- MeOTf- and TBD-Mediated Carbonylation of ortho-Arylanilines with CO2 Leading to Phenanthridinones
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Carbonylation of o-arylanilines utilizing CO2 as a carbonyl source for the synthesis of important phenanthridinones with a free (NH)-lactam motif has been described under metal-free condition. A range of o-arylanilines were transformed to the corresponding phenanthridinones in high yields.
- Wang, Sheng,Shao, Peng,Du, Gaixia,Xi, Chanjuan
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- Oxygen as oxidant in palladium-catalyzed inter- and intramolecular coupling reactions
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Facile palladium-catalyzed cyclizations of arylaminoquinones giving biologically important carbazoloquinones in high yields have been performed with oxygen as the single oxidant. By a slight modification of the catalyst, diphenylamine, diphenyl ether, and related compounds can be cyclized. The system could also be used in intermolecular couplings between naphthoquinones and benzene or naphthalene.
- Hagelin, Helena,Oslob, Johan D.,Akermark, Bjoern
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- Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes
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Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.
- Liu, Yao,Li, Ji-Lin,Liu, Xu-Ge,Wu, Jia-Qiang,Huang, Zhi-Shu,Li, Qingjiang,Wang, Honggen
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- Copper-catalyzed intramolecular C–N coupling reaction of aryl halide with amide
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An efficient and concise method for the ligand-free copper-catalyzed intramolecular C–N bond coupling was developed, which afforded various (NH)-phenanthridinones in good to excellent yields with tolerance of various substrates.
- Chen, Wei-Lin,Jhang, Yuan-Ye,Hsieh, Jen-Chieh
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- RADICALOID INTERMEDIATES IN THE PHOTOCHEMISTRY OF 6-CYANOPHENATHRIDINE N-OXIDE
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Irradiation of 6-cyanophenanthridine N-oxide in presence of 2,3-dimethyl-2-butene resulted in a novel type of photoaddition with rearrangement to give 2-cyano-8,8,9,9-tetramethyl--dibenzo-1,3-oxazonin and 6-(2-cyano-1,1,2-trimethylpropyloxy)phenanthridine as a minor product, which is regarded as strong evidence for an initial photochemical generation of a biradical, and not an oxaziridine as previously suggested.
- Albini, Angelo,Pasani, Elisa,Buchardt, Ole
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- Reactivity of cyclopalladated compounds derived from biphenyl-2-ylamine towards carbon monoxide, tbutyl isocyanide and alkynes
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The reactivity of the dimeric cyclopalladated compounds derived from biphenyl-2-ylamine (μ-X)2[κ2-N2′,C1-1-Pd-2-{(2′-NH2C6H4)C6H4}]2 [X = OAc (1), X = Cl (2)] towards unsaturated organic molecules is reported. Compound 1 reacted with carbon monoxide and tbutyl isocyanide producing phenanthridin-6(5H)-one and N-tert-butylphenanthridin-6-amine in 63% and 88% yield, respectively. Compound 2 reacted separately with diphenylacetylene and 3-hexyne, affording the mononuclear organopalladium compounds [κ2-N2″,C1-η2-C2,C3- 1-Pd{(R-C{double bond, long}C-R)2-2′-(2″-NH2C6H4)C6H4}Cl] [R = Ph (5), R = Et (6)] in 50-60% yield, which derived from the insertion of two alkyne molecules into the C-Pd σ bonds of 2. The crystal structure of compounds 5 and 6 has been determined. Compound 5 crystallized in the monoclinic space group P21/n with a = 13.3290(10) A?, b = 10.6610(10) A? and c = 22.3930(10) A? and β = 100.2690(10)°. Compound 6 crystallized in the triclinic space group P over(1, ?) with a = 7.271(7) A?, b = 10.038(3) A? and c = 16.012(5) A?, and α = 106.79(3)°, β = 96.25(4)° and γ = 99.62(4)°. The crystal structures of 5 and 6 have short intermolecular Pd-Cl?H-N-Pd non-conventional hydrogen bonds, which associated the molecules in chains in the first case and in dimers in the second.
- Albert, Joan,D'Andrea, Luci?a,Granell, Jaume,Zafrilla, Javier,Font-Bardia, Mercè,Solans, Xavier
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- Synthesis of 5(6H)-phenanthridones using Diels-Alder reaction of 3-nitro-2(1H)-quinolones acting as dienophiles
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Diels-Alder reactions of 3-nitro-2(1H)-quinolones with 1,3-butadiene derivatives were carried out to give the phenanthridone derivatives under both atmospheric and high pressure conditions. Furthermore, the reactivity of 3-substituted 2(1H)-quinolones acting as a dienophile with 2,3-dimethyl-1,3- butadiene was examined using molecular orbital (MO) calculation.
- Fujita, Reiko,Yoshisuji, Toshiteru,Wakayanagi, Sota,Wakamatsu, Hideaki,Matsuzaki, Hisao
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- Electrochemical Formation of N-Acyloxy Amidyl Radicals and Their Application: Regioselective Intramolecular Amination of sp2 and sp3 C-H Bonds
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Electrochemical generation of N-acyloxy amidyl radicals via an inner-sphere electron-transfer process is described for the first time. With NaBr as the catalyst and electrolyte, the in situ generated amidyl radicals undergo intramolecular C(sp2/sp3)-H aminations to give lactams with unprecedented regio- and chemoselectivities. Moreover, the synthetic utility of current method is demonstrated by the synthesis of PJ34 and Phenaglaydon.
- Zhang, Sheng,Li, Lijun,Xue, Mengyu,Zhang, Ruike,Xu, Kun,Zeng, Chengchu
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- Annulation of Benzamides with Arynes Using Palladium with Photoredox Dual Catalysis
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Efficient annulation of benzamides with arynes using palladium and photoredox dual catalysis under an oxygen atmosphere is disclosed, which circumvents the use of external toxic metal oxidant and proceeds readily via aryne insertion at room temperature to construct the phenanthridinone backbone.
