- Pure space steric hindrance effect on intramolecular proton transfer in excited state and photophysics of conjugated new dyes under near-IR laser irradiation
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This study presented a variety of new extended conjugated dyes bearing internal proton transfer segments, which were characterized with different extent of space steric hindrance. Besides, the dyes lack of proton transfer moieties were synthesized as the
- Su, Jihong,Lu, Yao,Ding, Ge,Wang, Zhenqiang,Huang, Fanrui,Gao, Fang,Luo, Ziping,Li, Hongru
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- Exploiting Iminoquinones as Electrophilic at Nitrogen "n+" Synthons for C-N Bond Construction
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New methods for C-N bond construction exploiting the N-centered electrophilic character of iminoquinones are reported. Iminoquinones, generated in situ via the condensation of o-vinylanilines with benzoquinones, undergo acid-catalyzed cyclization to afford N-arylindoles in excellent yields. Under similar reaction conditions, homoallylic amines react analogously to afford N-arylpyrroles. Additionally, organometallic nucleophiles are shown to add to the nitrogen atom of N-alkyliminoquinones to provide amine products. Finally, iminoquinones are shown to be competent electrophiles for copper-catalyzed hydroamination.
- Mori-Quiroz, Luis M.,Comadoll, Chelsea G.,Super, Jonathan E.,Clift, Michael D.
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supporting information
p. 7008 - 7013
(2021/09/18)
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- NiFe2O4@SiO2@ZrO2/SO42-/Cu/Co nanoparticles: A novel, efficient, magnetically recyclable and bimetallic catalyst for Pd-free Suzuki, Heck and C-N cross-coupling reactions in aqueous media
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The novel heterogeneous bimetallic nanoparticles of Cu-Co were synthesized based on magnetic nanoparticles, and the magnetic nanocatalyst was characterized by XRD, FE-SEM, EDX mapping, BET, TEM, HRTEM, FTIR, TGA, and VSM. This catalyst was successfully applied as a recyclable magnetically catalyst in Heck, Suzuki, and C-N cross-coupling reactions with various aryl halides (iodides, bromides, and chlorides as challengeable substrates), with olefins, phenylboronic acid, and amines, respectively. We considered the rise of synergetic effects from the different Lewis acid and Br?nsted acid sites present in the catalyst. The catalyst was synthesized with cheap, available materials and a simple synthesis method. The catalyst can be separated easily using an external magnet. It was recycled for more than ten runs without a sensible loss of its catalytic activity, and no significant leaching of the Cu and Co quantity was observed. The significant benefits of the method are high-level generality, simple operation, and there are no heavy metals and toxic solvents. This is a quick, easy, efficacious and environmentally friendly protocol, and no by-products are formed in the reaction. These features make it an appropriate practical alternative protocol. In comparison with recent works, the other advantage of this catalyst is the synthesis of a wide variety of C-C and C-N bond derivatives (more than 40 derivatives). The other significant advantage is the low temperature of the reaction and the use of the least possible amount of the catalyst (0.003 g). The efficiency was good to excellent and the catalyst selectivity has been high. We aspire that our study inspires more interest to design novel catalysts based on using low-cost metal ions (such as cobalt and copper) in the cross-coupling reactions. This journal is
- Alavi G., Seyyedeh Ameneh,Nasseri, Mohammad Ali,Kazemnejadi, Milad,Allahresani, Ali,Hussainzadeh, Mahdi
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p. 7741 - 7757
(2021/05/13)
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- Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
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Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
- Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
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supporting information
p. 4876 - 4894
(2021/09/20)
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- Carbocatalytic Cascade Synthesis of Polysubstituted Quinolines from Aldehydes and 2-Vinyl Anilines
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Oxidized active carbon (oAC) catalyses the formation of polysubstituted quinolines from o-vinyl anilines and aldehydes. The reaction proceeds in a cascade manner through condensation, electrocyclization and dehydrogenation, and gives access to a wide range of quinolines with alkyl and/or aryl substituents as demonstrated with 40 examples. The metal-free catalytic procedure allows a heterogeneous protocol for the synthesis of various polysubstituted quinolines. The mechanistic studies imply that both the acid and quinoidic groups in oAC are integral for the catalytic manifold. (Figure presented.).
