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Search for "carbazole" in Full Text gives 94 result(s) in Beilstein Journal of Organic Chemistry.
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts
Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2
- fluorophors, previously shown to exhibit strong organic phosphorescence when mixed with specific additives [1][2][3][4][5]. Carbazole units are also found in drugs and natural products. They are also used in electrochemistry and as reagents in transamidation reactions [6][7][8][9][10][11][12]. The traditional
- method to produce this versatile N-acyl carbazole motif involves combining 9H-carbazoles with acyl chlorides or similar activated acyl derivatives in the presence of a base (Scheme 1a) [13][14]. As an alternative, acyl carbazoles can be synthesized through step-wise metal-catalysed C–X-amidations
- [33][34]. Results and Discussion Initially, we investigated the synthesis of N-acyl carbazole by treatment of diaryliodonium salt 1a with valeramide using Cu(I) catalysts [18]. The results are shown in Table 1. In the first experiments in p-xylene at 120 °C with DMEDA as N,N-ligand, only modest
Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions
Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139
- emitter based on a pyridine-3,5-dicarbonitrile scaffold (to serve as an electron acceptor) directly linked to a carbazole moiety (to serve as an electron donor) was reported by the groups of Dong and Zhang in 2015 [4]. 2,6-Di(9H-carbazol-9-yl)-4-phenylpyridine-3,5-dicarbonitrile (CPC) showed an extremely
- )-4-(4-bromophenyl)pyridine-3,5-carbonitrile (4) was obtained by the interaction of 3,6-di-tert-butyl-9H-carbazole with compound 3 in THF/DMF solution. The ethynylphenyl-substituted pyridine 5 was synthesized by Sonogashira coupling of 4 with ethynyltrimethylsilane in the presence of PdCl2(PPh3)2 and
- transfer from the donor to the acceptor. The absorption spectrum of REF is included in Figure 2a for comparison. Compounds 6–9 are characterized by similar absorption bands also caused by electron transfer from the 3,6-di-tert-butyl-9H-carbazole units to the pyridine-3,5-dicarbonitrile moiety. The number
Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application
Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137
- layers are composed of various aromatic π-conjugated small molecules/polymers including thiophene, anthracene, carbazole, and triphenylamine [9][10][11][12][13]. Thienothiophenes are two annulated thiophene rings having four isomers, among which the most widely used isomer is thieno[3,2-b]thiophene (TT
N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction
Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136
- pyrazole derivatives (including indazole), benzimidazole, 1,2,3-triazole, indole, carbazole, indoline, quinazoline, and isoquinoline. Nevertheless, many heterocyclic motifs still remain beyond the attention of researchers. For example, glutarimides that incorporate tetrazole and 1,2,4-triazole substituents
A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices
Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122
- –donor (D–A–D)-type molecule and its application as a non-doped emitter in an organic light-emitting diode (OLED). The fluorophore TPECNz contains naphtho[2,3-c][1,2,5]thiadiazole (Nz) as a strong acceptor unit symmetrically functionalized with N-(4-(1,2,2-triphenylvinyl)phenyl)carbazole as a donor and
- twist angle between the D and A units, a strong electron deficiency of the Nz unit, and electron-donating and hole-transporting natures of carbazole, TPECNz exhibits a strong deep red emission (λem = 648 nm) with a high fluorescence quantum yield of 96%, outstanding thermal property (Tg = 236 °C), and
- energy gap between HOMO/LUMO hybrid orbits and drive fluorescence emission to longer wavelengths [48][49]. In this molecular design, the strong electron-deficient naphtho[2,3-c][1,2,5]thiadiazole (Nz) [13][50][51] as an acceptor and the strong electron-donating carbazole [52] as a donor unit were used in
Organic thermally activated delayed fluorescence material with strained benzoguanidine donor
Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95
- benzoguanidine donor and compare it with the benchmark carbazole-based material (4CzIPN). Extended π-conjugation in 4BGIPN material results in yellow-green luminescence at 512 nm with a fast radiative rate of 5.5 × 10−5 s−1 and a photoluminescence quantum yield of 46% in methylcyclohexane solution. Such a
- performance in OLED devices [1]. 4CzIPN is a donor–acceptor-type system where carbazole donor ligands are bound to the benzonitrile acceptor core moiety. In this work we have substituted the carbazole donors with 5H-benzo[d]benzo[4,5]imidazo[1,2-a]imidazole (benzoguanidine) ligands to give 4BGIPN, see Figure
