- A laser flash photolysis study on 2-azido-N,N-diethylbenzylamine - The reactivity of iminoquinone methides in solution
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Photolysis of 2-azido-N,N-diethylbenzylamine (1) in acetonitrile solution in the presence of various quenchers yields products of common nitrene chemistry (that is, derived from a didehydroazepine or a triplet nitrene), together with products arising from trapping of stereoisomeric iminoquinone methides. These intermediates are formed in a monophotonic process, by dediazotation of the precursor combined with a 1,4-hydrogen shift. The reactivity of the iminoquinone methides (IQM) towards a variety of quenchers, including dienophiles and various nucleophiles, has been explored, using acetonitrile, DMF, and n-hexane as solvents. IQM reacts efficiently with electron deficient dienophiles [kq(maleic anhydride) = 2.4·107 M-1 s-1], but not with simple olefins such as cyclohexene. IQM shows low to medium reactivity towards simple primary or secondary amines [kq(n-propylamine) = 6.4·104 M-1 s-1], medium reactivity with sterically unhindered simple alcohols [kq(methanol) = 4.6·106 M-1 s-1], and high to very high reactivity towards thiols [kq(n-dodecanethiol) = 1.1·109 M-1 s-1], diols, and triols [kq(glycerol) = 1.5·108 M-1 s-1], and sugars [kq(D-glucose) = 1.0·109 M-1 s-1]. IQM also reacts rapidly with cytosine: kq(cytosine) = 3.4·108 M-1 s-1, while the reaction with adenine or thymine is less efficient [kq(adenine) = 6.4·107 M-1 s-1, kq(thymine) = 7.7·106 M-1 s-1].
- Bucher, Goetz
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- The Elimination of Masses 27 and 28 from the + Ion of 2-Nitrotoluene
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The expulsion of neutral fragments of masses 27 and 28 from metastable + ions derived from 2-nitrotoluene has been observed.The relative abundances of the resulting fragment ions, together with the kinetic energy released in each process, has been compared with similar fragmentations of + ions derived from other precursor molecules.In this way, the nature of the neutral fragments and the structure of the + ions from 2-nitrotoluene has been investigated.The most likely structure is the 1,2-benzisoxazolenium cation although the coexistence of other structures cannot be ruled out on the present evidence.
- Herbert, C. G.,Larka, E. A.,Beynon, J. H.
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- Metal-Free Synthesis of Anthranils by PhIO Mediated Heterocyclization of ortho-Carbonyl Anilines
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Here, we report a metal-free synthesis of anthranils from ortho-carbonyl anilines using PhIO as a sole additive under ambient conditions. This methodology did not require any external additives and delivered anthranils in excellent yields with broad substrate scope. The mechanistic studies suggest that the reaction proceeds via in-situ generation of iminoiodane leading to nitrene and a subsequent nucleophilic attack from oxygen of ortho-carbonyl aniline on nitrene results in heterocyclization.
- Garia, Alankrita,Grover, Jatin,Jain, Nidhi
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p. 4125 - 4131
(2021/08/24)
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- Metal-Free [3+2] Annulation of Ynamides with Anthranils to Construct 2-Aminoindoles
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A novel metal-free [3+2] annulation of ynamides with anthranils provides a facile, flexible, environmentally friendly, and atom-economical route to 2-aminoindoles. This synthetic process proceeds with efficiency, excellent regioselectivity, and wide functional group tolerance under mild conditions. Moreover, the obtained 2-aminoindole products represent a multifunctional platform for the construction of various 2-aminoindolyl frameworks.
- Zhang, Jingyi,Li, Ying,Zhang, Chaofeng,Wang, Xiao-Na,Chang, Junbiao
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p. 2029 - 2035
(2021/04/05)
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- Palladium-catalyzed carbonylative cyclization of benzyl chlorides with anthranils for the synthesis of 3-arylquinolin-2(1: H)-ones
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An efficient carbonylative procedure for the synthesis of 3-arylquinoin-2(1H)-ones has been established. Through a palladium-catalyzed aminocarbonylation of benzyl chlorides with anthranils, a variety of 3-arylquinoin-2(1H)-one products were obtained in moderate to excellent yields with good functional group tolerance. This journal is
- Liu, Jian-Li,Xu, Ren-Rui,Wang, Wei,Qi, Xinxin,Wu, Xiao-Feng
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supporting information
p. 3584 - 3588
(2021/05/04)
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- I2-DMSO mediated oxidative amidation of methyl ketones with anthranils for the synthesis of: α -ketoamides
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An I2-DMSO mediated oxidative amidation of methyl ketones using anthranils as masked N-nucleophiles has been developed for the direct synthesis of α-ketoamides with high atom-economy. This metal-free process involves reductive N-O bond cleavage of anthranils and oxidative C-N bond formation of methyl ketones under mild conditions. The iodo group and electrophilic formyl group provide multiple possibilities for further functionalization of α-ketoamides.
