- To D or not to D?: On estimating the microenvironment polarity of biomolecular cavities
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Knowledge of the local polarity of specific cavities in biopolymers can facilitate the design of selective low MW ligands that impact the structure and function of macromolecules. The most common tools for interrogating local polarity are fluorescent probes that are sensitive to their microenvironment. Researchers often evaluate and express this local polarity using dielectric constants, a parameter that reflects an inherent bulk property. A more appropriate expression should take into account solvent-solute interactions at the molecular level. Reevaluation of commonly used fluorophores illustrates the improved correlation between observed Stokes shift changes and ET(30) values as compared to the corresponding dielectric constants. The Royal Society of Chemistry.
- Sinkeldam, Renatus W.,Tor, Yitzhak
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- Molecular transmission: Controlling the twist sense of a helical polymer with a single light-driven molecular motor
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Twisted sisters: Transmission of chirality from a light-driven rotary molecular motor to the macromolecular level of a polyisocyanate allows fully reversible control of the preferred helical sense of the polymer backbone (see picture). (Figure Presented).
- Pijper, Dirk,Feringa, Ben L.
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- Kinetics of the oxidation of fluoren-9-ols by 4-nitro-1-chlorobenzotriazole
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The oxidation of fluoren-9-ols by 4-nitro-1-chlorobenzotriazole in aqueous acetic acid is a second order reaction with a reaction constant of -1.4. The oxidation exhibits a kinetic deuterium isotope effect indicating the cleavage of the 9-C-H bond in the rate-determining step. The title oxidation is compared with that by 1-chlorobenzotriazole.
- Ulagi,Kuselan,Karunakaran
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- Direct deoxygenative intramolecular acylation of biarylcarboxylic acids
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A photocatalyzed intramolecular cyclization is developed for the synthesis of fluorenones. In this photoredox reaction, triphenylphosphine is used as an inexpensive and effective deoxygenative reagent for biarylcarboxylic acids to give acyl radicals, which quickly undergo intramolecular radical cyclization. Reactions in the presence of air and continuous flow photoredox technology demonstrate the generality and practicality of this process.
- Li, Yantao,Xu, Wentao,Zhu, Chengjian,Xie, Jin
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- A solution processable fluorene-fluorenone oligomer with aggregation induced emission enhancement
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Herein, we report a novel solution processable fluorenone based small molecule with an Aggregation Induced Emission Enhancement (AIEE) property. In contrast to previous reports, the presence of the fluorenone moiety in FF triggers the AIEE property.
- Ananthakrishnan, Soundaram Jeevarathinam,Varathan, Elumalai,Ravindran, Ezhakudiyan,Somanathan, Narayanasastri,Subramanian, Venkatesan,Mandal, Asit Baran,Sudha, Janardanan D.,Ramakrishnan, Rajaraman
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- New porphyrin dendrimers with fluorenyl-based connectors: a simple way to improving the optical properties over dendrimers featuring 1,3,5-phenylene connectors
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Two new meso-tetrafluorenylporphyrin-cored dendrimers 1 and 2 have been synthesized and characterized. The peripheral fluorenyl units of these dendrimers are linked to the central tetrafluorenylporphyrin (TFP) core by original fluorene-based connectors instead of the more classic 1,3,5-phenylene unit. Selected linear and non-linear optical (LO and NLO) properties were determined for these dendrimers via absorption or emission studies and by two-photon excited fluorescence (TPEF) measurements. Dendrimer 1, which has a conjugated and quite rigid structure, exhibits a significantly higher two-photon absorption (2PA) cross-section than dendrimer 2, presenting a non-conjugated and more flexible structure, as well as better luminescence and singlet oxygen activation quantum yields. Both dendrimers exhibit higher 2PA cross-sections than several closely related TFP-based dendrimers previously characterized. However, among them, dendrimer 1 is the only one outperforming all these compounds in terms of 2PA brightness and 2PA oxygen sensitization. Thus, the new type of connector (or dendrimeric node) introduced in 1 appears to be quite appealing for the design of photosensitizers aimed at theranostic uses in the future.