- Bulatov, Evgeny,Helaja, Juho,Hu, Tao,Lenarda, Anna,M?kel?, Mikko K.,Malinen, Kiia,Melchionna, Michele,Nieger, Martin,Talvitie, Juulia,Wirtanen, Tom
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supporting information
p. 3775 - 3782
(2021/07/20)
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- Photoredox Catalysis toward 2-Sulfenylindole Synthesis through a Radical Cascade Process
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A radical cascade process initiated through visible-light induced thiyl radical coupling with ortho-substituted arylisocianides followed by an intramolecular cyclization and subsequent aromatization to access 2-sulfenylindoles is described. The key thiyl radicals are promptly generated via a hydrogen atom transfer event. The redox-neutral protocol features broad substrate scope, excellent functional group tolerance, and mild reaction conditions. Furthermore, the implementation of a continuous flow variant allows smooth scalability with a short residence time through process intensification.
- Betim, Hugo L. I.,Campos Delgado, Jose Antonio,Corrêa, Arlene G.,Kisukuri, Camila M.,Paix?o, Márcio W.,Santos, Marilia S.
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supporting information
p. 4266 - 4271
(2020/06/27)
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- Synthesis and characterization of mesoporous organosilica supported palladium (SBA-Pr-NCQ-Pd) as an efficient nanocatalyst in the Mizoroki–Heck coupling reaction
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In the present study, the modification of a mesoporous organosilica nanocomposite SBA-15 (Santa Barbara Amorphous 15) was carried out in two steps, first through the surface functionalization of SBA-Pr-NH2 with 2-chloroquinoline-3-carbaldehyde to form SBA-Pr-NCQ, and then through a post-modification process with palladium ions. The target nanocompound structure of SBA-Pr-NCQ-Pd was characterized by different techniques (thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy). The catalytic performance of the porous inorganic–organic hybrid nanocomposite (SBA-Pr-NCQ-Pd) in one of the most important carbon–carbon bond-forming processes, the Mizoroki–Heck coupling reaction of aryl halides and methacrylate in water/ethanol media, was examined. Compared to previous reports, this protocol afforded some advantages, such as high yields of products, short reaction times, catalyst stability without leaching, simple methodology, easy workup, and greener conditions. Also, the nanocatalyst can be easily separated from the reaction mixture and reused several times without a significant decrease in activity and promises economic as well as environmental benefits.
- Moradi, Razieh,Mohammadi Ziarani, Ghodsi,Badiei, Alireza,Mohajer, Fatemeh
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- Mesoporous Hierarchically Hollow Flower-Like CoAl-LDH@N,S-doped Graphene@Pd Nanoarchitectures for Heck Couplings
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Abstract: A smart strategy for the synthesis of hierarchical CoAl-LDH hollow spheres assembled with nitrogen and sulfur co-doped graphene for high holding of palladium nanoparticles (CoAl-LDH@N,S-G@Pd) is reported. This architecture exhibited excellent activity in Heck reactions with TOF as high as 1633?h?1 due to a strong metal–support interaction, good electron transfers and high surface area. Graphic Abstract: [Figure not available: see fulltext.].
- Rohani, Sahar,Mohammadi Ziarani, Ghodsi,Badiei, Alireza,Ziarati, Abolfazl,Luque, Rafael
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p. 2984 - 2993
(2019/07/05)
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- Benzimidazolyl Palladium Complexes as Highly Active and General Bifunctional Catalysts in Sustainable Cross-Coupling Reactions
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A family of air- A nd moisture-stable dinuclear palladium complexes bearing 2-benzimidazolyl ligands is reported and shown to be a highly effective and general catalytic platform in diverse cross-coupling reactions. The rigidity and conformation of the ligand scaffold was readily modified via tethering of the 2-benzimidazolyl moiety to diamine ligands, resulting in significant changes in catalytic activity. Under optimal conditions, Suzuki, Heck, and Sonogashira-type couplings of aryl bromides can all be performed efficiently with good functional group compatibility using only 0.1 mola?% of catalyst, in aqueous or alcohol solvents. Experimental evidence highlights the importance of the bifunctional character of the ligand for catalytic activity, where the basic N-functionality in the ligand framework is proposed to accelerate (trans)metalation steps via intramolecular assistance.
- Zhu, Jiancheng,Lindsay, Vincent N. G.
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p. 6993 - 6998
(2019/08/26)
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- Arene Trifunctionalization with Highly Fused Ring Systems through a Domino Aryne Nucleophilic and Diels–Alder Cascade
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A convenient and efficient domino aryne process was developed under transition-metal-free conditions to generate a range of tetra- and pentacyclic ring systems. This transformation was realized via a 1,2-benzdiyne through a nucleophilic and Diels–Alder reaction cascade using styrene as the diene moiety. Three new chemical bonds, namely one C?N and two C?C bonds, and two benzofused rings could be constructed concomitantly, which was made possible by distinct chemoselective control at both the 1,2-aryne and 2,3-aryne stages. Moreover, in-depth studies were carried out on the domino aryne precursors and controlling the diastereoselectivity.
