- A new synthetic approach to the benzo[c]phenanthridine ring system
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The base-catalyzed reaction of 2-methylbenzonitrile and paraformaldehyde provided 6-amino-11,12-dihydrobenzo[c]phenanthridine, which was converted via the corresponding 6-oxo- and 6-thioxo-derivatives into benzo[c]phenanthridine.
- Kock, Ilka,Clement, Bernd
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- A Short Total Synthesis of Benzophenanthridine Alkaloids via a Rhodium(III)-Catalyzed C-H Ring-Opening Reaction
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The biologically important naturally available benzophenanthridines were prepared efficiently in three steps with overall good yields. A new synthetic methodology involving a rhodium(III) catalyzed redox-neutral ring-opening of 7-azabenzonorbornadienes with aromatic aldoximes is developed to synthesize the target molecules. The developed C-H ring-opening reaction is highly diastereoselective and compatible with various sensitive functional group substituted aromatic aldoximes as well as substituted 7-azabenzonorbornadienes. The ring-opening products were transformed into highly sensitive 13,14-dehydrobenzo phenanthridine derivatives by HCl hydrolysis. Subsequently, 13,14-dehydrobenzophenanthridines were converted into biologically important benzophenanthridine alkaloids in the presence of DDQ. A possible reaction mechanism was proposed for the C-H ring-opening reaction and supported by the deuterium labeling studies.
- Aravindan, Narasingan,Jeganmohan, Masilamani
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p. 14826 - 14843
(2021/10/20)
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- Sanguinarine as a new chemical entity of thioredoxin reductase inhibitor to elicit oxidative stress and promote tumor cell apoptosis
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The alteration of redox homeostasis is a hallmark of cancer cells. As a critical player in regulating cellular redox signaling, thioredoxin reductase (TrxR) enzymes are increasingly recognized as attractive targets for anticancer drug development. We repo
- Yao, Juan,Duan, Dongzhu,Song, Zi-Long,Zhang, Junmin,Fang, Jianguo
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p. 659 - 667
(2020/01/22)
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- Synthesis method of phenanthridine and derivative of phenanthridine
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The invention discloses a synthesis method of phenanthridine as shown in a formula (I) and a derivative of the phenanthridine. In the synthesis method, o-arylphenylsulfimide shown as a formula (II) isused as a raw material and reacts in an organic solvent under the action of a [Cu]/Selectfluor catalyst to obtain a corresponding target product (I). The synthesis method disclosed by the invention has the advantages of cheap and easily available and low-toxicity catalyst, environmental friendliness, mild reaction conditions, high universality of functional group and easiness and convenience in operation. The formulas (I) and (II) are shown in the description.
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Paragraph 0103-0105
(2018/03/24)
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- Palladium-Catalyzed α-Arylation of Silylenol Ethers in the Synthesis of Isoquinolines and Phenanthridines
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A diverse array of isoquinolines and phenanthridines have been accessed by developing a two-step, one-pot method constituting regioselective palladium-catalyzed Kuwajima-Urabe α-arylation of silylenol ethers and acid-mediated deprotection, annulation, and aromatization. Structural diversity in the silylenol ethers leads to three different classes of isoquinolines and phenanthridines from which related natural products can be derived. The synthetic utility of this method by the quick assembly of the natural product trispheridine is also demonstrated.
- Saini, Gaurav,Kumar, Pravin,Kumar, Gangam Srikanth,Mangadan, Arun Raj Kizhakkayil,Kapur, Manmohan
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supporting information
p. 441 - 444
(2018/01/28)
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- Synthesis of Phenanthridines through Palladium-Catalyzed Cascade Reaction of 2-Halo-N-Ms-arylamines with Benzyl Halides/Sulfonates
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An efficient palladium-catalyzed nucleophilic substitution/C–H activation/aromatization cascade reaction between readily available 2-halo-N-Ms-arylamines (Ms = methanesulfonyl) and benzyl halides/sulfonates has been described. A wide variety of phenanthridines were synthesized in a one-pot fashion in moderate to high yields (37–86 %). Notably, this method provides a straightforward, facile approach for the synthesis of phenanthridines. The practicality was further substantiated by successfully carrying out a gram-scale preparation.