- 1. Benzoguanidine has an extended π-conjugation compared with carbazole and is more nitrogen-rich (three N-atoms vs one in carbazole). Thompson et al. recently reported a series of carbene–metal–amide (CMA) (metal = Cu, Ag, Au) emitters employing a benzoguanidine ligand [10]. The extended π
Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors
Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88
- example could not be found where it was used in artificial photosynthesis or RFB research. The carbazole 9-ethyldodecahydro-1H-carbazole (DEC-H12) has an oxidation potential of 0.57 vs Fc/Fc+ and can carry 6 hydrogen equivalents [74] (DEC-H12 has been classified as an amine in Figure 5). The oxidation
- carbazole heterocyclic oxidation products [75]. LOHC compounds could potentially provide both protons and electrons for artificial photosynthesis. The thermodynamics of electrochemically hydrogenating several LOHCs using a modified water-splitting device have been investigated [40]. However, other
Photoredox catalysis harvesting multiple photon or electrochemical energies
Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81
The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads
Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79
- electron donor for the construction of electron donor–acceptor TADF molecules is carbazole. However, since our aim was to study the TADF photophysics with model TADF emitters, the use of phenothiazine (PTZ) instead of carbazole presents a few advantages. First, upon connection of the electron acceptor (i.e
- ., the NI unit) to the N atom of phenothiazine, a more restricted geometry is achieved than using carbazole. This is beneficial for the orthogonal geometry and thus TADF is ensured. Second, as compared with carbazole, the use of phenothiazine in the construction of TADF emitters offers an additional
Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach
Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71
- solvent at 100 °C (Scheme 6). Finally, compounds 13 were used to prepare various arylpyrrolo- and pyrazolopyrrolizinones for diverse biological activity. In 2007, Török and co-workers [60] reported a convenient one-pot synthesis of N-sulfonyl-substituted pyrroles, indoles, and carbazole via a modified
Strategies in the synthesis of dibenzo[b,f]heteropines
Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51
- of an N-triarylated dibenzo[b,f]azepine scaffold 129 by means of Au(I)-catalysed hydroarylation was reported by Ito et al. [70]. While the attempted synthesis of an N-phenyldibenzazepine derivative 127 was unsuccessful, the authors were able to prepare a fused carbazole-dibenzo[b,f]azepine 129 in 90
- metathesis as key step in the synthesis of dibenzo[b,f]heteropines. Alkyne–aldehyde metathesis in the synthesis of dibenzo[b,f]heteropines. Hydroarylation of 9-(2-alkynylphenyl)-9H-carbazole derivatives. Oxidative coupling of bisphonium ylide intermediate to give pacharin (13). Preparation of 10,11
Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells
Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136
- a green EL with a peak brightness of 572 cd m−2 and an EQEmax of 6.8% at 4.0 V. The half-life of their device reached 218 h at a brightness of 162 cd m−2. Recently, Su et al. reported two ionic TADF emitters incorporating a pyridinium moiety, Pym-CZ and Pym-tBuCZ as the acceptor and carbazole or
Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation
Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122
- the aggregated state have not yet been performed [28]. The acceptor core BPy, coupled with carbazole derivatives, produced BPy-pTC and BPy-p3C, respectively (Scheme 1). The detailed synthetic procedures and characterization data are given in the Experimental section and in Schemes S1 and S2 in
Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor
Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115
- nickel catalyst in a single material have been reported [23][25][26][27]. For example, some of us have shown that a bipyridine ligand decorated with two carbazole groups can be polymerized to afford a heterogeneous macroligand (poly-czbpy) that coordinates nickel and serves as an active catalyst for
- metallaphotoredox catalysis in continuous flow. The heterogeneous catalyst used, based on a bipyridine ligand decorated with two carbazole groups, served as both photo- and nickel catalyst, making the reactor packing simple and reproducible. Compared with homogeneous approaches to metallaphotoredox catalysis, this
Synthesis, optical and electrochemical properties of (D–π)2-type and (D–π)2Ph-type fluorescent dyes
Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106
- with two (diphenylamino)carbazole-thiophene units as D (electron-donating group)–π (π-conjugated bridge) moiety and the (D–π)2Ph-type fluorescent dye OTK-2 with the two D–π moieties connected through a phenyl ring were derived by oxidative homocoupling of a stannyl D–π unit and Stille coupling of a
- dyes [10][11][12][13][21][22][27][28][32]. In our previous work [33], we have reported the synthesis, optical and electrochemical properties of the (D–π)2Ph-type fluorescent dye OTK-2 with two (diphenylamino)carbazole-thiophene units as D–π moiety connected through a phenyl ring (Scheme 1). The ICT
- orbital (MO) calculations. Results and Discussion Using a toluene solution containing 1,3-diiodobenzene and (diphenylamino)carbazole-thiophenestannane derivative 1 [33] in the presence of Pd(PPh3)4, the (D–π)2-type and (D–π)2Ph-type fluorescent dyes OTK-2 [33] and OTT-2 were obtained by Stille coupling of
Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons
Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83
- 7 in Figure 5), which consisted of the twisted A–π–D–π–A structure with N-(4-aminophenyl)carbazole (CzPA) as electron donor unit, pyridine as electron acceptor unit, and 9,9-dioctylfluorene (F) as π-conjugated linker [32]. Compound 7 showed remarkable dual-fluorescence properties when mixed with a
- fluorene showed enhanced planarity of the molecule. The coordination tended to be more efficient if a stronger Lewis acid was employed. The bipolar host material 35DCzPPy (14, Figure 5) was initially synthesized by Kido’s group [39]. It combines two carbazole electron donors with high triplet energy and a
Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles
Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80
- dienophiles in refluxing toluene afforded diverse spirotetrahydrocarbazoles. This reaction is an important development of the Levy reaction by using 2-methylindole to replace ethyl indole-2-acetate and successfully provides facile access to important polysubstituted spiro[carbazole-3,3'-indolines], spiro
- [carbazole-2,3'-indolines], spiro[carbazole-3,5'-pyrimidines] and spiro[carbazole-3,1'-cycloalkanes] in satisfactory yields and with high diastereoselectivity. Keywords: Diels–Alder reaction; indole; indolo-2,3-quinodimethane; Levy reaction; tetrahydrocarbazole; spirooxindole; Introduction
- carbazole derivatives also show important applications in various functional materials [4][5][6][7]. Owing to their remarkable significance, developing convenient synthetic protocols for functionalized tetrahydrocarbazoles has attracted continual attention in synthetic and pharmaceutical chemistry [8][9][10
Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines
Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52
- of TADF compounds through the selection of different electron-donating or accepting fragments opens great possibilities to tune the emission properties and rates. Here we present the synthesis of a series of novel pyrimidine–carbazole emitters and their photophysical characterization in view of
- attached through a phenylene bridge. A modification of the pyrimidine unit with CN, SCH3, and SO2CH3 functional groups at position 2 is shown to enhance the emission yield up to 0.5 with pronounced TADF activity. Keywords: carbazole; pyrimidine; RTP; synthesis; thermally activated delayed fluorescence
- ]. Moreover, the number and nature of various side units on the emitter framework can also affect the properties of TADF compounds [3]. Among the electron-donating units, 9,10-dihydroacridine, carbazole or phenoxazine derivatives often are used as D units, while the π-electron-deficient nitrogen heterocycles
Chemoselective N-acylation of indoles using thioesters as acyl source
Beilstein J. Org. Chem. 2022, 18, 89–94, doi:10.3762/bjoc.18.9
- , heterocycles, such as carbazole, can also be used as nucleophiles in this reaction. Keywords: indole; N-acylation; nucleophilic substitution; thioesters; Introduction Molecules containing N-acylindoles have attracted wide attention in the synthetic polymers and pharmaceutical industry because of their unique
- ). Interestingly, S-methyl benzothioate and S-methyl 4-methylbenzothioate could also take part in this reaction and converted into the corresponding products 3s and 3t in 93% and 96% yield, respectively. Notably, carbazole could also be acylated with thioesters and 84% yield of the desired product was obtained
- be obtained efficiently. Beside indole, carbazole can also take part in this reaction. Representative pharmaceuticals containing N-acylindole moieties. A) Strategies for the synthesis of N-acylindoles; B) thioester as dicarbonylation reagent; C) recent work of our group; D) this work. Reactions of
