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

• -established features of natural or man-made compounds containing an indole backbone are of wide interest in pharmacological and agrochemical fields [26][27][28]. Thus, indole and carbazole nuclei are used in medicine for their antibacterial, antimicrobial, and anti-inflammatory effects and occupy a relevant

• role in the discovery of active antitumor drugs [29][30][31]. Carbazole derivatives also find applications in organic materials as chromophores and photoconductors [32]. For several years, the development of methodologies concerning indole synthesis and functionalization has been one of the most

• with Pd(OAc)2 as the catalyst and 1,4-benzoquinone as the oxidant, providing carbazole derivatives 38 (Scheme 19) [77]. The products arise from an endo-cyclization which gives the initially formed dihydrocarbazoles 37, which are easily oxidized to the products 38 by the excess of 1,4-benzoquinone

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

• Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany 10.3762/bjoc.8.135 Abstract Miniaturized microreactors enable photochemistry with laser irradiation in flow mode to convert azidobiphenyl into carbazole with high efficiency

• this study have four reaction chambers with varying volumes of the chambers due to increasing depth, and different connections for the reagent entrance (Figure 1). Photochemistry The combinatorial synthesis of heterocycles and among them of carbazole is of particular interest since they are potential

• active pharmaceutical compounds [33][34][35]. The photolysis of 2-azidobiphenyl (1) with the help of a conventional UV-lamp has been used for the synthesis of carbazole (2) since 1960 (Scheme 1) [36][37][38][39]. However, there are only a few examples of substituted products obtained by this reaction

An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines

• Zhiyuan Ma,
• Feng Ni,
• Grace H. C. Woo,
• Sie-Mun Lo,
• Philip M. Roveto,
• Scott E. Schaus and
• John K. Snyder

Beilstein J. Org. Chem. 2012, 8, 829–840, doi:10.3762/bjoc.8.93

• -carboline by Robinson in 1924 [15][36] proceeded through the acid-catalyzed decomposition of 1-(2-pyridyl)benzotriazole, a modification of the Graebe–Ullmann carbazole synthesis, which closes the indole ring. This procedure was improved upon and exploited for decades [37][38][39][40]. Later, reversing the

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

• described. The synthesis mainly relies on the ultrasound-assisted Rap–Stoermer reaction of 3-chloroacetyl- (1) or 3,6-dichloroacetyl-9-ethyl-9H-carbazole (4) with various salicylaldehydes 2a–k as well as 2-hydroxy-1-naphthaldehyde (2l) in CH3CN with the presence of PEG-400 as catalyst. The procedure offers

• easy access to benzofuroylcarbazoles in short reaction times and the products are obtained in moderate to good yields. Keywords: 2-benzofuroyl; carbazole; PEG-400; Rap–Stoermer reaction; salicylaldehydes; ultrasound-assisted; Introduction Carbazole, and especially heterocycle-containing carbazole

• common heterocyclic ring moiety fused with a carbazole ring, such as pyridocarbazoles [20][21], thienocarbazoles [22][23], pyranocarbazoles, pyrrolocarbazoles [24][25], indolocarbazoles [26][27][28], and synthetic analogues thereof. However, there are very few reports in which the heterocyclic moiety is

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

Cationic gold(I) axially chiral biaryl bisphosphine complex-catalyzed atropselective synthesis of heterobiaryls

• Tetsuro Shibuya,
• Kyosuke Nakamura and
• Ken Tanaka

Beilstein J. Org. Chem. 2011, 7, 944–950, doi:10.3762/bjoc.7.105

• addition, benzocoumarin 2c (Table 2, entry 3) was obtained in moderate ee, although the yield was low due to partial deprotection of the methoxymethoxynaphthalene moiety (Table 2, entry 3). The reactions of carbazole and dialkoxybenzene derivatives 1d–g, using (R)-DTBM-Segphos as a ligand, furnished the

Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

• Aamer Saeed,
• Madiha Irfan and
• Shahid Ameen Samra

Beilstein J. Org. Chem. 2011, 7, 638–647, doi:10.3762/bjoc.7.75

• novel class of carbazole-4-phenylpyridine co-polymers are described. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole–pyridine copolymers which involve costly catalysts. Thus, two series of polymers were