- He, Jia,Jia, Zizi,Tan, Hongcheng,Luo, Xiaohua,Qiu, Dachuan,Shi, Jiarong,Xu, Hai,Li, Yang
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supporting information
p. 18513 - 18518
(2019/11/19)
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- Structural development of tetrachlorophthalimides as liver X receptor β (LXRβ)-selective agonists with improved aqueous solubility
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LXRβ-selective agonists are promising candidates to improve atherosclerosis without increasing plasma or hepatic TG levels. We have reported a series of tetrachlorophthalimide analogs as an LXRβ-selective agonist. However, they exhibited poor aqueous solubility probably due to its high hydrophobicity and highly rigid and plane structure. In this report, we present further structural development of tetrachloro(styrylphenyl)phthalimides as the LXRβ-selective agonists with improved aqueous solubility.
- Nomura, Sayaka,Endo-Umeda, Kaori,Fujii, Shinya,Makishima, Makoto,Hashimoto, Yuichi,Ishikawa, Minoru
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p. 796 - 801
(2018/02/09)
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- Ligand-Free C–C Coupling Reactions Promoted by Hexagonal Boron Nitride-Supported Palladium(II) Catalyst in Water
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A micron-scale palladium(II) material has been successfully prepared using Schiff base-modified hexagonal boron nitride as a support and used for the first time as an efficient and recyclable catalyst in organic synthesis. The morphology, composition, metal loading and thermal stability of the catalyst were studied using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), inductively coupled plasma (ICP) and thermogravimetric (TG) analyses. Then, the micron material was tested in various C–C cross-coupling reactions and exhibited excellent catalytic activities in the Suzuki and Heck reactions. Moreover, the catalyst could be easily recovered by simple filtration and reused at least ten times without significant loss of its catalytic activity. In general, this work demonstrates the possibility of using Schiff-base@hexagonal boron nitride as an efficient support for heterogeneous catalysts. (Figure presented.).
- Cheng, Xu,Li, Weijian,Nie, Ruifang,Ma, Xiaojun,Sang, Rui,Guo, Li,Wu, Yong
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supporting information
p. 454 - 466
(2017/02/10)
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- Novel cyclodextrin-modified h-BN@Pd(II) nanomaterial: An efficient and recoverable catalyst for ligand-free C-C cross-coupling reactions in water
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An environmentally friendly palladium(II) catalyst supported on cyclodextrin-modified h-BN was successfully prepared. The catalyst was characterized by FT-IR, SEM, TG, XRD and XPS, and the loading level of Pd in h-BN@β-CD@Pd(II) was measured to be 0.088?mmol g?1 by ICP. It exhibits excellent catalytic activity for the Suzuki and Heck reactions in water, and can be easily separated and consecutively reused for at least nine times. In addition, a series of pharmacologically interesting products were successfully synthesized using this catalyst to demonstrate its potential applications in pharmaceutical industries. Above all, this work opens up an interesting and attractive avenue for the use of cyclodextrin-functionalized h-BN as an efficient support for hydrophilic heterogeneous catalysts.
- Ma, Xiaojun,Lv, Guanghui,Cheng, Xu,Li, Weijian,Sang, Rui,Zhang, Yong,Wang, Qiantao,Hai, Li,Wu, Yong
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- Iron-Catalyzed Intramolecular Aminations of C(sp3)?H Bonds in Alkylaryl Azides
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The nucleophilic iron complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular amination of unactivated C(sp3)?H bonds in alkylaryl azides, which results in the formation of substituted indoline and tetrahydroquinoline derivatives.
- Alt, Isabel T.,Guttroff, Claudia,Plietker, Bernd
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supporting information
p. 10582 - 10586
(2017/08/22)
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- Aryiolefins compound synthetic method
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The invention discloses an aryiolefins compound synthetic method and belongs to the field of organic chemistry synthesis. The aryiolefins compound synthetic method particularly includes dissolving an o-hydroxy (amino) aryl alkynes compound, a bis(pinacolato) borate compound, a transition metal (rhodium, iridium, palladium or platinum), alkali and a hydrogen source into an organic solvent at a nitrogen atmosphere prior to heating and stirring reaction, removing the organic solvent under reduced pressure after the reaction is terminated, and conducting column chromatography separation so as to obtain various o-hydroxy (amino) aryiolefins compounds. Compared with an existing method, the aryiolefins compound synthetic method has the advantages of simpler synthetic and reaction steps, mild reaction conditions, simplicity, convenience and feasibility in operation, cheap and easily available raw materials and capabilities of reaching more than 80% in product yield, inhibiting production of cyclization product benzofuran or indole derivatives and improving reaction efficiency and reactive atom economy, thereby being a novel approach to synthesis of the o-hydroxy (amino) aryiolefins compounds.