1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis
Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5
- amine (3-amino-N,N-dibutylaniline) under NiOAc2 catalysis to obtain the 4-arylated compound. As expected, 4-arylated-benzo[c]carbazole-5,6-dione 58 and 4-amino-1,2-naphthoquinone 59 were formed in 5% and 35% yields, respectively. However, the reaction of 18 with 3-butylamino-N,N-dibutylaniline in DMF in
- the presence of CuCl2 formed two isomers of 4-arylated-N-butylbenzo[c]carbazole-5,6-dione 60 and 4-amino-benzo[a]carbazol-5,6-dione 61 in 39% and 13% yields, respectively. These two reactions demonstrate the importance of the catalyst in complex formation with carbonyls of 18 that promote nucleophilic
- desulfoamination or nucleophilic desulfoarylation at position C4, and the following intramolecular cyclization occurs to produce 1,2-naphthoquinones fused with the benzo[a]carbazole or benzo[c]carbazole system (Scheme 17). An interesting reaction for the formation of 4-cyanoethyl-l,2-naphthoquinone from β-NQS−M
Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode
Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197
- light outcoupling in the device. Results and Discussion Synthesis The oxidative coupling conditions for the synthesis of carbazole dimers were initially applied to access the dimer of ICzTRZ [25][26]. Treating ICzTRZ with FeCl3 in dichloromethane (DCM) at room temperature for 12 hours did not lead to
- -butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole). The emission in CzSi at 488 nm, is only slightly red-shifted compared to that in toluene (Figure 4d). Gratifyingly, the ΦPL is substantially higher at 57% in 20 wt % doped CzSi film, compared to that in the 10 wt % PMMA films (Table 1). In this host
Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds
Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185
- carbazole derivatives 57 via asymmetric addition and chirality transfer. In the presence of CPA 9, axially chiral N-arylcarbazoles were obtained in moderate to good yields (51–97%) with good to excellent enatioselectivity (87–96% ee, Scheme 20a) [73]. More importantly, the same group reported the synthesis
- rearomatization-enabled central to axial chirality transfer pathway [73]. Citing the crucial role of di-carbazole-substituted arenes in OLED materials [74], Tan and co-workers have recently developed structural motifs with two chiral N-aryl axes from 2,6-diazonaphthalene 61 and carbazoles 62. For this reaction, a
Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction
Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159
- reaction and sequential aromatization process. Keywords: carbazole; chalcone; Diels–Alder reaction; maleimide; pyrrolo[3,4-c]carbazole; 3-vinylindole; Introduction Carbazole is one of the most well-known privileged nitrogen-containing heterocycles. The carbazole skeleton is widely occurring in natural
- hand, carbazole derivatives also have potential applications in optoelectronic materials, conducting polymers, and synthetic dyes [9][10][11]. Over the past decades, many efficient synthetic methodologies for functionalized carbazole derivatives have been successfully developed [12][13][14][15][16][17
- ][18]. Because indoles are readily available materials, the direct extension of indoles to carbazole skeletons has a great advantage [19][20][21][22][23][24][25][26][27]. Therefore, the Diels–Alder reaction of activated 2-vinylindolines or 3-vinylindolines with diverse dienophiles has become the most
Chemical syntheses and salient features of azulene-containing homo- and copolymers
Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139
- , in the NIR region. In addition, the azulene-2,1,3-benzothiadiazole containing D–A-type copolymers have also been used in photovoltaic device applications [43]. Azulene-carbazole copolymers The same group [44] also synthesized the azulene-carbazole-conjugated polymer 140 and a set of terpolymers 141
- –144 containing azulene-carbazole-benzothiadiazole, with varying composition of N-alkyl carbazole and benzothiadiazole units by a Suzuki protocol (Scheme 24). These polymers exhibited Mn in the range 4200–7200 Da with PDI 1.14–1.38. The oxidation potential of the benzothiadiazole-containing polymers
- 141–144 was low compared to all-azulene-carbazole polymer 140 due to the electron transfer from azulene to benzothiadiazole and, due to this, they exhibited better electrochromism. An electrochromic device (ECD) constructed with polymer 143 exhibited black to transmissive electrochromism with high
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