- Zhuang, Shi-Yi,Tang, Yong-Xing,Chen, Xiang-Long,Wu, Yan-Dong,Wu, An-Xin
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supporting information
p. 4258 - 4262
(2021/05/31)
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- Access to acridones by tandem copper(i)-catalyzed electrophilic amination/Ag(i)-mediated oxidative annulation of anthranils with arylboronic acids
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An efficient and practical approach for the synthesis of medicinally important acridones was developed from anthranils and commercially available arylboronic acids by a tandem copper(i)-catalyzed electrophilic amination/Ag(i)-mediated oxidative annulation strategy. This new and straightforward protocol displayed a broad substrate scope (25 examples) and high functional group tolerance. What's more, a possible mechanistic proposal was also presented.
- Huang, Yan-Xia,Huang, Zhuo-Jun,Jiang, Chun-Yong,Liang, Jing-Yi,Liang, Qiu-Ping,Shu, Bing,Xie, Hui,Zeng, Jun-Yi,Zhang, Shang-Shi,Zhou, Binhua
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supporting information
p. 8487 - 8491
(2021/10/20)
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- Ambient reductive synthesis of N-heterocyclic compounds over cellulose-derived carbon supported Pt nanocatalyst under H2atmosphere
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N-heterocyclic compounds are important chemicals, and their reductive synthesis using H2 under mild conditions is attractive but challenging. Herein, we report chemoselective hydrogenation of 2-nitroacylbenzenes to 2,1-benzisoxazoles under ambient conditions for the first time, wihch is achieved over cellulose-derived carbon (c-C) supported Pt nanocatalyst (Pt/c-C), and a series of 2,1-benzisoxazoles can be obtained in excellent yields. Pt/c-C also shows high performance for ambient reductive amination of levulinic acid with H2, accessing various pyrrolidones in excellent yields. The systematic studies indicated that the c-C support played multiple roles in catalysis with enhancing electron density of the Pt nanoparticles and activating reactant molecules. Especially, the O-containing groups on the c-C surface provided the c-C support with both acid and base features, thus endowing Pt/c-C with high performances. This work provides an accessible and highly efficient catalyst for reductive synthesis of N-heterocycles using H2 under ambient conditions, which may have promising applications.
- Wu, Yunyan,Wu, Yunyan,Zhao, Yanfei,Zhao, Yanfei,Wang, Huan,Wang, Huan,Zhang, Fengtao,Zhang, Fengtao,Li, Ruipeng,Li, Ruipeng,Xiang, Junfeng,Wang, Zhenpeng,Han, Buxing,Liu, Zhimin
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p. 3820 - 3826
(2020/07/06)
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- Practical Synthesis of Benzimidazo[1,2- A[quinolines via Rh(III)-Catalyzed C-H Activation Cascade Reaction from Imidamides and Anthranils
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We report a novel and practical one-pot Rh(III)-catalyzed strategy to construct benzimidazo[1,2-a]quinolines from readily available imidamides and anthranils. The cascade reaction proceeds via a C-H amination-cyclization-cyclization process in ionic liquid without any additives and possesses simple operation, moderate-to-high yield, and broad substrate scope features, which will provide the reference for the construction of biologically active fused benzimidazoles.
- Hu, Yao,Wang, Ting,Liu, Yanzhao,Nie, Ruifang,Yang, Ninghong,Wang, Qiantao,Li, Guo-Bo,Wu, Yong
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supporting information
p. 501 - 504
(2020/01/31)
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- Copper-Catalyzed Annulation or Homocoupling of Sulfoxonium Ylides: Synthesis of 2,3-Diaroylquinolines or α,α,β-Tricarbonyl Sulfoxonium Ylides
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An unprecedented copper-catalyzed reaction of sulfoxonium ylides and anthranils is reported that enables an easy access to 2,3-diaroylquinolines through a [4+1+1] annulation. Copper-catalyzed homocoupling of sulfoxonium ylides provided α,α,β-tricarbonyl sulfoxonium ylides, which provides a strategy to extend the carbon chain through C-C bond formation. The utility of the products as well as the mechanistic details of the process are presented.
