- Radiative depopulation of the excited intramolecular charge-transfer state of 9-(4-(N,N-dimethylamino)phenyl)phenanthrene
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Intramolecular photoinduced electron transfer in 9-(p-N,N-dimethylanilino)phenanthrene (9DPhen) has been studied in solution. The solvent dependence of the fluorescence spectra of 9DPhen indicates that the emission occurs from a highly polar excited state
- Onkelinx,De Schryver,Viaene,Van Der Auweraer,Iwai,Yamamoto,Ichikawa,Masuhara,Maus,Rettig
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Read Online
- Rediscovering Bacon's hydrazine/phenylhydrazine mediated cyclization of 2,2′-dicarbonylbi(hetero)aryls: Construction of (5-azo)-/indazolo[2,3-: A] quinolines
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Hydrazine/phenylhydrazine-mediated reductive dicarbonyl coupling reactions have been carried out under mild conditions to provide polycyclic aromatic compounds and azo-substituted polyaromatic compounds. This method has a broad substrate scope with good functional group compatibility. This journal is
- Dhote, Pawan S.,Ramana, Chepuri V.
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supporting information
p. 636 - 648
(2022/02/01)
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- Alumina-Mediated π-Activation of Alkynes
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The ability to induce powerful atom-economic transformation of alkynes is the key feature of carbophilic π-Lewis acids such as gold- and platinum-based catalysts. The unique catalytic activity of these compounds in electrophilic activations of alkynes is explained through relativistic effects, enabling efficient orbital overlapping with π-systems. For this reason, it is believed that noble metals are indispensable components in the catalysis of such reactions. In this study, we report that thermally activated γ-Al2O3activates enynes, diynes, and arene-ynes in a manner enabling reactions that were typically assigned to the softest π-Lewis acids, while some were known to be triggered exclusively by gold catalysts. We demonstrate the scope of these transformations and suggest a qualitative explanation of this phenomenon based on the Dewar-Chatt-Duncanson model confirmed by density functional theory calculations.
- Akhmetov, Vladimir,Amsharov, Konstantin,Feofanov, Mikhail,Sharapa, Dmitry I.
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p. 15420 - 15426
(2021/09/30)
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- Palladium-Catalyzed Sequential Vinyl C–H Activation/Dual Decarboxylation: Regioselective Synthesis of Phenanthrenes and Cyclohepta[1,2,3-de]naphthalenes
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The application of a C(vinyl), C(aryl)-palladacycle from vinyl-containing substrates is challenging due to the interference of a reactive double bond in palladium catalysis. This Letter describes a [4 + 2] or [4 + 3] cyclization based on a C(vinyl), C(aryl)-palladacycle by employing α-oxocarboxylic acids as the insertion units under a palladium/air system. The reaction proceeded through the key vinyl C–H activation and dual decarboxylation sequence, forming phenanthrenes and cyclohepta[1,2,3-de]naphthalenes regioselectively in good yields. The synthetic versatility of this protocol is highlighted by the gram-scale synthesis and synthesizing functional material molecule.
- Jiang, Guomin,Ye, Hao,Shi, Lei,Dai, Hong,Wu, Xin-Xing
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p. 9398 - 9402
(2021/12/09)
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- Tris-NHC-propagated self-supported polymer-based Pd catalysts for heterogeneous C-H functionalization
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Three-dimensionally propagated imidazolium-containing mesoporous coordination polymer and organic polymer-based platforms were successfully exploited to develop single-site heterogenized Pd-NHC catalysts for oxidative arene/heteroarene C-H functionalization reactions. The catalysts were efficient in directed arene halogenation, and nondirected arene and heteroarene arylation reactions. High catalytic activity, excellent heterogeneity and recyclability were offered by these systems making them promising candidates in the area of heterogeneous C-H functionalization, where efficient catalysts are still scarce.
- Choudhury, Joyanta,Dutta, Tapas Kumar,Mandal, Tanmoy,Mohanty, Sunit
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supporting information
p. 10182 - 10185
(2021/10/12)
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- Cobalt?NHC Catalyzed C(sp2)?C(sp3) and C(sp2)?C(sp2) Kumada Cross-Coupling of Aryl Tosylates with Alkyl and Aryl Grignard Reagents
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The first cobalt-catalyzed cross-coupling of aryl tosylates with alkyl and aryl Grignard reagents is reported. The catalytic system uses CoF3 and NHCs (NHC=N-heterocyclic carbene) as ancillary ligands. The reaction proceeds via highly selective C?O bond functionalization, leading to the corresponding products in up to 98 % yield. The employment of alkyl Grignard reagents allows to achieve a rare C(sp2)?C(sp3) cross-coupling of C?O electrophiles, circumventing isomerization and β-hydride elimination problems. The use of aryl Grignards leads to the formation of biaryls. The C?O cross-coupling sets the stage for a sequential cross-coupling by exploiting the orthogonal selectivity of the catalytic system.
