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Search for "carbazoles" in Full Text gives 42 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
- Michio Yamada
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- ]. In addition to anilino groups, a myriad of donor entities, including urea-substituted phenyl groups [18][19], carbazoles [20], phenothiazines [21][22], thiophenes [23][24][25][26], tetrathiafulvalenes (TTFs) [27], extended TTFs [28], ferrocenes [27][29][30][31][32][33][34][35][36][37][38][39][40][41
Graphical Abstract
Scheme 1: Pathway of the [2 + 2] CA–RE reaction of an electron-rich alkyne with TCNE or TCNQ. EDG = electron-...
Scheme 2: Reaction pathway for DMA-appended acetylene and TCNEO.
Scheme 3: Pathway of the [2 + 2] CA–RE reaction between 1 and DCFs.
Scheme 4: Sequential double [2 + 2] CA–RE reactions between 1 and TCNE.
Scheme 5: Divergent chemical transformation pathways of TCBD 6.
Scheme 6: Synthesis of 12.
Scheme 7: [2 + 2] CA–RE reaction of 1 with 14. TCE = 1,1,2,2-tetrachloroethane.
Scheme 8: Autocatalytic model proposed by Nielsen et al.
Scheme 9: Synthesis of anthracene-embedded TCBD compound 19.
Scheme 10: Sequence of the [2 + 2] CA–RE reaction between dibenzo-fused cyclooctyne or cyclooctadiyne and TCNE...
Scheme 11: [2 + 2] CA–RE reaction between the CPP derivatives and TCNE. THF = tetrahydrofuran.
Scheme 12: [2 + 2] CA–RE reaction between ethynylfullerenes 31 and TCNE and subsequent thermal rearrangement.
Scheme 13: Pathway of the [2 + 2] CA–RE reaction between TCNE and 34, followed by additional skeletal transfor...
Scheme 14: Synthesis scheme for heterocycle 38 from the reaction between TCNE and 1 in water and a surfactant.
Scheme 15: Synthesis scheme of the CDA product 41.
Scheme 16: Synthesis of rotaxanes 44 and 46 via the [2 + 2] CA–RE reaction.
Scheme 17: Synthesis of a CuI bisphenanthroline-based rotaxane 50.
Figure 1: Structures of the chiral push–pull chromophores 51–56.
Figure 2: Structures of the axially chiral TCBD 57 and DCNQ 58 bearing a C60 core.
Figure 3: Structures of the axially chiral SubPc–TCBD–aniline conjugates 59 and 60 and the subporphyrin–TCBD–...
Figure 4: Structures of 63 and the TCBD 64.
Figure 5: Structures of the fluorophore-containing TCBDs 65–67.
Figure 6: Structures of the fluorophore-containing TCBDs 68–72.
Figure 7: Structures of the urea-containing TCBDs 73–75.
Figure 8: Structures of the fullerene–TCBD and DCNQ conjugates 76–79 and their reference compounds 80–83.
Figure 9: Structures of the ZnPc–TCBD–aniline conjugates 84 and 85.
Figure 10: Structures of the ZnP–PCBD and TCBD conjugates 86–88.
Figure 11: Structures of the porphyrin-based donor–acceptor conjugates (89–104).
Figure 12: Structures of the porphyrin–PTZ or DMA conjugates 105–112.
Figure 13: Structures of the BODIPY–Acceptor–TPA or PTZ conjugates 113–116.
Figure 14: Structures of the corrole–TCBD conjugates 117 and 118.
Figure 15: Structure of the dendritic TCBD 119.
Figure 16: Structures of the TCBDs 120–126.
Figure 17: Structures of the precursor 127 and TCBDs 128–130.
Figure 18: Structures of 131–134 utilized for BHJ OSCs.
Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts
- Nils Clamor,
- Mattis Damrath,
- Thomas J. Kuczmera,
- Daniel Duvinage and
- Boris J. Nachtsheim
Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2
- Bremen, Germany 10.3762/bjoc.20.2 Abstract N-Acyl carbazoles can be efficiently produced through a single-step process using amides and cyclic diaryliodonium triflates. This convenient reaction is facilitated by copper iodide in p-xylene, using the commonly found activating ligand diglyme. We have
- tested this method with a wide range of amides and iodonium triflates, proving its versatility with numerous substrates. Beyond carbazoles, we also produced a variety of other N-heterocycles, such as acridines, phenoxazines, or phenazines, showcasing the robustness of our technique. In a broader sense
- , this new method creates two C–N bonds simultaneously based on a mono-halogenated starting material, thus allowing heterocycle formation with diminished halogen waste. Keywords: carbazoles; heteroaromatics; iodanes; metal-catalyzed; one-pot reaction; Introduction N-Acyl carbazoles are effective
Graphical Abstract
Scheme 1: Examples for direct syntheses of N-acyl heteroaromatic compounds.
Scheme 2: Scope of amides. aIsolated yields, 200 µmol scale, all reactions carried out in p-xylene, with 1.00...
Scheme 3: Scope of iodanes. aIsolated yields, 200 µmol scale, all reactions carried out in p-xylene, with 1.0...
Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions
- Karolis Leitonas,
- Brigita Vigante,
- Dmytro Volyniuk,
- Audrius Bucinskas,
- Pavels Dimitrijevs,
- Sindija Lapcinska,
- Pavel Arsenyan and
- Juozas Vidas Grazulevicius
Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139
- ) of 47.7 cd A−1, 42.8 lm W−1, and 21.2%, respectively (Figure 1). Since then, this moiety has been modified by many scientific groups to improve its electroactive properties. Various pyridine-3,5-dicarbonitriles bearing substituted carbazoles were synthesized using different donating and accepting
Graphical Abstract
Figure 1: Chemical structures of pyridine-3,5-dicarbonitrile-based TADF emitters.
Scheme 1: Synthesis of dicyanocarbazole 6. Reaction conditions: a) cyanoacetamide, piperidine, methanol, 40 °...
Scheme 2: Synthesis of dicyanocarbazoles 7–9. Reaction conditions: a) corresponding ethynyl arene, Pd(Ph3P)4 ...
Figure 2: Absorption (a, b) and PL (c, d) spectra of dilute toluene, THF, and chloroform solutions (10−5 M) a...
Figure 3: PL spectra (a) and PL decay curves (b) of air-equilibrated (as prepared) and deoxygenated toluene s...
Figure 4: Non-normalized (a) and normalized (b) PL spectra and PL decay curves (c) of the film of a 10 wt % m...
Figure 5: TGA (a) and DSC 2nd heating (b) curves of compounds 6–9.
Figure 6: CV curves of compounds 6–9.
Figure 7: Photoelectron emission spectra of the vacuum-deposited films of compounds 6–9 on glass substrates c...
Figure 8: The current transients (a) for electrons recorded at the different voltages for the vacuum-deposite...
A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices
- Suangsiri Arunlimsawat,
- Patteera Funchien,
- Pongsakorn Chasing,
- Atthapon Saenubol,
- Taweesak Sudyoadsuk and
- Vinich Promarak
Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122
- of the Nz moiety originating from its localized distribution of electrons and the high electronegativities of the N and S atoms, whereas its high HOMO level is attributed to the electron-donating property of the attached carbazoles and the π-conjugation of the carbazole–Nz–carbazole fragment. Such
Graphical Abstract
Scheme 1: Synthesis of D–A–D chromophore TPECNz.
Figure 1: a) The optimized structure and HOMO/LUMO distributions calculated by B3LYP/6-31G(d,p) method. b) Th...
Figure 2: UV–vis absorption and PL spectra in a) toluene solution (≈1 × 10−5 M) and b) thin film spin-coated ...
Figure 3: a) Normalized UV–vis absorption/PL spectra in different solvents. b) Lippert–Mataga plot of Stokes ...
Figure 4: a) PL spectra in THF/water mixtures (5 μM) with different water fractions (fw). b) Plot of relative...
Figure 5: a) DSC and TGA thermograms measured at a heating rate of 10 °C min−1 under N2 flow. b) Cyclic volta...
Figure 6: a) Schematic structure of the hole-only and electron-only MIS devices. b) Electric-field dependence ...
Figure 7: a) Schematic energy diagram of OLED and organic materials used in the device. b) EL spectra at vari...
Photoredox catalysis harvesting multiple photon or electrochemical energies
- Mattia Lepori,
- Simon Schmid and
- Joshua P. Barham
Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81
Graphical Abstract
Figure 1: Oxidative and reductive activations of organic compounds harvesting photoredox catalysis.
Figure 2: General catalytic cycles of radical ion conPET (left) and radical ion e-PRC (right).
Figure 3: “Beginner’s guide”: comparison between advantages, capacities, and prospectives of conPET and PEC.
Figure 4: A) conPET reductive dehalogenation of aryl halides with PDI. B) Reductive C–H arylation with pyrrol...
Figure 5: A) Chromoselective mono- and disubstitution or polybrominated pyrimidines with pyrroles. B) Sequent...
Figure 6: A) Synthesis of pyrrolo[1,2-a]quinolines. B) Synthesis of ullazines.
Figure 7: A) Reductive phosphorylation of aryl halides via conPET. B) Selected examples from the substrate sc...
Figure 8: A) Reductive dehalogenation of aryl halides via conPET and selected examples from the substrate sco...
Figure 9: A) Reductive C–H arylation of aryl halides via conPET (top) and selected examples from the substrat...
Figure 10: A) Reductive hydrodehalogenation of aryl halides with Mes-Acr-BF4. B) Selected examples from the su...
Figure 11: A) Reductive hydrodechlorination of aryl chlorides with 4-DPAIPN. B) Proposed formation of CO2•−. C...
Figure 12: A) Reductive conPET borylation with 3CzEPAIPN (top) and selected examples from the substrate scope ...
Figure 13: Scale-up of conPET phosphorylation with 3CzEPAIPN.
Figure 14: A) Borylation of 1d. B) Characteristics and structure of PC1 with green and red parts showing the l...
Figure 15: A) Reductive C–H arylation scope with polysulfide conPET (top) and selected examples from the subst...
Figure 16: Scale-up of A) C–H arylation and B) dehaloborylation with polysulfide photocatalysis in continuous-...
Figure 17: A) Formation of [Ir1]0 and [Ir2]0 upon PET between [Ir1]+ and Et3N. B) Mechanism of multi-photon ta...
Figure 18: A) Reductive hydrodehalogenation of aryl halides via multi-photon tandem photocatalysis. B) Selecte...
Figure 19: A) Carbonylative amidation of aryl halides in continuous flow. B) Selected examples from the substr...