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Paragraph 0057; 0058; 0059; 0060
(2016/10/09)
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- Palladium(II)-Schiff base complex immobilized covalently on h-BN: An efficient and recyclable catalyst for aqueous organic transformations
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A moisture- and air-stable palladium(II)-Schiff base complex supported on h-BN was simply prepared by using commercially available reagents. This nanomaterial was applied as an excellent and recyclable heterogeneous catalyst for the Suzuki and Heck cross-coupling reactions. And it has been characterized by FT-IR, XRD, SEM, XPS, TG and ICP-AES techniques. High yields, ligand-free, low reaction time, water as solvent, non-toxicity and recyclability of the catalyst are the main merits of these protocols. In addition, a series of pharmacologically relevant products were successfully synthesized using this catalyst. Above all, this work opens up an interesting and attractive avenue for the use of h-BN as an efficient support for heterogeneous catalysts.
- Li, Weijian,Lv, Guanghui,Cheng, Xu,Sang, Rui,Ma, Xiaojun,Zhang, Yong,Nie, Ruifang,Li, Jie,Guan, Mei,Wu, Yong
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supporting information
p. 8557 - 8564
(2016/12/07)
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- Enhancing catalytic activity towards Heck-reaction by using 4,5,9,10-tetra(arylimino)pyrenylidenyldipalladium tetrachlorides
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A series of binuclear 4,5,9,10-tetra(arylimino)pyrenylidenyldipalladium(ii) tetrachloride complexes (Pd1-Pd4) was synthesized and characterized by FT-IR and NMR spectroscopy as well as elemental analysis. The molecular structures of representative complexes Pd1 and Pd2 were determined by single crystal X-ray diffraction to reveal a square planar geometry around the palladium centre. The complex Pd1 dissolved in the presence of ethanol to form mono-palladium complex C1, whose structure was also confirmed by single crystal X-ray diffraction. All binuclear palladium complexes promote the Heck cross-coupling reactions with high activities; the reaction can be carried out for various substrates and activators (basic compounds) and also in various solvents. The binuclear palladium complexes exhibit significantly higher efficiency than do their mono-palladium complexes bearing 4,5-bis(arylimino)pyrenylidenes.
- Zhao, Tong,Xing, Qifeng,Song, Kuifeng,Ban, Qing,Liang, Tongling,Liu, Qingbin,Sun, Wen-Hua
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p. 14228 - 14234
(2015/02/19)
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- Regiodivergent access to five- and six-membered benzo-fused lactams: Ru-catalyzed olefin hydrocarbamoylation
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We report herein a new strategy of the Ru-catalyzed intramolecular olefin hydrocarbamoylation for the regiodivergent synthesis of five- and six-membered benzo-fused lactams starting from N-(2-alkenylphenyl)formamides. Using a combined catalyst of Ru3
- Li, Bin,Park, Yoonsu,Chang, Sukbok
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supporting information
p. 1125 - 1131
(2014/02/14)
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- Dichloropalladium complexes ligated by 4,5-bis(arylimino) pyrenylidenes: Synthesis, characterization, and catalytic behavior towards Heck-reaction
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A series of 4,5-bis(arylimino)pyrenylidenylpalladium(II) chloride complexes (C1-C4) were synthesized and characterized by FT-IR and NMR spectroscopy, elemental analysis as well as by single crystal X-ray diffraction for the representative complexes C1 and
- Song, Kuifeng,Kong, Shaoliang,Liu, Qingbin,Sun, Wen-Hua,Redshaw, Carl
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p. 453 - 457
(2014/03/21)
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- Palladium nanoparticles in glycerol: A versatile catalytic system for C-X bond formation and hydrogenation processes
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Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C-X bond formation processes (X=C, N, P, S) and C-C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular- and surface-like behaviour), has allowed attractive applications in one-pot multi-step transformations catalysed by palladium, such as C-C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor. Copyright
- Chahdoura, Faouzi,Pradel, Christian,Gomez, Montserrat
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supporting information
p. 3648 - 3660
(2014/01/06)
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- Synthesis of indoles: Sulfur-assisted reaction of 2-nitrostilbenes with carbon monoxide
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When 2-nitrostilbenes were treated with carbon monoxide in the presence of elemental sulfur, the reductive N-heterocyclization of the 2-nitrostilbenes smoothly proceeded to give the corresponding indoles in moderate to good yields.