- Zhao, Jie,Li, Hongji,Li, Pinhua,Wang, Lei
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- Dual Mechanisms for the Fragmentation of 1-Benzoylbenzotriazole upon Electron Impact
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The electron impact induced fragmentation of 1-benzoylbenzotriazole has been studied by 13C labelling experiments.It has been found that the loss of CO from the 2>+. ions proceeds by two routes; about 78percent of the ions decompose via the molecular ions of the corresponding thermal fragmentation product, 2-phenylbenzoxazole, and 22percent via those of the corresponding photochemical fragmentation product, 6-phenanthridone.
- Yamada, Shuzo,Kamiyama, Yojiro,Ohashi, Mamoru
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- Synthesis of Phenanthridinones by Palladium-Catalyzed Cyclization of N -Aryl-2-aminopyridines with 2-Iodobenzoic Acids in Water
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The first Pd-catalyzed cyclization of N -aryl-2-aminopyridines with 2-iodobenzoic acids for the synthesis of phenanthridinones through C-H bond activation under very low catalyst loadings (down to 0.1 molpercent Pd) in water is reported. This protocol features a broad substrate scope and provides easy efficient access to various phenanthridinones.
- Ding, Xiaojuan,Duan, Jindian,Guo, Kai,Mao, Yiyang,Rong, Binsen,Zhang, Lei,Zhu, Ning
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- Palladium/Silver Synergistic Catalysis in Direct Aerobic Carbonylation of C(sp2)H Bonds Using DMF as a Carbon Source: Synthesis of Pyrido-Fused Quinazolinones and Phenanthridinones
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An unprecedented Pd/Ag synergistic catalysis in the direct carbonylation of C(sp2)-H bonds utilizing DMF as the carbon source under oxygen is described and demonstrated in the synthesis of pyrido-fused quinazolinone and phenanthridinone scaffolds. Control experiments indicated that the C of the carbonyl group is derived from the methyl group of DMF and O originates from oxygen as in the case of Ge's recent work. This transformation offers an alternative avenue for CO-free carbonylations.
- Nageswar Rao,Rasheed, Sk.,Das, Parthasarathi
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- Novel Diels-Alder reaction of 4-nitro-1(2H)-isoquinolones
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A novel Diels-Alder (DA) reaction with 4-nitro-1(2H)-isoquinolones acting as the dienophile afforded 5(6H)-phenanthridone derivatives. The DA reaction of 4-nitro-1(2H)-isoquinolone with 1-methoxy-1,3-butadiene gave biologically active 5(6H)-phenanthridone possessing in a high yield. Regioselectivity of 4-nitro-1(2H)-isoquinolones with 1-methoxy-3-silyloxy-1,3-butadiene was calculated using molecular orbital (MO) calculations.
- Fujita, Reiko,Wakayanagi, Sota,Wakamatsu, Hideaki,Matsuzaki, Hisao
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- Intermolecular amidation of unactivated sp2 and sp3 C-H bonds via palladium-catalyzed cascade C-H activation/nitrene insertion
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This communication describes the Pd(OAc)2-catalyzed intermolecular amidation reactions of unactivated sp2 and sp3 C-H bonds using primary amides and potassium persulfate. The substrates containing a pendent oxime or pyridine group were amidated with excellent chemo- and regioselectivities. It is noteworthy that reactive C-X bonds were well-tolerated and a variety of primary amides can be effective nucleophiles for the Pd-catalyzed C-H amidation reactions. For the reaction of unactivated sp3 C-H bonds, β-amidation of 1° sp3 C-H bonds versus 2° C-H bonds is preferred. The catalytic reaction is initiated by chelation-assisted cyclopalladation involving C-H bond activation. Preliminary mechanistic study suggested that the persulfate oxidation of primary amides should generate reactive nitrene species, which then reacted with the cyclopalladated complex. Copyright
- Thu, Hung-Yat,Yu, Wing-Yiu,Che, Chi-Ming
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- A Pd-catalyzed, boron ester-mediated, reductive cross-coupling of two aryl halides to synthesize tricyclic biaryls
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Tricyclic biaryls are important scaffold structures in many natural products and lead compounds in drug discovery. The formation of a biaryl unit is often the key step for the synthesis of tricyclic biaryls. Despite significant progress toward the synthesis of biaryl compounds in recent years, the direct cross-coupling of two different aryl halides is still challenging and robust methods are lacking. Herein we report a direct cross-coupling of two different aryl halides in the presence of a palladium catalyst and boron ester, which provides a new and useful complementary method to synthesize tricyclic biaryls.
- Chen, Zhilong,Wang, Xiaodong
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- Palladium-Catalyzed C-H Bond Activation by Using Iminoquinone as a Directing Group and an Internal Oxidant or a Co-oxidant: Production of Dihydrophenanthridines, Phenanthridines, and Carbazoles
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A palladium-catalyzed C-H bond activation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C-H activation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence: C-H bond activation, coordination and insertion of activated olefins, β-hydride elimination, H-shift, insertion, and protonation or β-hydride elimination. In addition, carbazoles can be prepared efficiently by using this method without the addition of external oxidants.
- Raju, Selvam,Annamalai, Pratheepkumar,Chen, Pei-Ling,Liu, Yi-Hung,Chuang, Shih-Ching
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- Continuous flow photochemistry as an enabling synthetic technology: Synthesis of substituted-6(5: H)-phenanthridinones for use as poly(ADP-ribose) polymerase inhibitors
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Methods utilizing continuous flow photochemistry, an enabling synthetic technology, have been developed for the generation of phenanthridinones via an intramolecular photochemical cyclization of 2-chlorobenzamides for the purposes of generating poly(ADP-ribose) polymerase inhibitors. Herein we report 16 examples of a single-step flow photocyclization which produces substituted phenanthridinones in yields up to 99%, while a two-step method leads directly to phenanthridinones from 2-chlorobenzoyl chlorides and anilines via a novel continuous flow amidation/photocyclization protocol. Overall, the flow photocyclization reactions typically progress in good to excellent yields, and in a superior fashion to analogous batch methods, greatly enabling the drug discovery process.
