-neutral conditions. This protocol has a broad substrate scope and could be used in the late-stage modification of bioactive compounds. Mechanistic studies demonstrate that a radical pathway could be involved in this transformation.
- Liu, Jianzhong,Wu, Kai,Shen, Tao,Liang, Yujie,Zou, Miancheng,Zhu, Yuchao,Li, Xinwei,Li, Xinyao,Jiao, Ning
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supporting information
p. 563 - 567
(2017/01/18)
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- Simple and convenient copper-catalyzed amination of aryl halides to primary arylamines using NH4OH
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In this study, we investigated the direct synthesis of primary arylamines from aryl iodides and bromides by Cu-catalyzed amination using ammonium hydroxide (27% NH3in H2O) as nucleophile. In this article, two protocols are described: (1) a variety of aryl halides were treated with CuI (10?mol?%) and DMEDA (15?mol?%) in NH4OH/DMSO, or (2) with only CuI (10?mol?%) in NH4OH/PEG300. In each case, the desired primary arylamines were obtained in excellent yields. Although DMEDA and PEG have previously been employed as a ligand or solvent, respectively, the substrates were limited or additional ligands were required for successful conversion. Notably, our new protocols do not require additional inorganic bases, whereas previous methods have used a base. As such, these new protocols are one of the most simple, convenient, and efficient methods that have been reported, to date.
- Jung, Hee Seon,Yun, Taeil,Cho, Yungyeong,Jeon, Heung Bae
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p. 5988 - 5993
(2016/09/16)
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- A circulating aqueous phase system method of synthesizing aromatic primary amine
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The invention discloses a method for synthesizing an aromatic primary amine in a circulating water phase system. According to the method, an aryl halide and ammonia water are taken as raw materials, water is taken as a solvent, a carbonate, a fluoride, a phosphate or a hydroxide of an alkali metal or an alkaline-earth metal or a compound which can be converted to a corresponding alkali in water is taken as the alkali, polyamine carboxylic acid and a salt type compound thereof are taken as ligands, and a copper source catalyst is adopted for catalyzing the formation of the aromatic primary amine from the aryl halide and the ammonia water. According to the method disclosed by the invention, the water is used as the solvent, any phase transfer of the catalyst is not required, and the catalyst, the ligands and the reaction solvent, namely the water, can be recycled, so that the environment-friendly property of reaction is effectively improved, the method is more in line with requirements of green chemical development, a substrate particularly has a wide range of applications, and the method further has broad prospects in the aspects of preparation of natural products, medicaments and pesticides.
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Paragraph 0070; 0071
(2016/10/20)
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- A triazine-phosphite polymeric ligand bearing cage-like P,N-ligation sites: An efficient ligand in the nickel-catalyzed amination of aryl chlorides and phenols
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A novel P,N-ligand was introduced for efficient Ni-catalyzed amination of aryl chlorides. Reaction of cyanuric acid (1,3,5-triazine-2,4,6-triol) and trichlorophosphine (PCl3) resulted in the production of a new porous material (TPPM) containing triazine rings with phosphite moieties in a sheet morphology. Cavities in the prepared compound create sites on the surface of the material with appropriate ligation character to coordinate with metals for catalytic purposes. The nickel-catalyzed amination of aryl chlorides and of phenols in their 2,4,6-triaryloxy-1,3,5-triazine (TAT) protected form were efficiently accomplished in the presence of this easily prepared and reusable P,N-ligand under mild reaction conditions. More importantly, TPPM was reusable for 5 iterations following this protocol without significantly decreasing in its activity.