- Zhang, Xu,Ben Hassine, Sarra,Richy, Nicolas,Mongin, Olivier,Blanchard-Desce, Mireille,Paul, Frédéric,Paul-Roth, Christine O.
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- Towards dynamic control of wettability by using functionalized altitudinal molecular motors on solid surfaces
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We report the synthesis of altitudinal molecular motors that contain functional groups in their rotor part. In an approach to achieve dynamic control over the properties of solid surfaces, a hydrophobic perfluorobutyl chain and a relatively hydrophilic cyano group were introduced to the rotor part of the motors. Molecular motors were attached to quartz surfaces by using interfacial 1,3-dipolar cycloadditions. To test the effect of the functional groups on the rotary motion, photochemical and thermal isomerization studies of the motors were performed both in solution and when attached to the surface. We found that the substituents have no significant effect on the thermal and photochemical processes, and the functionalized motors preserved their rotary function both in solution and on a quartz surface. Preliminary results on the influence of the functional groups on surface wettability are also described. Copyright
- London, Gabor,Chen, Kuang-Yen,Carroll, Gregory T.,Feringa, Ben L.
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- New highly fluorescent phthalocyanines dendrimers with fluorenyl-based connectors vs phenyl-based connectors
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The design of dendrimers featuring conjugated fluorenyl dendrons via new connectors allows evaluating the importance of the role of these junctions and the nature of the core, on the optical properties of interest. In the continuation of our sustained interest for dendrimers and their use as luminescent labels for bioimaging, we wondered about the effect of changing the central porphyrin core for a phthalocyanine one in these macromolecular structures. Thus, a related phthalocyanine-based dendrimer possessing up to eight conjugated 9,9-dibutyl-2-fluorenyl endgroups was designed, and for the first time, these endgroups are linked to the central phthalocyanine core by new fluorenyl-based connectors C2 instead of the more classic 1,3,5-phenylene one C1. This original dendrimer was characterized and studied and as for porphyrin analogues, it was found that an efficient energy transfer occurs from the peripheral fluorenyl units to the central phthalocyanine core, leading to an intense red light emission. The luminescence is improved compared to that of their porphyrin-cored analogues for bioimaging, evidencing the key role played by the central core in this respect and the nature of the connector Cn. The impact of the structural changes of the core in relation with the impact resulting from the changes in dendron connectors is discussed.
- Ben Hassine, Sarra,Abid, Seifallah,Jamoussi, Bassem,Paul-Roth, Christine O.
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- Electrochemical oxidation-induced benzyl C–H carbonylation for the synthesis of aromatic α-diketones
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Electrochemical oxidation-induced direct carbonylation of benzyl C–H bond for the synthesis of aromatic α-diketones is described. In this process, tetrabutylammonium iodide (nBu4NI) not only acts as an electrolyte, but its iodine anion is oxidized to an iodine radical at the anode, acting as a hydrogen atom transfer agent. The iodine radical extracts the benzyl hydrogen atom and causes the carbonylation of the benzyl position, where O2 in the air is used as an oxygen source.
- Tan, Yu-Fang,Chen, Yuan,Li, Rui-Xue,Guan, Zhi,He, Yan-Hong
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supporting information
(2021/12/21)
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- Preparation method 2 -amino -9-9 - diphenyl fluorene
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The invention discloses a preparation method of 2 - amino -9 and 9 - diphenyl fluorene, which comprises the following steps: taking 9 - fluorenone as a raw material, and carrying out bromination reaction to obtain 2 - bromo -9 - fluorenone. 2 - Bromo -9 - fluorenone and bromobenzene formative reagent are reacted to obtain 2 - bromo -9 - phenyl -9 - hydroxyl - fluorene. 2 - Bromo -9 - phenyl -9 - hydroxy - fluorene was subjected to an alkylation reaction with benzene to give 2 - bromo -9, 9 - diphenylfluorene. 2 - Bromo -9, 9 - diphenylfluorene and cuprous oxide, palladium acetate (II) and N - methylpyrrolidinone were reacted in liquid ammonia to give 2 - amino -9, 9 - diphenylfluorene. The preparation method is used for preparing 2 - amino -9 and 9 - diphenylfluorene, the used preparation is easy to obtain, the technological process is simple, the product yield is high, the production cost is reduced, 2 - amino -9 and 9 - diphenyl fluorene are produced.
