- Copper-Catalysed Electrophilic Amination of Aryl(alkenyl) Boronic Acids with Nitrogen-Containing Hypervalent Iodine (III) Reagent
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A copper-catalysed electrophilic N-imination of aryl(alkenyl) boronic acids with a stable hypervalent iodine(III) reagent containing a transferable (diarylmethylene)amino group is developed. The electrophilic C?N cross-coupling reaction proceeds smoothly at room temperature under oxidant-free and base-free conditions, which is further characterized by the broad functional group compatibility, thereof, extending the N-electrophile scope of electrophilic C?N cross-coupling outside the limitation of N?O and N?Cl reagents. (Figure presented.).
- Hu, Yuanyuan,Zheng, Songlin,Fan, Wu,Yuan, Weiming
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supporting information
p. 4701 - 4707
(2021/08/23)
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- An expedient one-pot synthesis of benzophenone Schiff bases from benzene
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A simple and efficient one-pot synthesis of benzophenone Schiff bases from benzene, CCl4 and aromatic amines was developed based on the the reaction of benzene with CCl4·AlCl3 complex. This method affords Ph2CCl2 as well as the products of its subsequent reaction with aromatic amines, benzophenone Schiff bases, selectively and in good yields.
- Akhrem, Irena S.,Afanas'eva, Lyudmila V.,Avetisyan, Dzhul'etta V.,Artyushin, Oleg I.,Kagramanov, Nikolai D.
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p. 238 - 240
(2020/05/25)
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- Palladium-Catalyzed Diarylation of Isocyanides with Tetraarylleads for the Selective Synthesis of Imines and α-Diimines
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Using tetraaryllead compounds (PbAr4) as arylating reagents, isocyanides undergo selective diarylation in the presence of palladium catalysts such as Pd(OAc)2 or Pd(PPh3)4 to afford imines and/or α-diimines based on the isocyanide employed. With aliphatic isocyanides, imines are obtained preferentially, whereas α-diimines are formed in the case of electron-rich aromatic isocyanides. The differences in imine/α-diimine selectivity can be attributed to the stability of imidoylpalladium intermediates formed in this catalytic reaction. Compared with other arylating reagents, tetraaryllead compounds are excellent candidates for use in the selective transformations to imines and/or α-diimines, especially in terms of inhibiting the oligomerization of isocyanides, which results in a lower product selectivity in many transition-metal-catalyzed reactions of isocyanides.
- Tran, Cong Chi,Kawaguchi, Shin-Ichi,Kobiki, Yohsuke,Matsubara, Hitomi,Tran, Dat Phuc,Kodama, Shintaro,Nomoto, Akihiro,Ogawa, Akiya
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p. 11741 - 11751
(2019/10/02)
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- A Convenient Preparation Method for Benzophenone Imine Catalyzed by Tetrabutylammonium Fluoride
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Benzophenone imine is a useful ammonia equivalent in the Buchwald-Hartwig amination and an important intermediate for the synthesis of N-protected primary amines. However, the conventional synthesis of benzophenone imine requires stoichiometric amounts of metal reagents or high-pressure conditions. Herein we report a facile method for preparing benzophenone imine to enhance its potential utility. The reaction is performed by mixing commercially available benzophenone and bis(trimethylsilyl)amine in the presence of a catalytic amount of tetrabutylammonium fluoride at ambient temperature and pressure and can be readily applied to a multigram-scale synthesis even in a standard academic laboratory setup. Preliminary mechanistic studies and the application of the reaction to one-pot benzophenone imine synthesis/Buchwald-Hartwig amination are also reported.
- Kondo, Yuta,Morisaki, Kazuhiro,Hirazawa, Yoshinobu,Morimoto, Hiroyuki,Ohshima, Takashi
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p. 1718 - 1724
(2019/09/06)
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- Oxidative Rearrangement of Primary Amines Using PhI(OAc)2 and Cs2CO3
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An oxidative rearrangement of primary amines mediated by a hypervalent iodine(III) reagent is herein reported. The combination of PhI(OAc)2 and Cs2CO3 proves highly efficient at inducing the direct 1,2-C to N migration of primary amines, which can be applied to the preparation of both acyclic and cyclic amines. A mechanistic study shows that the rearrangement proceeds via a concerted mechanism.