- Fang,Tranmer
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- Novel amide and sulphonamide derivatives of 6-(piperazin-1-yl)phenanthridine as potent Mycobacterium tuberculosis H37Rv inhibitors
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A series of thirty three novel 6-(piperazin-1-yl)phenanthridine amide and sulphonamide analogues were synthesized, characterized and screened for their in vitro antimycobacterial activity against Mycobacterium tuberculosis (MTB) H37Rv strain. These compounds exhibited minimum inhibitory concentration (MIC) between >56 and 50 μg/mL. Out of these derivatives, few compounds 6l, 6r, 7b, 7f, 7g and 7k exhibited moderate activity (MIC = 6.25 μg/mL) and compounds 6b, 6e, 6k, 6n, 7h, 7i and 7n displayed good activity (MIC = 3.13 μg/mL), whereas compounds 6m, 6s and 7d exhibited excellent anti-tubercular activity (MIC = 1.56 μg/mL). In addition, MTT assay was accomplished on the active analogues of the series against mouse macrophage (RAW 264.7) cells to evaluate the toxicity profile of the newly synthesized compounds and selectivity index of the compounds was determined. Additionally, compounds 6b and 7d were docked to the ATPase domain of M. tuberculosis GyrB protein to know the interaction profile and structures of compounds 6b and 7d were further substantiated through single crystal XRD.
- Naidu, Kalaga Mahalakshmi,Nagesh, Hunsur Nagendra,Singh, Manjeet,Sriram, Dharmarajan,Yogeeswari, Perumal,Sekhar, Kondapalli Venkata Gowri Chandra
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- A convenient one-pot access to phenanthridinones via Suzuki-Miyaura cross-coupling reaction
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A convenient one-step access to biologically important phenanthridinones 1 has been realized based upon Suzuki-Miyaura cross-coupling reaction. Reactions of 2-aminophenylboronic acid 2 with 2-halobenzoate 3 took place smoothly to afford substituted phenanthridinones 1 in excellent yields in the presence of palladium(II) acetate and 2-dicyclohexylphosphino-2′,6′- dimethoxybiphenyl (SPhos) as pre-catalysts. A natural product phenaglydon 1b was synthesized in one-pot manner from readily available starting materials in 95% yield.
- Tanimoto, Kouichi,Nakagawa, Naomichi,Takeda, Kazutaka,Kirihata, Mitsunori,Tanimori, Shinji
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- Synthesis of Phenanthridin-6(5 H)-ones via Copper-Catalyzed Cyclization of 2-Phenylbenzamides
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Synthesis of phenanthridin-6(5H)-ones was achieved via copper-catalyzed cyclization of 2-phenylbenzamides using air as the oxidant and KOt-Bu as the base. It was discovered that, besides Ph3P, other ligands such as 1,10-phenanthroline, TMEDA as well as l-proline could also be used as the ligand to effect the transformation. Georg Thieme Verlag Stuttgart. New York.
- Gui, Qingwen,Yang, Zhiyong,Chen, Xiang,Liu, Jidan,Tan, Ze,Guo, Ruqing,Yu, Wei
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- Design, synthesis and evaluation of 6-(4-((substituted-1H-1,2,3-triazol-4- yl)methyl)piperazin-1-yl)phenanthridine analogues as antimycobacterial agents
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Focus in this Letter is made to design and synthesize a series of nineteen new 6-(4-((substituted-1H-1,2,3-triazol-4-yl)methyl)piperazin-1-yl) phenanthridine analogues employing click chemistry and evaluated for their anti-tubercular activity against Mycobacterium tuberculosis H37Rv. Among the tested compounds, 7f and 7j exhibited good activity (MIC = 3.125 μg/mL), while 8a displayed excellent activity (MIC = 1.56 μg/mL) against the growth of M. tuberculosis H37Rv. In addition, 7f, 7j and 8a compounds were subjected to cytotoxic studies against mouse macrophage (RAW264.7) cell lines and the selectivity index values are >15 indicating suitability of compounds for further drug development.
- Nagesh, Hunsur Nagendra,Naidu, Kalaga Mahalakshmi,Rao, Damarla Harika,Sridevi, Jonnalagadda Padma,Sriram, Dharmarajan,Yogeeswari, Perumal,Chandra Sekhar, Kondapalli Venkata Gowri
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- Schmidt reaction of ketones in dme solution in a continuous-flow microreactor
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The Schmidt reaction, the treatment with hydroazoic acid in the presence of a strong acid, converts ketones to amides directly and has been broadly applied in organic synthesis. In this communication, the Schmidt reaction of ketones was carried out in DME solution in a continuous-flow microreactor and gave the amide products. The enclosed small-volume feature of the microreactor made this reaction safe, fast, and cost-effective.
- Chen, Yuesu,Liu, Binjie,Liu, Xiaofeng,Yang, Yongtai,Ling, Yun,Jia, Yu
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- Lewis Acid Catalysed Cyclisation and Halogen Exchange Reactions of 1,1'-Biphenyl-2-yl Isocyanide Dihalides
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1,1'-Biphenyl-2-yl isocyanide dichloride and dibromide undergo unprecedented intramolecular Friedel-Crafts type cyclisation reactions catalysed by various Lewis acids affording useful synthetic methods for otherwise difficult to access 6-chloro- and 6-bromo-phenanthridines; nucleophilic displacement reactions of the latter and halogen exchange reactions of 1,1'-biphenyl-2-yl isocyanide dichloride and dibromide are also described.
- Currie, Kevin S.,Tennant, George
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- Photocyclisation of 2-Halogenobenzanilides: An Extreme Example of Halogen Atom, Solvent, and Isomer Dependence. A Practical Phenanthridine Synthesis
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2-Chlorobenzanilides photocyclise to phenanthridones by assisted homolysis of the carbon-chlorine bond.