Figure 20: A) General scheme for reductive (RQ) and oxidative quenching (OQ) protocols using [FeIII(btz)3](PF6)...
Figure 21: A) Carbonylative amidation of alkyl iodides with [IrIII(ppy)2(dtbbpy)]PF6. B) Selected examples fro...
Figure 22: A) Carboxylative C–N bond cleavage in cyclic amines. B) Selected examples from the substrate scope....
Figure 23: A) Formal reduction of alkenes to alkanes via transfer hydrogenation. B) Selected examples from the...
Figure 24: A) Birch-type reduction of benzenes with PMP-BPI. B) Selected examples from the substrate scope (sc...
Figure 25: Proposed mechanism of the OH− mediated conPET Birch-type reduction of benzene via generation of sol...
Figure 26: Reductive detosylation of N-tosylated amides with Mes-Acr-BF4. B) Selected examples from the substr...
Figure 27: A) Reductive detosylation of N-tosyl amides by dual PRC. B) Selected examples from the substrate sc...
Figure 28: A) Mechanism of the dual PRC based on PET between [Cu(dap)2]+ and DCA. B) Mechanism of the dual PRC...
Figure 29: A) N–O bond cleavage in Weinreb amides with anthracene. B) N–O bond cleavage in Weinreb amides rely...
Figure 30: A) Pentafluorosulfanylation and fluoride elimination. B) Mechanism of the pentafluorosulfanylation ...
Figure 31: A) α-Alkoxypentafluorosulfanylation (top) and selected examples from the substrate scope (bottom). ...
Figure 32: A) Oxidative amination of arenes with azoles catalyzed by N-Ph PTZ. B) Selected examples from the s...
Figure 33: A) C(sp3)–H bond activation by HAT via chloride oxidation by *N-Ph PTZ•+. B) Proposed mechanism for...
Figure 34: A) Recycling e-PRC C–H azolation of electron-rich arenes with pyrazoles using Mes-Acr+ as a photoca...
Figure 35: A) Radical ion e-PRC direct oxidation of unactivated arenes using TAC+ as an electro-activated phot...
Figure 36: A) Radical ion e-PRC direct oxidation of unactivated arenes using TPA as an electro-activated photo...
Figure 37: Proposed mechanism (top) and mode of preassembly (bottom).
Figure 38: A) Possible preassemblies of reactive (left) vs unreactive (right) arenes. B) Calculated spin densi...
Figure 39: A) Recycling e-PRC C(sp2 )–H acetoxylation of arenes using DDQ as a photocatalyst. B) Proposed cata...
Figure 40: Gram scale hydroxylation of benzene in a recirculated flow setup.
Figure 41: A) Radical ion e-PRC vicinal diamination of alkylarenes using TAC+ as an electro-activated photocat...
Figure 42: A) Sequential oxygenation of multiple adjacent C–H bonds under radical ion e-PRC using TAC+ as an e...
Figure 43: A) Enantioselective recycling e-PRC cyanation of benzylic C–H bonds using ADQS as photocatalyst. B)...
Figure 44: Proposed tandem mechanism by Xu and co-workers.
Figure 45: A) Enantioselective recycling e-PRC decarboxylative cyanation using Cu(acac)2, Ce(OTf)3 and a box l...
Figure 46: A) Enantioselective recycling e-PRC benzylic cyanation using Cu(MeCN)4BF4, box ligand and anthraqui...
Figure 47: A) Radical ion e-PRC acetoxyhydroxylation of aryl olefins using TAC+ as an electro-activated photoc...
Figure 48: Selected examples from the substrate scope.
Figure 49: Photoelectrochemical acetoxyhydroxylation in a recirculated flow setup.
Figure 50: A) Radical ion e-PRC aminooxygenation of aryl olefins using TAC+ as an electro-activated photocatal...
Figure 51: A) Recycling e-PRC C–H alkylation of heteroarenes with organic trifluoroborates using Mes-Acr+ as p...
Figure 52: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using CeCl3·7H2O as catalyst. B) ...
Figure 53: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using Fe(NH4)2(SO4)2·6H2O as cata...
Figure 54: A) Recycling e-PRC C–H alkylation of heteroarenes with alkyl oxalates and 4CzIPN as photocatalyst. ...
Figure 55: A) Recycling e-PRC decarboxylative C–H carbamoylation of heteroarenes using 4CzIPN as photocatalyst...
Figure 56: A) Photoelectrochemical HAT-mediated hydrocarbon activation via the chlorine radical. B) Proposed m...
Figure 57: A) Selected examples from the substrate scope. B) Gram and decagram scale semi-continuous flow PEC ...
Figure 58: A) Photoelectrochemical HAT-mediated dehydrogenative coupling of benzothiazoles with aliphatic C–H ...
Figure 59: A) Photoelectrochemical HAT activation of ethers using electro-activated TAC+ as photocatalyst. B) ...
Figure 60: Selected examples from the substrate scope.
Figure 61: A) Photoelectrochemical HAT-mediated synthesis of alkylated benzimidazo-fused isoquinolinones using...
Figure 62: A) Decoupled photoelectrochemical cerium-catalyzed oxydichlorination of alkynes using CeCl3 as cata...
Figure 63: Proposed decoupled photoelectrochemical mechanism.
Figure 64: A) Decoupled photoelectrochemical ring-opening bromination of tertiary cycloalkanols using MgBr2 as...
Figure 65: A) Recycling e-PRC ring-opening functionalization of cycloalkanols using CeCl3 as catalyst. B) Prop...
Figure 66: Selected examples from the substrate scope of the PEC ring-opening functionalization.
Figure 67: A) Radical ion e-PRC reduction of chloro- and bromoarenes using DCA as catalyst and various accepto...
Figure 68: A) Screening of different phthalimide derivatives as catalyst for the e-PRC reduction of aryl halid...
Figure 69: Screening of different organic catalysts for the e-PRC reduction of trialkylanilium salts.
Figure 70: A) e-PRC reduction of phosphonated phenols and anilinium salts. B) Selected examples from the subst...
Figure 71: A) ConPET and e-PRC reduction of 4-bromobenzonitrile using a naphthalene diimide (NDI) precatalyst ...
Figure 72: A) Radical ion e-PRC reduction of phosphinated aliphatic alcohols with n-BuO-NpMI as catalyst. B) C...
Figure 73: Selected examples from the substrate scope.
Figure 74: A) Recycling e-PRC reductive dimerization of benzylic chlorides using a [Cu2] catalyst. B) Proposed...
Figure 75: A) Decoupled photoelectrochemical C–H alkylation of heteroarenes through deamination of Katritzky s...
Figure 76: Proposed mechanism by Chen and co-workers.
1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis
- Ruan Carlos B. Ribeiro,
- Patricia G. Ferreira,
- Amanda de A. Borges,
- Luana da S. M. Forezi,
- Fernando de Carvalho da Silva and
- Vitor F. Ferreira
Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5
- naphtho[1,2-d]oxazoles from β-NQS. A) Arylation and vinylation of β-NQS catalyzed by Ni(II) salts. B) Transformation of the 1,2-dicarbonyl group in the fused imidazo[4,5-a] heterocycle. Benzo[a]carbazole and benzo[c]carbazoles fused with 1,2-naphthoquinone. Synthesis of 1,2-naphthoquinones having a C=C
Graphical Abstract
Figure 1: Naphthoquinones are commonly used in organic synthesis.
Figure 2: Some important natural and synthetic naphthoquinones.
Scheme 1: Synthetic studies of BNQs and reactions with amines.
Scheme 2: Methods described for the synthesis of β-NQS.
Figure 3: Drugs detected using β-NQSNa.
Scheme 3: Reactions between β-NQS and amines.
Scheme 4: Isomerization of 4-arylamino-1,2-naphthoquinones.
Scheme 5: Synthesis of unsymmetrical 2-amino-4-imino compounds.
Scheme 6: Synthesis of bis(isoxazolyl)naphthoquinones from β-NQS.
Scheme 7: The reaction of β-NQS with 30 followed by cycle condensation.
Scheme 8: Synthesis of 4-(2-amino-5-selenothiazoles)-1,2-naphthoquinones.
Scheme 9: Synthesis of amino- and phenoxy-1,2-naphthoquinones.
Scheme 10: Synthesis of 4-semicarbazide-1,2-naphthoquinone.
Scheme 11: Reactions of 4-azido-1,2-naphthoquinone.
Figure 4: Modifications that can be easily carried out from the products of β-NQS 8.
Scheme 12: Derivatives of 1,2-naphthoquinones obtained from β-NQS.
Scheme 13: Oximes as well as 4-amino- and 4-phenoxy-1,2-naphthoquinone as potential anti-inflammatory agents.
Scheme 14: Synthesis of triazoles from β-NQS.
Scheme 15: Synthesis of naphtho[1,2-d]oxazoles from β-NQS.
Scheme 16: A) Arylation and vinylation of β-NQS catalyzed by Ni(II) salts. B) Transformation of the 1,2-dicarb...
Scheme 17: Benzo[a]carbazole and benzo[c]carbazoles fused with 1,2-naphthoquinone.
Scheme 18: Synthesis of 1,2-naphthoquinones having a C=C bond from β-NQS. Method A: NaOH, EtOH/H2O, 40 °C, 2 h...
Scheme 19: C=C bond formation from β-NQS and substituted acetonitriles.
Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds
- Alemayehu Gashaw Woldegiorgis and
- Xufeng Lin
Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185
- 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
Graphical Abstract
Figure 1: Representative examples of axially chiral biaryls, heterobiaryls, spiranes and allenes as ligands a...
Figure 2: Selected examples of axially chiral drugs and bioactive molecules.
Figure 3: Axially chiral functional materials and supramolecules.
Figure 4: Important chiral phosphoric acid scaffolds used in this review.
Scheme 1: Atroposelective aryl–aryl-bond formation by employing a facile [3,3]-sigmatropic rearrangement.
Scheme 2: Atroposelective synthesis of axially chiral biaryl amino alcohols 5.
Scheme 3: The enantioselective reaction of quinone and 2-naphthol derivatives.
Scheme 4: Enantioselective synthesis of multisubstituted biaryls.
Scheme 5: Enantioselective synthesis of axially chiral quinoline-derived biaryl atropisomers mediated by chir...
Scheme 6: Pd-Catalyzed atroposelective C–H olefination of biarylamines.
Scheme 7: Palladium-catalyzed directed atroposelective C–H allylation.
