- Decarboxylative Ritter-Type Amination by Cooperative Iodine (I/III)─Boron Lewis Acid Catalysis
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Recent years have witnessed important progress in synthetic strategies exploiting the reactivity of carbocations via photochemical or electrochemical methods. Yet, most of the developed methods are limited in their scope to certain stabilized positions in molecules. Herein, we report a metal-free system based on the iodine (I/III) catalytic manifold, which gives access to carbenium ion intermediates also on electronically disfavored benzylic positions. The unusually high reactivity of the system stems from a complexation of iodine (III) intermediates with BF3. The synthetic utility of our decarboxylative Ritter-type amination protocol has been demonstrated by the functionalization of benzylic as well as aliphatic carboxylic acids, including late-stage modification of different pharmaceutical molecules. Notably, the amination of ketoprofen was performed on a gram scale. Detailed mechanistic investigations by kinetic analysis and control experiments suggest two mechanistic pathways.
- Narobe, Rok,Murugesan, Kathiravan,Schmid, Simon,K?nig, Burkhard
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p. 809 - 817
(2022/01/15)
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- Tropylium-promoted Ritter reactions
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The Ritter reaction used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuableN-alkyl amide products. However, this reaction has not been frequently used in modern organic synthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the tropylium ion to promote the Ritter reaction. This method works well on a range of alcohol and nitrile substrates, giving the corresponding products in good to excellent yields. This reaction protocol is amenable to microwave and continuous flow reactors, offering an attractive opportunity for further applications in organic synthesis.
- Doan, Son H.,Hussein, Mohanad A.,Nguyen, Thanh Vinh
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supporting information
p. 8901 - 8904
(2021/09/10)
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- SMALL MOLECULE ACTIVATORS OF NICOTINAMIDE PHOSPHORIBOSYLTRANSFERASE (NAMPT) AND USES THEREOF
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Provided herein are small molecule activators of Nicotinamide Phosphoribosyltransferase (NAMPT), compositions comprising the compounds, and methods of using the compounds and compositions.
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Paragraph 00506
(2018/08/03)
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- Substituted benzimidazole derivatives
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The invention belongs to the field of pharmaceutical chemistry, particularly relates to substituted benzimidazole derivatives as well as a preparation method and pharmaceutical composition thereof and further relates to an application of the substituted b
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Paragraph 0042; 0044; 0045; 0142
(2018/01/09)
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- Tandem synthesis of amides and secondary amines from esters with primary amines under solvent-free conditions
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An iridium(III)-catalyzed tandem synthesis of amides and amines from esters under solvent-free conditions is described. A commercially available iridium(III) complex, [Cp*IrCl2]2, with sodium acetate showed the best activity for the synthesis of amides and secondary amines. The amide was formed by ester-amide exchange which generates an alcohol in situ which is subsequently transformed to a secondary amine via hydrogen autotransfer. This synthetic protocol with high atom economy generates water as the sole by-product and can afford amides and amines from various esters in a one-pot reaction, expanding the synthetic versatility of ester transformations.
- Lee, Jeongbin,Muthaiah, Senthilkumar,Hong, Soon Hyeok
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p. 2653 - 2660
(2014/09/17)
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- Alcohols as electrophiles: Iron-catalyzed Ritter reaction and alcohol addition to alkynes
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A simple, iron-based catalytic system allows for a straightforward method for the synthesis of primary, secondary, and tertiary amides. The system also allows the addition of benzyl alcohols across phenylacetylene to produce substituted phenyl ketones. This transformation improves and expands the substrate scope beyond that previously reported and proceeds under mild reaction conditions, tolerating air and moisture.
- Jefferies, Latisha R.,Cook, Silas P.
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supporting information
p. 4204 - 4207
(2014/06/09)
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- Isopropenyl acetate, a remarkable, cheap and acylating agent of amines under solvent- and catalyst-free conditions: A systematic investigation
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Isopropenyl acetate was proved to be an efficient reagent for acetylation of amine in the absence of solvent and catalyst. The corresponding acetamides were obtained in very high yields without any purification.
- Pelagalli, Romina,Chiarotto, Isabella,Feroci, Marta,Vecchio, Stefano
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supporting information; experimental part
p. 2251 - 2255
(2012/09/08)
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- Intermolecular ritter-type C-H amination of unactivated sp3 carbons
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Intermolecular Ritter-type C-H amination of unactivated sp3 carbons has been developed. This new reaction proceeds under mild conditions using readily available reagents and an inexpensive source of nitrogen (acetonitrile). A broad scope of substrates can be aminated with this method since many functional groups are tolerated. This reaction also allows for the direct, innate C-H amination of a variety of hydrocarbons such as cyclohexane without the need of prefunctionalization or installation of a directing group.
- Michaudel, Quentin,Thevenet, Damien,Baran, Phil S.
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experimental part
p. 2547 - 2550
(2012/04/04)
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- HBF4·OEt2 as a mild and versatile reagent for the Ritter amidation of olefins: A facile synthesis of secondary amides
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A variety of alkenes undergo smooth amidation with nitriles in the presence of HBF4·OEt2 at room temperature under mild conditions to afford the corresponding secondary amides in good to excellent yields. This is a highly efficient method for the preparation of α-aryl ethyl amides especially from vinyl arenes without any side reactions such as olefin polymerization. The use of readily available and easy to handle reagent HBF4·OEt2 makes this method simple, convenient, and practical.