- Umeda, Rui,Nishimoto, Yuuta,Mashino, Tsukasa,Nishiyama, Yutaka
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p. 1241 - 1247
(2013/07/19)
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- Preparation of a titania-supported highly dispersed palladium nano-catalyst and its application in Suzuki and Heck coupling reactions
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In this work, palladium complexes nanoparticles in titania are prepared by a pH-controlled adsorption and without pH-controlled adsorption method. This method results in high-dispersion palladium on the titania surface. We demonstrate the use of the titania-supported palladium as an efficient catalyst for Suzuki and Heck reactions of a representative range of aryl bromides and chlorides. The reusability of catalyst was tested, and deactivation process of the catalyst was not observed after four recycles. The catalysts were characterized by FT-IR, NMR, elemental analysis, field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Copyright
- Karami, Kazem,Shehni, Mahlagha Bahrami,Rahimi, Nasser
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p. 437 - 443
(2013/08/23)
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- Pd-catalyzed intramolecular oxidative C-H amination: Synthesis of carbazoles
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A Pd-catalyzed oxidative C-H amination of N-Ts-2-arylanilines under ambient temperature using Oxone as an inexpensive, safe, and easy-to-handle oxidant has been developed. This process represents a green and practical method for the facile construction of carbazoles with a broad substrate scope and wide functional group tolerance.
- Youn, So Won,Bihn, Joon Hyung,Kim, Byung Seok
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supporting information; experimental part
p. 3738 - 3741
(2011/09/13)
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- Amides as precursors of imidoyl radicals in cyclisation reactions
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Amides have been successfully used as precursors of imidoyl radicals for radical cyclisation. The amides have been converted to imidoyl selanides via reaction with phosgene to yield imidoyl chlorides followed by reaction with potassium phenylselanide. Imidoyl selanides were reacted with tributyltin hydride (Bu3SnH) as the radical mediator with triethylborane or AIBN as initiators to yield imidoyl radicals for cyclisation reactions. Imidoyl radicals have been cyclised onto alkenes to yield 2,3-substituted-indoles and -quinolines and also onto pyrroles and indoles to give bi- and tricyclic heteroarenes.
- Bowman, W. Russell,Fletcher, Anthony J.,Pedersen, Jan M.,Lovell, Peter J.,Elsegood, Mark R.J.,Hernández López, Elena,McKee, Vickie,Potts, Graeme B.S.
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p. 191 - 203
(2007/10/03)
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- Synthesis of indoles using cyclization of imidoyl radicals
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Imidoyl radicals, generated from imidoyl phenylselanide precursors, have been used for the synthesis of 2,3-disubstituted indoles. A facile high yielding synthesis of imidoyl phenylselanides has been developed. The potential for neophyl rearrangement of 5
- Bowman, W. Russell,Fletcher, Anthony J.,Lovell, Peter J.,Pedersen, Jan M.
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p. 1905 - 1908
(2007/10/03)
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- Deoxygenation Reactions of ortho-Nitrostyrenes with Carbon Monoxide Catalysed by Metal Carbonyls: a New Route to Indoles
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The metal carbonyls Fe(CO)5, Ru3(CO)12, and Rh6(CO)16 are catalysts for the deoxygenation of ortho-nitrostyrenes under carbon monoxide pressure to give indole derivatives; the crystal structure of a non-catalytically active rhodium complex obtained during the synthesis of (5e) is reported.
- Crotti, Corrado,Cenini, Sergio,Rindone, Bruno,Tollari, Stefano,Demartin, Francesco
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p. 784 - 786
(2007/10/02)
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- NITRATION OF BENZOTHIENOBENZOTHIOPHENE
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The nitration of benzothienobenzothiophene with concentrated nitric acid in acetic acid leads to the formation of 2-nitro- and 4-nitrobenzothienobenzothiophene, from which the corresponding amines were obtained.
- Barudi, A.,Kudryavtsev, A. B.,Zheltov, A. Ya.,Stepanov, B. I.
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p. 391 - 395
(2007/10/02)
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