- Piontek, Aleksandra,Och?dzan-Siod?ak, Wioletta,Bisz, Elwira,Szostak, Michal
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p. 202 - 206
(2020/12/01)
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- Compound, electron transport material, organic electroluminescent device and display device
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The present application provides a compound of general formula (I), which can be used in electron transport materials. The compound has a mother structure of sym-triphenyl diphenanthrene substituted triazine, has high bond energy between atoms, has good t
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Paragraph 0126-0127; 0132
(2021/08/11)
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- σ-Bond initiated generation of aryl radicals from aryl diazonium salts
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σ-Bond nucleophiles and molecular oxygen transform aryl diazonium salts into aryl radicals. Experimental and computational studies show that Hantzsch esters transfer hydride to aryl diazonium species, and that oxygen initiates radical fragmentation of the diazene intermediate to produce aryl radicals. The operational simplicity of this addition-fragmentation process for the generation of aryl radicals, by a polar-radical crossover mechanism, has been illustrated in a variety of bond-forming reactions.
- Chan, Bun,McErlean, Christopher S. P.,Nashar, Philippe E.,Tatunashvili, Elene
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supporting information
p. 1812 - 1819
(2020/03/17)
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- Suzuki-Miyaura Cross-Coupling of Sulfoxides
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The utilization of diphenyl sulfoxides as versatile electrophilic coupling partners for the Suzuki-Miyaura reaction via C-S bond cleavage was successfully developed under palladium-N-heterocyclic carbene catalysis. The reactions showed good functional group compatibility, proceeded well under mild conditions, and provided biaryls in yields of up to 96%. A wide range of useful functional groups, such as fluoro, chloro, ether, hydroxyl, amide, cyano, keto, trimethylsilyl (TMS), and ester were tolerated under the reaction conditions; however, the use of phenylboronic anhydride and arylboronic acid pinacol esters generally would lead low yields. Good regioselectivity for the electron-poor phenyl group was achieved when unsymmetrical diphenyl sulfoxides were used. The protocol is applicable at the gram scale even with half the amount of catalyst. Density functional theory calculations were performed to investigate the reaction mechanism, indicating that the reaction occurred through oxidative addition, transmetalation, and reductive elimination to provide the final coupling product.
- Abduhulam, Hayrul,Cao, Changsheng,Chen, Qianwei,Dang, Yanfeng,Li, Chengxi,Shi, Yanhui,Wu, Shufeng,Yan, Shuqin
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p. 8168 - 8176
(2020/09/18)
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- Preparation method of fused ring compound
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The invention discloses a preparation method of a fused ring compound III. The preparation method comprises the following step: in a solvent and in the presence of palladium acetate, alkali and a ligand, carrying out a reaction shown in the specification on a compound I and a compound II to obtain a compound III. The preparation method disclosed by the invention is relatively good in compatibilitywith a substrate, various polycyclic aromatic hydrocarbon compounds can be simply obtained in a short period of time through convergent synthesis, and particularly, heteroatom-containing polycyclic aromatic hydrocarbon shows extremely excellent regioselectivity.
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Paragraph 0116-0119; 0140-0143; 0145-0146
(2020/12/10)
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- Amino-Induced 2D Cu-Based Metal–Organic Framework as an Efficient Heterogeneous Catalyst for Aerobic Oxidation of Olefins
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With the assistance of hydrogen bonds of the o-amino group, we have successfully tuned a coordination structure from a metal–organic polyhedron (MOP) to a two-dimensional (2D) metal–organic framework (MOF). The amino group forms hydrogen bonds with the two vicinal carboxylic groups, and induces the ligand to coordinate with copper ions to form the 2D structure. The obtained 2D Cu-based MOF (Cu-AIA) has been applied as an efficient heterogeneous catalyst in the aerobic epoxidation of olefins by using air as oxygen source. Without the aggregation problem of active sites in MOPs, Cu-AIA possesses much higher reactivity than MOP-1. Furthermore, the amino group of the framework has been used as a modifiable site through post-synthetic metalation (PSMet) to prepare a 2D MOF-supported Pd single-site heterogeneous catalyst, which shows excellent catalytic performance for the Suzuki reaction. It indicates that Cu-AIA can also work as a good 2D MOF carrier for the derivation of other heterogeneous catalysts.
- Bao, Shixiong,Cai, Mengke,Ding, Shujiang,Li, Guangqin,Tang, Jia,Tao, Jinzhang,Wang, Xiaoxia,Xie, Guanqun
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supporting information
(2020/03/13)
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- Catalytic Dehydrogenative Cyclization of o-Teraryls under pH-Neutral and Oxidant-Free Conditions
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A cobaloxime-catalyzed acceptorless dehydrogenative cyclization of o-teraryls was developed. In stark contrast to the established methods such as the Scholl or Mallory reactions, this method does not require any strong acids or oxidants, and shows high atom economy and a broad substrate scope. It operates at near room temperature with light as the source of energy. Acid- or oxidant-sensitive functional groups, such as 4-methoxyphenyl, unprotected benzyl alcohol, silyl ether, and thiophene groups are tolerated. Remarkably, aryls with electron-withdrawing groups, and electron-poor heteroarenes, such as pyridine and pyrimidine, can also react. Preliminary mechanistic study reveals that hydrogen gas is released during the reaction, and both light and the cobalt catalyst are important for the dehydrogenation step.