- Grimshaw, James,Silva, A. Prasanna de
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- One-pot formation of C-C and C-N bonds through palladium-catalyzed dual C-H activation: Synthesis of phenanthridinones
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Two cycles in one pot! The synthesis of biologically important phenanthridinones has been achieved by the one-pot formation of C-C and C-N bonds through a palladium-catalyzed dual C-H activation, which involves four bond ruptures and two bond formations (see scheme). The conversion of phenanthridinones into natural product like derivatives further demonstrates the utility of this synthetic achievement.
- Wang, Guan-Wu,Yuan, Ting-Ting,Li, Dan-Dan
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- Rhodium(III)-catalyzed ortho-arylation of anilides with aryl halides
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An efficient o-arylation of pivalamides by aryl iodides via rhodium(III)-catalyzed C-H activation is demonstrated for the first time. Further, the biaryl products can be converted effectively into biologically active phenanthridine and phenanthridinone derivative.
- Haridharan, Radhakrishnan,Muralirajan, Krishnamoorthy,Cheng, Chien-Hong
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- Photoinduced Annulation of N-Phenylbenzamides for the Synthesis of Phenanthridin-6(5H)-Ones
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A general concise method for the synthesis phenanthridin-6(5H)-ones via photoinduced intramolecular annulation of N-phenylbenzamides was developed. Under argon atmosphere and room temperature, phenanthridin-6(5H)-ones were obtained via irradiation N-phenylbenzamides with a 280 nm UV lamp in the presence of methanesulfonic acid in toluene. The mechanism is illustrated and believed to proceed in the order of amides tautomerization, 6π-electric cyclization, [1,5]-H shift, amide-imidine tautomerization, keto-enol tautomerism and evolution hydrogen. (Figure presented.).
- Wang, Nana,Wang, Ding,He, Yun,Xi, Jin,Wang, Tao,Liang, Yong,Zhang, Zunting
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p. 1150 - 1155
(2022/02/25)
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- Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
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A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
- Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
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p. 208 - 218
(2021/12/29)
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- Synthesis of Aza[ n]phenacenes (n = 4-6) via Photocyclodehydrochlorination of 2-Chloro- N-aryl-1-naphthamides
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A novel methodology for the synthesis of aza[n]phenacenes was successfully developed utilizing photocyclodehydrochlorination reaction of 2-chloro-N-aryl-1-naphthamides. In these key intermediates, the factors influencing the photoreaction were studied. The target aza[n]phenacenes were obtained by triflation or chlorination from prepared phenanthridinones, followed by hydrogenation. The introduction of a nitrogen atom into a phenacene skeleton induced changes in the physicochemical properties. The important properties of prepared aza[n]phenacenes (n = 4-6) were studied experimentally and by density functional theory calculations and were compared to those of their carbo analogues. Furthermore, some important features of the crystalline aza[n]phenacenes were investigated, including intermolecular interaction in the crystal lattice and the increased solubility or decreased melting points.
- Váňa, Lubomír,Jakubec, Martin,Sykora, Jan,Císa?ová, Ivana,Storch, Jan,Církva, Vladimír
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p. 13252 - 13264
(2021/10/01)
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- Novel phenanthridine amide analogs as potential anti-leishmanial agents: In vitro and in silico insights
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In the current work, sixteen novel amide derivatives of phenanthridine were designed and synthesized using 9-fluorenone, 4-Methoxy benzyl amine, and alkyl/aryl acids. The characterization of the title compounds was performed using LCMS, elemental analysis, 1HNMR, 13CNMR and single crystal XRD pattern was also developed for compounds A8. All the final analogs were screened in vitro for anti-leishmanial activity against promastigote form of L. infantum strain. Among the tested analogs, four compounds (A-06, A-11, A-12, and A-15) exhibited significant anti-leishmanial activity with EC50 value ranges from 8.9 to 21.96 μM against amastigote forms of tested L. infantum strain with SI ranges of 1.0 to 4.3. From the activity results it was found that A-11 was the most active compound in both promastigote and amastigotes forms with EC50 values 8.53 and 8.90 μM respectively. In-silico ADME prediction studies depicted that the titled compounds obeyed Lipinski's rule of five as that of the approved marketed drugs. The predicted in-silico toxicity profile also confirmed that the tested compounds were non-toxic. Finally, molecular docking and molecular dynamics study was also performed for significantly active compound (A-11) in order to study it's putative binding pattern at the active site of the selected leishmanial trypanothione reductase target as well as to understand the stability pattern of target-ligand complex for 100 ns. Single crystal XRD of compound A-08 revealed that the compound crystallizes in monoclinic C2/c space group and showed interesting packing arrangements.
- Aggarwal, Himanshu,Bala?a-Fouce, Rafael,Chandra Sekhar, Kondapalli Venkata Gowri,Karan Kumar, Banoth,Melcón-Fernandez, Estela,Murugesan, Sankaranarayanan,Nandikolla, Adinarayana,Pérez-Pertejo, Yolanda,Srinivasarao, Singireddi
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supporting information
(2021/11/01)
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- Tetrabutylammonium Iodide (TBAI) Catalyzed Electrochemical C-H Bond Activation of 2-Arylated N -Methoxyamides for the Synthesis of Phenanthridinones
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An electrochemical method for the synthesis of phenanthridinones through constant-potential electrolysis (CPE) mediated by Bu 4 NI (TBAI) is reported. The protocol is metal and oxidant free, and proceeds with 100% current efficiency. TBAI plays a dual role as both a redox catalyst and a supporting electrolyte. The intramolecular C-H activation proceeds under mild reaction conditions and with a short reaction time through electrochemically generated amidyl radicals. The reaction has been scaled up to a gram level, showing its practicability, and the synthetic utility and applicability of the protocol have been demonstrated by a direct one-step synthesis of the bioactive compound phenaglaydon.
- Subramanian, Kripa,Yedage, Subhash L.,Sethi, Kashish,Bhanage, Bhalchandra M.