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Paragraph 0054-0060; 0074-0079; 0090-0095
(2021/11/03)
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- Organic compound and electronic element and electronic device comprising same
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The invention provides an organic compound and an electronic element and an electronic device thereof, and belongs to the technical field of organic electroluminescence. The organic compound has a structural formula shown 1, wherein the organic compound has excellent photoelectric properties, the light emitting efficiency and the service life of the device can be improved, and the working voltage can be reduced.
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Paragraph 0109-0112
(2021/11/14)
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- Hole transport material and organic electroluminescent device containing same
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The invention discloses a hole transport material and an organic electroluminescent device containing the same, and relates to the field of organic electroluminescent materials, wherein the structuralformula is shown in the specification. According to the invention, compared with a control example, the organic electroluminescent device prepared from the hole transport material has the advantagesthat the voltage is greatly reduced, and the light-emitting efficiency is remarkably improved, so that the compound provided by the invention can greatly reduce the driving voltage of the device, greatly reduces the consumption of electric energy, and remarkably improves the luminous efficiency; and by reducing the driving voltage, the service life of the organic electroluminescent device is remarkably prolonged.
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Paragraph 0046; 0049-0050; 0079; 0082; 0085; 0087; 0115
(2021/02/24)
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- Mn(III) active site in hydrotalcite efficiently catalyzes the oxidation of alkylarenes with molecular oxygen
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Developing efficient heterogeneous catalytic systems based on easily available materials and molecular oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni2Mn-LDH) has been found as an efficient catalyst in the oxidation of alkylarenes using molecular oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system have been observed. Mn3+ species was proposed to be the efficient active site, and Ni2+ played an important role in stabilizing the Mn3+ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni2Mn-LDH with the activation energy (Ea) and pre-exponential factor (A0) being 85.7 kJ mol?1 and 1.8 × 109 min?1, respectively. The Gibbs free energy (ΔG≠) was determined to be -10.4 kJ mol-1 K-1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by molecular oxygen and H2O or hydroxyl species, respectively, to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.
- Wang, Anwei,Zhou, WeiYou,Sun, Zhonghua,Zhang, Zhong,Zhang, Zhihui,He, MingYang,Chen, Qun
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- Spirooxazine photochromic compound changing from colorless to blue as well as preparation method and application of spirooxazine photochromic compound
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The invention discloses a spirooxazine photochromic compound changing from colorless to blue as well as a preparation method and application of the spirooxazine photochromic compound, and belongs to the technical field of organic functional materials. The objective of the invention is to develop and meet aesthetic needs of customers. The invention discloses a photochromic compound with high outdoor stability and a formula of a coating thereof. The spirooxazine photochromic compound changing from colorless to blue prepared by the invention has the advantages of high photoresponse speed, high fading speed, stable performance in a closed-loop state in outdoor use, low-price and easily available synthetic raw materials and high operability of a synthetic process, and meets the market aestheticrequirements.