- Zhu, Shuai,Shi, Kai,Zhu, Hao,Jia, Zhe-Kang,Xia, Xiao-Feng,Wang, Dawei,Zou, Liang-Hua
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supporting information
p. 1504 - 1509
(2020/03/03)
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- Gold-Catalyzed Intermolecular Formal [4 + 2 + 2]-Cycloaddition of Anthranils with Allenamides
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The construction of eight-membered rings is a challenging issue due to unfavorable transannular strain and entropic barriers. We report herein a gold-catalyzed formal [4 + 2 + 2] cycloaddition reaction of anthranils with allenamides to deliver oxa-bridged eight-membered heterocycles in accepted yields with unique E/Z configuration. Moreover, the asymmetric [4 + 2 + 2] cycloaddition by using chiral phosphoramidite gold catalyst has also been conducted.
- Wang, Cheng,Xu, Guangyang,Shao, Ying,Tang, Shengbiao,Sun, Jiangtao
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supporting information
p. 5990 - 5994
(2020/08/12)
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- Copper-catalyzed coupling of anthranils and α-keto acids: Direct synthesis of α-ketoamides
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Copper-catalyzed coupling of α-keto acids with anthranils is reported for the synthesis of α-ketoamides. This process involves N-O/C-O bond cleavages and C-N bond formation. Furthermore, the decarboxylation of α-keto acids can be successfully suppressed under redox-neutral conditions.
- Li, Ping-Gui,Zhu, Hao,Fan, Min,Yan, Cheng,Shi, Kai,Chi, Xi-Wen,Zou, Liang-Hua
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supporting information
p. 5902 - 5907
(2019/06/24)
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- Gold-Catalyzed Annulations of N-Propargyl Ynamides with Anthranils with Two Distinct Chemoselectivities
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Gold-catalyzed annulation of N-propargyl ynamides with anthranils can proceed by two distinct mechanisms. In the case of a terminal N-propargyl ynamide, its resulting α-imino gold carbene reacts with a tethered alkyne to generate a vinyl cation to enable hydrolysis, which ultimately yields a pyrrolo[2,3-b]quinoline derivative after treatment with p-toluenesulfonic acid. For an internal alkyne, its α-imino gold carbene reacts with a tethered alkyne via either a vinyl cation or an alkenylgold carbene; both paths ultimately lead to a 4-ketone-2-aminopyrrole derivative. Our mechanistic analysis indicates that water is a better nucleophile than anthranil for terminal ynamides, whereas water and anthranils are equally reactive for internal ynamides.
- Hsu, Yu-Chen,Hsieh, Shu-An,Liu, Rai-Shung
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supporting information
p. 5288 - 5297
(2019/03/26)
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- Simple and scalable electrochemical synthesis of 2,1-benzisoxazoles and quinoline: N -oxides
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Cathodic reduction of the nitro moiety and subsequent intramolecular cyclization affords different substituted 2,1-benzisoxazoles and quinoline N-oxides. This methodology allows the synthesis of two different types of heterocycles from common simple starting materials, using electrons as a sole reagent for this transformation. The electrolysis can be conducted in a very simple undivided electrolysis cell under constant current conditions. This permits working on a larger scale compared to other electrochemical methodologies and represents a significant advantage.
- Rodrigo, Eduardo,Baunis, Haralds,Suna, Edgars,Waldvogel, Siegfried R.
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supporting information
p. 12255 - 12258
(2019/10/22)
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- RhIII-Catalyzed Straightforward Synthesis of Benzophenanthroline and Benzophenanthrolinone Derivatives using Anthranils
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An efficient pot-economic and step-economic RhIII-catalyzed site-selective direct amination/annulation strategy was developed for the synthesis of benzophenanthroline derivatives using quinoline N-oxides and anthranils. The method was further extended to the synthesis of nitrogen-containing extended π-conjugated benzophenanthrolinone derivatives. Late-stage functionalizations of cinchonidine and cinchophen derivatives and synthesis of a bioactive quinolino-indole were achieved.
- Biswas, Aniruddha,Sarkar, Souradip,Samanta, Rajarshi
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supporting information
p. 3000 - 3004
(2019/02/13)
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- Gold(III)-catalyzed chemoselective annulations of anthranils with N-allylynamides for the synthesis of 3-azabicyclo[3.1.0]hexan-2-imines
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We herein report the gold(iii)-catalyzed selective annulation of anthranils with N-allylynamides under mild conditions. By trapping the in situ-generated α-imino gold carbenes, 3-azabicyclo[3.1.0]hexan-2-imines were obtained in high synthetic efficiency. The reaction, which can be conducted in the gram scale, tolerates electron-rich and electron-deficient anthranils as well as a diverse set of functionalized ynamides (aryl- and alkyl-substituted terminal).
