- Redox-neutral decarboxylative photocyclization of anthranilic acids
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A mild metal-, catalyst-, and oxidant-free photoredox neutral system has been found to efficiently enable intramolecular decarboxylative cyclization of anthranilic acids. This facile protocol provides an alternative method for the synthesis of carbazoles. Mechanistic studies reveal a key photoinduced 6π-electrocyclization process and formic acid was released as the sole byproduct.
- Huang, Huawen,Deng, Kun,Deng, Guo-Jun
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p. 8243 - 8247
(2020/12/29)
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- Method for preparing carbazole compound
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The invention discloses a method for synthesizing a carbazole compound by utilizing N,N-di-substituted o-aminobenzoate compound. The synthesis method comprises the following steps of adopting a palladium salt as a catalyst, mixing the palladium salt, the N,N-di-substituted o-aminobenzoate compound, an oxidant and an organic solvent, and carrying out heating reaction to obtain the carbazole compound. The method disclosed by the invention has the advantages that the preparation route is short, the universality of a substrate is good, the synthesis yield is high, the used catalyst is simple and easy to obtain and the like.
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Paragraph 0068; 0069; 0070; 0071; 0072; 0073
(2019/04/13)
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- Pd-Catalyzed Intramolecular Chemoselective C(sp2)-H and C(sp3)-H Activation of N-Alkyl- N-arylanthranilic Acids
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A controllable palladium-catalyzed intramolecular C-H activation of N-alkyl-N-arylanthranilic acids has been developed. The methodology allows selective synthesis of 1,2-dihydro-(4H)-3,1-benzoxazin-4-ones and carbazoles from the same starting materials and palladium catalyst. The selectivity is controlled by the oxidant. Silver oxide promotes C(sp3)-H activation/C-O cyclization to provide 1,2-dihydro-(4H)-3,1-benzoxazin-4-ones, while copper acetate contributes to C(sp2)-H activation/decarboxylative arylation to afford carbazoles. This protocol is demonstrated by its wide substrate scope and good functional group tolerance.
- Hu, Zhe-Yao,Zhang, Yan,Li, Xin-Chang,Zi, Jing,Guo, Xun-Xiang
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supporting information
p. 989 - 992
(2019/05/16)
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- Photoinduced Cross-Coupling of Amines with 1,2-Diiodobenzene and Its Application in the Synthesis of Carbazoles
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A facile and efficient process for the preparation of various tertiary aminobenzenes and carbazole derivatives via photoinduced cross-coupling of amines with 1,2-diiodobenzene is reported. Mechanistic investigations indicate that the transformation proceeds via nucleo-philic addition of an amine to the benzyne intermediate accompanied with a proton transfer process, followed by an oxidative cyclization of the generated diphenylamine to furnish the corresponding carbazole products.
- Zhao, Xinxin,Chen, Ming,Huang, Binbin,Yang, Chao,Gao, Yuan,Xia, Wujiong
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p. 2981 - 2989
(2018/05/15)
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- An Expedient Synthesis of Carbazoles through Potassium tert-Butoxide-Promoted Intramolecular Direct C–H Bond Arylation
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Transition-metal-free access to carbazoles was achieved through base-mediated intramolecular C–C bond formation. Reactions of N-substituted o-halodiarylamines with potassium tert-butoxide in the presence of ethylene glycol or 1,10-phenanthroline provided carbazoles in moderate to excellent yields. This transformation may proceed through a radical pathway according to a control experiment with a radical scavenger.
- Lin, Songbo,He, Xingrui,Meng, Jinpeng,Gu, Haining,Zhang, Peizhi,Wu, Jun
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supporting information
p. 443 - 447
(2017/02/05)
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- Palladium Nanoparticles in Water: A Reusable Catalytic System for the Cycloetherification or Benzannulation of α-Allenols
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A convenient ligand-free catalytic system has been developed for the chemoselective cyclization reaction of various α-allenol derivatives by palladium nanoparticles (PdNPs) in an aqueous reaction medium. (Figure presented.) .
- Alcaide, Benito,Almendros, Pedro,González, Ana M.,Luna, Amparo,Martínez-Ramírez, Sagrario
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p. 2000 - 2006
(2016/07/06)
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- Nickel-catalyzed cross-coupling of anisole derivatives with trimethylaluminum through the cleavage of carbonoxygen bonds
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Nickel-catalyzed cross-coupling of methoxyarenes with trimethylaluminum is described. The use of 1,3-dicyclohexylimidazol-2-ylidene as a ligand and NaO'Bu as a base promotes the methylation of anisole derivatives via the cleavage of normally unreactive aryl carbonoxygen bonds.