- Dong, Guangbin,Tsukamoto, Tatsuhiro
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supporting information
p. 15249 - 15253
(2020/06/30)
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- Sequential Cross-Coupling/Annulation of ortho-Vinyl Bromobenzenes with Aromatic Bromides for the Synthesis of Polycyclic Aromatic Compounds
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A sequential cross-coupling/annulation of ortho-vinyl bromobenzenes with aromatic bromides was realized, providing a direct and modular approach to access polycyclic aromatic compounds. A vinyl-coordinated palladacycle was proposed as the key intermediate for this sequential process. Excellent chemoselectivity and regioselectivity were observed in this transformation. The practicability of this method is highlighted by its broad substrate scope, excellent functional group tolerance, and rich transformations associated with the obtained products.
- Wei, Dong,Li, Meng-Yao,Zhu, Bin-Bin,Yang, Xiao-Di,Zhang, Fang,Feng, Chen-Guo,Lin, Guo-Qiang
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supporting information
p. 16543 - 16547
(2019/11/03)
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- Br?nsted acid-catalysed hydroarylation of unactivated alkynes in a fluoroalcohol-hydrocarbon biphasic system: Construction of phenanthrene frameworks
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Transition metal-free hydroarylation of unactivated alkynes was achieved by combining a Br?nsted acid catalyst and a two-phase solvent system consisting of 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) and cyclohexane. This protocol is applicable to a wide variety of 2-alkynylbiaryls which leads to the synthesis of substituted phenanthrenes via 6-endo-selective ring closure. The biphasic system achieves highly efficient ring closure by appropriate separation of cationic intermediates from neutral compounds. The vinyl carbocation intermediates are stabilised in the HFIP phase, while the substrates and products are distributed in the cyclohexane phase to suppress intermolecular side reactions.
- Takahashi, Ikko,Fujita, Takeshi,Shoji, Noriaki,Ichikawa, Junji
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supporting information
p. 9267 - 9270
(2019/08/08)
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- Nickel-Catalyzed Kumada Coupling of Boc-Activated Aromatic Amines via Nondirected Selective Aryl C-N Bond Cleavage
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A nickel-catalyzed Kumada coupling of aniline derivatives was developed by selective cleavage of aryl C-N bonds under mild reaction conditions. Without preinstallation of an ortho directing group on anilines, the cross-coupling reactions of Boc-protected aromatic amines with aryl Grignard reagents afforded unsymmetric biaryls. Mechanistic studies by DFT calculations revealed that the nickel-mediated C-N bond cleavage is the rate-limiting step.
- Zhang, Zheng-Bing,Ji, Chong-Lei,Yang, Ce,Chen, Jie,Hong, Xin,Xia, Ji-Bao
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supporting information
p. 1226 - 1231
(2019/02/14)
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- Br?nsted Acid-Catalyzed Carbocyclization of 2-Alkynyl Biaryls
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Ortho-alkynyl biaryls react in the presence of catalytic amount of Br?nsted acids to give phenanthrenes in high yields under mild conditions. The activity and selectivity of this transformation are governed by the substitution pattern of the diarylalkyne moiety. Selectivity shifts are observed between the carbophilic Lewis and Br?nsted acid-catalyzed cycloisomerization involving alkyne activation. (Figure presented.).
- Gicquiaud, Julien,Hac?hasano?lu, Antoine,Hermange, Philippe,Sotiropoulos, Jean-Marc,Toullec, Patrick Y.
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supporting information
p. 2025 - 2030
(2019/03/28)
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- Metal-free cycloisomerizations of: O -alkynylbiaryls
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We describe a novel and highly efficient metal-free strategy to construct 9,9-disubstituted fluorenes and phenanthrenes via the TfOH-catalyzed cycloisomerizations of o-alkynylbiaryls. Notably, the significant effects of the electronic properties and steric hindrance of the alkyne terminus on the reaction selectivity have been observed.
- Zhang, Jingyi,Li, Siqi,Qiao, Yan,Peng, Cheng,Wang, Xiao-Na,Chang, Junbiao
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supporting information
p. 12455 - 12458
(2018/11/20)
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- Oxidative, Iodoarene-Catalyzed Intramolecular Alkene Arylation for the Synthesis of Polycyclic Aromatic Hydrocarbons
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A catalytic, metal-free and chemoselective oxidative intramolecular coupling of arene and alkene C?H bonds is reported. The active hypervalent iodine (HVI) reagent, generated catalytically in situ from iodotoluene and meta-chloroperoxybenzoic acid (m-CPBA), reacts with o-vinylbiphenyls to generate polyaromatic hydrocarbons in up to 95 % yield. Experimental evidence suggests the reactions proceed though vinyliodonium and, possibly, vinylenephenonium intermediates.
- Zhao, Zhensheng,Britt, Liam H.,Murphy, Graham K.
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p. 17002 - 17005
(2018/11/01)
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- Chromium-Catalyzed Regioselective Kumada Arylative Cross-Coupling of C(aryl)-O Bonds with a Traceless Activation Strategy
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We report here the chromium-catalyzed regioselective Kumada arylative cross-coupling of C(aryl)-O bonds at ambient temperature. By using a simple and low-cost chromium(II) chloride salt as a precatalyst, accompanied by a 2-pyridyl ligation, the catalytic cleavage and arylative coupling of C(aryl)-O bonds were achieved with a traceless activation strategy, overcoming the regioselectivity obstacle when several C-O bonds coexist in the Kumada coupling system.