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Paragraph 0035-0038; 0052-0055
(2020/11/02)
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- Synthesis, Crystal Structure, and Catalytic Property of a Copper Coordination Compound Based on In Situ Generated 2-Hydroxynicotinic Acid
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Abstract: The copper coordination complex [CuCl(2-OHNA)H2O]·H2O (1) was synthesized by the reaction of CuCl2·2H2O with in situ generated 2-hydroxynicotinic acid and its crystal structure was determined by single X-ray diffraction methods. It was further characterized by FT-IR spectroscopy, elemental analyses, and thermogravimetric analysis. Complex 1 crystallizes in monoclinic space group P21/c with a = 8.9797(13), b = 14.196(2), c = 7.0738(11) ?, β = 96.897(2), V = 895.2(2) ?3, Mr = 273.12, Dc = 2.027?g/cm3, and Z = 4. In the structure, complex 1 is linked into 2D sheets via intermolecular hydrogen bonding [N1–H1···O2 (?x+1, y ? 1/2, ? z+1/2); O5–H10···O2 (? x+1, y + 1/2, ? z+1/2); O4–H9···O5 (x, y ? 1, z); O4–H8···O5 (? x+2, y + 1, ? z)]. The catalytic property of 1 was also investigated in the selective oxidation of benzyl-alkanes using TBHP as oxidant. Under optimized conditions, 1 exhibited high catalytic activity and selectivity toward the corresponding aryl ketones. Graphic Abstract: The copper coordination complex [CuCl(2-OHNA)H2O]·H2O (1) was synthesized by the reaction of CuCl2·2H2O with in situ generated 2-hydroxynicotinic acid and the catalytic property of 1 was also investigated in the selective oxidation of benzyl-alkanes using TBHP as oxidant.[Figure not available: see fulltext.].
- Wu, Ren-Tao,Li, Ji-Kun,Wei, Chuan-Ping,Ma, Xian
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p. 234 - 240
(2019/12/24)
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- Preparation method of key intermediate of anti-hepatitis C drug ledipasvir
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The invention provides a preparation method of a key intermediate 1-(7-bromo-9,9-difluoro-9H-fluoren-2-yl)-2-chloroethanone. The method comprises the steps as follows: 2-amino-5-bromobenzoic acid is taken as a raw material, and subjected to diazotization, iodination,synthesis of 5-bromo-2-iodobenzoic acid, methylation, coupling reaction with phenylboronic acid, ester hydrolysis, acyl chlorination,intramolecular Friedel-Crafts alkylation, carbonyl reduction, iodization, fluorination and final reaction with 2-chloro-N-methoxy-N-methylacetamide to prepare the target product. The process adopts easily available starting raw materials, is low in price and free of hazardous process and has mild reaction conditions..
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Paragraph 0065-0067
(2019/05/08)
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- Amphiphilic ligands for Cu-catalyzed aerobic oxidation to synthesize 9-fluorenones in water
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A series of amphiphilic PEG-functionalized nitrogen ligands were developed for the highly efficient copper-catalyzed aerobic oxidation of 9-fluorenes, with molecular oxygen as the sole oxidant in neat water. A broad range of functional groups are well tolerated and thus offer the opportunity for further functionalization.
- Li, Longjia,Liu, Zibo,Tang, Shanyu,Li, Jiao,Ren, Xuanhe,Yang, Guanyu,Li, Heng,Yuan, Bingxin
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- Method for synthesizing fluorenone ketone compound through molecular oxygen oxidation in water phase
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Aiming at the technical problems that in the prior art a method for synthesizing a fluorenone ketone compound has organic solvent pollution and byproducts can be generated, the invention provides a method for synthesizing a fluorenone ketone compound through molecular oxygen oxidation in a water phase. The method comprises the following steps: by taking a fluorenone compound as a substrate, dispersing into an alkali solution, and at 40-120 DEG C, in the presence of oxygen, and with a water-soluble transition metal compound as a catalyst, stirring to carry out reactions, thereby obtaining the fluorenone ketone compound. By adopting the method, molecular oxygen is adopted as an oxidant, and water is adopted as a solvent, so that an organic solvent is avoided, and the problem that multiple byproducts are generated because of peroxidation can be avoided.
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Paragraph 0050-0053
(2019/08/20)
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- Bicontinuous mesoporous Co, N co-doped carbon catalysts with high catalytic performance for ethylbenzene oxidation
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A series of bicontinuous mesoporous Co, N co-doped carbon catalysts (Co-N-C), which have large pore sizes and high specific surface areas with remarkable catalytic activity, were prepared through a method using KIT-6 silica as a hard template, and cobalt porphyrin and sucrose as precursors. And morphological and structural characterizations were performed using N2 adsorption-desorption isotherm, XRD, Raman, TEM and XPS techniques. The results showed that the ethylbenzene oxidation with TBHP as an oxidant over the bicontinuous mesoporous Co, N co-doped carbon catalysts achieved 93% of ethylbenzene conversion with about 99% of selectivity to acetophenone. The superior catalytic performance of the catalysts was attributed to the synergistic effect of factors such as high surface area and well-dispersed metal active sites.