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p. 999 - 1003
(2021/04/19)
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- Method for efficiently preparing phenanthridone and derivatives thereof without metal participation
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The invention discloses a method for efficiently preparing phenanthridone and derivatives without metal participation. The preparation method comprises the step of carrying out cyclization reaction on a compound shown in a formula II under the catalysis of methyl trifluoromethanesulfonate to obtain a phenanthridone compound shown in a formula I. According to the invention, the phenanthridone compound is generated in one step by catalyzing the cyclization reaction of the o-aryl phenyl isocyanate through the trifluoromethanesulfonate, and a practical method is provided for synthesizing the substituted phenanthridone derivative with biological activity. The method is free of using any metal reagent, environmentally friendly, easy to operate, high in yield and simple and convenient in post-treatment. In addition, the substrate obtained by the method is high in designability, a compound with the required structurecan be designed and synthesized according to actual needs, and the practicability is high.
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Paragraph 0028-0034
(2021/06/26)
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- Organocatalyst in Direct C(sp2)-H Arylation of Unactivated Arenes: [1-(2-Hydroxyethyl)-piperazine]-Catalyzed Inter-/Intra-molecular C-H Bond Activation
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This article describes the identification of 1-(2-hydroxyethyl)-piperazine as a new, cost-effective, highly efficient organocatalyst, which promotes both inter- A nd intra-molecular direct C(sp2)-H arylations of unactivated arenes in the presence of potassium tert-butoxide. While the inter-molecular C-H arylation of unactivated benzenes with aryl halides (Ar-X; X = I, Br, Cl) toward biaryl syntheses underwent smoothly in the presence of only 10 mol percent organocatalyst, the intra-molecular C-H arylation catalytic system composed of 40 mol percent each of the catalyst and the additive (4-dimethylaminopyridine (DMAP)). The novel catalyst was also able to perform both inter- A nd intra-molecular direct arylations simultaneously in a single pot. The mechanistic studies confirmed the involvement of aryl radical anions and proceeded via a single-electron-transfer (SET) mechanism. The large substrate scope, high functional group tolerance, competition experiments, gram-scale synthesis, and kinetic studies further highlight the importance and versatile nature of the methodology as well as the compatibility of the new catalyst. To the best of our knowledge, this is the first report on any organocatalyst that reported detailed investigations of both inter- A nd intra-molecular direct C(sp2)-H arylations of unactivated arenes in a single representation.
- Yadav, Lalit,Tiwari, Mohit K.,Shyamlal, Bharti Rajesh Kumar,Chaudhary, Sandeep
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p. 8121 - 8141
(2020/07/16)
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- Method for synthesizing phenanthridone compound
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The invention discloses a method for synthesizing a phenanthridone compound. The method comprises the following steps of: adding an N-hydrocarbon acyloxy amide compound, a transition metal catalyst, acocatalyst and an organic solvent into a reaction container in a nitrogen atmosphere, reacting at 0-40 DEG C for 1-12 hours, and separating and purifying a reaction product to obtain the phenanthridone compound. The method for synthesizing the phenanthridone compound, disclosed by the invention, has the following advantages that: 1, the reaction conditions are mild; 2, less catalyst is used; 3, aligand and an acid-base additive are not needed, the substrate application range is wide, and the method can be compatible with various functional groups such as halogen. 4, the operation is simple;5, the product selectivity is high.
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Paragraph 0047-0061
(2020/12/15)
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- Switching from biaryl formation to amidation with convoluted polymeric nickel catalysis
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A stable, reusable, and insoluble poly(4-vinyl-pyridine) nickel catalyst (P4VP-NiCl2) was prepared through the molecular convolution of poly(4-vinylpyridine) (P4VP) and nickel chloride. We proposed a coordination structure of the Ni center in the precatalyst based on elemental analysis and Ni K-edge XANES, and we confirmed that it is consistent with Ni K-edge EXAFS. The Suzuki?Miyaura-type coupling of aryl halides and arylboronic esters proceeded using P4VP-NiCl2 (0.1 mol % Ni) to give the corresponding biaryl compounds in up to 94% yield. Surprisingly, when the same reaction of aryl halides and arylboronic acid/ester was carried out in the presence of amides, the amidation proceeded predominantly to give the corresponding arylamides in up to 99% yield. In contrast, the reaction of aryl halides and amides in the absence of arylboronic acid/ester did not proceed. P4VP-NiCl2 successfully catalyzed the lactamization for preparing phenanthridinone. P4VP-NiCl2 was reused five times without significant loss of catalytic activity. Pharmaceuticals, natural products, and biologically active compounds were synthesized efficiently using P4VPNiCl2 catalysis. Nickel contamination in the prepared pharmaceutical compounds was not detected by ICP-MS analysis. The reaction was scaled to multigrams without any loss of chemical yield. Mechanistic studies for both Suzuki?Miyaura and amidation were performed.
- Sen, Abhijit,Dhital, Raghu N.,Sato, Takuma,Ohno, Aya,Yamada, Yoichi M.A.
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p. 14410 - 14418
(2020/12/21)
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- Cu(0)/Selectfluor system-catalyzed intramolecular Csp2-H/Csp2-H cross-dehydrogenative coupling (CDC)
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A Cu(0)/Selectfluor system-catalyzed intramolecular Csp2-H/Csp2-H bond cross-dehydrogenative coupling of 2-aryloxybenzaldehydes is described. A variety of substituted xanthone derivatives are synthesized in moderate to excellent yields. Reaction can also be extended to the synthesis of 9H-thioxanthen-9-one 10,10-dioxide and phenanthridin-6(5H)-ones, respectively.