- Song, Lina,Tian, Xianhai,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 9007 - 9010
(2019/08/01)
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- Catalyst-free cyclization of anthranils and cyclic amines: One-step synthesis of rutaecarpine
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An efficient synthesis of a variety of quinazolinone derivatives via a direct cyclization reaction between commercially available anthranils and cyclic amines is described. The developed transformation proceeds with the merits of high step- and atom-efficiency, a broad substrate scope, and good to excellent yields, without additional catalysts, and offers a practical way for the preparation of rutaecarpine and its derivatives with structural diversity.
- Li, Jian,Wang, Zheng-Bing,Xu, Yue,Lu, Xue-Chen,Zhu, Shang-Rong,Liu, Li
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supporting information
p. 12072 - 12075
(2019/10/14)
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- Cu(II)/Ag(I)-Catalyzed Cascade Reaction of Sulfonylhydrazone with Anthranils: Synthesis of 2-Aryl-3-sulfonyl Substituted Quinoline Derivatives
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In this paper, a Cu(II)/Ag(I)-catalyzed cascade reaction of anthranils with sulfonylhydrazone to construct 2-phenyl-3-sulfonyl disubstituted quinoline derivatives under mild conditions was studied. The mechanism study indicated that this reaction involves radical addition, and new C-C, C-N, and C-S bonds were constructed in one step.
- Wang, Fei,Xu, Pei,Wang, Shun-Yi,Ji, Shun-Jun
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supporting information
p. 2204 - 2207
(2018/04/30)
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- Gold(III)-Catalyzed Site-Selective and Divergent Synthesis of 2-Aminopyrroles and Quinoline-Based Polyazaheterocycles
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A facile, site-selective, and divergent approach to construct 2-aminopyrroles and quinoline-fused polyazaheterocycles enabled by a simple gold(III) catalyst from ynamides and anthranils under mild reaction conditions is described. This one-pot strategy uses readily available starting materials, proceeds in a highly step- and atom-economical manner, with broad substrate scope and scale-up potential. The key element for success in this tandem reaction is a catalyst-directed preferred quenching of the in situ generated gold carbene intermediates by a nucleophilic benzyl/2-furylmethyl moiety on the ynamides as an alternative to the known C?H annulation leading to indoles.
- Zeng, Zhongyi,Jin, Hongming,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 16549 - 16553
(2018/11/23)
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- One-pot and catalyst-free synthesis of pyrroloquinolinediones and quinolinedicarboxylates
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A method for the catalyst-free synthesis of pyrroloquinolinediones and quinolinedicarboxylates is developed through a one-pot synthesis involving denitrogenation of azide, benzisoxazole formation, aza-Diels-Alder cycloaddition, and dehydrative aromatization. Only stoichiometric amounts of N2 and H2O are produced as by-products. A comprehensive green chemistry metrics analysis indicated that this method is much more efficient and greener than two reported methods for the synthesis of pyrroloquinolinediones.
- Zhang, Xiaofeng,Dhawan, Gagan,Muthengi, Alex,Liu, Shuai,Wang, Wei,Legris, Marc,Zhang, Wei
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supporting information
p. 3851 - 3855
(2017/08/22)
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- Chemoselective Reductive Heterocyclization by Controlling the Binomial Architecture of Metal Particles and Acid-Base Properties of the Support
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2,1-Benzisoxazoles have been selectively synthesized through reductive heterocyclization of 2-nitroacylarenes using Pt-supported nanoparticles. The reaction involves a cascade process in which the first step is the reduction of the nitro group into hydroxylamine followed by heterocyclization through the nucleophilic attack of the hydroxylamine group to the carbonyl of the acyl group and further dehydration. The reaction was performed on Pt/C, Pt/TiO2, and Pt/MgO using hydrogen as the reducing agent under mild reaction conditions. The results showed that Pt/MgO was the most active and selective catalyst. The study of the influence of the crystal size of the metal on the activity and selectivity, combined with the reaction mechanism examined by in situ Fourier transform infrared spectroscopy of the adsorbed reactant, showed that the maximum activity and selectivity to the target compound can be achieved by controlling the architecture of metal particles and acid-base properties of the support. The effect of temperature on selectivity, the stability of the Pt/MgO catalyst, and the scope of the reaction have been studied. Finally, reductive heterocyclization using different metals (Pd and Au) supported on MgO has also been performed.