- Fan, Fei,Tang, Jinghua,Luo, Meiming,Zeng, Xiaoming
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p. 13549 - 13559
(2018/10/31)
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- Ni-Catalyzed Cross-Coupling of Dimethyl Aryl Amines with Arylboronic Esters under Reductive Conditions
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Herein, we reported a successful Suzuki-Miyaura coupling of dimethyl aryl amines to forge biaryl skeleton via Ni catalysis in the absence of directing groups and preactivation. This transformation proceeded with high efficiency in the presence of magnesium. Preliminary mechanism studies demonstrated dual roles of magnesium: (i) a reductant that reduced Ni(II) species to active Ni(I) catalyst; (ii) a unique promoter that facilitated the Ni(I)/Ni(III) catalytic cycle.
- Cao, Zhi-Chao,Xie, Si-Jun,Fang, Huayi,Shi, Zhang-Jie
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supporting information
p. 13575 - 13579
(2018/10/24)
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- Nickel-Catalyzed Deamidative Step-Down Reduction of Amides to Aromatic Hydrocarbons
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To date, cleavage of the C-N bond in aromatic amides has been achieved in molecules with a distorted constitutional framework around the nitrogen atom. In this report, a nickel-catalyzed reduction of planar amides to the corresponding lower hydrocarbon homologue has been reported. This involves a one-pot reductive cleavage of the C-N bond followed by a tandem C-CO bond break in the presence of a hydride source. Substrate scope circumscribes deamidation examples which proceed via oxidative addition of nickel in the amide bonds of nontwisted amides. Mechanistic studies involving isolation and characterization of involved intermediates via different spectroscopic techniques reveal a deeper introspection into the plausible catalytic cycle for the methodology.
- Dey, Aniruddha,Sasmal, Sheuli,Seth, Kapileswar,Lahiri, Goutam Kumar,Maiti, Debabrata
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p. 433 - 437
(2017/06/05)
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- Highly Emissive Organic Single-Molecule White Emitters by Engineering o-Carborane-Based Luminophores
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The development of organic single-molecule solid-state white emitters holds a great promise for advanced lighting and display applications. Highly emissive single-molecule white emitters were achieved by the design and synthesis of a series of o-carborane-based luminophores. These luminophores are able to induce multiple emissions to directly emit high-purity white light in solid state. By tuning both molecular and aggregate structures, a significantly improved white-light efficiency has been realized (absolute quantum yield 67 %), which is the highest value among the known organic single-molecule white emitters in the solid state. The fine-tuning of the packing modes from H- to J- and cross-stacking aggregates as well as intermolecular hydrogen bonds are successful in one molecular skeleton. These are crucial for highly emissive white-light emission in the solid state.
- Tu, Deshuang,Leong, Pakkin,Guo, Song,Yan, Hong,Lu, Changsheng,Zhao, Qiang
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supporting information
p. 11370 - 11374
(2017/09/11)
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- A new route to π-extended polycyclic aromatic hydrocarbons via cross-dehydrogenative coupling
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A palladium-catalyzed cross-dehydrogenative coupling of phenanthrenes with simple arenes was developed. This protocol provides an opportunity for producing π-extended polycyclic aromatic hydrocarbons with minimum waste and high atomic efficiency under mild and ligand-free conditions.
- Jafarpour, Farnaz,Ayoubi-Chianeh, Mojgan,Abbasnia, Masoumeh,Azizzade, Meysam
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p. 2930 - 2934
(2017/08/15)
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- Extended Study of Visible-Light-Induced Photocatalytic [4 + 2] Benzannulation: Synthesis of Polycyclic (Hetero)Aromatics
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Herein we report an extended study of [4 + 2] benzannulation reactions of 2-(hetero)aryl-substituted anilines with alkynes by visible light photocatalysis. The method requires the use of tBuONO as a diazotizing agent and 0.3 mol % of fac-Ir(ppy)3 as a photocatalyst at room temperature. The reaction proceeded in a chemo- and regioselective manner with high functional group tolerance under mild conditions allowing the preparation of a wide variety of polycyclic (hetero)aromatic compounds, including phenanthrenes, in moderate to high yields. This procedure is amenable to gram-scale synthesis of 9-phenylphenanthrene.
- Chatterjee, Tanmay,Lee, Da Seul,Cho, Eun Jin
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p. 4369 - 4378
(2017/04/28)
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- Polycyclic Aromatic Hydrocarbons via Iron(III)-Catalyzed Carbonyl-Olefin Metathesis
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Polycyclic aromatic hydrocarbons are important structural motifs in organic chemistry, pharmaceutical chemistry, and materials science. The development of a new synthetic strategy toward these compounds is described based on the design principle of iron(III)-catalyzed carbonyl-olefin metathesis reactions. This approach is characterized by its operational simplicity, high functional group compatibility, and regioselectivity while relying on FeCl3 as an environmentally benign, earth-abundant metal catalyst. Experimental evidence for oxetanes as reactive intermediates in the catalytic carbonyl-olefin ring-closing metathesis has been obtained.