- Yamakoshi, Wataru,Arisawa, Mitsuhiro,Murai, Kenichi
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supporting information
(2019/05/08)
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- Visible-Light-Mediated Umpolung Reactivity of Imines: Ketimine Reductions with Cy2NMe and Water
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A novel carbanionic reactivity of imines mediated by photoredox catalysis is demonstrated. The umpolung imine reactivity is exemplified by proton abstraction from water as a key step in the reduction of benzophenone ketimines to amines (up to 98% yield). Deuterium is introduced into amines efficiently using D2O as an inexpensive deuterium source (≥95% D ratio). The mechanism of this unusual transformation is probed.
- Wang, Rui,Ma, Mengyue,Gong, Xu,Panetti, Grace B.,Fan, Xinyuan,Walsh, Patrick J.
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supporting information
p. 2433 - 2436
(2018/04/27)
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- Photocatalytic and Chemoselective Transfer Hydrogenation of Diarylimines in Batch and Continuous Flow
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A visible-light photocalytic method for the chemoselective transfer hydrogenation of imines in batch and continuous flow is described. The reaction utilizes Et3N as both hydrogen source and single-electron donor, enabling the selective reduction of imines derived from diarylketimines containing other reducible functional groups including nitriles, halides, esters, and ketones. The dual role of Et3N was confirmed by fluorescence quenching measurements, transient absorption spectroscopy, and deuterium-labeling studies. Continuous-flow processing facilitates straightforward scale-up of the reaction.
- Van As, Dean J.,Connell, Timothy U.,Brzozowski, Martin,Scully, Andrew D.,Polyzos, Anastasios
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supporting information
p. 905 - 908
(2018/02/22)
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- Efficient Synthesis of Amines by Iron-Catalyzed C=N Transfer Hydrogenation and C=O Reductive Amination
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Here we report the catalytic transfer hydrogenation (CTH) of non-activated imines promoted by a Fe-catalyst in the absence of Lewis acid co-catalysts. Use of the (cyclopentadienone)iron complex 1, which is much more active than the classical ‘Kn?lker complex’ 2, allowed to reduce a number of N-aryl and N-alkyl imines in very good yields using iPrOH as hydrogen source. The reaction proceeds with relatively low catalyst loading (0.5–2 mol%) and, remarkably, its scope includes also ketimines, whose reduction with a Fe-complex as the only catalyst has little precedents. Based on this methodology, we developed a one-pot CTH protocol for the reductive amination of aldehydes/ketones, which provides access to secondary amines in high yield without the need to isolate imine intermediates. (Figure presented.).
- Facchini, Sofia Vailati,Cettolin, Mattia,Bai, Xishan,Casamassima, Giuseppe,Pignataro, Luca,Gennari, Cesare,Piarulli, Umberto
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supporting information
p. 1054 - 1059
(2018/01/27)
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- Manganese-Catalyzed C?H Annulation of Ketimines with Allenes: Stereoselective Synthesis of 1-Aminoindanes
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A manganese-catalyzed C?H annulation of ketimines with poly-substituted ester-activated allenes toward the synthesis of 1-aminoindanes bearing two vicinal all-substituted carbon stereocenters and an exocyclic double bond was developed. The reaction featur
- Lei, Chong,Peng, Lijie,Ding, Ke
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supporting information
p. 2952 - 2958
(2018/08/17)
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- Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C?O and C?C Bond Activation
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An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.
- Yue, Huifeng,Guo, Lin,Liao, Hsuan-Hung,Cai, Yunfei,Zhu, Chen,Rueping, Magnus
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supporting information
p. 4282 - 4285
(2017/04/03)
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- Rh(III)-catalyzed synthesis of 1-substituted isoquinolinium salts via a C-H bond activation reaction of ketimines with alkynes
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An efficient synthesis of highly substituted isoquinolinium salts from ketimines and alkynes via a Rh(III)-catalyzed C-H bond activation and annulation reaction is described. The Royal Society of Chemistry.