- Yang, Si-Yi,Han, Wen-Yong,Zhang, Ding-Lei,Zhou, Xiao-Jian,Bai, Mei,Cui, Bao-Dong,Wan, Nan-Wei,Yuan, Wei-Cheng,Chen, Yong-Zheng
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p. 996 - 1003
(2017/02/15)
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- A preparation method of compound phenanthridine apperception (by machine translation)
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The invention discloses a method for preparing phenanthridine apperception composition, comprising: adding the reactant in the solvent 2 - halogenated -N- Protection of the aromatic amine and benzylic or benzyl sulfonic acid ester compound, then adding metal palladium catalyst, a ligand and an alkali, in heating and inert gas protection under the conditions of the chemical reaction, the reaction is complete after treatment to obtain the compound of the present invention pure product. Preparation method of this invention adopts the simple and easily obtained 2 - halogenated -N- Protection of the aromatic amine and benzylic or benzyl sulfonic acid ester compound as a raw material, by nucleophilic substitution/C - H activation/aromatization series reaction to obtain the phenanthridine compound, with raw materials are easy, simple operation, after treatment is simple, and high yield. (by machine translation)
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Paragraph 0038; 0041; 0042
(2017/05/12)
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- Regioselective Synthesis of Polycyclic and Heptagon-embedded Aromatic Compounds through a Versatile π-Extension of Aryl Halides
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A versatile π-extension reaction was developed based on the three-component cross-coupling of aryl halides, 2-haloarylcarboxylic acids, and norbornadiene. The transformation is driven by the direction and subsequent decarboxylation of the carboxyl group, while norbornadiene serves as an ortho-C?H activator and ethylene synthon via a retro-Diels–Alder reaction. Comprehensive DFT calculations were performed to account for the catalytic intermediates.
- Fu, Wai Chung,Wang, Zheng,Chan, Wesley Ting Kwok,Lin, Zhenyang,Kwong, Fuk Yee
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supporting information
p. 7166 - 7170
(2017/06/13)
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- Visible-light-promoted iminyl-radical formation from Acyl oximes: A unified approach to pyridines, quinolines, and phenanthridines
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A unified strategy involving visible-light-induced iminyl-radical formation has been established for the construction of pyridines, quinolines, and phenanthridines from acyl oximes. With fac-[Ir(ppy)3] as a photoredox catalyst, the acyl oximes were converted by 1 e- reduction into iminyl radical intermediates, which then underwent intramolecular homolytic aromatic substitution (HAS) to give the N-containing arenes. These reactions proceeded with a broad range of substrates at room temperature in high yield. This strategy of visible-light-induced iminyl-radical formation was successfully applied to a five-step concise synthesis of benzo[c]phenanthridine alkaloids.
- Jiang, Heng,An, Xiaode,Tong, Kun,Zheng, Tianyi,Zhang, Yan,Yu, Shouyun
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supporting information
p. 4055 - 4059
(2015/03/30)
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- Visible-light-promoted and one-pot synthesis of phenanthridines and quinolines from aldehydes and o -Acyl hydroxylamine
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A one-pot synthesis of phenanthridines and quinolines from commercially available or easily prepared aldehydes has been reported. O-(4-Cyanobenzoyl)hydroxylamine was utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes catalyzed by Bronsted acid. O-Acyl oximes were then subjected to visible light photoredox catalyzed cyclization via iminyl radicals to furnish aza-arenes. A variety of phenanthridines and quinolines have been prepared assisted by Bronsted acid and photocatalyst under visible light at room temperature with satisfactory yields.
- An, Xiao-De,Yu, Shouyun
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supporting information
p. 2692 - 2695
(2015/06/16)
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- Palladium-Catalyzed Nucleophilic Substitution/C-H Activation/Aromatization Cascade Reaction: One Approach to Construct 6-Unsubstituted Phenanthridines
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A facile and practical palladium-catalyzed nucleophilic substitution/C-H activation/aromatization cascade reaction has been developed. A range of 6-unsubstituted phenanthridines could be obtained in moderate to good yields (31-85%) with readily prepared N-Ms arylamines and commercially available 2-bromobenzyl bromide derivatives as starting materials. The potential application of the protocol was also demonstrated by the expeditious synthesis of the natural alkaloid trisphaeridine.