- McAtee, Christopher C.,Riehl, Paul S.,Schindler, Corinna S.
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supporting information
p. 2960 - 2963
(2017/03/11)
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- AlCl 3 -Catalyzed Intramolecular Hydroarylation of Arenes with Alkynes
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Herein, we wish to report the main-group metal Lewis acid catalyzed intramolecular hydroarylation of arenes with alkynes. This cyclization proceeds efficiently in the presence of a catalytic amount of AlCl 3, affording phenanthrenes in moderate
- Li, Yang,Wang, Yu,Xu, Dawen,Jin, Ruiwen,Gu, Guangxin,Guo, Hao
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supporting information
p. 2159 - 2162
(2017/09/26)
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- Palladium nanoparticles immobilized on magnetic methionine-functionalized chitosan: A versatile catalyst for Suzuki and copper-free Sonogashira reactions of aryl halides at room temperature in water as only solvent
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The preparation of an efficient heterogeneous catalyst system based on the immobilization of palladium nanoparticles on a magnetic nanoparticle core (ImmPd(0)-MNPs) is described. The new catalytic system was characterized using transmission and scanning electron microscopies, X-ray diffraction, energy-dispersive X-ray and Fourier transform infrared spectroscopies, thermogravimetric analysis, vibrating sample magnetometry and inductively coupled plasma analysis. We have demonstrated that ImmPd(0)-MNPs is an efficient and reusable catalyst for the Suzuki–Miyaura and Sonogashira coupling reactions of various types of aryl halides in water as a green and environmentally acceptable solvent. Moreover, the reactions were carried out efficiently at room temperature. The catalyst was easily separated using an external magnet from the reaction mixture and recycled ten times without significant loss of activity.
- Hajipour, Abdol R.,Tavangar-Rizi, Zeinab
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- Synthesis of cyclopenta-fused polycyclic aromatic hydrocarbons utilizing aryl-substituted anilines
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Cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs), potentially electronically and biologically highly active materials, were synthesized from readily available 2-aryl-substituted anilines. Reactions occur under extremely mild, room temperature conditions using tBuONO as the sole reagent. The use of a nitrite source generates a reactive diazonium intermediate in situ that then reacts with a tethered polycyclic aromatic moiety by intramolecular aromatic substitution. This protocol could be presented as one of the simplest methods to access CP-PAHs.
- Choi, Yeojin,Chatterjee, Tanmay,Kim, Jun,Kim, Jun Soo,Cho, Eun Jin
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p. 6804 - 6810
(2016/07/23)
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- Nickel-Catalyzed Cross-Coupling of Organolithium Reagents with (Hetero)Aryl Electrophiles
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Nickel-catalyzed selective cross-coupling of aromatic electrophiles (bromides, chlorides, fluorides and methyl ethers) with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene (NHC) complex allows the reaction with a variety of (hetero)aryllithium compounds, including those prepared via metal-halogen exchange or direct metallation, whereas a commercially available electron-rich nickel-bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product. These reactions proceed rapidly (1 h) under mild conditions (room temperature) while avoiding the undesired formation of reduced or homocoupled products. Nickel-catalyzed cross-coupling of aromatic electrophiles with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene complex allows reaction with a variety of (hetero)aryllithium compounds, whereas a commercially available electron-rich nickel bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product.
- Heijnen, Dorus,Gualtierotti, Jean-Baptiste,Hornillos, Valentín,Feringa, Ben L.
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supporting information
p. 3991 - 3995
(2016/03/16)
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- Merging photoredox catalysis with Lewis acid catalysis: Activation of carbon-carbon triple bonds
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Here, we demonstrate that merging photoredox catalysis with Lewis acid catalysis provides a fundamentally new activation mode of C-C triple bonds, to achieve the bond-forming reaction of alkynes with weak nucleophiles. Using a synergistic merger of Eosin
- Jin, Ruiwen,Chen, Yiyong,Liu, Wangsheng,Xu, Dawen,Li, Yawei,Ding, Aishun,Guo, Hao
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supporting information
p. 9909 - 9912
(2016/08/11)
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- Cu(II)-Catalyzed 6π-Photocyclization of Dienynes
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The first 6π-photocyclization of dienynes was developed, which provides a new and effective protocol for the synthesis of the phenyl ring in excellent yields with nice functional group tolerance. In this transformation, the Cu(OTf)2 catalyst pl
- Jin, Ruiwen,Chen, Jinjin,Chen, Yiyong,Liu, Wangsheng,Xu, Dawen,Li, Yawei,Ding, Aishun,Guo, Hao
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p. 12553 - 12558
(2016/12/23)
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- Neodymium-catalyzed intramolecular alkyne-hydroarylation with arenes
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A Nd(OTf)3-catalyzed alkyne-hydroarylation with arenes is reported. This reaction shows a wide range of functional group tolerance. Such a catalytic methodology enriches lanthanide element chemistry and provides a new route for synthesizing phe
- Xu, Dawen,Jin, Ruiwen,Liu, Wangsheng,Ba, Feifei,Li, Yawei,Ding, Aishun,Guo, Hao
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supporting information
p. 3235 - 3238
(2016/07/06)
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- In situ generated and stabilized Pd nanoparticles by N2,N4,N6-tridodecyl-1,3,5-triazine-2,4,6-triamine (TDTAT) as a reactive and efficient catalyst for the Suzuki-Miyaura reaction in water
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In situ generated Pd nanoparticles in the presence of N2,N4,N6-tridodecyl-1,3,5-triazine-2,4,6-triamine (TDTAT) were found to be an efficient catalyst for the Suzuki-Miyaura coupling reaction in water. It seems that TDTAT not only acts as a ligand for stabilization of the produced nanoparticles, but also as a surfactant to facilate the reaction in water, and reduces Pd(ii) to Pd(0). The TEM analysis of the reaction mixture showed that Pd nanoparticles with an average size of ～5 nm are produced, which act as an efficient catalyst in the Suzuki-Miyaura coupling reaction.