- Marti,Sanchez,Climent, Maria J.,Corma,Iborra,Romanelli,Concepcion
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p. 8255 - 8262
(2017/12/08)
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- Gold-Catalyzed [4+2] Annulation/Cyclization Cascades of Benzisoxazoles with Propiolate Derivatives to Access Highly Oxygenated Tetrahydroquinolines
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This work describes gold-catalyzed annulations of electron-deficient alkynes with benzisoxazoles to yield quinoline oxides chemoselectively. Chemical functionalizations of these resulting azacyclic compounds afforded various oxygenated tetrahydroquinolines which are present as the cores of many bioactive molecules. With the same reactants, a new relay catalysis using gold and zinc(II) catalysts affords highly oxygenated tetrahydroquinoline derivatives stereoselectively.
- Sahani, Rajkumar Lalji,Liu, Rai-Shung
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supporting information
p. 12736 - 12740
(2017/09/11)
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- Cp*RhIII-Catalyzed Directed Amidation of Aldehydes with Anthranils
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An approach towards construction of amide C–N bonds under mild conditions through rhodium(III) catalysis has been explored. Previous waste-free amidations were generally limited to the condensation of carboxylic acids and amines. In this report, we directly applied amination of the aldehyde C(sp2)–H bond to extend the scope of amidation reactions. The amination shows a wide substrates scope, and several important functional groups were tolerated under the benign reaction conditions. The synthesized amides are important precursors for the preparation of benzoxazinone derivatives, found in various bioactive natural products.q.
- Debbarma, Suvankar,Sudan Maji, Modhu
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p. 3699 - 3706
(2017/07/22)
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- Vasicine from Adhatoda vasica as an organocatalyst for metal-free Henry reaction and reductive heterocyclization of o-nitroacylbenzenes
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Vasicine, a quinazoline alkaloid, from the leaves of Adhatoda vasica, has been utilized as an efficient catalyst for metal and base free Henry reaction of various aldehydes with nitro alkanes. The method can be used in the synthesis of various β-nitro alcohols under mild reaction conditions without use of hazardous organic solvents and expensive catalysts. Vasicine is also applied successfully for one pot synthesis of 2,1-benzisoxazoles from o-nitroacylbenzenes in good yields under mild conditions.
- Sharma, Sushila,Kumar, Manoranjan,Bhatt, Vinod,Nayal, Onkar S.,Thakur, Maheshwar S.,Kumar, Neeraj,Singh, Bikram,Sharma, Upendra
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supporting information
p. 5003 - 5008
(2016/10/25)
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- Gold-Catalyzed C-H Annulation of Anthranils with Alkynes: A Facile, Flexible, and Atom-Economical Synthesis of Unprotected 7-Acylindoles
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The gold-catalyzed C-H annulation of anthranil derivatives with alkynes offers a facile, flexible, and atom-economical one-step route to unprotected 7-acylindoles. An intermediate α-imino gold carbene, generated by an intermolecular reaction, promotes ortho-aryl C-H functionalization to afford the target products. The transformation proceeds with a broad range of substrates under mild conditions. Moreover, the obtained functionalized indole products represent a versatile platform for the construction of diverse indolyl frameworks.
- Jin, Hongming,Huang, Long,Xie, Jin,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
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supporting information
p. 794 - 797
(2016/02/27)
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- Selective synthesis of Rh5 carbonyl clusters within a polyamine dendrimer for chemoselective reduction of nitro aromatics
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The selective synthesis of the [Rh5(CO)15] - cluster within the PPI dendrimer was successfully demonstrated. The dendrimer-encapsulated [Rh5(CO)15]- was resistant to decomposition under the catalytic reaction conditions and exhibited extremely high selectivity for the chemoselective reduction of nitro groups of various nitro aromatics with other reducible groups using CO/H2O as a reductant. This journal is the Partner Organisations 2014.
- Maeno, Zen,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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p. 6526 - 6529
(2014/06/09)
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- One-pot synthesis of 2,1-benzisoxazoles (anthranils) by a stannous chloride-mediated tandem reduction-heterocyclization of 2-nitroacylbenzenes under neutral conditions
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Classically, 2,1-benzisoxazoles (anthranils) are prepared from 2-nitroacylbenzenes by a reductive heterocyclization reaction with Sn or SnCl2 concentrated HCl. Acid sensitive functionalities are expected to be incompatible with these conditions; milder approaches to the synthesis of 2,1-benzisoxazoles would be welcomed. We demonstrate that SnCl 2·2H2O in a 1:1 mixture of EtOAc/MeOH is capable of mediating the tandem reduction-heterocyclization of a variety of 2-nitroacylbenzenes to their corresponding 2,1-benzisoxazoles in good to excellent yields under essentially neutral conditions. Importantly, several commonly used acid-labile protecting groups, including Boc carbamate, tert-butyl ether, and tert-butyl ester, proved orthogonal to these reaction conditions.
