Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• scientific community involved in the area. The complex was used to access Cu-containing homopolymers 45 and copolymers 47 under metathesis polymerization with the Grubbs 3rd generation catalyst (Scheme 18 and Scheme 19). Further variations in the spacer subunit from a norbornene carbazole comonomer 46

• )s. Lanthanide-containing polymers Recently, new polynorbornenes of type 53, functionalized with terpyridine and carbazole moieties and integrating a europium complex in the pendant chains, were described by Rozhkov et al. [67]. They were obtained by a metathesis copolymerization with Grubbs 3rd

• copolymerizing the europium complex of the terpyridine monomer 51 with the carbazole-substituted norbornene 50. In solution or in thin film these Eu-containing products exhibited important metal-centered photoluminescence recommending them for novel applications. Unveiling and rationalizing the interactions

Synthesis of constrained analogues of tryptophan

• Elisabetta Rossi,
• Valentina Pirovano,
• Marco Negrato,
• Giorgio Abbiati and
• Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

• -1,2,3,4-tetrahydrocarbazole-3-carboxylic acid as a rigid analogue of α-methyltryptophan, a well known unnatural amino acid able to inhibit α-chymotrypsin activity, Figure 2 (A). Hardening tryptophan in β-carboline or carbazole frameworks has been used by Hénichart and co-workers in their studies devoted

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• %, Scheme 12). In another occasion, Rajakumar and co-workers [102] have synthesized a series of stilbenophanes (e.g., 81) involving N-arylated carbazole moieties possessing small and large cavities. The precursor 80 required for the McMurry reaction was synthesized by the N-arylation of carbazole with the

A new and efficient procedure for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones

• Marcelo Isidoro P. Reis,
• Vinícius R. Campos,
• Jackson A. L. C. Resende,
• Fernando C. Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2015, 11, 1235–1240, doi:10.3762/bjoc.11.137

• naphthoquinones (Figure 1) such as naphtho[2,3-b]furan [5][6][7][8][9][10][11][12][13][14], naphtho-pyran [15][16][17][18], benzo[f]indole [19][20][21][22][23][24], benzo[g]quinolone [25], benzo[b]carbazole [26], naphtho[2,3-b]thiophene [27][28][29][30][31][32][33] and naphtho[2,3-b]]oxazole [34] have been

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• ][17][18]. Moreover, various species of` PAEs with quinoline [19][20], quinoxaline [21][22], thiadiazole [17][23], carbazole [18][24], 1,2,4-triazoles [25], thiazole [26] and azametallocyclic [27] units incorporated into a polymer chain have been described. Since ligands based on pyridazine rings can

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• demonstrated that this in situ generated reagent works more efficiently in such cyclizations than the more frequently used PIFA reagent. For instance, cyclization of biaryl 35 to carbazole 36 was achieved using this indirect electrochemical approach (Scheme 14) [59][60]. The transformation represents the key

Mono- and multilayers of molecular spoked carbazole wheels on graphite

• Stefan-S. Jester,
• A. Vikas Aggarwal,
• Daniel Kalle and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 2783–2788, doi:10.3762/bjoc.10.295

• , which is filled with a star-shaped (spoke) system and central darker spot (hub; cf. definition in Figure 1). In other words, the rim units appear (mostly) as a continuous line. The six rim segments contain central carbazole units (cf. chemical structure in Figure 1), so that they are only slightly

• curved (or bent; as seen in the molecular model in Figure 2c and d where one of the six carbazole units is marked by a white arrow). They are still not directly connected, but terminated with acetylene units. However, a gap can rarely be estimated from the brightness modulation (cf. circle in Figure 2c

• ). Moreover, the six kinks that are seen in the STM images (one of which is marked by the white circle in Figure 2c and d) correspond (not to the carbazole units but) to the intersections of the terminal acetylenes of the rim segments. According to the space-filling model, only three of the four pseudo

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• carbazole moieties as donors, and comprehensive physical organic studies of electronic and electrochemical properties investigated by steady state UV–vis and fluorescence spectroscopy as well as cyclic voltammetry. The obtained data are interpreted in the light of the Weller approximation to estimate the

• to the parent system 1. The carbazole-based dyads 8e and 8f only show quasi-reversible oxidation waves at an estimated E1/20/+1 of 1220 and 1170 mV, yet in good agreement with the behavior of the carbazole-only reference 10b with an estimated E1/20/+1 at 1320 mV. The carbazole–anthraquinone dyads 8e

