- Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
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Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
- Zhao, Huaibo,Leonori, Daniele
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supporting information
p. 7669 - 7674
(2021/03/08)
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- Streamlined Synthesis of Diaminopyridines by Pd-Catalyzed Ammonia Coupling with Deactivated Amino-Chloropyridines
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An efficient and cost-effective two-step synthesis of diaminopyridines, fundamental building blocks of biologically active compounds, is reported. The advantages over previously reported routes include cost and wider availability of the bromo-chloropyridine starting materials and the straightforward accessibility to an extended array of diaminopyridine regioisomers. The key enabler of this synthetic strategy is the development of an unprecedented palladium-catalyzed coupling reaction of ammonia with chloropyridines deactivated by the presence of an alkylamino substituent. The coupling reaction was accomplished with very low catalyst loadings under remarkably mild reaction conditions, making the system particularly suitable for both academic and industrial applications. The utility of this methodology is exemplified by the application to the synthesis of highly relevant scaffolds, including the synthetic intermediates of the marketed drugs Ribociclib and Palbociclib.
- Bourriquen, Florian,Bruneau-Voisine, Antoine,Jeandin, Aliénor,Stihle, Etienne,Fantasia, Serena
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supporting information
p. 9006 - 9011
(2019/06/24)
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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 0257
(2018/03/25)
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- Non-deprotonative primary and secondary amination of (hetero)arylmetals
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Herein we disclose a novel method for the facile transfer of primary (-NH2) and secondary amino groups (-NHR) to heteroaryl-as well as arylcuprates at low temperature without the need for precious metal catalysts, ligands, excess reagents, protecting and/or Erecting groups. This one-pot transformation allows unprecedented functional group tolerance and it is wellsuited for the amination of electron-rich, electron-deficient as well as structurally complex (hetero)arylmetals. In some of the cases, only catalytic amounts of a copper (l) salt is required.
- Zhou, Zhe,Ma, Zhiwei,Behnke, Nicole Erin,Gao, Hongyin,Kürti, László
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supporting information
p. 115 - 118
(2017/05/16)
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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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- Nickel-catalyzed monoarylation of ammonia
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Structurally diverse (hetero)aryl chloride, bromide, and tosylate electrophiles were employed in the Ni-catalyzed monoarylation of ammonia, including chemoselective transformations. The employed JosiPhos/[Ni(cod)2] catalyst system enables the use of commercially available stock solutions of ammonia, or the use of ammonia gas in these reactions, thereby demonstrating the versatility and potential scalability of the reported protocol. Proof-of-principle experiments established that air-stable [(JosiPhos)NiCl2] precatalysts can be employed successfully in such transformations. Lighten Up: The substrate scope of the title reaction includes (hetero)aryl chloride, bromide, and tosylate electrophiles. The versatility and potential scalability of the reported method is demonstrated by the use of either commercially available stock solutions of ammonia or ammonia gas.
- Borzenko, Andrey,Rotta-Loria, Nicolas L.,Macqueen, Preston M.,Lavoie, Christopher M.,McDonald, Robert,Stradiotto, Mark
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supporting information
p. 3773 - 3777
(2015/03/18)
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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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- Efficient synthesis of aminopyridine derivatives by copper catalyzed amination reactions
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A copper(i) catalyzed amination reaction utilizing aqueous ammonia and operating under mild conditions is presented. This method was employed for the efficient synthesis of various aminopyridine derivatives bearing electron withdrawing and electron donating groups. The Royal Society of Chemistry 2010.
- Elmkaddem, Mohammed K.,Fischmeister, Cedric,Thomas, Christophe M.,Renaud, Jean-Luc
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supporting information; experimental part
p. 925 - 927
(2010/06/12)
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- ANTIDIABETIC AZAINDOLES AND DIAZAINDOLES
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Azaindoles and diazaindoles having aromatic substituents on the 5-membered ring are agonists or partial agonists of the PPAR receptor and are useful in the treatment and control of type 2 diabetes and of symptoms of diabetes, including hyperglycemia, dyslipidemia, hyperlipidemia, hypercholesterolemia, hypertriglyceridemia, and obesity that are often associated with type 2 diabetes.
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Page/Page column 66
(2009/03/07)
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- Amination of aryl halides using copper catalysis
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Bromopyridine 4 was converted into aminopyridine 5 under Cu2O catalysis with an ethylene glycol solution of ammonia in excellent yield (90%). The amination reaction features low (0.5 mol%) catalyst loading, mild reaction temperature (80°C) and low reaction pressure (50 psi). This protocol is further studied in the amination of a variety of aryl halides.
- Lang, Fengrui,Zewge, Daniel,Houpis, Ioannis N.,Volante
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p. 3251 - 3254
(2007/10/03)
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- Substituent Effects on the Isomer Ratios in the Rearrangement of Some 2- and 4-Nitraminopyridines
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The preparation, and rearrangement in 92percent sulfuric acid, of 4-X-2-nitramino- (1), 2-X-4-nitramino- (2), and 6-X-2-nitramino-pyridines (3) is reported (X=H,Me,MeO,Br,Cl,CO2H).The product isomer ratios can be explained by differential electronic stabilization of the appropriate ? complexes for aromatic nitration and steric effects seem relatively unimportant.Deuteration had no effect on the product distribution
- Deady, Leslie W.,Korytsky, Olga L.,Rowe, Jeffrey E.
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p. 2025 - 2034
(2007/10/02)
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