- Subba Reddy,Sivasankar Reddy,Madan, Ch.,Yadav
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experimental part
p. 4827 - 4829
(2010/10/02)
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- Safe and efficient ritter reactions in flow
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Efficient mixing, temperature control and small environmental exposures allow reactions carried out in microfluidic de-vices to perform superior to their batch-type counterparts in conventional flasks. The Ritter reaction has been optimised for flow conditions leading to short reaction times and higher yields and also is more feasible with regards to safety, productivity and tolerance towards substrate functionalities.
- Brandt, Johan C.,Elmore, Simon C.,Robinson, Richard I.,Wirth, Thomas
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experimental part
p. 3099 - 3103
(2011/02/25)
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- PROTEIN KINASE INHIBITORS
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The present invention provides a compound of formula (I): or a pharmaceutically acceptable salt thereof which is useful in the treatment of cell proliferative diseases.
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Page/Page column 10
(2010/07/04)
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- Metal-free conversion of methane and cycloalkanes to amines and amides by employing a borylnitrene
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(Chemical Equation Presented) C-H insertion: Borylnitrenes, which are generated in situ by photoylsis of azides, convert unactivated alkanes by intermolecular C-H insertion into aminoboranes (see scheme), which in turn can be reacted further to give amines or amides. The boryl group serves two purposes: it converts the nitrene into a highly reactive BN vinylidene analogue, and it is easily cleaved from the product.
- Bettinger, Holger F.,Filthaus, Matthias,Bornemann, Holger,Oppel, Iris M.
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experimental part
p. 4744 - 4747
(2009/02/06)
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- COUPLING OF β-ACETAMIDO RADICALS WITH α-CHLORO ACRYLONITRILE - A NEW ACCESS TO DISUBSTITUTED PROLINE DERIVATIVES
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β-Acetamido radicals are prepared by reduction of organomercurials and coupled with α-chloro-acrylonitrile.The coupling products are further converted to proline derivatives.
- Henning, R.,Urbach, H.
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p. 5343 - 5346
(2007/10/02)
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- Amidomercuriation: A General Addition of Amides and Related Compounds to Olefins
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The addition of different carboxamides and related compounds such as urethane or urea to olefins using mercury(II) nitrate followed by sodium borohydride reduction to give the corresponding N-substituted amides, urethanes, or ureas, respectively, is described.The monoalkylated ureas, through the same amidomercuriation-demercuriation procedure, yield symmetrical and unsymmetrical N,N'-disubstituted ureas.This amidomercuriation-demercuriation process provides a new, convenient, and general method for the Markovnikov amidation of carbon-carbon double bonds.
- Barluenga, Jose,Jimenez, Carmen,Najera, Carmen,Yus, Miguel
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p. 591 - 593
(2007/10/02)
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- The Effect of Electrochemically Generated Positive Bromine Species in Acetonitrile on the Cleavage of C-Br and C-Cl Bonds.
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The fate of bromine formed from C-Br cleavage during the course of anodic oxidation of alkyl bromides in acetonitrile on platinum has been investigated potentiostatically.It is suggested that positive bromine species are formed and they are potentially reactive towards alkyl bromides, yielding similar products to those obtained by direct anodic oxidation of the same bromides.Furthermore, whereas alkyl chlorides do not undergo C-Cl fission by direct anodic oxidation it is shown that positive bromine species are energetically sufficient to break C-Cl bonds, although not very efficiently.We suggest that a possible structure for the complex between acetonitrile and positive bromine species is mainly +Br3- and the mechanism for its formation is discussed.The spectrum of this species found identical to that of Br3- (269 nm) in acetonitrile.
- Becker, James Y.,Zemach, Dvora
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p. 336 - 340
(2007/10/02)
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- Amidomercuration; a New and Regiospecific Addition of Amides to Olefins
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The reaction of olefins with anhydrous mercury(II) nitrate in the presence of primary amides leads, after in situ alkaline sodium borohydride reduction, to the corresponding N-substituted amides; this procedure provides a new, convenient method for the Markovnikov amidation of carbon-carbon double bonds.
- Barluenga, Jose,Jimenez, Carmen,Najera, Carmen,Yus, Miguel
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p. 670 - 671
(2007/10/02)
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- Amidoselenation of Olefins and Its Utilization for Synthesis of Allylic Amides
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The reaction of phenylselenyl chloride with olefins in acetonitrile containing trifluoromethanesulfonic acid and water affords β-acetamidoalkyl phenyl selenides in good to excellent yields.This represents the first example of one-pot amidoselenation of mono- and disubstituted olefins.The reaction can be carried out in benzonitrile, propionitrile, butyronitrile, or ethyl cyanoacetate.It was confirmed that the amidoselenation reaction proceeds with trans stereospecifity.Oxidative elimination of the produced β-amidoalkyl phenyl selenides gives allylic amides selectively in good to excellent yields.These two reactions constitute a good method for conversion of olefins to allylic amides.
- Toshimitsu, Akio,Aoai, Toshiaki,Owada, Hiroto,Uemura, Sakae,Okano, Masaya
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p. 4727 - 4733
(2007/10/02)
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