- Iranpoor, Nasser,Rahimi, Sajjad,Panahi, Farhad
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p. 3084 - 3090
(2016/01/16)
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- KOt-Bu/DMF promoted intramolecular cyclization of 1,1′-biphenyl aldehydes and ketones: An efficient synthesis of phenanthrenes
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A new synthesis of phenanthrene derivatives has been achieved through intramolecular cyclization of 1,1′-biphenyl aldehydes and ketones promoted by KOt-Bu/DMF. A free radical reaction pathway is proposed.
- Chen, Yan-Yan,Zhang, Niu-Niu,Ye, Lin-Miao,Chen, Jia-Hua,Sun, Xiang,Zhang, Xue-Jing,Yan, Ming
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p. 48046 - 48049
(2015/06/16)
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- Synthesis of Functionalized Phenanthrenes via Regioselective Oxidative Radical Cyclization
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The majority of Sn-mediated cyclizations are reductive and, thus, cannot give a fully conjugated product. This is a limitation in the application of Sn-mediated radical cascades for the preparation of fully conjugated molecules. In this work, we report an oxidatively terminated Bu3Sn-mediated cyclization of an alkyne where AIBN, the commonly used initiator, takes on a new function as an oxidative agent. Sn-mediated radical transformation of biphenyl aryl acetylenes into functionalized phenanthrenyl stannanes can be initiated via two potentially equilibrating vinyl radicals, one of which can be trapped by the fast 6-endoclosure at the biphenyl moiety in good to excellent yields. The efficient preparation of Sn-substituted phenanthrenes opens access to convenient building blocks for the construction of larger polyaromatics.
- Pati, Kamalkishore,Michas, Christopher,Allenger, David,Piskun, Ilya,Coutros, Peter S.,Dos Passos Gomes, Gabriel,Alabugin, Igor V.
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p. 11706 - 11717
(2015/12/11)
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- Synthesis of Multisubstituted Triphenylenes and Phenanthrenes by Cascade Reaction of o-Iodobiphenyls or (Z)-β-Halostyrenes with o-Bromobenzyl Alcohols through Two Sequential C-C Bond Formations Catalyzed by a Palladium Complex
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o-Bromobenzyl alcohol has been developed as a novel annulating reagent, bearing both nucleophilic and electrophilic substituents, for the facile synthesis of polycyclic aromatic hydrocarbons. A palladium/electron-deficient phosphine catalyst efficiently coupled o-iodobiphenyls or (Z)-β-halostyrenes with o-bromobenzyl alcohols to afford triphenylenes and phenanthrenes, respectively. The present cascade reaction proceeded through deacetonative cross-coupling and sequential intramolecular cyclization. An array of experimental data suggest that the reaction mechanism involves the equilibrium of 1,4-palladium migration.
- Iwasaki, Masayuki,Araki, Yasuhiro,Iino, Shohei,Nishihara, Yasushi
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p. 9247 - 9263
(2015/09/28)
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- Palladium-quaternary phosphonium phase transfer catalyst brush assembly as reusable and environmentally benign catalyst for coupling of aryl halides and sodium tetraphenylborate in neat water
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A first example of simultaneous covalent anchoring of a palladate anion-phosphonium cation matrix on the surface of silica nanoparticles and application in the Suzuki coupling reaction of a variety of different haloarenes and sodium tetraphenylborate in neat aqueous media without the addition of any organic co-solvent are described.