- Zhang, Lushuang,Jie, Shanshan,Liu, Zhigang
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supporting information
p. 7275 - 7281
(2019/05/24)
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- Design, synthesis and biological evaluation of 1,4-Diazobicylco[3.2.2]nonane derivatives as α7-Nicotinic acetylcholine receptor PET/CT imaging agents and agonists for Alzheimer's disease
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α7-Nicotinic acetylcholine receptor (α7-nAChR) agonists are promising therapeutic drug candidates for treating the cognitive impairment associated with Alzheimer's disease (AD). Thus, a novel class of derivatives of 1,4-diazobicylco[3.2.2]nonane has been synthesized and evaluated as α7-nAChR ligands. Five of them displayed high binding affinity (Ki = 0.001–25 nM). In particular, the Ki of 14 was 0.0069 nM, which is superior to that of the most potent ligand that was previously reported by an order of magnitude. Four of them had high selectivity for α7-nAChRs over α4β2-nAChRs and no significant hERG (human ether-a-go-go-related gene) inhibition. Their agonist activity was also discussed preliminarily. One of the compounds, 15 (Ki = 2.98 ± 1.41 nM), was further radiolabeled with 18F to afford [18F]15 for PET imaging, which exhibited high initial brain uptake (11.60 ± 0.14%ID/g at 15 min post injection), brain/blood value (9.57 at 30 min post injection), specific labeling of α7-nAChRs and fast clearance from the brain. Blocking studies demonstrated that [18F]15 was α7-nAChR selective. In addition, micro-PET/CT imaging in normal rats further indicated that [18F]15 had obvious accumulation in the brain. Therefore, [18F]15 was proved to be a potential PET radiotracer for α7-nAChR imaging.
- Wang, Shuxia,Fang, Yu,Wang, Huan,Gao, Hang,Jiang, Guohua,Liu, Jianping,Xue, Qianqian,Qi, Yueheng,Cao, Mengying,Qiang, Bingchao,Zhang, Huabei
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p. 255 - 266
(2018/10/17)
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- Sodium copper chlorophyllin catalyzed chemoselective oxidation of benzylic alcohols and diarylmethanes in water
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We report the highly efficient and chemoselective oxidation of benzylic alcohols catalyzed by sodium copper chlorophyllin in water, producing corresponding arylcarbonyl compounds. Importantly, the catalytic system exhibits a wide substrate scope and high functional group tolerance. Moreover, secondary alcohols and even diarylmethanes were smoothly oxidized to the desired aryl ketones with excellent yields.
- Liu, Shi-juan,Zhang, Miao,Lu, Rong,Li, Xiu-ying,Che, Guang-bo
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- Transition-metal-free C(sp3)–H oxidation of diarylmethanes
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An efficient direct C(sp3)–H oxidation of diarylmethanes has been demonstrated by this study. This method employs environment-friendly O2 as an oxidant and is promoted by commercially available MN(SiMe3)2 [M = K, Na or Li], which provides a facile method for the synthesis of various diaryl ketones in excellent yields. This protocol is metal-free, mild and compatible with a number of functional groups on substrates.
- Yang, Fan,Zhou, Bihui,Chen, Pu,Zou, Dong,Luo, Qiannan,Ren, Wenzhe,Li, Linlin,Fan, Limei,Li, Jie
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- Nitric acid-catalyzed aerobic oxidation of benzylic sp3 C–H bonds of isochromans, xanthenes and 9-fluorenone under additive-free conditions
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HNO3 was demonstrated to be an effective catalyst for aerobic oxidation of benzylic sp3 C–H bonds under additive-free conditions. A series of isochromans, xanthenes and fluorenes underwent this transformation to give the targeted products in low to high yields under the catalysis of HNO3, which provided an effective method for the synthesis of the synthetically and biologically valued isochromanones, xanthones and 9-fluorenones.
