Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives

• Roman A. Irgashev,
• Nikita A. Kazin,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2017, 13, 1396–1406, doi:10.3762/bjoc.13.136

• , Russia 10.3762/bjoc.13.136 Abstract A new general approach to double nitration of 6,12-di(hetero)aryl-substituted and 6,12-unsubstituted 5,11-dialkyl-5,11-dihydroindolo[3,2-b]carbazoles by acetyl nitrate has been developed to obtain their 2,8-dinitro and 6,12-dinitro derivatives, respectively. A

• formation of mono-nitro derivatives (at C-2 or C-6) from the same indolo[3,2-b]carbazoles has also been observed in several cases. Reduction of 2-nitro and 2,8-dinitro derivatives with zinc powder and hydrochloric acid has afforded 2-amino- and 2,8-diamino-substituted indolo[3,2-b]carbazoles, while

• reduction of 6,12-dinitro derivatives under similar reaction conditions has been accompanied by denitrohydrogenation of the latter compounds into 6,12-unsubstituted indolo[3,2-b]carbazoles. Formylation of 6,12-dinitro derivatives has proved to occur only at C-2, while bromination of these compounds has

Characterization of the synthetic cannabinoid MDMB-CHMCZCA

• Carina Weber,
• Stefan Pusch,
• Dieter Schollmeyer,
• Sascha Münster-Müller,
• Michael Pütz and
• Till Opatz

Beilstein J. Org. Chem. 2016, 12, 2808–2815, doi:10.3762/bjoc.12.279

• -alkylated carbazole instead of an indole core. Carbazoles are the core structures of an emerging group of cannabimimetics [11][12]. Several N-alkylated carbazole-3-carboxamides were patented by Diaz, Diaz, and Petrov in 2012 as tricyclic cannabinoid receptor modulators, explored against neuropathic pain [13

Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

• Chao Yang,
• Kai Lin,
• Lan Huang,
• Wei-dong Pan and
• Sheng Liu

Beilstein J. Org. Chem. 2016, 12, 2490–2494, doi:10.3762/bjoc.12.243

• methods for the construction of the indolo[3,2-a]carbazole skeleton were developed by Bergman [4][5], Cachet [6], and Zhiping Li [7]. Very recently, we also reported a novel strategy toward indolo[3,2-a]carbazoles [8], and the key transformations involved a biomimetic transamination/aromatic cyclization

• sequence to deliver 9-methoxycarbonyl indolo[3,2-a]carbazole derivatives. Previous literature aimed at providing rapid and efficient access to indolo[3,2-a]carbazoles, however, most of them have some disadvantages. Few methods were reported to be suitable for scale-up preparation and the introduction of

• substituents to aromatic rings was also inconvenient. It could still be necessary to exploit more practical methods and economic procedures to assemble these polycyclic molecules. In this paper, we describe a concise, 3 to 4 steps procedure for the synthesis of indolo[3,2-a]carbazoles via palladium-catalyzed

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• synthesis of 2,3-disubstituted furans 210 (Scheme 60) [330]. The benzannulation of indoles 211 can be performed with γ-carbonyl tert-butyl peroxides 212 catalyzed by trifluoromethanesulfonic acid to give carbazoles 213. The key step of this approach is based on the acid-catalyzed rearrangement of tert-butyl

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• polymers. The linkage through the 3,6-positions of the carbazole unit forms a linear conjugation between the nitrogen atoms, which facilitates the electron removal from the conjugated main chain. In contrast, the nitrogen atoms through the 2,7-linked carbazoles are classified as a formal cross-conjugated

Palladium-catalyzed synthesis of N-arylated carbazoles using anilines and cyclic diaryliodonium salts

• Stefan Riedmüller and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2013, 9, 1202–1209, doi:10.3762/bjoc.9.136

• The direct synthesis of N-arylated carbazoles through a palladium-catalyzed amination of cyclic iodonium salts with anilines is described. In particular, electron-poor aniline derivatives reacted smoothly with only 5 mol % of Pd(OAc)2 as catalyst to give the desired products in up to 71% yield