Scheme 8: Enantioselective synthesis of axially chiral (a) aryl indoles and (b) biaryldiols.
Scheme 9: Asymmetric arylation of indoles enabled by azo groups.
Scheme 10: Proposed mechanism for the asymmetric arylation of indoles.
Scheme 11: Enantioselective synthesis of axially chiral N-arylindoles [38].
Scheme 12: Enantioselective [3 + 2] formal cycloaddition and central-to-axial chirality conversion.
Scheme 13: Organocatalytic atroposelective arene functionalization of nitrosonaphthalene with indoles.
Scheme 14: Proposed reaction mechanism for the atroposelective arene functionalization of nitrosonaphthalenes.
Scheme 15: Asymmetric construction of axially chiral naphthylindoles [65].
Scheme 16: Enantioselective synthesis of axially chiral 3,3’-bisindoles [66].
Scheme 17: Atroposelective synthesis of 3,3’-bisiindoles bearing axial and central chirality.
Scheme 18: Enantioselective synthesis of axially chiral 3,3’-bisindoles bearing single axial chirality.
Scheme 19: Enantioselective reaction of azonaphthalenes with various pyrazolones.
Scheme 20: Enantioselective and atroposelective synthesis of axially chiral N-arylcarbazoles [73].
Scheme 21: Atroposelective cyclodehydration reaction.
Scheme 22: Atroposelective construction of axially chiral N-arylbenzimidazoles [78].
Scheme 23: Proposed reaction mechanism for the atroposelective synthesis of axially chiral N-arylbenzimidazole...
Scheme 24: Atroposelective synthesis of axially chiral arylpyrroles [21].
Scheme 25: Synthesis of axially chiral arylquinazolinones and its reaction pathway [35].
Scheme 26: Synthesis of axially chiral aryquinoline by Friedländer heteroannulation reaction and its proposed...
Scheme 27: Povarov cycloaddition–oxidative chirality conversion process.
Scheme 28: Atroposelective synthesis of oxindole-based axially chiral styrenes via kinetic resolution.
Scheme 29: Synthesis of axially chiral alkene-indole frame works [45].
Scheme 30: Proposed reaction mechanism for axially chiral alkene-indoles.
Scheme 31: Atroposelective C–H aminations of N-aryl-2-naphthylamines with azodicarboxylates.
Scheme 32: Synthesis of brominated atropisomeric N-arylquinoids.
Scheme 33: The enantioselective syntheses of axially chiral SPINOL derivatives.
Scheme 34: γ-Addition reaction of various 2,3-disubstituted indoles to β,γ-alkynyl-α-imino esters.
Scheme 35: Regio- and stereoselective γ-addition reactions of isoxazol-5(4H)-ones to β,γ-alkynyl-α-imino ester...
Scheme 36: Synthesis of chiral tetrasubstituted allenes and naphthopyrans.
Scheme 37: Asymmetric remote 1,8-conjugate additions of thiazolones and azlactones to propargyl alcohols.
Scheme 38: Synthesis of chiral allenes from 1-substituted 2-naphthols [107].
Visible-light-mediated copper photocatalysis for organic syntheses
- Yajing Zhang,
- Qian Wang,
- Zongsheng Yan,
- Donglai Ma and
- Yuguang Zheng
Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169
- transferred electrons to organic halides, thereby achieving the cross-coupling. The detailed mechanistic studies are shown in section 3.2. In 2013, Fu and co-workers [81] reported the photoinduced copper-catalyzed alkylation of carbazoles 41 with alkyl halides 42 and completed the corresponding mechanistic
- ] discovered the asymmetric cross-coupling of racemic tertiary alkyl halides 43 with carbazoles or indoles 44 in the CuI/chiral phosphine system. Under irradiation conditions, excitation of the copper–nucleophile complex A results in the excited state species B that engages in the electron transfer with the
- alkyl halide to generate a copperII–nucleophile complex C and an alkyl radical. The formation of the R–Nu bond might occur through an in-cage pathway involving complex C (Scheme 20). In addition to carbazoles, the authors further described the C–N coupling of organic halides 45 with amides [83] and
Graphical Abstract
Scheme 1: Photoredox catalysis mechanism of [Ru(bpy)3]2+.
Scheme 2: Photoredox catalysis mechanism of CuI.
Scheme 3: Ligands and CuI complexes.
Scheme 4: Mechanism of CuI-based photocatalysis.
Scheme 5: Mechanisms of CuI–substrate complexes.
Scheme 6: Mechanism of CuII-base photocatalysis.
Scheme 7: Olefinic C–H functionalization and allylic alkylation.
Scheme 8: Cross-coupling of unactivated alkenes and CF3SO2Cl.
Scheme 9: Chlorosulfonylation/cyanofluoroalkylation of alkenes.
Scheme 10: Hydroamination of alkenes.
Scheme 11: Cross-coupling reaction of alkenes, alkyl halides with nucleophiles.
Scheme 12: Cross-coupling of alkenes with oxime esters.
Scheme 13: Oxo-azidation of vinyl arenes.
Scheme 14: Azidation/difunctionalization of vinyl arenes.
Scheme 15: Photoinitiated copper-catalyzed Sonogashira reaction.
Scheme 16: Alkyne functionalization reactions.
Scheme 17: Alkynylation of dihydroquinoxalin-2-ones with terminal alkynes.
Scheme 18: Decarboxylative alkynylation of redox-active esters.
Scheme 19: Aerobic oxidative C(sp)–S coupling reaction.
Scheme 20: Copper-catalyzed alkylation of carbazoles with alkyl halides.
Scheme 21: C–N coupling of organic halides with amides and aliphatic amines.
Scheme 22: Copper-catalyzed C–X (N, S, O) bond formation reactions.
Scheme 23: Arylation of C(sp2)–H bonds of azoles.
Scheme 24: C–C cross-coupling of aryl halides and heteroarenes.
Scheme 25: Benzylic or α-amino C–H functionalization.
Scheme 26: α-Amino C–H functionalization of aromatic amines.
Scheme 27: C–H functionalization of aromatic amines.
Scheme 28: α-Amino-C–H and alkyl C–H functionalization reactions.
Scheme 29: Other copper-photocatalyzed reactions.
Scheme 30: Cross-coupling of oxime esters with phenols or amines.
Scheme 31: Alkylation of heteroarene N-oxides.
Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction
- Ren-Jie Fang,
- Chen Yan,
- Jing Sun,
- Ying Han and
- Chao-Guo Yan
Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159
- diastereoisomers of tetrahydropyrrolo[3,4-c]carbazoles, which can be dehydrogenated by DDQ oxidation in acetonitrile at room temperature to give the aromatized pyrrolo[3,4-c]carbazoles in high yields. On the other hand, the one-pot reaction of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones with chalcones or
- benzylideneacetone in acetonitrile in the presence of p-TsOH and DDQ resulted in polyfunctionalized carbazoles in satisfactory yields. The reaction mechanism included the DDQ oxidative dehydrogenation of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones to the corresponding 3-vinylindoles, their acid-catalyzed Diels–Alder
- convenient synthesis of polyfunctionalized carbazole derivatives. Results and Discussion According to our previously established reaction conditions for the preparation of spiro[indoline-3,5'-pyrrolo[3,4-c]carbazoles] [48], an equivalent amount of 3-(indol-3-yl)maleimide with chalcone was stirred in toluene
Graphical Abstract
Figure 1: Representative bioactive carbazole derivatives.
Scheme 1: Synthesis of tetrahydropyrrolo[3,4-c]carbazoles 3a and 3b.
Figure 2: Single crystal structure of the isomer 3a.
Figure 3: Single crystal structure of the isomer 3b.
Figure 4: Single crystal structure of the isomer 4g.
Scheme 2: Proposed domino reaction mechanism for the formation of carbazoles 6.
Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation
- Dongyang Chen and
- Eli Zysman-Colman
Beilstein J. Org. Chem. 2021, 17, 210–223, doi:10.3762/bjoc.17.21
- results showed that when the carbazoles were both located ortho to the cyano acceptor the molecule (2,6-2CzBN) possessed a highly twisted structure and a corresponding small ΔEST (0.27 eV in toluene). The ΔESTs increased to 0.41 (2,4-2CzBN) and 0.40 eV (3,5-2CzBN) in toluene when at least one of the
- carbazoles was disposed meta or para to the cyano acceptor [19]. OLEDs fabricated using 2,6-2CzBN as the emitter exhibited deep blue emission with λEL = 418 nm and CIE coordinate of (0.15, 0.05); however, due to the low photoluminescence quantum yields (ΦPLs) (28% in 10 wt % DPEPO films) and relatively slow
- located on the central benzene ring and the acceptor group while the HOMOs are mainly localized on the carbazoles, thereby leading to small ΔESTs. The calculated ΔESTs for 2CzSCF3/2CzSF5 are 0.22 eV and 0.07 eV, respectively, which are comparable to the calculated results for 2CzBN (0.18 eV) and 2CzTRZ
Graphical Abstract
Figure 1: Molecular structures of emitters discussed in this work.
Figure 2: a) Calculated HOMO, LUMO, S1 and T1 energies, as well as HOMO and LUMO topologies of PhCF3, PhOCF3, ...
Figure 3: Calculated HOMO, LUMO, S1 and T1 energies, as well as HOMO and LUMO topologies of 2CzCF3, 2CzOCF3, ...
Figure 4: Calculated HOMO, LUMO, S1 and T1 energies, as well as HOMO and LUMO topologies of 2CzBN, 2CzTRZ, an...
Figure 5: HOMO and LUMO distribution, HONTO and LUNTO of lowest singlet (S1) and triplet excited (T1) states ...
Figure 6: HOMO and LUMO distribution, HONTO and LUNTO of lowest singlet (S1) and triplet excited (T1) states ...
Figure 7: Calculated HOMO, LUMO, S1 and T1 energies, as well as HOMO and LUMO topologies of 5CzCF3, 5CzOCF3, ...
Figure 8: Calculated HOMO, LUMO, S1 and T1 energies, as well as HOMO and LUMO topologies of 5CzBN, 5CzTRZ, an...
Figure 9: HOMO and LUMO distribution, HONTO and LUNTO of lowest singlet (S1) and triplet excited (T1) states ...
Figure 10: HOMO and LUMO distribution, HONTO and LUNTO of lowest singlet (S1) and triplet excited (T1) states ...
Figure 11: HONTOs and LUNTOs of 2CzCF3 in higher excited states (isovalue = 0.02).
Figure 12: HONTOs and LUNTOs of 5CzCF3 in higher excited states (isovalue = 0.02).
Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring
- Daria I. Tonkoglazova,
- Anna V. Gulevskaya,
- Konstantin A. Chistyakov and
- Olga I. Askalepova
Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2
- -2-carbazolylpyridine 6 in 74% yield (Scheme 3). Electrophilic cyclizations of 3-alkynyl-2-carbazolylazines 2a,b and 6 into azine-fused carbazoles 7a–c were carried out with ICl in dry acetonitrile at room temperature in the dark (Table 3). In the cases of compounds 2a,b, the reaction was found to be
Graphical Abstract
Scheme 1: Overview of the synthetic methods for the carbazole-based heterohelicenes. i) Pd2dba3, xantphos, K3...
Scheme 2: Synthetic strategy for the carbazole-based [6]helicenes fused with an azine ring.
Scheme 3: Sonogashira coupling of compound 4b with phenylacetylene. i) Pd(PPh3)2Cl2, CuI, iPr2NH, DMSO, 80 °C...
Figure 1: Molecular structure of carbazole-based [6]helicenes 10a (a), 10b (b) and 10c (c) (X-ray data).
Figure 2: Crystal packing of carbazole-based [6]helicenes 10a (a, b), 10b (c,d) and 10c (e). Hydrogen atoms a...
Synthesis and characterization of S,N-heterotetracenes
- Astrid Vogt,
- Florian Henne,
- Christoph Wetzel,
- Elena Mena-Osteritz and
- Peter Bäuerle
Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214
- provide carbazoles covering a wide substrate and functional group spectrum [41]. Moreover, penta- and heptafused heteroacenes were prepared by the Cadogan reaction by annulation of nitrophenyl or nitrobenzothienyl precursors [42][43][44][45]. In this respect, we recently reported a Cadogan cyclization of
Graphical Abstract
Figure 1: Heteroacenes: tetrathienoacene (TTA), S,N-heteroacenes SN4, SN4', and SN4''.
Scheme 1: Synthesis of fused S,N-heterotetracene SN4 9 starting from thieno[3,2-b]thiophene (1).
Scheme 2: Synthesis of parent H-SN4 13 via the azide route.
Scheme 3: Synthesis of tetracyclic H-SN4 13 via the Cadogan route.
Scheme 4: Synthesis of tetracyclic indole derivative 19 via the Cadogan route.
Scheme 5: Synthesis of hexacyclic heteroacene SN4' 22 via the Cadogan route.
Scheme 6: Synthesis of heterotetracene SN4'' 33 via the azide and Buchwald–Hartwig amination route.
Figure 2: UV–vis absorption spectra of TTA, Hex-SN4 9, Pr-SN4'' 33 and fluorescence spectrum of 33 in THF at ...
Figure 3: Energy diagram of the frontier molecular orbitals of heterotetracenes TTA, 9, 13, 19, 22, and 33, a...
Recent developments in enantioselective photocatalysis
- Callum Prentice,
- James Morrisson,
- Andrew D. Smith and
- Eli Zysman-Colman
Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197
Graphical Abstract
Scheme 1: Amine/photoredox-catalysed α-alkylation of aldehydes with alkyl bromides bearing electron-withdrawi...
Scheme 2: Amine/HAT/photoredox-catalysed α-functionalisation of aldehydes using alkenes.
Scheme 3: Amine/cobalt/photoredox-catalysed α-functionalisation of ketones and THIQs.
Scheme 4: Amine/photoredox-catalysed α-functionalisation of aldehydes or ketones with imines. (a) Using keton...
Scheme 5: Bifunctional amine/photoredox-catalysed enantioselective α-functionalisation of aldehydes.
Scheme 6: Bifunctional amine/photoredox-catalysed α-functionalisation of aldehydes using amine catalysts via ...
Scheme 7: Amine/photoredox-catalysed RCA of iminium ion intermediates. (a) Synthesis of quaternary stereocent...
Scheme 8: Bifunctional amine/photoredox-catalysed RCA of enones in a radical chain reaction initiated by an i...
Scheme 9: Bifunctional amine/photoredox-catalysed RCA reactions of iminium ions with different radical precur...
Scheme 10: Bifunctional amine/photoredox-catalysed radical cascade reactions between enones and alkenes with a...
Scheme 11: Amine/photocatalysed photocycloadditions of iminium ion intermediates. (a) External photocatalyst u...
Scheme 12: Amine/photoredox-catalysed addition of acrolein (94) to iminium ions.
Scheme 13: Dual NHC/photoredox-catalysed acylation of THIQs.
Scheme 14: NHC/photocatalysed spirocyclisation via photoisomerisation of an extended Breslow intermediate.
Scheme 15: CPA/photoredox-catalysed aza-pinacol cyclisation.
Scheme 16: CPA/photoredox-catalysed Minisci-type reaction between azaarenes and α-amino radicals.
Scheme 17: CPA/photoredox-catalysed radical additions to azaarenes. (a) α-Amino radical or ketyl radical addit...
Scheme 18: CPA/photoredox-catalysed reduction of azaarene-derived substrates. (a) Reduction of ketones. (b) Ex...
Scheme 19: CPA/photoredox-catalysed radical coupling reactions of α-amino radicals with α-carbonyl radicals. (...
Scheme 20: CPA/photoredox-catalysed Povarov reaction.
Scheme 21: CPA/photoredox-catalysed reactions with imines. (a) Decarboxylative imine generation followed by Po...
Scheme 22: Bifunctional CPA/photocatalysed [2 + 2] photocycloadditions.
Scheme 23: PTC/photocatalysed oxygenation of 1-indanone-derived β-keto esters.
Scheme 24: PTC/photoredox-catalysed perfluoroalkylation of 1-indanone-derived β-keto esters via a radical chai...
Scheme 25: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloadditions of quinolon...
Scheme 26: Bifunctional hydrogen bonding/photocatalysed intramolecular RCA cyclisation of a quinolone.
Scheme 27: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloadditions of quinolon...
Scheme 28: Bifunctional hydrogen bonding/photocatalysed [2 + 2] photocycloaddition reactions. (a) First use of...
Scheme 29: Bifunctional hydrogen bonding/photocatalysed deracemisation of allenes.
Scheme 30: Bifunctional hydrogen bonding/photocatalysed deracemisation reactions. (a) Deracemisation of sulfox...
Scheme 31: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloaddition of coumarins....
Scheme 32: Bifunctional hydrogen bonding/photocatalysed [2 + 2] photocycloadditions of quinolones. (a) Intramo...
Scheme 33: Hydrogen bonding/photocatalysed formal arylation of benzofuranones.
Scheme 34: Hydrogen bonding/photoredox-catalysed dehalogenative protonation of α,α-chlorofluoro ketones.
Scheme 35: Hydrogen bonding/photoredox-catalysed reductions. (a) Reduction of 1,2-diketones. (b) Reduction of ...
Scheme 36: Hydrogen bonding/HAT/photocatalysed deracemisation of cyclic ureas.
Scheme 37: Hydrogen bonding/HAT/photoredox-catalysed synthesis of cyclic sulfonamides.
Scheme 38: Hydrogen bonding/photoredox-catalysed reaction between imines and indoles.
Scheme 39: Chiral cation/photoredox-catalysed radical coupling of two α-amino radicals.
Scheme 40: Chiral phosphate/photoredox-catalysed hydroetherfication of alkenols.
Scheme 41: Chiral phosphate/photoredox-catalysed synthesis of pyrroloindolines.
Scheme 42: Chiral anion/photoredox-catalysed radical cation Diels–Alder reaction.
Scheme 43: Lewis acid/photoredox-catalysed cycloadditions of carbonyls. (a) Formal [2 + 2] cycloaddition of en...
Scheme 44: Lewis acid/photoredox-catalysed RCA reaction using a scandium Lewis acid between α-amino radicals a...
Scheme 45: Lewis acid/photoredox-catalysed RCA reaction using a copper Lewis acid between α-amino radicals and...
Scheme 46: Lewis acid/photoredox-catalysed synthesis of 1,2-amino alcohols from aldehydes and nitrones using a...
Scheme 47: Lewis acid/photocatalysed [2 + 2] photocycloadditions of enones and alkenes.
Scheme 48: Meggers’s chiral-at-metal catalysts.
Scheme 49: Lewis acid/photoredox-catalysed α-functionalisation of ketones with alkyl bromides bearing electron...
Scheme 50: Bifunctional Lewis acid/photoredox-catalysed radical coupling reaction using α-chloroketones and α-...
Scheme 51: Lewis acid/photocatalysed RCA of enones. (a) Using aldehydes as acyl radical precursors. (b) Other ...
Scheme 52: Bifunctional Lewis acid/photocatalysis for a photocycloaddition of enones.
Scheme 53: Lewis acid/photoredox-catalysed RCA reactions of enones using DHPs as radical precursors.
Scheme 54: Lewis acid/photoredox-catalysed functionalisation of β-ketoesters. (a) Hydroxylation reaction catal...
Scheme 55: Bifunctional copper-photocatalysed alkylation of imines.
Scheme 56: Copper/photocatalysed alkylation of imines. (a) Bifunctional copper catalysis using α-silyl amines....
Scheme 57: Bifunctional Lewis acid/photocatalysed intramolecular [2 + 2] photocycloaddition.
Scheme 58: Bifunctional Lewis acid/photocatalysed [2 + 2] photocycloadditions (a) Intramolecular cycloaddition...
Scheme 59: Bifunctional Lewis acid/photocatalysed rearrangement of 2,4-dieneones.
Scheme 60: Lewis acid/photocatalysed [2 + 2] cycloadditions of cinnamate esters and styrenes.
Scheme 61: Nickel/photoredox-catalysed arylation of α-amino acids using aryl bromides.
Scheme 62: Nickel/photoredox catalysis. (a) Desymmetrisation of cyclic meso-anhydrides using benzyl trifluorob...
Scheme 63: Nickel/photoredox catalysis for the acyl-carbamoylation of alkenes with aldehydes using TBADT as a ...
Scheme 64: Bifunctional copper/photoredox-catalysed C–N coupling between α-chloro amides and carbazoles or ind...
Scheme 65: Bifunctional copper/photoredox-catalysed difunctionalisation of alkenes with alkynes and alkyl or a...
Scheme 66: Copper/photoredox-catalysed decarboxylative cyanation of benzyl phthalimide esters.
Scheme 67: Copper/photoredox-catalysed cyanation reactions using TMSCN. (a) Propargylic cyanation (b) Ring ope...