- Chauhan, Jay,Fletcher, Steven
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supporting information
p. 4951 - 4954
(2012/11/07)
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- Revisiting the thermal decomposition of five ortho-substituted phenyl azides by calorimetric techniques
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The thermal decomposition (TD) of 2-azidophenylmethanol (1), 2-azidobenzenecarbaldehyde (2), 1-(2-azidophenyl)-1-ethanone (3), (2-azidophenyl)(phenyl)methanone (4) and 1-azido-2-nitrobenzene (5) was analysed by DSC, TG and C80 calorimetric techniques under both oxidative and non-oxidative conditions. The TD of these azides in solution is well known to give the corresponding benzoxazoles, generally in good yields, with the exception of azide 1. When both the outcomes from the solid phase and in 'solution phase' TD reactions combined with the results from EI-MS experiments were considered, sufficient information was available to estimate the azides intrinsic molecular reactivity (MIR).
- Cardillo, Paolo,Gigante, Lucia,Lunghi, Angelo,Zanirato, Paolo
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experimental part
p. 191 - 198
(2010/08/04)
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- Green-light photocatalytic reduction using dye-sensitized TiO2 and transition metal nanoparticles
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Nitrobenzenes are cleanly reduced to anilines using Ru-sensitized TiO 2 photocatalysts and green light irradiation, if very small amounts of transitions metal salts are added, which form metal nanoparticles of narrow size distribution under the experimental conditions. The catalyst system is prepared by simple mixing of the components and is therefore easy to apply in organic synthesis. As light sources, commercial high power LEDs or sunlight are used. We report the optimization of the reaction conditions, the effect of trace amounts of added metal salts and demonstrate the use of green light photoreduction in the conversion of several nitrobenzene derivatives.
- Fueldner, Stefan,Mild, Ralph,Siegmund, Heiko Ingo,Schroeder, Josef A.,Gruber, Michael,Koenig, Burkhard
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experimental part
p. 400 - 406
(2010/08/06)
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- Reductive heterocyclizations via indium-iodine-promoted conversion of 2-nitroaryl imines or 2-nitroarenes to 2,3-diaryl-substituted indazoles
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While N-(2-nitrobenzylidene)anilines produced mixtures of 2,1-benzisoxazoles and 3-anilino-2-aryl-2H-indazoles in the presence of indium and iodine in MeOH, N-(2-nitrobenzylidene)anilines were transformed into 3-anilino-2-aryl-2H-indazoles as the predominant major product through the change of the solvent from protic MeOH to aprotic THF. In an indium-mediated one-pot reductive reaction, 2-benzaldehydes and anilines in THF were also successfully transformed into the corresponding indazoles. This journal is The Royal Society of Chemistry.
- Ahn, Gil Hwan,Lee, Jung June,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
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p. 2472 - 2485
(2008/02/13)
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- Reductive heterocyclizations via indium/iodine-promoted one-pot conversion of 2-nitroaryl aldehydes, ketones, and imines
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2-Nitroaryl aldehydes, ketones, and imines were reductively cyclized to 2,1-benzisoxazoles with good yields in the presence of indium and iodine in MeOH. Under a similar condition, N-(2-nitrobenzylidene)anilines were produced mixtures of 2,1-benzisoxazoles and 3-anilino-2-phenyl-2H-indazoles.
- Han, Rongbi,Son, Kee In,Ahn, Gil Hwan,Jun, Young Moo,Lee, Byung Min,Park, Younbong,Kim, Byeong Hyo
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p. 7295 - 7299
(2007/10/03)
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- Inhibitors of protein tyrosine kinases
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Disclosed herein are small molecule, non-peptidyl inhibitors of protein tyrosine kinases, and methods for their use. The instant inhibitors are based on a 1,4-benzodiazepin-2-one nucleus. Methods are provided for inhibition of specific protein tyrosine kinases, for example pp60c-src. Methods are further provided for the use of these inhibitors in situations where the inhibition of a protein tyrosine kinase is indicated, for example, in the treatment of certain diseases in mammals, including humans.
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- Indium mediated reductive heterocyclization of 2-nitroacylbenzenes or 2- nitroiminobenzenes toward 2,1-benzisoxazoles in aqueous media
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2-Nitro-substituted acylbenzenes or iminobenzenes such as 2- nitrobenzaldehydes, 2'-nitroacetophenone, and N(2-nitrobenzylidene)anilines were cyclized toward 2,1-benzisoxazoles in the presence of 2-bromo-2- nitropropane and indium in an MeOH/H2O solution in excellent yields. (C) 2000 Elsevier Science Ltd.