- Morioka, Toshifumi,Nishizawa, Akihiro,Nakamura, Keisuke,Tobisu, Mamoru,Chatani, Naoto
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supporting information
p. 1729 - 1731
(2016/02/19)
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- Iodine recycling via 1,3-migration in iodoindoles under metal catalysis
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3-Substituted (indol-2-yl)-α-allenols show divergent patterns of reactivity under metal catalysis. An unprecedented intramolecular 1,3-iodine migration is described.
- Alcaide, Benito,Almendros, Pedro,Alonso, Jose M.,Cembellin, Sara,Fernandez, Israel,Del Campo, Teresa Martinez,Torres, M. Rosario
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supporting information
p. 7779 - 7781
(2013/09/02)
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- Palladium-catalyzed carbocyclization-cross-coupling reactions of two different allenic moieties: Synthesis of 3-(buta-1,3-dienyl) carbazoles and mechanistic insights
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A palladium-catalyzed chemo-, regio- and stereoselective carbocyclization-cross-coupling sequence of two different α-allenols to afford 3-(E-buta-1,3-dienyl) carbazoles is reported.
- Alcaide, Benito,Almendros, Pedro,Alonso, Jose M.,Fernandez, Israel
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supporting information; experimental part
p. 6604 - 6606
(2012/08/08)
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- Gold- or palladium-catalyzed allene carbocyclization/functionalization: Simple and efficient synthesis of carbazoles
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Gold- and palladium-catalyzed cyclization of easily accessible indole-tethered allenols allows the efficient synthesis of carbazole derivatives under mild conditions. Copyright
- Alcaide, Benito,Almendros, Pedro,Alonso, Jose M.,Quiros, M. Teresa,Gadzinski, Pawel
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supporting information; experimental part
p. 1871 - 1876
(2011/10/04)
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- Novel palladium-catalyzed acyloxylation/cyclization of 2-(3′-alkenyl) indoles
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A new and mild palladium(II)-catalyzed reaction for the intramolecular acyloxylation/cyclization of 2-(3′-alkenyl)indoles was developed. The newly formed cycles involve oxygen-containing functionalized groups, which might be transferred further to provide other indole derivatives.
- Han, Xiuling,Lu, Xiyan
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supporting information; experimental part
p. 2381 - 2384
(2009/10/10)
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- Highly efficient construction of benzene ring in carbazoles by palladium-catalyzed endo-mode oxidative cyclization of 3-(3′-alkenyl) indoles
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A highly efficient construction of the benzene ring in carbazoles by palladium-catalyzed endo-mode oxidative cyclization of 3-(3′-alkenyl)- indoles was developed. The reaction utilizes benzoquinone as the stoichiometric oxidant and is conducted under mild conditions.
- Kong, Aidi,Han, Xiuling,Lu, Xiyan
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p. 1339 - 1342
(2007/10/03)
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- A novel catalytic one-pot synthesis of carbazoles via consecutive amination and C-H activation
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Sequential palladium catalysed amination and C-H activation reactions occur between 2-chloro-N-alkylated anilines and aryl bromides to give carbazoles in one pot.
- Bedford, Robin B.,Cazin, Catherine S. J.
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p. 2310 - 2311
(2007/10/03)
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- Aromatic and heteroaromatic annelation studies on 3-[bis(methylthio)methylene]-1-methyloxindole: Synthesis of carbazoles and an efficient route to pyrido[2,3-b]indoles
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The 3-[bis(methylthio)methylene]-1-methyloxindole (2) is shown to undergo cycloaromatization with allyl and methallyl magnesium chlorides to afford substituted carbazoles. A novel route to 2-substituted-3-cyano-4-methylthio/aminopyrido[2,3-b]indoles has been developed via heteroaromatic annelation of 2 with in situ generated 2-lithioamino-2-substituted acrylonitriles.
- Suresh,Syam Kumar,Ila,Junjappa
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p. 781 - 789
(2007/10/03)
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- Diels-Alder Reaction of 2-Vinylindoles with Maleic Anhydride
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N-Methyl-2-(2-methyl- (1), 2-methoxy- (2), and 2-ethoxycarbonyl- (3) -vinyl)indoles furnish the corresponding Diels-Alder adducts 5, 6 and 7 when treated with maleic anhydride.Under similar conditions N-methyl-2-(2-nitrovinyl)indole (4) undergoes dimerisation to give the dimer (8).Dimerisation to compound 17 is also observed during attempted separation of the mixture of cis- and trans-isomers of N-methyl-2-(2-methylvinyl)indole (1) on silica gel.The Diels-Alder adducts (5 and 7), on hydrolysis, followed by lead tetraacetate oxidation give the carbazoles, 11 and 14a + 14b respectively.
- Narasimhan, N. S.,Kusurkar, R. S.,Dhavale, D. D.
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p. 1004 - 1010
(2007/10/02)
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