- Han, Wenyong,Zhou, Xiaojian,Yang, Siyi,Xiang, Guangyan,Cui, Baodong,Chen, Yongzheng
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p. 11580 - 11587
(2015/12/01)
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- Palladium-catalyzed regiocontrolled domino synthesis of N-sulfonyl dihydrophenanthridines and dihydrodibenzo[c, e]azepines: Control over the formation of biaryl sultams in the intramolecular direct arylation
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A palladium-catalyzed domino N-benzylation/intramolecular direct arylation involving sulfonanilides and 2-bromobenzyl bromides has been developed for the first time, providing a workable access to N-sulfonyl dihydrophenanthridines in good to excellent yields. Under the optimized conditions, the formation of 5,6-dihydrophenanthridines was largely controlled over the formation of biaryl sultams containing a seven member ring. The optimized condition was found extendable to the regiocontrolled domino formation of N-sulfonyl-6,7-dihydro-5H-dibenzo[c,e]azepines over the biaryl sultam formation. Using an appropriate substrate, a biaryl sultam has been obtained exclusively.
- Laha, Joydev K.,Dayal, Neetu,Jain, Roli,Patel, Ketul
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p. 10899 - 10907
(2015/01/08)
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- Expeditious approach to pyrrolophenanthridones, phenanthridines, and benzo[ c ]phenanthridines via organocatalytic direct biaryl-coupling promoted by potassium tert -butoxide
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A methodology involving a "transition metal-free" intramolecular biaryl-coupling of o-halo-N-arylbenzylamines has been developed in the presence of potassium tert-butoxide and an organic molecule as catalyst. The reaction appears to proceed through KOtBu-promoted intramolecular homolytic aromatic substitution (HAS). Interestingly, this biaryl coupling also works in the presence of potassium tert-butoxide as sole promoter. On extending our approach further, we found that N-acyl 2-bromo-N-arylbenzylamines undergo a one-pot N-deprotection/biaryl coupling followed by oxidation, thus offering an expeditious route to the phenanthridine and benzo[c]phenanthridine skeletons. The strategy has been applied to a concise synthesis of Amaryllidaceae alkaloids viz. oxoassoanine (1b), anhydrolycorinone (1d), 5,6-dihydrobicolorine (2d), trispheridine (2b), and benzo[c]phenanthridines alkaloids dihydronitidine (3b), dihydrochelerythidine (3d), dihydroavicine (3f), nornitidine (3h), and norchelerythrine (3j).
- De, Subhadip,Mishra, Sourabh,Kakde, Badrinath N.,Dey, Dhananjay,Bisai, Alakesh
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p. 7823 - 7844
(2013/09/12)
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- Formal synthesis of nitidine and NK109 via palladium-catalyzed domino direct arylation/N-arylation of aryl triflates
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The use of aryl triflates as reaction partners in a palladium-catalyzed domino direct arylation/N-arylation provides a great advantage due to the availability of starting materials. Furthermore, it allows expedient access to biologically interesting benzo
- Blanchot, Mathieu,Candito, David A.,Larnaud, Florent,Lautens, Mark
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supporting information; experimental part
p. 1486 - 1489
(2011/06/09)
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- Expeditious synthesis of phenanthridines from benzylamines via dual palladium catalysis
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A method for the synthesis of phenanthridines from benzylamines and aryl iodides which uses a dual palladium-catalyzed process is developed. The domino sequence ends via an intramolecular amination and an oxidative dehydrogenation. No protecting group or
- Maestri, Giovanni,Larraufie, Marie-Helene,Derat, Etienne,Ollivier, Cyril,Fensterbank, Louis,Lacote, Emmanuel,Malacria, Max
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supporting information; experimental part
p. 5692 - 5695
(2011/03/18)
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- Electron-transfer-mediated synthesis of phenanthridines by intramolecular arylation of anions from n-(ortho-Halobenzyl)arylamines: regiochemical and mechanistic analysis
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The synthesis of a series of substituted phenanthridines by photostimulated C-C cyclization of anions from N-(orrAo-halobenzyl)arylamines has been found to proceed in very good to excellent yields (79-95%) in liquid ammonia and in DMSO. The N-(ortho-halobenzyl)arylamines are obtained in good to very good isolated yields (44-85%) by nucleophilic substitution of orthohalobenzylchlorides with different arylamines. The reaction of the anions of a diverse set N-(orthohalobenzyl)arylamines was studied, and the methodology was extended to the synthesis of trispheridine, a natural product, in very good yield, In order to explain the regiochemical outcome of these reactions, a theoretical analysis was performed with DFT methods and the B3LYP functional.