- Kim, Byeong Hyo,Jin, Youngoo,Jun, Young Moo,Han, Rongbi,Baik, Woonphil,Lee, Byung Min
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p. 2137 - 2140
(2007/10/03)
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- Reductive reactions of nitroarenes in the presence of allyl bromide and zinc dust
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Under the mild condition, allyl bromide/Zn mediated reductive N,O- diallylation of nitrobenzene was observed. In case of o-nitroarenes such as 2-nitrobenzaldehyde derivatives, 2'-nitroacetophenone, and N-(2- nitrobenzylidene)anilines, reductive cyclizations were accomplished in good to excellent yields. Synthesis and mechanistic details are discussed.
- Kim, Byeong Hyo,Kim, Tae Kyu,Cheong, Jae Wook,Lee, Sang Woo,Jun, Young Moo,Baik, Woonphil,Lee, Byung Min
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p. 1921 - 1928
(2007/10/03)
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- 2-bromo-2-nitropropane/zn promoted reductive cyclizations of ortho-carbonyl, imino, or azo substituted nitrobenzenes
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Under the mild conditions, reductive cyclizations of 2-nitrobenzaldehydes, 2'-nitroacetophenone, and N-(2-nitrobenzylidene)anilines were accomplished in the presence of 2-bromo-2-nitropropane/Zn in methanolic solution. Under the similar conditions in MeOH/CH2Cl2, o-nitro-substituted phenylazobenzenes have been converted into 2-aryl-2H-benzotriazoles via reductive cyclizations that are widely used as UV absorbers. Synthesis and mechanistic details are discussed.
- Kim, Byeong Hyo,Lee, Yoon Seok,Kwon, Woong,Jin, Youngoo,Tak, Jung Ae,Jun, Young Moo,Baik, Woonphil,Lee, Byung Min
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p. 2581 - 2592
(2007/10/03)
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- Electrochemical synthesis of 2,1-benzisoxazoles by controlled potential cathodic electrolysis
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Using a divided cell, reductive cyclization of nitroarene compounds into 2,1-benzisoxazoles in .mild conditions was successfully accomplished by the controlled potential cathodic electrolysis reactions. Optimum reaction potential of each reaction was determined based on cyclic voltametric behavior in methanol solution at Pb or Ft cathode, and Pt anode.
- Kim, Byeong Hyo,Jim, Young Moo,Choi, Yong Rack,Lee, Doo Byung,Baik, Woonphil
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p. 749 - 754
(2007/10/03)
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- Synthesis of 2-nitroindoles via the Sundberg indole synthesis
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A three-step sequence has been developed for converting o-nitrobenzaldehydes into 2-nitroindoles. The key step involves the thermolysis of 2-(o-azidophenyl)nitroethylene (10) in xylenes which gives 2-nitroindole (4) in 54% yield, akin to the classic Sundberg indole synthesis. This procedure has also been utilized to synthesize 5,6-dimethoxy-2-nitroindole (14).
- Pelkey, Erin T.,Gribble, Gordon W.
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p. 5603 - 5606
(2007/10/03)
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- 2-Bromo-2-nitropropane/Zn promoted reductive cyclizations of ortho-substituted nitroarenes toward 2,1-benzisoxazole derivatives
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Under the mild conditions, reductive cyclizations of 2-nitrobenzaldehydes or 2′-nitroacetophenone towards 2,1-benzisoxazoles were accomplished in the presence of 2-bromo-2-nitropropane/Zn in methanolic solution. The synthetic utility and the role of 2-bromo-2-nitropropane were investigated.
- Kim, Byeong Hyo,Jun, Young Moo,Kim, Tae Kyu,Lee, Yoon Seok,Baik, Woonphil,Lee, Byung Min
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p. 235 - 240
(2007/10/03)
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- One-Step Conversion of Aryl Nitro Compounds to N-Monosubstituted Formamides
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A concise general route to N-monosubstituted formamides starting from aryl nitro compounds substituted with H, Cl, OMe, CHO, and NHCHO is described.
- Hrvatin, Paul,Sykes, Andrew G.
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p. 1069 - 1070
(2007/10/03)
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- Palladium Complex-Catalyzed Reductive N-Heterocyclization of Nitroarenes: Novel Synthesis of Indole and 2H-Indazole Derivatives
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The dichlorobis(triphenylphosphine)palladium (PdCl2(PPh3)2)-tin(II)chloride (SnCl2) system shows high catalytic activity for the reductive N-heterocyclization of various 2-nitrostyrene and N-(2-nitrobenzylidene)amine derivatives when employed at 100 deg C for 16 h under 20 kg cm-2 of initial carbon monoxide pressure, to give the corresponding indole and 2H-indazole derivatives in good yield.For example, 2-phenylindole was obtained in 75percent yield from the reductive N-heterocyclization of 2-nitrostilbene.Similarly, 2-propyl-2H-indazole was readily prepared in 83percent yield by the reductive N-heterocyclization of N-(2-nitrobenzylidene)propylamine.A nitrene intermediate for the present reaction is proposed on the basis of deuterium-labeling experiments and the investigation of alkyl rearrangement in the construction of the indole skeleton.Carbon monoxide effectively operates as a deoxygenating agent of the nitro group to afford a nitrene intermediate.