• . The weight average molecular masses (Mw) of the polymers were estimated by the laser light scattering (LLS) technique. Keywords: carbazole–pyridine copolymers; fluorescent materials; organic light emitting diode (OLED); photoluminescence spectra; UV spectra; Introduction An immense research effort

• for employing organic materials as LEDs [7] and carbazole containing polymers are the most studied group amongst the different polymers intended for OLED applications [8][9][10][11][12][13][14][15]. Carbazole containing polymers exhibit excellent electron-donating properties together with intense

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

• intermediate for carvedilol is 4-hydroxy-9H-carbazole (141) [42]. In analogy to the Fischer indole synthesis, cyclohexane-1,3-dione monophenyl hydrazone 139 is prepared via condensation of phenylhydrazine (138) with 1,3-cyclohexanedione (121, Scheme 29). This compound can then undergo an acid catalysed Fischer

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

• Carolin Fischer and
• Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

• demanding N-nucleophile at two positions. Murrazoline (23), a carbazole alkaloid isolated from the shrub Murraya, is used in folk medicine for the treatment of eczema, rheumatism and dropsy, as an analgesic, and in anaesthesia. It is known to be a potent platelet aggregation inhibitor. The double N

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

• reaction between 3-acetyl-9-ethyl-9H-carbazole or 3,6-diacetyl-9-ethyl-9H-carbazole and β-aminoaldehydes or β-aminoketones is described. All of the title compounds were obtained in good yields of 52–72% and their structures were confirmed by IR, 1H NMR, MS, and elemental analysis. Keywords

• : acetylcarbazole; β-aminoaldehyde; β-aminoketone; Friedländer condensation; sodium ethoxide; Introduction Nitrogen-containing heterocycles are a very important group of organic compounds because of their wide application in medicine, agriculture, and technology. Among these, quinoline and carbazole derivatives

• system especially in the area of medicinal chemistry, and moreover it is a ubiquitous sub-structure found in many biologically active natural products [4][5][6][7][8]. Carbazole-based compounds are also embodied in many naturally occurring products and these too display a wide variety of biological

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• ]. The polymers consisted of dialkylated DPP units and carbazole, triphenylamine, benzo[2,1,3]thiadiazole, anthracene, or fluorene units in alternating fashion. They were prepared via Suzuki coupling, from the DPP monomers M-1 or DPP-3,6-diphenyl(4,4´-bis(pinacolato)boron ester. A number of readily

• (Table 6). Encouraged by the good performance of thiophenylDPP-based solar cells, further polymers P-29 - P-46 were recently synthesized and their photovoltaic properties investigated. Among these were alternating copolymers containing the thiophenylDPP, or bithiophenylDPP unit [58], and carbazole [58

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• contrast, in the case of 1-benzyl-2-methyl indolizine [81] both the pyrrole and the aromatic ring of the benzyl group undergo trifluoromethylsulfanylation. Only N-substitution occurs in the case of carbazole [80]. N-Methylpyrrole can be variously substituted depending on the conditions as illustrated in

Synthesis of indolo[3,2-b]carbazole-based new colorimetric receptor for anions: A unique color change for fluoride ions

• Ajit Kumar Mahapatra,
• Giridhari Hazra and
• Prithidipa Sahoo

Beilstein J. Org. Chem. 2010, 6, No. 12, doi:10.3762/bjoc.6.12

• CH3CN in the presence of I2 for 45 min afforded the desired receptor 1 in 82% yield. To look into the orientation of hydrogen bond donors around the carbazole motif, we optimized the structure by the AM1 method [45] (Figure 2). It is evident from Figure 2 that the two catechol units do not lie in the

• same plane as the carbazole unit. Interaction studies UV–vis study The anion-binding properties of receptor 1 were investigated by UV–vis, fluorescence and 1H NMR spectroscopic methods. The sensing ability of chemosensor 1 with a series of tetrabutylammonium salts ([Bu4N]+X−, X = F−, Cl−, Br−, I−, AcO