- Hajipour, Abdol R.,Azizi, Ghobad
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p. 712 - 717
(2015/09/28)
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- N-heterocyclic-carbene complexes readily prepared from Di-μ-hydroxopalladacycles catalyze the Suzuki arylation of 9-bromophenanthrene
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New cyclometalated palladium complexes of general formula [Pd(Bmim)(X)(C^N)] have been synthesized by a novel reaction route involving di-μ-hydroxo-palladacycles [{Pd(μ-OH)(C^N)}2] (C^N = 2-benzoylpyridine (Bzpy
- Serrano, J. Luis,Perez, Jose,Garcia, Luis,Sanchez, Gregorio,Garcia, Joaquin,Lozano, Pedro,Zende, Vidya,Kapdi, Anant
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p. 522 - 533
(2015/02/05)
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- Proline-functionalized chitosan-palladium(ii) complex, a novel nanocatalyst for C-C bond formation in water
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An environmentally friendly palladium-based catalyst supported on proline-functionalized chitosan was successfully prepared and evaluated as a heterogeneous nanocatalyst in the Suzuki cross-coupling reaction of various aryl halides with phenylboronic acid. The catalyst was characterized by FT-IR, FE-SEM, TEM, XRD, SEM-EDX, ICP and TGA techniques and exhibited reasonable catalytic activity in the reaction system, producing substituted biaryls in good to excellent yields. In addition, the catalyst could be recovered in a facile manner from the reaction mixture and recycled several times.
- Hajipour,Boostani,Mohammadsaleh
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p. 24742 - 24748
(2015/03/30)
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- Iridium-catalyzed annulative coupling of 2-arylbenzoyl chlorides with alkynes: Selective formation of phenanthrene derivatives
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2-Arylbenzoyl chlorides undergo annulative coupling with internal alkynes in the presence of a catalyst system of [IrCl(cod)]2/P(t-Bu)3 to selectively afford the corresponding phenanthrene derivatives accompanied by elimination of carbon monoxide and hydrogen chloride. The reaction occurs without addition of any external base. Deuterium-labeling experiments using 2-(d5-phenyl)benzoyl chloride suggest that the rate-determining step does not involve the C2′-H bond cleavage. Formation of a [(t-Bu)3PH][(biphenyl-2,2′-diyl)Ir(CO)Cl2] complex dimer, of which the structure was determined by single-crystal X-ray analysis, from a stoichiometric reaction at 60 °C without addition of alkyne also supports the facile C-H cleavage.
- Nagata, Tomoya,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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p. 8960 - 8967
(2015/02/19)
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- METHOD FOR PRODUCING POLYCYCLIC AROMATIC COMPOUND SUBSTITUTED BY ARYL GROUP
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PAH is subjected to C-H/C-B coupling using a specific boron compound, a palladium compound, and o-chloranil to produce a compound in which a C-H bond of the PAH is directly arylated regioselectively in a simple manner. When the substrate and the boron compound are appropriately selected, a larger PAH can also be obtained by further performing an annulation reaction after the coupling reaction. Similarly, when PAH is subjected to C-H/C-H cross-coupling using a specific aromatic compound, a palladium compound, and o-chloranil, a compound in which a C-H bond of the PAH is directly arylated regioselectively can be produced in a simple manner. When the substrate and the aromatic compound are appropriately selected in this case, a larger PAH can also be obtained by further performing an annulation reaction after the cross-coupling reaction.
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Paragraph 0234; 0235; 0236; 0237
(2014/05/24)
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- 2,3-Dichloro-5,6-dicyano-para-benzoquinone (DDQ)/methanesulfonic acid (MsOH)-mediated intramolecular arene-alkene oxidative coupling
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An efficient intramolecular arene-alkene oxidative coupling of 1,4-diaryl-1,3-butadienes has been developed involving the use of a 2,3-dichloro-5,6-dicyano-para-benzoquinone (DDQ)/acid catalyst. The reaction involves the generation of a radical cation by abstraction of an electron from the substrate with DDQ, an intramolecular Friedel-Crafts-type reaction, and the loss of hydrogen radical.
- Kim, Ko Hoon,Lim, Cheol Hee,Lim, Jin Woo,Kim, Jae Nyoung
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supporting information
p. 697 - 704
(2014/04/03)
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- Hiyama cross-coupling reaction catalyzed by a palladium salt of 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride under microwave irradiation
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An efficient catalytic system using 1-benzyl-4-aza-1-azoniabicyclo[2.2.2] octane chloride ((BeDABCO)2Pd2Cl6) was developed for the Hiyama cross-coupling reaction of various aryl halides with triethoxy(phenyl)silane. The substituted biaryls were produced in excellent yields in short reaction times using a catalytic amount of this catalyst in NMP at 100 °C. Copyright
- Hajipour, Abdol R.,Rafiee, Fatemeh,Najafi, Narges
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p. 217 - 220
(2014/04/03)
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- Synthesis of phenanthrenes by cationic chromium(III) porphyrin-catalyzed dehydration cycloaromatization
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Readily available biphenyl derivatives with ortho oxirane moiety react in the presence of cationic chromiun(III) porphyrin catalyst to afford phenanthrenes. The reaction is considered to be triggered by activation of the oxirane moiety through coordination to the Lewis acidic cationic chromium to give aldehyde via 1,2-hydride shift, which reacts with arene through intramolecular electrophilic aromatic substitution and subsequent dehydration. The reaction allows constructing a variety of polycyclic aromatic and heteroaromatic compounds.