Scheme 68: Palladium/photoredox-catalysed allylic alkylation reactions. (a) Using alkyl DHPs as radical precur...
Scheme 69: Manganese/photoredox-catalysed epoxidation of terminal alkenes.
Scheme 70: Chromium/photoredox-catalysed allylation of aldehydes.
Scheme 71: Enzyme/photoredox-catalysed dehalogenation of halolactones.
Scheme 72: Enzyme/photoredox-catalysed dehalogenative cyclisation.
Scheme 73: Enzyme/photoredox-catalysed reduction of cyclic imines.
Scheme 74: Enzyme/photocatalysed enantioselective reduction of electron-deficient alkenes as mixtures of (E)/(Z...
Scheme 75: Enzyme/photoredox catalysis. (a) Deacetoxylation of cyclic ketones. (b) Reduction of heteroaromatic...
Scheme 76: Enzyme/photoredox-catalysed synthesis of indole-3-ones from 2-arylindoles.
Scheme 77: Enzyme/HAT/photoredox catalysis for the DKR of primary amines.
Scheme 78: Bifunctional enzyme/photoredox-catalysed benzylic C–H hydroxylation of trifluoromethylated arenes.
When metal-catalyzed C–H functionalization meets visible-light photocatalysis
- Lucas Guillemard and
- Joanna Wencel-Delord
Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147
- . Thus, an efficient method for the synthesis of carbazoles via an intramolecular C–H amination was developed, using N-substituted 2-aminobiaryl derivatives as the substrates (Figure 11) [76]. This procedure was carried out at 80 °C and led to the formation of various interesting coupling products with
- hydrogen, benzyl, or alkyl, resulted in the shut of reactivity and no formation of the corresponding N-substituted carbazoles was observed. Concerning the mechanism, the carbazole-forming reaction also required aerobic conditions in order to reoxidize the Ir-photocatalyst with molecular oxygen (Figure 12
Graphical Abstract
Figure 1: Concept of dual synergistic catalysis.
Figure 2: Classification of catalytic systems involving two catalysts.
Figure 3: General mechanism for the dual nickel/photoredox catalytic system.
Figure 4: General mechanisms for C–H activation catalysis involving different reoxidation strategies.
Figure 5: Indole synthesis via dual C–H activation/photoredox catalysis.
Figure 6: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 7: Oxidative Heck reaction on arenes via the dual catalysis.
Figure 8: Proposed mechanism for the Heck reaction on arenes via dual catalysis.
Figure 9: Oxidative Heck reaction on phenols via the dual catalysis.
Figure 10: Proposed mechanism for the Heck reaction on phenols via dual catalysis.
Figure 11: Carbazole synthesis via dual C–H activation/photoredox catalysis.
Figure 12: Proposed mechanism for the carbazole synthesis via dual catalysis.
Figure 13: Carbonylation of enamides via the dual C–H activation/photoredox catalysis.
Figure 14: Proposed mechanism for carbonylation of enamides via dual catalysis.
Figure 15: Annulation of benzamides via the dual C–H activation/photoredox catalysis.
Figure 16: Proposed mechanism for the annulation of benzamides via dual catalysis.
Figure 17: Synthesis of indoles via the dual C–H activation/photoredox catalysis.
Figure 18: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 19: General concept of dual catalysis merging C–H activation and photoredox catalysis.
Figure 20: The first example of dual catalysis merging C–H activation and photoredox catalysis.
Figure 21: Proposed mechanism for the C–H arylation with diazonium salts via dual catalysis.
Figure 22: Dual catalysis merging C–H activation/photoredox using diaryliodonium salts.
Figure 23: Direct arylation via the dual catalytic system reported by Xu.
Figure 24: Direct arylation via dual catalytic system reported by Balaraman.
Figure 25: Direct arylation via dual catalytic system reported by Guo.
Figure 26: C(sp3)–H bond arylation via the dual Pd/photoredox catalytic system.
Figure 27: Acetanilide derivatives acylation via the dual C–H activation/photoredox catalysis.
Figure 28: Proposed mechanism for the C–H acylation with α-ketoacids via dual catalysis.
Figure 29: Acylation of azobenzenes via the dual catalysis C–H activation/photoredox.
Figure 30: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 31: Proposed mechanism for the C2-acylation of indoles with aldehydes via dual catalysis.
Figure 32: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 33: Perfluoroalkylation of arenes via the dual C–H activation/photoredox catalysis.
Figure 34: Proposed mechanism for perfluoroalkylation of arenes via dual catalysis.
Figure 35: Sulfonylation of 1-naphthylamides via the dual C–H activation/photoredox catalysis.
Figure 36: Proposed mechanism for sulfonylation of 1-naphthylamides via dual catalysis.
Figure 37: meta-C–H Alkylation of arenes via visible-light metallaphotocatalysis.
Figure 38: Alternative procedure for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 39: Proposed mechanism for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 40: C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 41: Proposed mechanism for C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 42: Undirected C–H aryl–aryl cross coupling via dual gold/photoredox catalysis.
Figure 43: Proposed mechanism for the undirected C–H aryl–aryl cross-coupling via dual catalysis.
Figure 44: Undirected C–H arylation of (hetero)arenes via dual manganese/photoredox catalysis.
Figure 45: Proposed mechanism for the undirected arylation of (hetero)arenes via dual catalysis.
Figure 46: Photoinduced C–H arylation of azoles via copper catalysis.
Figure 47: Photo-induced C–H chalcogenation of azoles via copper catalysis.
Figure 48: Decarboxylative C–H adamantylation of azoles via dual cobalt/photoredox catalysis.
Figure 49: Proposed mechanism for the C–H adamantylation of azoles via dual catalysis.
Figure 50: General mechanisms for the “classical” (left) and Cu-free variant (right) Sonogoshira reaction.
Figure 51: First example of a dual palladium/photoredox catalysis for Sonogashira-type couplings.
Figure 52: Arylation of terminal alkynes with diazonium salts via dual gold/photoredox catalysis.
Figure 53: Proposed mechanism for the arylation of terminal alkynes via dual catalysis.
Figure 54: C–H Alkylation of alcohols promoted by H-atom transfer (HAT).
Figure 55: Proposed mechanism for the C–H alkylation of alcohols promoted by HAT.
Figure 56: C(sp3)–H arylation of latent nucleophiles promoted by H-atom transfer.
Figure 57: Proposed mechanism for the C(sp3)–H arylation of latent nucleophiles promoted by HAT.
Figure 58: Direct α-arylation of alcohols promoted by H-atom transfer.
Figure 59: Proposed mechanism for the direct α-arylation of alcohols promoted by HAT.
Figure 60: C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 61: Proposed mechanism for the C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 62: C–H functionalization of nucleophiles via excited ketone/nickel dual catalysis.
Figure 63: Proposed mechanism for the C–H functionalization enabled by excited ketones.
Figure 64: Selective sp3–sp3 cross-coupling promoted by H-atom transfer.
Figure 65: Proposed mechanism for the selective sp3–sp3 cross-coupling promoted by HAT.
Figure 66: Direct C(sp3)–H acylation of amines via dual Ni/photoredox catalysis.
Figure 67: Proposed mechanism for the C–H acylation of amines via dual Ni/photoredox catalysis.
Figure 68: C–H hydroalkylation of internal alkynes via dual Ni/photoredox catalysis.
Figure 69: Proposed mechanism for the C–H hydroalkylation of internal alkynes.
Figure 70: Alternative procedure for the C–H hydroalkylation of ynones, ynoates, and ynamides.
Figure 71: Allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 72: Proposed mechanism for the allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 73: Asymmetric allylation of aldehydes via dual Cr/photoredox catalysis.
Figure 74: Proposed mechanism for the asymmetric allylation of aldehydes via dual catalysis.
Figure 75: Aldehyde C–H functionalization promoted by H-atom transfer.
Figure 76: Proposed mechanism for the C–H functionalization of aldehydes promoted by HAT.
Figure 77: Direct C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 78: Proposed mechanism for the C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 79: Direct C–H trifluoromethylation of strong aliphatic bonds promoted by HAT.
Figure 80: Proposed mechanism for the C–H trifluoromethylation of strong aliphatic bonds.
Recent advances in photocatalyzed reactions using well-defined copper(I) complexes
- Mingbing Zhong,
- Xavier Pannecoucke,
- Philippe Jubault and
- Thomas Poisson
Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42
- large panel of carbazoles. The selectivity of the reaction using an unsymmetrical triarylamine depended on the electronic density of the aromatic ring, furnishing, in some cases constitutional isomers. Importantly, in the case of heteroaryl-substituted triarylamines, the heterocycle was incorporated in
Graphical Abstract
Scheme 1: [Cu(I)(dap)2]Cl-catalyzed ATRA reaction under green light irradiation.
Scheme 2: Photocatalytic allylation of α-haloketones.
Scheme 3: [Cu(I)(dap)2]Cl-photocatalyzed chlorosulfonylation and chlorotrifluoromethylation of alkenes.
Scheme 4: Photocatalytic perfluoroalkylchlorination of electron-deficient alkenes using the Sauvage catalyst.
Scheme 5: Photocatalytic synthesis of fluorinated sultones.
Scheme 6: Photocatalyzed haloperfluoroalkylation of alkenes and alkynes.
Scheme 7: Chlorosulfonylation of alkenes catalyzed by [Cu(I)(dap)2]Cl. aNo Na2CO3 was added. b1 equiv of Na2CO...
Scheme 8: Copper-photocatalyzed reductive allylation of diaryliodonium salts.
Scheme 9: Copper-photocatalyzed azidomethoxylation of olefins.
Scheme 10: Benzylic azidation initiated by [Cu(I)(dap)2]Cl.
Scheme 11: Trifluoromethyl methoxylation of styryl derivatives using [Cu(I)(dap)2]PF6. All redox potentials ar...
Scheme 12: Trifluoromethylation of silyl enol ethers.
Scheme 13: Synthesis of annulated heterocycles upon oxidation with the Sauvage catalyst.
Scheme 14: Oxoazidation of styrene derivatives using [Cu(dap)2]Cl as a precatalyst.
Scheme 15: [Cu(I)(dpp)(binc)]PF6-catalyzed ATRA reaction.
Scheme 16: Allylation reaction of α-bromomalonate catalyzed by [Cu(I)(dpp)(binc)]PF6 following an ATRA mechani...
Scheme 17: Bromo/tribromomethylation reaction using [Cu(I)(dmp)(BINAP)]PF6.
Scheme 18: Chlorotrifluoromethylation of alkenes catalyzed by [Cu(I)(N^N)(xantphos)]PF6.