- Tian, Xinzhe,Ren, Fangping,Zhao, Bo,Ren, Yun-Lai,Zhao, Shuang,Wang, Jianji
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- Synthesis and radiofluorination of novel fluoren-9-one based derivatives for the imaging of α7 nicotinic acetylcholine receptor with PET
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By structure–activity relationship studies on the tilorone scaffold, the ‘one armed’ substituted dibenzothiophenes and the fluoren-9-ones were identified as the most potential α7 nAChR ligands. While the suitability of dibenzothiophene derivatives as PET tracers is recognized, the potential of fluoren-9-ones is insufficiently investigated. We herein report on a series of fluoren-9-one based derivatives targeting α7 nAChR with compounds 8a and 8c possessing the highest affinity and selectivity. Accordingly, with [18F]8a and [18F]8c we designed and initially evaluated the first fluoren-9-one derived α7 nAChR selective PET ligands. A future application of these radioligands is facilitated by the herein presented successful implementation of fully automated radiosynthesis.
- Teodoro, Rodrigo,Scheunemann, Matthias,Wenzel, Barbara,Peters, Dan,Deuther-Conrad, Winnie,Brust, Peter
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supporting information
p. 1471 - 1475
(2018/04/10)
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- Ligand compound of alpha7 nicotinic acetylcholine receptor and application of ligand compound
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The embodiment of the invention provides a ligand compound of an alpha7 nicotinic acetylcholine receptor, the ligand compound has one of the following general formulas: wherein (1) X and R1 are shown in the description, and R7 is halogen; (2) R2 is hydrogen, and R3 is halogen or amino; or R3 is hydrogen, and R2 is halogen or amino; (3) R6 is hydrogen, and R4 and R5 are synthesized into a compound shown in the description; or R4 is hydrogen, and R5 and R6 are synthesized into a compound shown in the description; R8 is halogen; and (4) Y is nitrogen or carbon, Z is shown in the description, and R9 and R10 are respectively halogens. The provided ligand compound is an excellent ligand compound of the alpha7 nicotinic acetylcholine receptor. After being chemically marked radioactively, the provided ligand compound of the alpha7 nicotinic acetylcholine receptor can serve as a PET photographic developer.
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Paragraph 0057; 0058; 0059
(2017/10/09)
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- A heterocycle-containing organic electroluminescent compound and its device
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The invention provides a heterocycle-contained organic electroluminescent compound as shown in a structural formula I, and a device thereof. The compound has good thermal stability, high luminous efficiency and high luminous purity, and can be used for production of organic electroluminescent devices and applied in the fields of organic solar cells, organic thin-film transistors or organic photoreceptors. The invention also provides an organic electroluminescent device which comprises an anode, a cathode and organic layers, wherein the organic layers comprise one layer or more layers selected from the group consisting of a luminous layer, a hole injection layer, a hole transport layer, a hole blocking layer, an electron injection layer and an electron transport layer; and at least one layer of the organic layers contains the compound as shown in the structural formula I.
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Paragraph 0062-0063
(2017/10/28)
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- Regioselective monobromination of aromatics via a halogen bond acceptor-donor interaction of catalytic thioamide and N-bromosuccinimide
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Regioselective monobromination of various aromatics was achieved at room temperature using N-bromosuccinimide and 5 mol% of thioamides in acetonitrile. With thiourea as catalyst, activated aromatics, such as anisole, acetanilide, benzamide and phenol analogues containing electron donating or withdrawing groups, were brominated with high regioselectivity. Room temperature brominations of weakly activated aromatics and deactivated 9-fluorenone were accomplished by 5 mol% thioacetamide, higher substrates concentrations and longer reaction times. A backbonding of the bromine lone pairs with the π*of C[dbnd]S group and a halogen bond between the halogen bond donor bromine and the halogen bond acceptor sulfur of the thioamide are thought to be the principal interactions and cause of N-bromosuccinimide activation.