- Akazome, Motohiro,Kondo, Teruyuki,Watanabe, Yoshihisa
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p. 3375 - 3380
(2007/10/02)
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- Homogenous Gas-Phase Formation and Destruction of Anthranil from o-Nitrotoluene Decomposition
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Dilute quantities of o-nitrotoluene and anthranil have been pyrolyzed in comparative rate single pulse shock tube experiments.Rather than C-NO2 bond cleavage and NO2 isomerization found as major channels in p-nitrotoluene decomposition, we demonstrate that the important pathway for pyrolysis involves the formation of anthranil with the following overall rate expression: k(o-nitrotoluene -> anthranil) = 1.2 x 1013 exp(-26020/T)/s.The anthranil that is formed is very unstable under our conditions; the rate expression for disappearence has been found to be the following: k(anthranil)d = 3.7 x 1015 exp(-25800/T)/s.Arguments are presented that suggest that the first rate expression is representative of a retroene reaction and the second expression is for the breaking of the N-O bond in anthranil.These conclusions emphasize the difference in results from shock tube and laser pyrolysis experiments.Their implications on the initiation reactions in the decomposition of nitroaromatic explosives are discussed.
- He, Y. Z.,Cui, J. P.,Mallard, W. G.,Tsang, W.
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p. 3754 - 3759
(2007/10/02)
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- Pyrolyses of o-Alkoxy- and o-Alkylthio-N-Allylanilines and of Some Related O- and S-Allyl Compounds
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The o-substituted allyl compounds (1)-(12) have been pyrolysed in order to generate aminyl, phenoxyl, and thiophenoxyl radicals with adjacent substituents.In all cases, products are formed by intramolecular hydrogen transfer from the substituent to the radical centre.This process may be followed by rearrangement to give an aldehyde, by heteroatom extrusion to give an alkene, or by ring formation to give five-membered ring heterocycles (Scheme 1, routes A, B1, and B2 respectively.The distribution of products formed by each route is dependent both on the nature of the o-substituent, and on the nature of the initial radical.
- Cadogan, J. I. G.,Hickson, Clare L.,McNab, Hamish
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p. 1885 - 1890
(2007/10/02)
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- PURIFICATION AND PROPERTIES OF INDOLE 2,3-DIOXYGENASE FROM MAIZE LEAVES
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An indole 2,3-dioxygenase was purified ca 38-fold from maize leaves.The enzyme had an MW of about 98000, an optimum pH of 5.0 and the energy of activation was 9.1 kcal/mol.The Km for indole was 1.4E-4 M.The enzyme was inhibited by diethyldithiocarbamate, salicylaldoxime and sodium dithionite.The inhibition by diethyldithiocarbamate was specifically reversed by Cu2+.The dialyzed enzyme was stimulated by Cu2+.Four atoms of oxygen were utilized in the disappearance of 1 mole of indole.Inhibition of the enzyme by -SH compounds and -SH group inhibitors, and their partial removal by Cu2+ only, suggested the involvement of -SH groups in binding of Cu2+ at the catalytic site.Key Word Index - Zea mays; Gramineae; maize leaf; indole oxidation; indole oxidase; indole 2,3-dioxygenase; purification; Cu2+; -SH groups.
- Pundir, C. S.,Garg, G. K.,Rathore, V. S.
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p. 2423 - 2428
(2007/10/02)
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- Pyrolysis of Aryl Azides. V. Characterization of Phenylazo, Benzoyl and Formyl as Neighbouring Groups
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The enhancements of thermolysis rate of azidobenzene produced by ortho phenylazo, benzoyl and formyl substituents are 21180, 70.0 and 22.8 at 393.2 K (decalin solutions).The same ortho substituents produce much smaller enhancements (169, 8.56 and 10.7 respectively) in the pyrolysis rate of 1-azido-2,4-dibromobenzene.These results are interpreted as steric effects on an electrocyclic thermolysis mechanism, and are not consistent with the alternative pathway of intramolecular 1,3-dipolar addition which continues to be advocated by Hall and Dolan.
- Dickson, Noel J.,Dyall, Leonard K.
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