• a lower intensity band around 325 nm (Figure 5). According to the phenothiazine-only (10a) and anthraquinone-only (3) references phenothiazine as well as anthraquinone absorb in the same region. In the spectrum of the carbazole dyad 8e the carbazole-typical absorption maxima can be found (cf

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

Gold(I)-catalyzed domino cyclization for the synthesis of polyaromatic heterocycles

• Mathieu Morin,
• Patrick Levesque and
• Louis Barriault

Beilstein J. Org. Chem. 2013, 9, 2625–2628, doi:10.3762/bjoc.9.297

• = H) and furan 11g (R1 = Ph and R2 = H) were effectively transformed to the desired carbazole 12f and benzofuran 12g in 95% yields. It can be noticed that large substituents at R1 and R2 did not affect the efficiency of the reaction. The gold(I)-catalyzed cyclization of 11h (R1 = R2 = Ph) and 11i (R1

• , benzothiophene, carbazole and hydrindene in high yields. The use of σ-donor ligands such as IPr (L1) was exceptionally selective for the 5-exo-dig pathway. This Au(I)-catalyzed cyclization occurring in cascade provides a direct access to synthetically useful motifs commonly found in natural products and

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• , no starting carbazole was found in the reaction mixture after 2 hours (NMR). This reaction led to the selective formation of thietane 3e, isolated in 67% yield (Scheme 3). The structure of 3e was established by single crystal X-ray diffraction (Figure 2). Interestingly, the 19F and 1H NMR spectra of

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

• ., alkaloids) and pharmaceuticals [1]. In addition, the carbazole motif constitutes an immense class of materials in the rapidly growing field of molecular electronics. In particular N-arylcarbazoles have promising electroluminescent properties and have subsequently found diverse applications as hole-transport

• ] or the direct arylation [14][15] of the free NH-functionality of carbazole (path B). In the past decade, hypervalent iodine chemistry has undergone a renaissance and has developed to become a powerful area in synthetic organic chemistry. Open-chained iodonium salts are well explored in transition

• proposed to give 2'-iodobiphenyl-2-phenylamine (I). In a second, Pd-mediated intramolecular cross-coupling, 9-phenyl-9H-carbazole (3a) should be observed (Scheme 2). Results and Discussion First, we decided to prepare cyclic iodonium salt 1 as the triflate salt, to avoid unwanted side-reactions in solution

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• , Py_3, Py_4, Py_9, Py_10) two functionalized triazines (Py_7, Py_12), a triphenylamine (Py_6), a carbazole (Py_11) and a benzothiadiazole (Py_8) (Scheme 3). The idea is to get a high absorption around 380–410 nm where Xe–Hg lamps, Xe lamps, LED, laser diodes and even household halogen lamps are usable

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• -6(7H)-ones (5, Figure 1) instead of the mechanistically possible products 2-phenyl-3,6-dioxa-4,5-dioxonaphtho[2,1-b]-7H-indole 6 or a carbazole derivative 7 or 3-alkenylindolin-2-ones 8 (Scheme 2 and Scheme 3). Further, reactions of 3 and 4 in the presence of NaH as a base in THF under reflux gave a

Recent progress in the discovery of small molecules for the treatment of amyotrophic lateral sclerosis (ALS)

• Allison S. Limpert,
• Margrith E. Mattmann and
• Nicholas D. P. Cosford

Beilstein J. Org. Chem. 2013, 9, 717–732, doi:10.3762/bjoc.9.82

• (Figure 12). In a screen of a chemically diverse compound library, Pieper et al. identified an aminopropyl carbazole, P7C3, which was found to increase adult hippocampal neurogenesis in an in vivo assay [53]. Further optimization of this compound through structure–activity relationship (SAR) analysis led

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• reaction of anthracene-1,4-diones 4 led unexpectedly to the corresponding 2-thioxo-2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 10. The reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] 1d, 2d with Et3N in chlorobenzene under reflux yielded 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones 15, 16, i.e

• ., ring contraction and fusion products. A plausible mechanism was proposed for the formation of the products. Keywords: anthracene-1,4-diones; 1H-carbazole-6,11-diones; fused thiazoles; fusion reaction; heterocycles; naphthoquinones; ring contraction; sulfur–nitrogen; Introduction The 1,4

• ]carbazole-6,11-dione (15) [20]. Anthraquinonothiazole 2d reacted with triethylamine in the same way as naphthoquinone 1d giving fused pyrrole 16 with the same yield. The most plausible pathway for this reaction is given in Scheme 9. The key steps are assumed to be the thiazole ring opening with the

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