- Senthilkumar, Natarajan,Gandeepan, Parthasarathy,Jayakumar, Jayachandran,Cheng, Chien-Hong
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supporting information
p. 3106 - 3108
(2014/03/21)
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- Cu(OAc)2-mediated cross-coupling reaction of benzophenone N,N,N-trimethylhydrazonium salts and aryl boronic acids
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Cu(OAc)2-mediated coupling of benzophenone N,N,N- trimethylhydrazonium salts and aryl boronic acids proceeded to afford N-aryl imines.
- Kitamura, Mitsuru,Tokuda, Yu,Tashiro, Norifumi,Okauchi, Tatsuo
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p. 1687 - 1690
(2013/03/13)
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- Facile synthesis of triarylmethanimine promoted by a lewis acidbase pair: Theoretical and experimental studies
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An efficient method for triarylmethanimine synthesis promoted by a Lewis acidbase pair (AlCl3Et3N) was designed using mechanistic analysis with the aid of density functional theory. A series of triarylmethanimines were successfully prepared under mild con
- Liu, Yan,Yang, Qiwu,Hao, Dongling,Zhang, Wenqin
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p. 1390 - 1395,6
(2020/09/02)
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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 66
(2012/06/01)
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- A highly versatile catalyst system for the cross-coupling of aryl chlorides and Amines
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The syntheses of 2-(di-tertbutylphosphino)-N,N-dimethylaniline (L1, 71%) and 2-(di-1-adamantylphosphino)-N,N-dimethylaniline (L2, 74%), and their application in BuchwaldHartwig amination, are reported. In combination with [Pd(allyl)Cl]2 or [Pd(cinnamyl)Cl]2, these structurally simple and air-stable P,N ligands enable the cross-coupling of aryl and heteroaryl chlorides, including those bearing as substituents enolizable ketones, ethers, esters, carboxylic acids, phenols, alcohols, olefins, amides, and halogens, to a diverse range of amine and related substrates that includes primary alkyl- and arylamines, cyclic and acyclic secondary amines, N-H imines, hydrazones, lithium amide, and ammonia. In many cases, the reactions can be performed at low catalyst loadings (0.5-0.02 mol % Pd) with excellent functional group tolerance and chemoselectivity. Examples of cross-coupling reactions involving 1,4-bromochlorobenzene and iodobenzene are also reported. Under similar conditions, inferior catalytic performance was achieved when using Pd(OAc)2, PdCl2, [PdCl2(cod)] (cod = 1,5-cyclooctadiene), [PdCl 2(MeCN)2], or [Pd2(dba)3] (dba = dibenzylideneacetone) in combination with L1 or L2, or by use of [Pd(allyl)Cl]2 or [Pd(cinnamyl)Cl]2 with variants of L1 and L2 bearing less basic or less sterically demanding substituents on phosphorus or lacking an ortto-dimethylamino fragment. Given current limitations associated with established ligand classes with regard to maintaining high activity across the diverse possible range of C-N coupling applications, L1 and L2 represent unusually versatile ligand systems for the cross-coupling of aryl chlorides and amines
- Lundgren, Rylan J.,Sappong-Kumankumah, Antonia,Stradiotto, Mark
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supporting information; experimental part
p. 1983 - 1991
(2010/07/03)
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- Hydride, hydrogen, proton, and electron affinities of imines and their reaction intermediates in acetonitrile and construction of thermodynamic characteristic graphs (TCGs) of imines as a molecule ID card
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(Chemical Equation Presented) A series of 61 imines with various typical structures were synthesized, and the thermodynamic affinities (defined as enthalpy changes or redox potentials in this work) of the imines to abstract hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the imines to abstract hydrogen atoms and protons, and the thermodynamic affinities of the hydrogen adducts of the imines to abstract electrons in acetonitrile were determined by using titration calorimetry and electrochemical methods. The pure heterolytic and homolytic dissociation energies of the C=N π-bond in the imines were estimated. The polarity of the C=N double bond in the imines was examined using a linear free-energy relationship. The idea of a thermodynamic characteristic graph (TCG) of imines as an efficient Molecule ID Card was introduced. The TCG can be used to quantitatively diagnose and predict the characteristic chemical properties of imines and their various reaction intermediates as well as the reduction mechanism of the imines. The information disclosed in this work could not only supply a gap of thermodynamics for the chemistry of imines but also strongly promote the fast development of the applications of imines. 2009 American Chemical Society.