- Bao, Hanyang,Hu, Xiaojun,Zhang, Jian,Liu, Yunkui
-
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- Application of phenanthridine compounds to pesticides
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The invention relates to an application of phenanthridine compounds shown in general formula (1) to pesticides. Part of the compounds is used as a plant virus agent and can well inhibit the tobacco mosaic virus; when used as a bactericide, the compounds have good inhibitory activity on tomato early blight, wheat scab, potato late blight, phytophthora capsici, rape sclerotinia rot, cucumber gray mould, rice sheath blight disease, cucumber fusarium wilt, cercospora brown spot of peanut, apple ring rot, wheat sharp eyespot, corn southern leaf blight, watermelon anthracnose and rice bakanae disease; when used as an insecticide, the compounds have poisonous activity on armyworms, mosquito larvae, cotton bollworms, ostrinia nubilalis, aphids, adult mites and plutella xylostella. In the formula,when molecular nitrogen is not imine, R can represent hydrogen atoms, methyl, acetyl and benzoyl; R and R represent a hydrogen atom or an oxygen atom simultaneously; R and R can represent hydroxyl, acetoxyl, methoxyl, methyleneoxy, a fluorine atom and the hydrogen atom; R is a bromine atom or the fluorine atom; R is the hydrogen atom or vinyl. When nitrogen is imine, R doesnot represent any group; one of R and R does not represent any group, and the other can represent the hydrogen atom, methoxyl, ethyoxyl, benzyloxy and a chlorine atom; R, R, R and Rrepresent the hydrogen atom.
- -
-
Paragraph 0020; 0029; 0031
(2019/10/01)
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- Rhodium(I)-Catalyzed Aryl C-H Carboxylation of 2-Arylanilines with CO2
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An unprecedented Rh(I)-catalyzed, amino-group-assisted C-H carboxylation of 2-arylanilines with CO2 under redox-neutral conditions has been developed. This reaction was promoted by a phosphine ligand with t-BuOK as the base and did not require the use of additional strong organometallic reagent. It enabled an efficient direct conversion of a broad range of 2-(hetero)arylanilines including electron-deficient heteroarenes to various phenanthridinones. Possible intermediates of the reaction were also evaluated in the preliminary mechanistic studies.
- Gao, Yuzhen,Cai, Zhihua,Li, Shangda,Li, Gang
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p. 3663 - 3669
(2019/05/17)
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- Iodine-mediated aryl transfer reaction from arylhydrazine hydrochlorides to nitriles
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An iodine-promoted, metal-, base-, and solvent-free cross-coupling reaction was developed for the synthesis of various useful secondary amides via an aryl N-addition reaction of aryl groups to cyano groups. This aryl transfer reaction proceeds with arylhydrazine hydrochlorides serving as the aryl donors. A labelling experiment shows that the N atom in the product comes from the cyano group of the nitriles, which are low in cost. A plausible radical-driven mechanism is also proposed.
- Zhang, Zhiguo,Li, Xiang,Li, Yinghua,Guo, Yan,Zhao, Xunan,Yan, Yan,Sun, Kai,Zhang, Guisheng
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supporting information
p. 3628 - 3635
(2019/05/29)
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- Palladium-catalyzed intramolecular C-H arylation of 2-halo-: N -Boc- N -arylbenzamides for the synthesis of N-H phenanthridinones
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A palladium catalyzed synthesis of N-H phenanthridinones was developed via C-H arylation. The protocol gives phenanthridinones regioselectively by one-pot reaction without deprotection. It exhibits broad substrate scope and affords targets in up to 95% yields. Importantly, it could be applied for the less reactive o-chlorobenzamides.
- Hu, Quan-Fang,Gao, Tian-Tao,Shi, Yao-Jie,Lei, Qian,Yu, Luo-Ting
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p. 13879 - 13890
(2018/04/25)
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- Preparation method of phenanthridone compounds
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The invention provides a preparation method of phenanthridone compounds. The preparation method comprises the steps: dissolving a raw material, namely an N-o-aryl-formylaniline derivative I as shown in the formula I, into an organic solvent by taking a copper salt as a catalyst and a fluorine reagent as an oxidant, carrying out a reaction in a pressure-resistant sealed tube at 50-90 DEG C for 12-30h, and separating and purifying the obtained reaction liquid to prepare the phenanthridone compound as shown in the formula I. The synthesis method provided by the invention is simple in reaction step, good in substrate adaptability, high in atom economy, free of using expensive and poisonous catalysts or ligands in a reaction process, safe and environment-friendly, and all substituent groups canbe cyclized. The preparation method can be used for cyclizing oxidized C-H/C-H and is a novel method for synthesizing various phenanthridone compounds containing substituent groups.
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-
Paragraph 0027-0029; 0031-0033; 0034-0036; 0038-0040
(2018/04/02)
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- Carbene-catalyzed aerobic oxidation of isoquinolinium salts: Efficient synthesis of isoquinolinones
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A mild and environmentally friendly carbene-catalyzed aerobic oxidation of isoquinolinium salts was successfully realized. Accordingly, a diverse set of isoquinolinones and phenanthridinones was efficiently prepared in good to excellent yields. The mechanistic study indicates that the formation of an aza-Breslow intermediate is the crucial step in this transformation. This reaction features ambient air as the sole oxidant and oxygen source, a broad substrate scope, and excellent functional-group tolerance and proceeds under mild reaction conditions. Furthermore, a highly efficient synthesis of bioactive molecules and natural products including N-methylcrinasiadine, N-isopentylcrinasiadine, N-phenethylcrinasiadine, isoindolo[2,1-b]isoquinolin-5(7H)-one, PJ-34, rac-Gusanlung D, rosettacin, 8-oxopseudopalmatine and ilicifoline B was accomplished.
- Wang, Guanjie,Hu, Wanyao,Hu, Zhouli,Zhang, Yuxia,Yao, Wei,Li, Lin,Fu, Zhenqian,Huang, Wei
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p. 3302 - 3307
(2018/07/29)
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- Metal-Oxidant-Free Cobalt-Catalyzed C(sp2)-H Carbonylation of ortho-Arylanilines: An Approach toward Free (NH)-Phenanthridinones
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A traceless directing group assisted Co-catalyzed C(sp2)-H carbonylation of ortho-arylanilines for the synthesis of free (NH)-phenanthridinones in metal-based-oxidant-free fashion was accomplished. This protocol employs diisopropyl azodicarboxylate as the CO source and oxygen as the sole oxidant, and provides good yields with various functional tolerance. The methodology has been applied for the total synthesis of PARP inhibitor PJ-34. Furthermore, the kinetic isotopic effect experiments reveal the C-H bond cleavage probably occurred in the rate-determining step.