Scheme 19: Chlorosulfonylation of styrene and alkyne derivatives by ATRA reactions.
Scheme 20: Reduction of aryl and alkyl halides with the complex [Cu(I)(bcp)(DPEPhos)]PF6. aIrradiation was car...
Scheme 21: Meerwein arylation of electron-rich aromatic derivatives and 5-exo-trig cyclization catalyzed by th...
Scheme 22: [Cu(I)(bcp)(DPEPhos)]PF6-photocatalyzed synthesis of alkaloids. aYield over two steps (cyclization ...
Scheme 23: Copper-photocatalyzed decarboxylative amination of NHP esters.
Scheme 24: Photocatalytic decarboxylative alkynylation using [Cu(I)(dq)(binap)]BF4.
Scheme 25: Copper-photocatalyzed alkylation of glycine esters.
Scheme 26: Copper-photocatalyzed borylation of organic halides. aUnder continuous flow conditions.
Scheme 27: Copper-photocatalyzed α-functionalization of alcohols with glycine ester derivatives.
Scheme 28: δ-Functionalization of alcohols using [Cu(I)(dmp)(xantphos)]BF4.
Scheme 29: Photocatalytic synthesis of [5]helicene and phenanthrene.
Scheme 30: Oxidative carbazole synthesis using in situ-formed [Cu(I)(dmp)(xantphos)]BF4.
Scheme 31: Copper-photocatalyzed functionalization of N-aryl tetrahydroisoquinolines.
Scheme 32: Bicyclic lactone synthesis using a copper-photocatalyzed PCET reaction.
Scheme 33: Photocatalytic Pinacol coupling reaction catalyzed by [Cu(I)(pypzs)(BINAP)]BF4. The ligands of the ...
Scheme 34: Azide photosensitization using a Cu-based photocatalyst.
Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations
- Rafia Siddiqui and
- Rashid Ali
Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26
- amination of ortho positions: synthesis of carbazoles Although a handful of methods for the construction of carbazoles, which are biologically important, is available in the literature, these procedures suffer from the need for an elevated temperature and the requirement of stoichiometric amounts of strong
- formation of carbazoles from biaryl derivatives. Mechanism for the synthesis of phenol derivatives with photoredox catalyst 8. Possible mechanism for the generation of phenols with the aid of photoredox catalyst 5. Proposed mechanism for the synthesis of monobrominated compounds. Mechanism for the synthesis
- purines via dual photoredox catalysis. Arylation of substituted arenes with an organic photoredox catalyst. C–H trifluoromethylation. Synthesis of benzo-3,4-coumarin derivatives. Oxidant-free oxidative phosphonylation. Nitration of anilines. Synthesis of carbazoles via intramolecular amination. Synthesis
Graphical Abstract
Figure 1: List of photoredox catalysts used for C–H bond functionalizations.
Figure 2: List of metal-based photoredox catalysts used in this review article.
Figure 3: Jablonski diagram.
Figure 4: Photoredox catalysis via reductive or oxidative pathways. D = donor, A = acceptor, S = substrate, P...
Figure 5: Schematic representation of the combination of photoredox catalysis and transition metal catalysis.
Scheme 1: Weinreb amide C–H olefination.
Figure 6: Mechanism for the formation of 21 from 19 using photoredox catalyst 11.
Scheme 2: C–H olefination of phenolic ethers.
Scheme 3: Decarboxylative acylation of acetanilides.
Figure 7: Mechanism for the formation of 30 from acetanilide derivatives.
Scheme 4: Synthesis of fluorenone derivatives by intramolecular deoxygenative acylation of biaryl carboxylic ...
Figure 8: Mechanism for the photoredox-catalyzed synthesis of fluorenone derivatives.
Scheme 5: Synthesis of benzothiazoles via aerobic C–H thiolation.
Figure 9: Plausible mechanism for the construction of benzothiazoles from benzothioamides.
Scheme 6: Synthesis of benzothiazoles via oxidant-free C–H thiolation.
Figure 10: Mechanism involved in the synthesis of benzothiazoles via oxidant-free C–H thiolation.
Scheme 7: Synthesis of indoles via C–H cyclization of anilides with alkynes.
Scheme 8: Preparation of 3-trifluoromethylcoumarins via C–H cyclization of arylpropiolate esters.
Figure 11: Mechanistic pathway for the synthesis of coumarin derivatives via C–H cyclization.
Scheme 9: Monobenzoyloxylation without chelation assistance.
Figure 12: Plausible mechanism for the formation of 71 from 70.
Scheme 10: Aryl-substituted arenes prepared by inorganic photoredox catalysis using 12a.
Figure 13: Proposed mechanism for C–H arylations in the presence of 12a and a Pd catalyst.
Scheme 11: Arylation of purines via dual photoredox catalysis.
Scheme 12: Arylation of substituted arenes with an organic photoredox catalyst.
Scheme 13: C–H trifluoromethylation.
Figure 14: Proposed mechanism for the trifluoromethylation of 88.
Scheme 14: Synthesis of benzo-3,4-coumarin derivatives.
Figure 15: Plausible mechanism for the synthesis of substituted coumarins.
Scheme 15: Oxidant-free oxidative phosphonylation.
Figure 16: Mechanism proposed for the phosphonylation reaction of 100.
Scheme 16: Nitration of anilines.
Figure 17: Plausible mechanism for the nitration of aniline derivatives via photoredox catalysis.
Scheme 17: Synthesis of carbazoles via intramolecular amination.
Figure 18: Proposed mechanism for the formation of carbazoles from biaryl derivatives.
Scheme 18: Synthesis of substituted phenols using QuCN.
Figure 19: Mechanism for the synthesis of phenol derivatives with photoredox catalyst 8.
Scheme 19: Synthesis of substituted phenols with DDQ (5).
Figure 20: Possible mechanism for the generation of phenols with the aid of photoredox catalyst 5.
Scheme 20: Aerobic bromination of arenes using an acridinium-based photocatalyst.
Scheme 21: Aerobic bromination of arenes with anthraquinone.
Figure 21: Proposed mechanism for the synthesis of monobrominated compounds.
Scheme 22: Chlorination of benzene derivatives with Mes-Acr-MeClO4 (2).
Figure 22: Mechanism for the synthesis of 131 from 132.
Scheme 23: Chlorination of arenes with 4CzIPN (5a).
Figure 23: Plausible mechanism for the oxidative photocatalytic monochlorination using 5a.
Scheme 24: Monofluorination using QuCN-ClO4 (8).
Scheme 25: Fluorination with fluorine-18.
Scheme 26: Aerobic amination with acridinium catalyst 3a.
Figure 24: Plausible mechanism for the aerobic amination using acridinium catalyst 3a.
Scheme 27: Aerobic aminations with semiconductor photoredox catalyst 18.
Scheme 28: Perfluoroalkylation of arenes.
Scheme 29: Synthesis of benzonitriles in the presence of 3a.
Figure 25: Plausible mechanism for the synthesis of substituted benzonitrile derivatives in the presence of 3a....
Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst
- Abhijit Paul,
- Debnath Chatterjee,
- Srirupa Banerjee and
- Somnath Yadav
Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16
- years, as these are the vital structural motifs of several biologically and medicinally important compounds [1][2][3][4]. Also, 3-alkenylindoles act as fundamental building blocks for the synthesis of materials such as carbazoles [5][6], indole alkaloids [7][8][9], etc. Again, 3-alkenylindoles also form
Graphical Abstract
Figure 1: Biologically and medicinally important 3-alkenylindoles.
Scheme 1: a) Previous and b) present work related to the synthesis of 3-alkenylindoles.
Scheme 2: Substrate scope for the C–H alkenylation of the indoles 1. Reaction conditions: 1 (1 mmol), 2 (2 mm...
Scheme 3: a) Three-phase test to determine a homogeneous or heterogeneous catalytic mechanism of action for t...
Scheme 4: Probable catalytic mechanism for the transformation of 1a by the RuNC.
Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds
- Daniel R. Sutherland,
- Nidhi Sharma,
- Georgina M. Rosair,
- Ifor D. W. Samuel,
- Ai-Lan Lee and
- Eli Zysman-Colman
Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285
- carbazoles with respect to the bridging benzene of ca. 44° in both 3 and 4 (Figure 2). Theoretical properties Density functional theory (DFT) calculations were performed in the gas phase to assess the electronic structures of 2–5 (see Supporting Information File 1 for details). The S1 and T1 excited states
Graphical Abstract
Scheme 1: Mild and direct C–H monofunctionalization of BQ 1: previous [14] and this work.
Figure 1: Benzoquinone derivatives synthesized for this study, with the donor in red and the benzoquinone acc...
Scheme 2: Synthesis of 2–4 via mild and direct C–H monofunctionalization of BQ (1).
Scheme 3: Synthesis of 5 via double Suzuki coupling.
Figure 2: Crystal structures of 3 and 4.
Figure 3: HOMO/LUMO and S1/T1 energies as well as HOMO/LUMO electron density distribution profiles of 2–5.
Figure 4: Cyclic voltammograms and differential pulse voltammograms of 2–5 in degassed DCM (scan rate = 100 m...
Figure 5: UV–vis absorption spectra of 2–5 in DCM and photoluminescence spectrum of 3 in degassed DCM and in ...
Figure 6: Time-resolved PL plots. a) Prompt decay and b) delayed decay curve of 3 in thin film (λexc = 378 nm...
Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives
- Hai-Yun Huang,
- Haoran Li,
- Thierry Roisnel,
- Jean-François Soulé and
- Henri Doucet
Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204
- groups. The one pot access to α,β-diarylated lilolidines with two identical aryl groups is also possible by using a larger amount of aryl bromide. The synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles from lilolidine via three successive direct arylations is also described. Therefore, this
- aryl groups at α- and β-positions via two-fold Pd-catalyzed C–H bond functionalizations, iii) on the synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles via three successive C–H bond functionalization steps (Scheme 1c). Results and Discussion Based on our previous results on the arylation of
- ) catalyst associated to KOAc provided the desired diarylated lilolidines 23–26 in 55–87% yields. The structure of 23 was confirmed by X-ray diffraction. Finally, the synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles via β-arylation of the previously obtained α-arylated lilolidines followed by
Graphical Abstract
Figure 1: Structures of lilolidine, tivantinib and tarazepide.
Scheme 1: Access to α- and β-arylated lilolidine derivatives.
Scheme 2: Synthesis of α-arylated lilolidine derivatives.