- Panahi, Farhad,Roozbin, Fatemeh,Rahimi, Sajjad,Moayyed, Mohammadesmaeil,Valaei, Aria,Iranpoor, Nasser
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supporting information
p. 80670 - 80678
(2016/10/12)
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- 3,4-methylenedioxy aniline preparation method
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A 3,4-methylenedioxy aniline preparation method applied to the field of chemosynthesis comprises the following steps: (1) adding dilute nitric acid into a reaction vessel for heating; (2) dropwise adding 1,2-methylenedioxy benzene into the reaction vessel slowly, carrying out intense stirring during the dropwise adding, and carrying out heat preservation after the dropwise adding is finished; (3) carrying out cooling and filtration to obtain a wet product of 3,4-methylenedioxy nitrobenzene, carrying out washing with purified water till the pH value of the wet product reaches 7, and carrying out vacuum drying to obtain 3,4-methylenedioxy nitrobenzene; (4) putting 3,4-methylenedioxy nitrobenzene, a nickel catalyst and one or more reaction solvents into a high-pressure reaction kettle for heating, injecting hydrogen, filtering out the nickel catalyst after the reaction is finished, carrying out high vacuum distillation after a low-boiling-point substance is removed through reduced pressure distillation, and collecting fractions to obtain 3,4-methylenedioxy aniline. The 3,4-methylenedioxy aniline preparation method has the advantages that nitrification reduction and hydrogenation reduction processes are adopted; less waste water, waste gas and solid waste are treated; the selectivity is high; the product treatment is easy; the product yield and the product quality are high; nitric acid, the hydrogenation catalyst and the hydrogenation organic solvents can be recovered for direct application.
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Paragraph 0010; 0011
(2016/11/14)
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- Low-valent titanium-catalyzed deprotection of allyl- and propargyl-carbamates to amines
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In the presence of Me3SiCl, Ti(O-i-Pr)4/Mg and CpTiCl3/Mg reagents effectively catalyzed the deprotection of allyloxycarbonyl (alloc)- and propargyloxycarbonyl (poc)-protected amines in THF at around room temperature to produce parent amines in good yields. Alloc- and poc-protected secondary amines were smoothly deprotected to parent amines by a reaction catalyzed by a Ti(O-i-Pr)4/Me3SiCl/Mg reagent. The deprotection of alloc- and poc-protected primary amines was successfully catalyzed by a CpTiCl3/Me3SiCl/Mg reagent.
- Madhavan, Suchithra,Takagi, Hiromasa,Fukuda, Shunpei,Okamoto, Sentaro
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p. 2074 - 2077
(2016/04/26)
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- Transition-metal-free access to primary anilines from boronic acids and a common +NH2 equivalent
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Diversely substituted anilines are prepared by treatment of functionalized arylboronic acids with a common, inexpensive source of electrophilic nitrogen (H2N-OSO3H, HSA) under basic aqueous conditions. Electron-rich substrates are found to be the most reactive by this method. However, even moderately electron-poor substrates are well tolerated under the room temperature conditions. Sterically hindered substrates appear to be equally effective compared to unhindered ones. Highly electron-deficient substrates afford product in very low yields at room temperature, but moderate to good yields are obtained at refluxing temperatures. Our method is also amenable to electrophilic amination of several common boronic acid derivatives (e.g., pinacol esters). We demonstrate that it can be combined with metal-halogen exchange reactions or a variety of directed ortho metalation protocols in a "one-pot" sequence for the synthesis of aromatic amines with unique substitution patterns. DFT studies, in combination with experimental results, suggest that the reaction occurs via base-mediated activation of HSA, followed by 1,2 aryl B-N migration. This mode of activation appears to be critical for the success of the reaction and allows, for the first time, a general, electrophilic amination of boronic acids at ambient temperature.
- Voth, Samantha,Hollett, Joshua W.,Mccubbin, J. Adam
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p. 2545 - 2553
(2015/03/18)
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- Assembly of Primary (Hetero)Arylamines via CuI/Oxalic Diamide-Catalyzed Coupling of Aryl Chlorides and Ammonia
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A general and practical catalytic system for aryl amination of aryl chlorides with aqueous or gaseous ammonia has been developed, with CuI as the catalyst and bisaryl oxalic diamides as the ligands. The reaction proceeds at 105-120°C to provide a diverse set of primary (hetero)aryl amines in high yields with various functional groups.