• . Furthermore, the reactivity of cyclic iodonium salts is compared with the reactivity of the corresponding cyclic bromonium analogues. Keywords: amination; carbazoles; hypervalent; iodine; iodonium salts; Introduction Carbazoles play an important role as core structural elements in natural products (e.g

• , the efficient synthesis of N-arylated carbazoles is an attractive goal and numerous synthetic methods are known so far from the literature. The main synthetic routes are shown in Scheme 1. The majority are transition-metal mediated. Starting from functionalized 2,2'-biphenyls (path A) [10][11][12][13

Zanthoxoaporphines A–C: Three new larvicidal dibenzo[de,g]quinolin-7-one alkaloids from Zanthoxylum paracanthum (Rutaceae)

• Fidelis N. Samita,
• Louis P. Sandjo,
• Isaiah O. Ndiege,
• Ahmed Hassanali and
• Wilber Lwande

Beilstein J. Org. Chem. 2013, 9, 447–452, doi:10.3762/bjoc.9.47

• , namely isoquinolines represented by benzophenanthridines [8], oxoaporphines [9], aporphines [10] and benzylisoquinoline [11]; and quinolines represented by quinolones [12] and furoquinolines [10]. Others include carbazoles [13], pyrido-indoles [12] and quinazolines [14]. Arylethanamides and amines have

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• ]indole skeleton by intramolecular C-2 alkenylation. Synthesis of azepinoindoles by oxidative Heck cyclization. Enantioselective synthesis of 4-vinyl-substituted tetrahydro-β-carbolines. Pd-catalyzed endo-cyclization of 3-alkenylindoles for the construction of carbazoles. Pd-catalyzed hydroamination of 2

Photochemistry with laser radiation in condensed phase using miniaturized photoreactors

• Elke Bremus-Köbberling,
• Arnold Gillner,
• Frank Avemaria,
• Céline Réthoré and
• Stefan Bräse

Beilstein J. Org. Chem. 2012, 8, 1213–1218, doi:10.3762/bjoc.8.135

• ][48]. Moreover, triazene-resins are perfectly suitable for the synthesis of arylazides 5 (Scheme 2) [49]. The photochemical decomposition of arylazides into carbazoles is appropriate for application in miniaturized photoreactors, since significant results can be observed by an online analysis through

Double N-arylation reaction of polyhalogenated 4,4’-bipyridines. Expedious synthesis of functionalized 2,7-diazacarbazoles

• Mohamed Abboud,
• Emmanuel Aubert and
• Victor Mamane

Beilstein J. Org. Chem. 2012, 8, 253–258, doi:10.3762/bjoc.8.26

• ][2][3][4][5] and up to date no general method is available in the literature. However, these diaza analogues of carbazoles [6] have shown interesting biological [7][8][9][10] and photophysical [11][12][13] properties and have been used as ligands in catalysis [14]. The double palladium-catalyzed N

• -arylation strategy for the synthesis of carbazoles has been extensively used in the literature [15][16][17][18][19][20][21][22]. The methodology was further applied for the preparation of dithienopyrroles [23] and dibenzothienopyrroles [24]. One example was found in a patent concerning the synthesis of 3,6

A novel and facile synthesis of 3-(2-benzofuroyl)- and 3,6-bis(2-benzofuroyl)carbazole derivatives

• Wentao Gao,
• Meiru Zheng and
• Yang Li

Beilstein J. Org. Chem. 2011, 7, 1533–1540, doi:10.3762/bjoc.7.180

• Wentao Gao Meiru Zheng Yang Li Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China 10.3762/bjoc.7.180 Abstract A facile synthesis of hitherto unreported 3-(2-benzofuroyl)carbazoles 3a–k, 3,6-bis(2-benzofuroyl)carbazoles 5a–k, and naphtho[2,1-b]furoylcarbazoles 3l and 5l is

• important role in electroactive and photoactive devices [11][12][13][14]. Therefore, a number of methodologies for the construction of heterocycle-containing carbazoles have been reported in recent years [15][16][17][18][19]. Most heterocycle-containing carbazoles reported in the literature comprise a