Scheme 3: Synthesis of α,β-di(hetero)arylated lilolidine derivatives.
Scheme 4: Synthesis of α,β-diarylated lilolidine derivatives via successive direct arylations.
Scheme 5: Synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles via successive direct arylations.
Oxidative radical ring-opening/cyclization of cyclopropane derivatives
- Yu Liu,
- Qiao-Lin Wang,
- Zan Chen,
- Cong-Shan Zhou,
- Bi-Quan Xiong,
- Pan-Liang Zhang,
- Chang-An Yang and
- Quan Zhou
Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23
- [2,3-c]dihydrocarbazoles 70 and [2,3-c]carbazoles 71 (Scheme 15) [91]. This process permitted the use of readily available and cheap AgOAc as the catalyst and oxidant, and DMF as the solvent. Notably, the product 70 was easily transformed into 71 in the presence of chloranil (1.4 equiv) at 120 °C under
Graphical Abstract
Scheme 1: The oxidative radical ring-opening/cyclization of cyclopropane derivatives.
Scheme 2: Mn(OAc)3-mediated oxidative radical ring-opening and cyclization of MCPs with malonates.
Scheme 3: Mn(III)-mediated oxidative radical ring-opening and cyclization of MCPs with 1,3-dicarbonyl compoun...
Scheme 4: Heat-promoted ring-opening/cyclization of MCPs with elemental chalgogens.
Scheme 5: Copper(II) acetate-mediated oxidative radical ring-opening and cyclization of MCPs with diphenyl di...
Scheme 6: AIBN-promoted oxidative radical ring-opening and cyclization of MCPs with benzenethiol.
Scheme 7: AIBN-mediated oxidative radical ring-opening and cyclization of MCPs with diethyl phosphites.
Scheme 8: Organic-selenium induced radical ring-opening and cyclization of MCPs derivatives (cyclopropylaldeh...
Scheme 9: Copper(I)-catalyzed oxidative radical trifluoromethylation/ring-opening/cyclization of MCPs with To...
Scheme 10: Ag(I)-mediated trifluoromethylthiolation/ring-opening/cyclization of MCPs with AgSCF3.
Scheme 11: oxidative radical ring-opening and cyclization of MCPs with α-C(sp3)-–H of ethers.
Scheme 12: Oxidative radical ring-opening and cyclization of MCPs with aldehydes.
Scheme 13: Cu(I) or Fe(II)-catalyzed oxidative radical trifluoromethylation/ring-opening/cyclization of MCPs d...
Scheme 14: Rh(II)-catalyzed oxidative radical ring-opening and cyclization of MCPs.
Scheme 15: Ag(I)-catalyzed oxidative radical amination/ring-opening/cyclization of MCPs derivatives.
Scheme 16: Heating-promoted radical ring-opening and cyclization of MCP derivatives (arylvinylidenecyclopropan...
Scheme 17: Bromine radical-mediated ring-opening of alkylidenecyclopropanes.
Scheme 18: Fluoroalkyl (Rf) radical-mediated ring-opening of MCPs.
Scheme 19: Visible-light-induced alkylation/ring-opening/cyclization of cyclopropyl olefins with bromides.
Scheme 20: Mn(III)-mediated ring-opening and [3 + 3]-annulation of cyclopropanols and vinyl azides.
Scheme 21: Ag(I)-catalyzed oxidative ring-opening of cyclopropanols with quinones.
Scheme 22: Ag(I)-catalyzed oxidative ring-opening of cyclopropanols with heteroarenes.
Scheme 23: Cu(I)-catalyzed oxidative ring-opening/trifluoromethylation of cyclopropanols.
Scheme 24: Cu(I)-catalyzed oxidative ring-opening and trifluoromethylation/trifluoromethylthiolation of cyclop...
Scheme 25: Ag(I)-mediated oxidative ring-opening/fluorination of cyclopropanols with Selectfluor.
Scheme 26: Photocatalyzed ring-opening/fluorination of cyclopropanols with Selectfluor.
Scheme 27: Na2S2O8-promoted ring-opening/alkynylation of cyclopropanols with EBX.
Scheme 28: Ag(I)-catalyzed ring-opening and chlorination of cyclopropanols with aldehydes.
Scheme 29: Ag(I)-catalyzed ring-opening/alkynylation of cyclopropanols with EBX.
Scheme 30: Na2S2O8-promoted ring-opening/alkylation of cyclopropanols with acrylamides.
Scheme 31: Cyclopropanol ring-opening initiated tandem cyclization with acrylamides or 2-isocyanobiphenyls.
Scheme 32: Ag(II)-mediated oxidative ring-opening/fluorination of cyclopropanols with AgF2.
Scheme 33: Cu(II)-catalyzed ring-opening/fluoromethylation of cyclopropanols with sulfinate salts.
Scheme 34: Cu(II)-catalyzed ring-opening/sulfonylation of cyclopropanols with sulfinate salts.
Scheme 35: Na2S2O8-promoted ring-opening/arylation of cyclopropanols with propiolamides.
Scheme 36: The ring-opening and [3 + 2]-annulation of cyclopropanols with α,β-unsaturated aldehydes.
Scheme 37: Cu(II)-catalyzed ring-opening/arylation of cyclopropanols with aromatic nitrogen heterocyles.
Scheme 38: Ag(I)-catalyzed ring-opening and difluoromethylthiolation of cyclopropanols with PhSO2SCF2H.
Scheme 39: Ag(I)-catalyzed ring-opening and acylation of cyclopropanols with aldehydes.
Scheme 40: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of 2-oxyranyl ketones.
Scheme 41: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of linear enones.
Scheme 42: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of metabolite.
Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region
- Aude-Héloise Bonardi,
- Frédéric Dumur,
- Guillaume Noirbent,
- Jacques Lalevée and
- Didier Gigmes
Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282
- ]. Its absorption extends from UV until 450 nm and can thus be activated at 405 nm with a blue light. Eventually, the peripheral carbazoles can be substituted with halogens. This increases the rate of RISC, and red-shifts the absorption spectrum [81]. For example, with a bromo atom on the peripheral
- hydrocarbons [93], heteropolyacenes [90][91], carbazoles [80][81][94], triazines [95], pentacenes [96], diketopyrrolopyrroles [24] and perylene [97][98] derivatives have been investigated as organocatalysts as exemplified in Scheme 5. 3 Comparison of the efficiency of these photoredox catalysts in
Graphical Abstract
Figure 1: Typical oxidative and reductive cycle for a photoredox catalyst (PC).
Figure 2: Transitions involved in absorbing species containing π, σ and n electrons.
Figure 3: Ligand to metal charge transfer (illustrated here for a d6 metal complex).
Figure 4: Metal to ligand charge transfer (illustrated here for a d5 metal complex).
Scheme 1: Structures of additives involved in the photoredox catalytic cycles.
Figure 5: Catalytic cycles involved with iodonium salt and (A) (TMS)3SiH, (B) NVK and (C) EDB.
Scheme 2: Structures of photoredox metal-based catalysts.
Scheme 3: Photocatalytical cycle for the Ru complex.
Scheme 4: Structures of photoredox organocatalysts.
Scheme 5: Diversity of the chemical structures of photoredox organocatalysts.
Scheme 6: Structures of benchmarked monomers.
Scheme 7: Structure of the CARET additive.
Scheme 8: Photoredox catalysis mechanism of a visible light-mediated living radical polymerization. (Abbrevia...
Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis
- Gwendal Grelier,
- Benjamin Darses and
- Philippe Dauban
Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128
- requires the use of 4 mol % of Pd2(dba)3, 12 mol % of Xantphos, 2.8 equivalents of Cs2CO3 and 1.2 equivalents of benzylamine to afford the corresponding δ-carboline in a 65% yield. Two years later, the group of Nachtsheim has designed a similar strategy for the preparation of N-(aryl)carbazoles 61 from
- electron-poor anilines afford better results than their electron-rich congeners, while a hindered amine (t-BuNH2) completely inhibits the reaction. Shortly after, a similar synthesis of carbazoles involving Cu(OAc)2 as the catalyst in the presence of ethylene glycol both as a ligand and the co-solvent has
- Jiang has very recently described a complementary method for the synthesis of carbazoles by combining cyclic diaryl-λ3-iodanes with sodium azide in the presence of copper(I) thiophene-2-carboxylate (CuTc) and triphenylphosphine. The reaction affords the expected of N–H free derivatives 63 in moderate to
Graphical Abstract
Scheme 1: Strategies to address the issue of sustainability with polyvalent organoiodine reagents.
Scheme 2: Functionalization of ketones and alkenes with IBX.
Scheme 3: Functionalization of pyrroles with DMP.
Scheme 4: Catalytic benzoyloxy-trifluoromethylation reported by Szabó.
Scheme 5: Catalytic benzoyloxy-trifluoromethylation reported by Mideoka.
Scheme 6: Catalytic 1,4-benzoyloxy-trifluoromethylation of dienes.
Scheme 7: Catalytic benzoyloxy-trifluoromethylation of allylamines.
Scheme 8: Catalytic benzoyloxy-trifluoromethylation of enynes.
Scheme 9: Catalytic benzoyloxy-trifluoromethylation of allenes.
Scheme 10: Alkynylation of N-(aryl)imines with EBX for the formation of furans.
Scheme 11: Catalytic benzoyloxy-alkynylation of diazo compounds.
Scheme 12: Catalytic asymmetric benzoyloxy-alkynylation of diazo compounds.
Scheme 13: Catalytic 1,2-benzoyloxy-azidation of alkenes.
Scheme 14: Catalytic 1,2-benzoyloxy-azidation of enamides.
Scheme 15: Catalytic 1,2-benzoyloxy-iodination of alkenes.
Scheme 16: Seminal study with cyclic diaryl-λ3-iodane.
Scheme 17: Synthesis of alkylidenefluorenes from cyclic diaryl-λ3-iodanes.
Scheme 18: Synthesis of alkyne-substituted alkylidenefluorenes.
Scheme 19: Synthesis of phenanthrenes from cyclic diaryl-λ3-iodanes.
Scheme 20: Synthesis of dibenzocarbazoles from cyclic diaryl-λ3-iodanes.
Scheme 21: Synthesis of triazolophenantridines from cyclic diaryl-λ3-iodanes.
Scheme 22: Synthesis of functionalized benzoxazoles from cyclic diaryl-λ3-iodanes.
Scheme 23: Sequential difunctionalization of cyclic diaryl-λ3-iodanes.
Scheme 24: Double Suzuki–Miyaura coupling reaction of cyclic diaryl-λ3-iodanes.