- Bovonsombat, Pakorn,Teecomegaet, Pattaradra,Kulvaranon, Panisanun,Pandey, Aditi,Chobtumskul, Kittithorn,Tungsirisurp, Sireethorn,Sophanpanichkul, Punyanuch,Losuwanakul, Satreerat,Soimaneewan, Dechathon,Kanjanwongpaisan, Patcharida,Siricharoensang, Pornpawit,Choosakoonkriang, Sirirat
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p. 6564 - 6572
(2017/10/17)
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- Cu(II)-Catalyzed Ligand-Free Oxidation of Diarylmethanes and Second Alcohols in Water
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We developed a simple and efficient Cu(II)-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% tert-butyl hydroperoxide (TBHP) in water. A series of diarylmethanes were directly oxidized into diaryl ketones in 67%–98% yields. Additionally, various secondary alcohols were also transformed into the desired products in 48%–98% yields. Importantly, the catalytic system in the absence of any organic solvent, surfactant, or phase transfer agent, had a wide substrate scope and a high tolerance for various functional groups.
- Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
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supporting information
p. 1391 - 139
(2017/09/30)
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- Two 2-D multifunctional cobalt(ii) compounds: field-induced single-ion magnetism and catalytic oxidation of benzylic C-H bonds
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Two cobalt(ii) compounds, namely, {[Co(HL)(bpy)(H2O)2]·DMF}n (1), and {[Co(HL)(bpe)]·0.5bpe}n (2) (H3L = 1,3-bis(2-carboxylphenoxy)benzoic acid, bpy = 4,4′-bipyridine, bpe = 4,4′-vinylenedipyridine), have been synthesized using cobalt(ii) transition metal salt with phenolic carboxylic acid and different N-donor ligands. The compounds were fully characterized by elemental analysis, infrared spectroscopy (IR), single crystal X-ray diffraction analysis, and thermogravimetric analysis (TGA). Both compounds exhibit 2-D (4,4)-sql networks but with a wavelike and a double layered arrangement, respectively. Remarkably, these two compounds not only exhibit field-induced single-ion relaxation magnetization but also exceptional catalytic activities of benzylic C-H oxidation (conv. 90.3-99%; sele. 98.1-99%).
- Ma, Ranran,Chen, Zhiwei,Cao, Fan,Wang, Suna,Huang, Xianqiang,Li, Yunwu,Lu, Jing,Li, Dacheng,Dou, Jianmin
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p. 2137 - 2145
(2017/02/26)
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- Immobilization of Keggin polyoxovanadoniobate in crystalline solids to produce effective heterogeneous catalysts towards selective oxidation of benzyl-alkanes
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Two ionic organic-inorganic hybrid compounds, [CuII(C2N2H8)2]4[CuII(C2N2H8)2(H2O)2]2[PNb12O40VVVIVO2]·(OH)2·11H2O (1) and [CoIII(C2N2H8)3]2[CoIII(C2N2H8)2(H2O)2]0.5[H2.5PNb12O40 VVVIVO2]·20H2O (2), based on P-centered dicapped polyoxoniobates and organometallic cations were isolated and structurally characterized by routine techniques. The trivalent cobalt complex-containing compound exhibits a looser arrangement compared with its divalent copper complex-containing counterpart, with a space volume of 34.9% for the former and 17.0% for the latter. The two compounds were proved to be effective in facilitating the oxidation of benzyl-alkanes to ketone products in a heterogeneous manner, evidencing the feasiblity of the strategy of self-immobilization of catalytically active, readily soluble PNb12O40(VO)2 species in crystalline solids.
- Hu, Jufang,Dong, Jing,Huang, Xianqiang,Chi, Yingnan,Lin, Zhengguo,Li, Jikun,Yang, Song,Ma, Hongwei,Hu, Changwen
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p. 8245 - 8251
(2017/07/10)
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- CBr4 promoted intramolecular aerobic oxidative dehydrogenative arylation of aldehydes: application in the synthesis of xanthones and fluorenones
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A simple and practical carbon tetrabromide promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for 2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes as substrates. Preliminary studies of the reaction mechanism indicated that the reaction may proceed through a radical pathway.