- Zhu, Xiao-Qing,Liu, Qiao-Yun,Chen, Qiang,Mei, Lian-Rui
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scheme or table
p. 789 - 808
(2010/04/29)
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- N-substituted imines by the copper-catalyzed N-imination of boronic acids and organostannanes with O-acyl ketoximes
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Catalytic quantities of copper(I) or copper(II) sources catalyze the N-imination of boronic acids and organostannanes through reaction with oxime O-carboxylates under nonbasic conditions. This method tolerates various functional groups and takes place efficiently using aryl, heteroaryl, and alkenyl boronic acids and stannanes.
- Liu, Songbai,Yu, Ying,Liebeskind, Lanny S.
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p. 1947 - 1950
(2008/02/02)
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- Base-induced rearrangement of tritylamines to imines: discovery and investigation of the mechanism
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An unexpected compound, the aniline derived benzophenone imine, was isolated when tritylamine was treated with n-BuLi and alkyl halides, during the formation of N-alkyl tritylamines, in the process of preparing primary amines. A nucleophilic attack of the nitrogen anion of tritylamide on the adjacent C-bonded phenyl, either substituted or not, involving a bridging anionic intermediate, is proposed for this base-induced tritylamine rearrangement to produce the corresponding imine. Electron-withdrawing groups in the aromatic ring, favoring the negative charge development, affect the relative migratory tendencies.
- Theodorou, Vassiliki,Skobridis, Konstantinos,Karkatsoulis, Aris
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p. 4284 - 4289
(2007/10/03)
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- Amination reactions of aryl halides with nitrogen-containing reagents mediated by palladium/imidazolium salt systems
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Nucleophilic N-heterocyclic carbenes have been conveniently used as catalyst modifiers in amination reactions involving aryl chlorides, aryl bromides, and aryl iodides with various nitrogen-containing substrates. The scope of a coupling process using a Pd(0) or Pd(II) source and an imidazolium salt in the presence of a base, KOtBu or NaOH, was tested using various substrates. The Pd2(dba)3/IPr·HCl (1, IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) system presents the highest activity with respect to electron-neutral and electron-rich aryl chlorides. The ligand is also effective for the synthesis of benzophenone imines, which can be easily converted to the corresponding primary amines by acid hydrolysis. Less reactive indoles were converted to N-aryl-substituted indoles using as supporting ligand the more donating SIPr·HCl (5, SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene). The Pd(OAc)2/SIPr·HCl/NaOH system is efficient for the N-arylation of diverse indoles with aryl bromides. The general protocol developed has been applied successfully to the synthesis of a key intermediate in the synthesis of an important new antibiotic. Mechanistically, palladium-to-ligand ratio studies strongly support an active species bearing one nucleophilic carbene ligand.
- Grasa,Viciu,Huang,Nolan
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p. 7729 - 7737
(2007/10/03)
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- Arylamine synthesis
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The present invention provides a method for the preparation of a wide range of primary arylamines. The arylamines are prepared in two efficient, straightforward transformations: 1) an activated aryl group and an imine group are combined, in the presence o
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- An ammonia equivalent for the palladium-catalyzed amination of aryl halides and triflates
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Commercially available benzophenone imine serves as a convenient ammonia equivalent in the palladium-catalyzed amination of aryl halides and triflates. The benzophenone imine adducts can be cleaved directly to the corresponding primary anilines by catalytic hydrogenation or treatment with hydroxylamine hydrochloride or a catalytic amount of HCl in wet THF.
- Wolfe, John P.,Ahman, Jens,Sadighi, Joseph P.,Singer, Robert A.,Buchwald, Stephen L.
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p. 6367 - 6370
(2007/10/03)
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- Preparation of Methoxy-substituted Diaryl Ketone Anils via Phenyliminodimagnesium Intermediate
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Phenyliminodimagnesium reagent (PhN(MgBr)2) and its o- and p-methoxy derivatives, prepared in THF by treatment of anilines with EtMgBr, were found to be effective for condensation with benzopheneones and fluorenone.The corresponding anils (N-(diarylmethylene)anilines) were prepared in good yields.
- Okubo, Masao,Ueda, Sonoko
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p. 281 - 282
(2007/10/02)
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