- Buden, Maria E.,Dorn, Viviana B.,Gamba, Martina,Pierini, Adriana B.,Rossi, Roberto A.
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experimental part
p. 2206 - 2218
(2010/06/17)
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- Syntheses of phenanthridines and benzophenanthridines by intramolecular ortho-arylation of aryl amide ions with aryl halides via SRN1 reactions
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The photostimulated reaction of N-(2-halo-benzyl)aryl amines with t-BuOK in liquid ammonia affords fused azaheterocycles by the SRN1 mechanism. The starting materials are easily obtained by the reaction of 2-halo-benzyl chloride and aromatic amines to prepare the secondary amines. Through this approach, phenanthridine (90%), 4-phenylphenanthridine (87%), benzo[a]phenanthridine (98%), and benzo[c]phenanthridine (84%) were synthesized.
- Budén, Maria E.,Rossi, Roberto A.
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p. 8739 - 8742
(2008/03/18)
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- Electrochemical Cyclization of 1-Phenyl-2(-1'-chlorophenyl)-substituted Five-membered Nitrogen Heterocycles. Application to the Synthesis of Phenanthridines
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Pyrrolophenanthridine (compound 4), 3-phenylimidazophenanthridine 8, tetrazolophenanthridine 11 and benzotetrazolophenanthridine 12 have been prepared using an electrochemical cyclizatin procedure.Treatment of the imidazophenanthridine with singlet oxygen yields a phenanthridone by degradation of the heterocyclic system.Lithium aluminium hydride reduction of the tetrazolophenanthridines yields the phenanthridine.
- Grimshaw, James,Hewitt, S. Armstrong
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p. 2995 - 2998
(2007/10/02)
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- Benzyne Cyclization Route to Benzophenanthridine Alkaloids. Synthesis of Chelerythrine, Decarine, and Nitidine
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The alkaloids chelerythrine (8b) and decarine (7c) have been synthesized through a benzyne-mediated cyclization of N-(2-halobenzyl)-1-naphthylamines 4 with KNH2 in ammonia/ether.The 7-hydroxybenzophenanthridine structure 16a proposed for the alkaloid fagaridine is questioned on the basis of comparison with a model compound (16b) synthesized by benzyne cyclization.For the 8,9-oxygenated alkaloids like nitidine (8i), this cyclization proceeded poorly, but a dramatic improvement occurred when LDA/THF at -78 deg C was used instead of KNH2/NH3.
- Kessar, Satinder V.,Gupta, Yash P.,Balakrishnan, Prasanna,Sawal, Kewal K.,Mohammad, Taj,Dutt, Mahesh
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p. 1708 - 1713
(2007/10/02)
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- Direct Synthesis of Benzophenanthridines and Benzophenanthridones via SRN1 Reactions
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A straightforward and high-yield route to the 11,12-dihydrobenzophenanthridine (3) and 11,12-dihydrobenzophenanthridone (14) ring systems is based upon an SRN1 reaction between 2-halobenzylamines 1 or 2-halobenzoic acids 11 and enolates derived from tetralones 2.The efficient dehydrogenation of 3 or 14 gives the benzophenthridines 4 or benzophenanthridones 15.Use of properly substituted reactants leads to nitidine, avicine, and fagaronine and to analogues of those natural products.
- Beugelmans, Rene,Chastanet, Jacqueline,Ginsburg, Helene,Quintero-Cortes, Leticia,Roussi, Georges
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p. 4933 - 4938
(2007/10/02)
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