- Ling, Fei,Zhang, Chaowei,Ai, Chongren,Lv, Yaping,Zhong, Weihui
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p. 5698 - 5706
(2018/05/23)
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- Palladium-Catalyzed β-C?H Arylation of Ketones Using Amino Amide as a Transient Directing Group: Applications to Synthesis of Phenanthridinone Alkaloids
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The direct arylation of aromatic and aliphatic ketones was carried out via palladium-catalyzed inert C?H bond functionalization with 2-amino-N-isopropyl-acetamide as a new catalytic transient directing group. The reaction showed excellent functional group compatibility and site selectivity. We demonstrated that α-amino amide forming N,N-bidentate coordination with Pd catalyst is more favorable for the β-arylation of ketones than α-amino acid forming N,O-bidentate coordination with Pd catalyst under relatively mild conditions. This elegant approach provides straightforward access to important structural motifs in organic and medicinal chemistry and is demonstrated here in the efficient synthesis of phenanthridinone alkaloids. (Figure presented.).
- Wang, Junliang,Dong, Cong,Wu, Liangfei,Xu, Mingkai,Lin, Jun,Wei, Kun
-
supporting information
p. 3709 - 3715
(2018/09/14)
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- Environment-friendly synthetic method of 6(5H)-phenanthridine derivative
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The invention discloses an environment-friendly synthetic method of a 6(5H)-phenanthridine derivative. The method specifically comprises the step of carrying out catalyzed oxidation by virtue of metalcobalt, so as to realize the high-selectivity and high-yield preparation of the 6(5H)-phenanthridine derivative, wherein N-([1,1'-biphenyl]-2-yl)pyridine amide is take as the raw material, azodiformate is taken as a carbonyl source for replacing poisonous and harmful carbon monoxide, and oxygen is taken as an oxidant. The environment-friendly synthetic method has the characteristics that the rawmaterial is easily available, the operation is simple and convenient, the chemical selectivity and the regional selectivity are high, and the like; and the environment-friendly synthetic method has relatively high implement values and social and economic values.
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-
Paragraph 0015-0021
(2018/11/22)
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- Iridium(III)-Catalyzed Regiocontrolled Direct Amidation of Isoquinolones and Pyridones
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Iridium(III)-catalyzed highly regiocontrolled C3/C8 amidation of isoquinolones and C6 amidation of 2-pyridones has been successfully accomplished with various azides. The optimized method is operationally simple with a broad substrate scope. The protocol has been found to be scalable. (Figure presented.).
- Das, Debapratim,Samanta, Rajarshi
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p. 379 - 384
(2017/12/26)
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- Phenanthridine ketone compounds
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The invention relates to a synthetic method of phenanthridine ketone compounds, which comprises the steps of taking and adding o-haloaromaticamine and aryl methyl alcohol (or arylamine and o-haloaryl methyl alcohol) as well as a ruthenium catalyst, palladium chloride, azacyclo-imidazolium salt and alkali into an organic solvent, heating at the protection of N2 gas, and generating the phenanthridine ketone compounds by one step through a hydrogen transfer reaction and a carbon-hydrogen bond activation reaction, so as to provide a practical method for synthesizing substituted phenanthridine ketone derivatives with biological activity; the method has the advantages that the operation is simple, and a reaction substrate is cheap, wide in range and high in yield, and has important application value.
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-
Paragraph 0032-0033
(2017/07/01)
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- Photoreductive Removal of O-Benzyl Groups from Oxyarene N-Heterocycles Assisted by O-Pyridine-pyridone Tautomerism
-
Facile photoreductive protocols have been developed to remove benzyl O-protective groups from oxyarene N-heterocycles at positions capable for 2-/4-O-pyridine-2-/4-pyridone tautomerism. Blue light irradiation, a [Ru] or [Ir] photocatalyst, and ascorbic acid in a water-acetonitrile solution debenzylates a variety of aryl N-heterocycles cleanly and selectively. Ascorbic acid has two functions in the reaction. On the one hand, it protonates the N-heterocycles that reduces their reduction potentials notably and on the other hand it acts as a sacrificial reductant. Reduction potentials and free energy barriers calculated at the CPCM-B3LYP/6-31+G? level can predict the reactivities of the studied substrates.
- Todorov, Aleksandar R.,Wirtanen, Tom,Helaja, Juho
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p. 13756 - 13767
(2017/12/26)
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- Palladium-Catalyzed C-H Activation and Cyclization of Anilides with 2-Iodoacetates and 2-Iodobenzoates: An Efficient Method toward Oxindoles and Phenanthridones
-
A concise approach to the synthesis of oxindoles and phenanthridones from anilides is described. In the presence of catalytic amount of Pd(OAc)2, 2-iodoacetates and 2-iodobenzoates can be used to functionalize ortho C-H bond of anilides, which subsequently undergo intramolecular cyclization to give the products. A possible reaction mechanism that involves a PdII/PdIV catalytic cycle is proposed with the support of detailed mechanistic studies.
- Gandeepan, Parthasarathy,Rajamalli, Pachaiyappan,Cheng, Chien-Hong
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p. 1872 - 1879
(2016/06/15)
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- Transition-metal-free synthesis of phenanthridinones from biaryl-2-oxamic acid under radical conditions
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Na2S2O8-promoted decarboxylative cyclization of biaryl-2-oxamic acid for phenanthridinones has been developed. This work illustrates the first example of intramolecular decarboxylative amidation of unactivated arene under transition-metal-free conditions. Additionally, this approach provides an efficient and economical method to access biologically interesting phenanthridinones, an important structure motif in many natural products. (Chemical Equation Presented).