Scheme 25: Synthesis of a δ-carboline from cyclic diaryl-λ3-iodane.
Scheme 26: Synthesis of N-(aryl)carbazoles from cyclic diaryl-λ3-iodanes.
Scheme 27: Synthesis of carbazoles from cyclic diaryl-λ3-iodanes.
Scheme 28: Synthesis of carbazoles and acridines from cyclic diaryl-λ3-iodanes.
Scheme 29: Synthesis of dibenzothiophenes from cyclic diaryl-λ3-iodanes.
Scheme 30: Synthesis of various sulfur heterocycles from cyclic diaryl-λ3-iodanes.
Scheme 31: Synthesis of dibenzothioheterocycles from cyclic diaryl-λ3-iodanes.
Scheme 32: Synthesis of dibenzosulfides and dibenzoselenides from cyclic diaryl-λ3-iodanes.
Scheme 33: Synthesis of dibenzosulfones from cyclic diaryl-λ3-iodanes.
Scheme 34: Seminal study with linear diaryl-λ3-iodanes.
Scheme 35: N-Arylation of benzotriazole with symmetrical diaryl-λ3-iodanes.
Scheme 36: Tandem catalytic C–H/N–H arylation of indoles with diaryl-λ3-iodanes.
Scheme 37: Tandem N-arylation/C(sp2)–H arylation with diaryl-λ3-iodanes.
Scheme 38: Catalytic intermolecular diarylation of anilines with diaryl-λ3-iodanes.
Scheme 39: Catalytic synthesis of diarylsulfides with diaryl-λ3-iodanes.
Scheme 40: α-Arylation of enolates using [bis(trifluoroacetoxy)iodo]arenes.
Scheme 41: Mechanism of the α-arylation using [bis(trifluoroacetoxy)iodo]arene.
Scheme 42: Catalytic nitrene additions mediated by [bis(acyloxy)iodo]arenes.
Scheme 43: Tandem of C(sp3)–H amination/sila-Sonogashira–Hagihara coupling.
Scheme 44: Tandem reaction using a λ3-iodane as an oxidant, a substrate and a coupling partner.
Scheme 45: Synthesis of 1,2-diarylated acrylamidines with ArI(OAc)2.
Recent advances in phosphorescent platinum complexes for organic light-emitting diodes
- Cristina Cebrián and
- Matteo Mauro
Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124
Graphical Abstract
Figure 1: Molecular structure of neutral platinum(II) complex 1 bearing four monodentate ligands; cy = cycloh...
Figure 2: Chemical structure of the dinuclear Pt complexes 2a–b and 3 [20].
Figure 3: Molecular structure of platinum(II) complexes bearing isoquinolinylpyrazolates; dip = 2,6-diisoprop...
Figure 4: Selected neutral platinum(II) complexes featuring dianionic biazolate and neutral bipyridines [27].
Figure 5: Selected neutral platinum(II) complexes from bipyrazolate and carbene-based chelates [34,35].
Figure 6: Cyclometalated thiazol-2-ylidene platinum(II) complexes with different acetylacetonate ligands [37].
Figure 7: Neutral platinum(II) complexes 13–15 bearing azolate ligands [13].
Figure 8: Chemical structure of neutral platinum(II) complexes 16–18 bearing azine-pyrazolato bidentate ligan...
Figure 9: Molecular structure of carbene-containing cyclometallated alkynylplatinum(II) complexes 19–21 [41].
Figure 10: Chemical structure of platinum(II) complexes 22a–d bearing asymmetric C^N^N tridentate ligands [53].
Figure 11: Chemical structure of platinum(II) complexes 23 bearing bis-cyclometalating 2,6-dipyridylbenzene ty...
Figure 12: Molecular structure of dendritic carbazole-containing alkynyl-platinum(II) complexes 24a–d [62].
Figure 13: Molecular structure of bipolar alkynyl-platinum(II) complexes 25 bearing carbazole and electron-acc...
Figure 14: Molecular structures of neutral platinum(II) complexes comprising donor-acceptor alkynyls (26) or e...
Figure 15: Chemical structure of the asymmetric Pt(II) derivatives 28 bearing triazole and tetrazole moieties ...
Figure 16: Molecular structure of the tetradentate platinum complexes 29–32 bearing N^C^C^N and C^C^C^N ligand...
Figure 17: Chemical structure of the tetradentate Pt complexes 33–38 based on N^C^C^N-type of ligands [80-84].
Figure 18: Chemical structure of the macrocyclic tetradentate platinum complexes reported by Wang and co-worke...
Figure 19: Molecular structure of complex 41–46 [88,89].
Figure 20: Molecular structure of asymmetric derivatives 47–49 based on triaryl-type of bridge [90].
Figure 21: Chemical structure of the asymmetric tetradentate derivatives 50 and 51 based on spirofluorene link...
Figure 22: Molecular structure of the pyridylazolate-based complexes 52–54 reported by Chi and co-workers [97].
Figure 23: Chemical structure of the red-to-NIR emitting complexes 55–57 bearing donor–acceptor triphenylamino...
Figure 24: Molecular structures of the Pt(IV) derivatives 58 and 59 employed as triplet emitters in solution-p...
Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)
- Thanh-Tuân Bui,
- Fabrice Goubard,
- Malika Ibrahim-Ouali,
- Didier Gigmes and
- Frédéric Dumur
Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18
- carbazoles in T16 compared to T15, a decrease of ΔEST was logically observed (0.06 eV for T15 and 0.03 eV for T16) [54]. A large torsion angle of 66° and 67° were, respectively, determined by theoretical calculations for T15 and T16, favorable to the separation of the two orbitals. In devices, a remarkable
- , the number of donors being increased. The low efficiency roll-off of T16-based devices was assigned to the specific design of the emitter, with the triazine acceptor being totally surrounded by carbazoles. As a result, triplet–triplet annihilation by the Dexter mechanism could be efficiently prevented
Graphical Abstract
Figure 1: Radiative deactivation pathways existing in fluorescent, phosphorescent and TADF materials.
Figure 2: Boron-containing TADF emitters B1–B10.
Figure 3: Diphenylsulfone-based TADF emitters D1–D7.
Figure 4: Triazine-based TADF emitters T1–T3, T5–T7 and azasiline derivatives T3 and T4.
Figure 5: Triazine-based TADF emitters T8, T9, T11–T14 and carbazole derivative T10.
Figure 6: Triazine-based TADF emitters T15–T19.
Figure 7: Triazine- and pyrimidine-based TADF emitters T20–T26.
Figure 8: Pyrimidine-based TADF emitters T27–T30.
Figure 9: Triazine-based TADF polymers T31–T32.
Figure 10: Phenoxaphosphine oxide and phenoxathiin dioxide-based TADF emitters P1 and P2.
Figure 11: CN-Substituted pyridine and pyrimidine derivatives CN-P1–CN-P8.
Figure 12: CN-Substituted pyridine derivatives CN-P9 and CN-P10.
Figure 13: Phosphine oxide-based TADF blue emitters PO-1–PO-3.
Figure 14: Phosphine oxide-based TADF blue emitters PO-4–PO-9.
Figure 15: Benzonitrile-based emitters BN-1–BN-5.
Figure 16: Benzonitrile-based emitters BN-6–BN-11.
Figure 17: Benzoylpyridine-carbazole hybrid emitters BP-1–BP-6.
Figure 18: Benzoylpyridine-carbazole hybrid emitters BP-7–BP-10.
Figure 19: Triazole-based emitters Trz-1 and Trz-2.
Figure 20: Triarylamine-based emitters TPA-1–TPA-3.
Figure 21: Distribution of the CIE coordinates of ca. 90 blue TADF emitters listed in this review.
New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties
- Daria G. Selivanova,
- Alexei A. Gorbunov,
- Olga A. Mayorova,
- Alexander N. Vasyanin,
- Igor V. Lunegov,
- Elena V. Shklyaeva and
- Georgii G. Abashev
Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158
- groups terminated with an aromatic moiety (substituted or non-substituted benzenes, carbazoles, biphenyls, etc.) can be used for these purposes [8][9]. The incorporation of bulky side chains is applied in order to exclude the possible interaction of polymer chains with each other. Such interaction often
- ] (Scheme 1). 9-[ω-(4-Methoxyphenoxy)alkyl]-9H-carbazole-3-carbaldehydes 2a and 2b, the carbonyl components for the future crotonic condensation, were prepared by Vilsmeier–Haack formylation of 9-[ω-(4-methoxyphenoxy)alkyl]-9H-carbazoles 1a,b [19] (Scheme 2). 3-Acetyl-9-[ω-(4-methoxyphenoxy)alkyl]-9H
- -carbazoles 3a,b were obtained via acetylation of the same carbazoles 1a,b [20]. The presence of an acetyl group in the resulted compounds 3a and 3b gives the opportunity to extend their conjugation chain via incorporation of an thiophene moiety with the help of a Vilsmeier–Haack–Arnold reaction. The reaction
Graphical Abstract
Scheme 1: Synthesis of 9-[ω-(methoxyphenoxy)alkyl]-9H-carbazoles 1a,b.
Scheme 2: Synthesis of 9-[ω-(4-methoxyphenoxy)alkyl]-9H-carbazole-3-carbaldehydes 2a,b and 1-(5-arylthiophen-...
Scheme 3: Synthesis of quadrupolar chromophores 6a,b−8a,b.
Figure 1: Comparison of UV–vis absorption and fluorescence spectra of compounds 2a–5a (a) and 2b–5b (b) in CH...
Figure 2: Comparison of UV–vis absorption and fluorescence spectra of compounds 6a (a, b), 6b (c, d) in vario...
Figure 3: Comparison of UV–vis absorption and fluorescence spectra of compounds 7a (a, b) and 7b (c, d) in va...
Figure 4: Correlation between Kamlet–Taft π* parameters [29] and the absorption and emission maxima wavelength of...
Figure 5: Comparison of UV–vis absorption spectra of 2-amino-4,6-di(4-bromophenyl)pyrimidine and 2-amino-4-[4...
Figure 6: UV–vis absorption and fluorescence spectra of compounds 8a (a), 8b ( b) in CHCl3 (c = 10−4 mol L−1)....
Figure 7: Cyclic voltammograms of compounds 2b (a), 5b (b); WE – carbon-pyroceramic electrode, 10 cycles, Et4...
Figure 8: Cyclic voltammograms of compounds 6b (a), 7b (b), 8b (с); WE – carbon-pyroceramic electrode, 10 cyc...