- Fan, Mengyang,Zhou, Wei,Jiang, Yongwen,Ma, Dawei
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supporting information
p. 5934 - 5937
(2015/12/11)
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- A simple and recyclable copper/DTPA catalyst system for amination of aryl halides with aqueous ammonia in water
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Commercially available CuO/DTPA (diethylenetriaminepentaacetic acid) was established to be a low-cost, recyclable, and environmentally benign homogeneous catalyst system for direct amination of aryl halides with ammonia. Primary aryl amines can be readily prepared from both electron-withdrawing and electron-donating aryl halides in good yields in water without the addition of surfactants.
- Yang, Bo,Liao, Lihao,Zeng, Yongheng,Zhu, Xinhai,Wan, Yiqian
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p. 100 - 103
(2014/01/06)
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- Mild and highly selective palladium-catalyzed monoarylation of ammonia enabled by the use of bulky biarylphosphine ligands and palladacycle precatalysts
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A method for the Pd-catalyzed arylation of ammonia with a wide range of aryl and heteroaryl halides, including challenging five-membered heterocyclic substrates, is described. Excellent selectivity for monoarylation of ammonia to primary arylamines was achieved under mild conditions or at rt by the use of bulky biarylphosphine ligands (L6, L7, and L4) as well as their corresponding aminobiphenyl palladacycle precatalysts (3a, 3b, and 3c). As this process requires neither the use of a glovebox nor high pressures of ammonia, it should be widely applicable.
- Cheung, Chi Wai,Surry, David S.,Buchwald, Stephen L.
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supporting information
p. 3734 - 3737
(2013/08/23)
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- Metal-free C-N bond-forming reaction: Straightforward synthesis of anilines, through cleavage of aryl C-O bond and amide C-N bond
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An efficient metal-free C-N bond forming reaction through cleavage of aryl C-O bond and amide C-N bond has been developed. This process represents a practical method for the facile construction of anilines with a broad substrate scope and wide functional group tolerance in moderate to excellent yields.
- Yu, Jianzhong,Zhang, Peizhi,Wu, Jun,Shang, Zhicai
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supporting information
p. 3167 - 3170
(2013/06/27)
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- NOVEL CATALYSTS
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The present invention provides novel compounds and ligands that are useful in transition metal catalyzed cross-coupling reactions. For example, the compounds and ligands of the present invention are useful in palladium or gold catalyzed cross-coupling reactions.
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Page/Page column 61-62
(2012/06/01)
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- Amination of aryl halides by using an environmentally benign, recyclable copper catalyst
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The combination of CuSO4 with naturally occurring sucrose in a biodegradable aqueous solution of PEG-200 has been confirmed as a novel, recyclable, and environmentally benign homogeneous catalyst system for the direct amination of aryl halides with NH3·H2O. Electron-rich, electron-poor, and even ortho-substituted aryl bromides and iodides could be aminated to provide the desired primary arylamines in high yields at 90 °C without the need of an inert atmosphere. The combination of CuSO4 with naturally occurring sucrose in a biodegradable, aqueous solution of PEG-200 has been confirmed to be a novel, recyclable, and environmentally benign homogeneous catalyst system for the direct amination of aryl halides with NH3·H2O. Copyright
- Huang, Manna,Wang, Leilei,Zhu, Xinhai,Mao, Zuxing,Kuang, Daizhi,Wan, Yiqian
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supporting information
p. 4897 - 4901
(2013/01/14)
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- A P,N-Ligand for palladium-catalyzed ammonia arylation: Coupling of deactivated aryl chlorides, chemoselective arylations, and room temperature reactions
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(Figure Presented) Amazing ammonia: A new air-stable P,N-ligand (Mor-DalPhos) is reported that enables the palladium-catalyzed crosscoupling of ammonia to a variety of aryl chloride and aryl tosylate substrates with high chemoselectivity and, for the first time, at room temperature (see scheme; Ad = adamantyl, Ts=para-toluenesulfonyl).