- Wakabayashi, Ryota,Kurahashi, Takuya,Matsubara, Seijiro
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supporting information
p. 2297 - 2301
(2013/11/06)
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- Visible-light photoredox in homolytic aromatic substitution: Direct arylation of arenes with aryl Halides
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Direct arylation of unactivated arenes or heteroarenes with aryl halides could be carried out in the presence of potassium tert-butoxide and dimethyl sulfoxide under visible-light irradiation. Ir(ppy)3 was found to be an effective photoredox catalyst for this reaction. The reactions of aryl iodides occurred at room temperature. Elevated temperature was required for aryl bromides. Homolytic aromatic substitution was proposed to be the operative reaction pathway.
- Cheng, Yannan,Gu, Xiangyong,Li, Pixu
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supporting information
p. 2664 - 2667
(2013/07/11)
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- Palladium N-Heterocyclic carbene catalysts for the ultrasound-promoted suzuki-miyaura reaction in glycerol
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Novel palladium N-heterocyclic-carbene (NHC)-based complexes with 3,4,5-trimethoxybenzyl, alkyl and sulfonate N-substituents were obtained and fully characterized. The new complexes were used as pre-catalysts in the Suzuki-Miyaura coupling of various aryl halides/boron sources in glycerol under pulsed-ultrasound (P-US) activation. High yields were obtained under mild reaction conditions, without formation of undesired by-products. The pure final cross-coupling products were easily recovered without column chromatography and the catalytic/solvent system could be recycled. TEM (transmission electron microscopy) and XPS (X-ray photoelectron spectroscopy) were used to characterize the nanoparticles and to investigate the fate of the catalysts. Copyright
- Azua, Arturo,Mata, Jose A.,Heymes, Pauline,Peris, Eduardo,Lamaty, Frederic,Martinez, Jean,Colacino, Evelina
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supporting information
p. 1107 - 1116
(2013/05/22)
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- Room-temperature photoinduced direct C-H-arylation via base-promoted homolytic aromatic substitution
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Conceptually different approach toward biaryl syntheses by photoinduced direct C-H arylation of benzene and thiophene in the presence of t-BuOK is reported. The reaction proceeds through photo- and base-promoted homolytic aromatic substitution. The o-, m- and p- substituted ArI, as well as the electron-donating and electron-withdrawing nature of the substituents were found be good to excellent substrates. Heteroaryl, ArBr, ArCl and double C-H arylation were successfully achieved.
- Budén, María E.,Guastavino, Javier F.,Rossi, Roberto A.
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supporting information
p. 1174 - 1177
(2013/04/24)
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- Catalyst-free intramolecular formal carbon insertion into σ-C-C bonds: A new approach toward phenanthrols and naphthols
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The different reactivity of two kinds of carbonyl groups in keto aldehyde substrates has been exploited for the synthesis of phenanthrols, naphthols, and their heteroatom-containing analogues. Key to this highly efficient and robust methodology is the catalyst-free intramolecular formal diazo carbon insertion of N-tosylhydrazones into keto C-C bonds (see scheme). Copyright
- Xia, Ying,Qu, Peiyuan,Liu, Zhenxing,Ge, Rui,Xiao, Qing,Zhang, Yan,Wang, Jianbo
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supporting information
p. 2543 - 2546
(2013/04/10)
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- Synthesis of substituted biaryls via Suzuki, Stille and Hiyama cross-coupling and homo-coupling reactions by CN-dimeric and monomeric ortho-palladated catalysts
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The catalytic activity of dimeric [Pd{C6H2(CH 2CH2NH2)-(OMe)2,2,3}(μ-Br)] 2 and monomeric [Pd{C6H2(CH2CH 2NH2)-(OMe)2,2,3}Br(PPh3)] complexes as efficient, stable and air- and moisture-tolerant catalysts was investigated in the Suzuki, Stille and Hiyama cross-coupling and homo-coupling reactions of various aryl halides. Substituted biaryls were produced in excellent yields in short reaction times using catalytic amounts of these complexes. The monomeric complex was demonstrated to be more active than the corresponding dimeric catalyst for the cross-coupling reaction of unreactive aryl bromides and chlorides. The combination of homogeneous metal catalysts and microwave irradiation gave higher yields of products in shorter reaction times. Copyright
- Hajipour, Abdol R.,Rafiee, Fatemeh
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p. 412 - 418
(2013/07/26)
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- (BeDABCO)2Pd2Cl6 (1-benzyl-4-aza-1- azoniabicyclo[2.2.2]octane chloride) as a highly active catalytic system for the Stille cross-coupling reaction under microwave irradiation
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An efficient catalytic system using (BeDABCO)2Pd 2Cl6 was developed for the Stille cross-coupling reaction. The substituted biaryls were produced in excellent yields in short reaction times using a catalytic amount of this catalyst in DMF at 120 °C. The ionic character of homogeneous catalyst and microwave irradiation and also DMF as microwave-active polar solvent gave higher yields and shorter reaction times than conventional heating. Benzyl DABCO as an efficient ligand and also a quaternary ammonium salt had an efficient stabilizing effect on the Pd(0) species. Copyright 2013 John Wiley & Sons, Ltd. A palladium catalyst is synthesized using N-benzyl DABCO chloride and palladium chloride and the efficiency of this catalytic system is evaluated for Stille reaction. Copyright
- Hajipour, Abdol R.,Najafi, Narges,Rafiee, Fatemeh
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p. 228 - 231
(2013/05/09)
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