• benzofuroyl-based compounds [39][40][41][42][43]. We have recently reported the synthesis of quinolyl-substituted carbazoles [44] and benzofuranyl-substituted quinoline [45]. Thus, in light of the above findings and in the context of our ongoing work on the synthesis of new heterocyclic compounds, we found it

NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas

• Damjan Makuc,
• Jennifer R. Hiscock,
• Mark E. Light,
• Philip A. Gale and
• Janez Plavec

Beilstein J. Org. Chem. 2011, 7, 1205–1214, doi:10.3762/bjoc.7.140

• heterocycles, such as carbazole, 2,2'-biindole and indolo[1,2-b]carbazoles, have recently attracted significant attention [24][25][26][27][28][29][30][31]. Indole contains a single hydrogen bond donor group, which is employed in biological systems to bind anions such as chloride [32] and sulfate [14]. We have

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• ]carbazoles, dihydrobenzo[g]indoles, and azepino- or oxepinoindole derivatives through an intramolecular cascade 5-endo-dig hydroamination followed by a 6- or 7-endo-dig cycloisomerization. Dudnik et al. reported a gold(I)-catalyzed cycloisomerization of propargylic esters 294 which led to unsymmetrically

One-pot gold-catalyzed synthesis of 3-silylethynyl indoles from unprotected o-alkynylanilines

• Jonathan P. Brand,
• Clara Chevalley and
• Jérôme Waser

Beilstein J. Org. Chem. 2011, 7, 565–569, doi:10.3762/bjoc.7.65

• construction of tetrahydrofurans [21] and aryl-annulated[a]carbazoles [22]. Nakamura examined the cyclization of N-tosyl-o-alkynylanilines and observed an internal transfer of the sulfonyl group to the 3-position of the formed indoles [23][24]. Similar transformations were also achieved for the transfer of

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

• considered and executed process optimisation study. Carbazoles Carvedilol (136, Coreg) is a general non-selective β-blocker, used in the treatment of mild to moderate congestive heart failure. The structure comprises of a core carbazole ring that plays an important role in its increased activity. The

• carvedilol has an additional antioxidant mode of action. It has been proposed that the carbazole ring may be involved in scavenging oxygen radicals thereby accounting for reduced myocardial damage [41]. Since carbazoles are similar to indoles, analogous methods can be used for their synthesis. The key

Synthesis of 3-(quinolin-2-yl)- and 3,6-bis(quinolin-2-yl)-9H-carbazoles

• Yang Li and
• Wentao Gao

Beilstein J. Org. Chem. 2010, 6, 966–972, doi:10.3762/bjoc.6.108

• Yang Li Wentao Gao Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China 10.3762/bjoc.6.108 Abstract A simple and efficient synthesis of novel 3-(quinolin-2-yl)- and 3,6-bis(quinolin-2-yl)-9H-carbazoles, utilizing sodium ethoxide as a catalyst via a Friedländer condensation

• regard, Meesala et al. [30] recently described a short and facile route to the synthesis of new 3,6-bis(pyrazol-4-yl)carbazoles from 3,6-diacetylcarbazoles through a Vilsmeier reaction. Later, Chaitanya et al. [31] reported a new synthesis of 3-(3-nitrochromenyl)carbazoles, 3,6-bis(3-nitrochromenyl

• )carbazoles under solvent-free conditions by the reaction of β-nitrovinylcarbazole or bis(β-nitrovinyl)carbazole with salicylaldehydes. In light of these findings, and in view of the prominent role structural diversity plays in medicinal and combinatorial chemistry, we felt that there was a real need for the

Anion receptors containing thiazine-1,1-dioxide heterocycles as hydrogen bond donors

• Hong-Bo Wang,
• James A. Wisner and
• Michael C. Jennings

Beilstein J. Org. Chem. 2010, 6, No. 50, doi:10.3762/bjoc.6.50

• of nitrogen-based hydrogen bond donor groups such as amides [3][4], ureas [5], pyrroles/indoles/carbazoles [6][7] and sulfonamides [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] to complex the anionic targets in a topologically complementary fashion. Sulfonamides are an interesting