- Yuan, Ming,Chen, Li,Wang, Junwei,Chen, Shenjie,Wang, Kongchao,Xue, Yongbo,Yao, Guangmin,Luo, Zengwei,Zhang, Yonghui
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p. 346 - 349
(2015/02/19)
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- Synthesis and evaluation of anti-tubercular activity of 6-(4-substitutedpiperazin-1-yl) phenanthridine analogues
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A series of seventeen new 6-(4-substitutedpiperazin-1-yl)phenanthridine derivatives were designed, synthesized, and evaluated for their anti-tubercular activity against Mycobacterium tuberculosis H37Rv by Microplate Alamar Blue Assay and most active compounds were tested for cytotoxicity studies against mouse macrophage cell lines (RAW264.7). Among the tested compounds, ten compounds exhibited significant activity against the growth of M.tuberculosis (MIC ranging from 1.56 to 6.25 μg/mL). In particular, compounds 5e, 5j and 5k displayed excellent activity against the growth of M.tuberculosis (MIC 1.56 μg/mL). The selectivity index values were found to be >25, indicating compounds likeliness in drug development for tuberculosis. The structure of 5k is substantiated by X-ray crystallographic study. Structure-activity correlation indicates the importance of substituent at 4th position of piperazinyl phenanthridine ring.
- Nagesh, Hunsur Nagendra,Suresh, Narva,Mahalakshmi Naidu, Kalaga,Arun, Boyineni,Padma Sridevi, Jonnalagadda,Sriram, Dharmarajan,Yogeeswari, Perumal,Sekhar, Kondapalli Venkata Gowri Chandra
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p. 333 - 339
(2014/02/14)
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- Palladium-catalyzed intramolecular oxidative coupling involving double C(sp2)-H bonds for the synthesis of annulated biaryl sultams
-
The palladium-catalyzed intramolecular oxidative coupling described herein involves a double C(sp2)-H bond functionalization in sulfonanilides, providing a workable access to biaryl sultams annulated into a six-membered ring that are otherwise difficult to obtain by literature methods. The other synthetic applications of this protocol including the synthesis of biaryl sultams containing a seven-membered ring and analogous sultones are also presented.
- Laha, Joydev K.,Jethava, Krupal P.,Dayal, Neetu
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p. 8010 - 8019
(2015/03/18)
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- Palladium-catalyzed cyclization of benzamides with arynes: Application to the synthesis of phenaglydon and N-methylcrinasiadine
-
N-Methyl or methoxy benzamides reacted with benzynes in the presence of Pd(OAc)2, organic acid and K2S2O8 in CH3CN yielding tricyclic phenanthridinone derivatives in good yields. This journal is
- Pimparkar, Sandeep,Jeganmohan, Masilamani
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p. 12116 - 12119
(2014/12/11)
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- Novel syntheses of fluorenones via nitrile-directed palladium-catalyzed C-H and dual C-H bond activation
-
Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
- Wan, Jung-Chih,Huang, Jun-Min,Jhan, Yu-Huei,Hsieh, Jen-Chieh
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p. 2742 - 2745
(2013/07/19)
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- Pd(II)-catalyzed C(sp2)-H carbonylation of biaryl-2-amine: Synthesis of phenanthridinones
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A Pd(OAc)2-catalyzed C(sp2)-H carbonylation protocol of arenes under carbon monoxide atmosphere has been developed. The scope of the carbonylation reaction is broad and tolerates a variety of useful functional groups. This reaction provides a novel and efficient method for the synthesis of biologically and pharmaceutically significant phenanthridinones.
- Liang, Zunjun,Zhang, Jitan,Liu, Zhanxiang,Wang, Kai,Zhang, Yuhong
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p. 6519 - 6526
(2013/07/26)
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- Synthesis of phenanthridinones via palladium-catalyzed C(sp2)-H aminocarbonylation of unprotected o-arylanilines
-
An efficient synthesis of free (NH)-phenanthridinones through Pd-catalyzed C(sp2)-H aminocarbonylation of unprotected o-arylanilines under an atmospheric pressure of CO has been developed. Some ortho heteroarene substituted anilines as well as
- Liang, Dongdong,Hu, Ziwei,Peng, Jiangling,Huang, Jinbo,Zhu, Qiang
-
supporting information
p. 173 - 175
(2013/02/23)
-
- KOtBu mediated synthesis of phenanthridinones and dibenzoazepinones
-
Synthesis of substituted phenanthridinones and dibenzoazepinones has been realized from 2-halo-benzamides in the presence of potassium tert-butoxide and a catalytic amount of 1,10-phenanthroline or AIBN. This new carbon-carbon bond forming reaction gives direct access to various biaryl lactams containing six- and seven-membered rings chemoselectively. Carbon-carbon coupling seems to proceed by the generation of a radical in the amide ring which leads to C-H arylation of aniline.
- Bhakuni, Bhagat Singh,Kumar, Amit,Balkrishna, Shah Jaimin,Sheikh, Javeed Ahmed,Konar, Sanjit,Kumar, Sangit
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supporting information; experimental part
p. 2838 - 2841
(2012/07/28)
-
- Synthesis OF 5,6-dihydrophenanthridine (DHPA) sulfonamides and subsequent acid-catalyzed rearrangement to diaryl sulfones
-
As part of an ongoing investigation into the rearrangement of cyclic aryl aminesulfonanilides to diarylsulfones, a series of novel 5,6- dihydrophenanthridine (DHPA) sulfonamides were synthesized. Acid catalysts were used to rearrange them to DHPA arylsulfones. Taylor & Francis Group, LLC.
- Marie, Lisa,Meseroll, Neuls,McKee, James R.,Zanger, Murray
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experimental part
p. 2557 - 2568
(2011/08/07)
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- Synthesis of phenanthridinones and phenanthridine derivatives through palladium-catalyzed oxidative CH coupling of benzanilides
-
A palladium-catalyzed oxidative CH coupling reaction of benzanilides using molecular oxygen as the oxidant furnishes phenanthridinones. The palladium-catalyzed reaction in combination with simple derivatization provides an efficient access to a phenanthridine skeleton starting from readily available benzoic acids and anilines.
- Ishida, Naoki,Nakanishi, Yuuta,Moriya, Taisaku,Murakami, Masahiro
-
supporting information; experimental part
p. 1047 - 1049
(2011/12/05)
-