- Lundgren, Rylan J.,Peters, Brendan D.,Alsabeh, Pamela G.,Stradiotto, Mark
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supporting information; experimental part
p. 4071 - 4074
(2010/07/05)
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- Analogues of camptothecin, their use as medicaments and the pharmaceutical compositions containing them
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A compound of the formula wherein the substituents are defined as in the specification which compounds are useful in the treatment of cancer.
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- New analogues of camptothecin, their use as medicaments and the pharmaceutical compositions containing them
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A compound of the formula wherein the substituents are defined as in the specification which compounds are useful in the treatment of cancer.
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- Phenylureas. Part 2. Mechanism of the acid hydrolysis of phenylureas
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The mechanism of the hydrolytic decomposition of phenylureas in acid media is investigated. It includes, in part, knowledge already present in the literature. Over the investigated pH range the occurrence of a rate maximum in the pH curves due to the strongly reduced water activity at higher acid strengths is observed. An addition-elimination mechanism with rate-determining attack of water at the N-protonated substrate is proposed. The reversion of the substituent influence on the reaction rate with increasing acidity of the reaction medium points to a change of the hydrolytic decomposition mechanism in strongly acidic media.
- Laudien, Robert,Mitzner, Rolf
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p. 2230 - 2232
(2007/10/03)
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- Palladium-catalyzed synthesis of arylamines from aryl halides and lithium bis(trimethylsilyl)amide as an ammonia equivalent
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(Equation presented) A simple, palladium-catalyzed method to convert aryl halides to the parent anilines using lithium bis(trimethylsilyl)amide (LiN(SiMe3)2) is reported. The reaction is catalyzed by Pd(dba)2 and P(t-Bu)3 and can be run with as little as 0.2 mol % of catalyst. The reaction is faster than competing generation of benzyne intermediates and, therefore, provides the aniline products regiospecifically.
- Lee, Sunwoo,Jorgensen, Morten,Hartwig, John F.
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p. 2729 - 2732
(2007/10/03)
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- Camptothecin analogues, preparation methods therefor, use thereof as drugs, and pharmaceutical compositions containing said analogues
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A camptothecin analog characterized in that the hydroxy lactone of the camptothecin is a β-hydroxy lactone or the corresponding β-hydroxyacid, resulting from the opening of said lactone, or a derivative of said β-hydroxyacid, or a Pharmaceutically acceptable salt thereof, is disclosed. In particular, compounds of formulae (I) and (II) are disclosed. Methods for preparing the compounds of formulae (I) and (II), pharmaceutical compositions containing said containing said compounds, and their use, particularly as topoisomerase inhibitors and antitumoral drugs, are also disclosed.
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- Continuous hydrogenation of organic compounds in supercritical fluids
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A small flow reactor (5 ml volume) is used for continuous hydrogenation in supercritical CO2 or propane with polysiloxane-supported noble metal catalysts; a wide range of organic functionalities can be hydrogenated with good throughput (up to 1200 ml h-1 in favourable cases) and the various parameters (temperature, pressure, concentration of H2, etc.) can be controlled independently to optimise the selectivity for a particular product.
- Hitzler, Martin G.,Poliakoff, Martyn
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p. 1667 - 1668
(2007/10/03)
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- Polar Effects in Free Radical Reactions. Homolytic Aromatic Amination by the Amino Radical Cation, +NH3: Reactivity and Selectivity
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Small amounts of Fe(II) salt initiate redox chains with hydroxyamino-O-sulfonic acid (HSA) and aromatic compounds leading to the amination of the aromatic ring.The positional and substrate selectivity with a variety of substituted benzenes show the important role of the electrophilic character of the radical +NH3.Hammett relationships with ? and ?+ are roughly observed.The lower sensitivity to polar effects of the radical +NH3 compared with (CH3)2+NH is explained by the different reaction enthalpies.The different positional selectivity obtained with anisole and the redox system +NH3OH/Ti(III) is discussed.
- Citterio, Attilio,Gentile, Anna,Minisci, Francesco,Navarrini, Valter,Serravalle, Marco,Ventura, Susanna
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p. 4479 - 4482
(2007/10/02)
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