- Tang, Jing,Zhao, Shijun,Wei, Yuanyuan,Quan, Zhengjun,Huo, Congde
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supporting information
p. 1589 - 1592
(2017/02/23)
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- A simple, mild and efficient oxidation of benzylic alcohols in the presence of NBS/KOAc in aqueous solution
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Background: The oxidation of benzylic alcohols to carbonyl compounds is a fundamental reaction in organic synthesis. In traditional oxidation processes, a large amount of toxic and volatile organic solvents and metal oxidants are used. Thus, developing environmentally benign oxidation processes is an important goal. N-Bromosuccinimide (NBS) is an inexpensive and convenient oxidant widely used in a variety of oxidative reactions under acidic or alkaline conditions. Methods: In this paper, we developed a simple, mild, and efficient oxidation of benzylic alcohols in the presence of N-bromosuccinimide (NBS)/KOAc in aqueous solution (H2O/CH2Cl2 = 3:1). Results: A series of benzylic alcohols were oxidized selectively to the corresponding ketones in moderate to excellent yields at room temperature. Conclusion: This reaction was carried out using a wide variety of substrates, required no metal catalyst, and proved to be tolerant towards a variety of different functional groups.
- Wu, Jianglong,Liu, Yan,Liu, Ping,Gu, Chengzhi
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p. 254 - 260
(2017/07/15)
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- A 2-bromo-9-fluorenone, synthetic method
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The invention discloses a synthetic method of 2-Bromo-9-fluorenon and belongs to the technical field of synthesis of organic compounds. The synthetic method of the 2-Bromo-9-fluorenon includes the following steps that firstly, 9-fluorenone and a phase transfer catalyst are mixed with an ammonium bromide aqueous solution and then are heated to 40 DEG C to 95 DEG C, the mixed solution is added to potassium bromate for reaction in batches, and the mole ratio of the 9-fluorenone, the ammonium bromide and the potassium bromate is 1:2-4:1-1.25;secondly, the mixed solution is cooled to the indoor temperature after reaction is completed, bromine removal fluid is added, and then the 2-Bromo-9-fluorenon is obtained through filtering and washing. The synthetic method of the 2-Bromo-9-fluorenon is easy and safe to operate, good in reaction selectivity and high in yield.
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Paragraph 0032-0036
(2017/03/21)
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- A fluorine hole transport compound
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The invention provides a fluorene-based hole transport compound with a structural formula (I) as shown in the specification. The compound has relatively good thermal stability, high luminous efficiency and high luminous purity, can be used for making organic light-emitting devices and is applied to the fields of organic solar cells, organic thin-film transistors or organic photoreceptors.
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Paragraph 0061-0065
(2016/11/17)
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- A fluorine hole transport compound (by machine translation)
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The invention provides a fluorene-based hole transport compound represented by the following structural formula (I). The compound has the advantages of relatively good thermal stability, high luminous efficiency, high luminous purity and low driving voltage and can be used to fabricate an organic electroluminescent device and applied in the fields of organic solar cells, organic thin-film transistor or organic photoreceptor.
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Paragraph 0056-0058
(2017/01/17)
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- A liquid-phase process for preparing 2- [...] method
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The invention belongs to the field of fine chemical engineering, and particularly relates to a method for preparing 2-bromofluorenone by liquid-phase oxidation. The method comprises the following steps: dissolving 2-bromofluorene in N,N-dimethylformamide, adding a catalyst, stirring at 30-40 DEG C under normal pressure, carrying out air oxidation, reacting for 2-4 hours, distilling, filtering, washing with water, and drying to obtain the 2-bromofluorenone. The yield is 96%, and the purity is 99-99.5%. The weight ratio of the 2-bromofluorene to the N,N-dimethylformamide is 1:(3.5-5); and the mole ratio of the 2-bromofluorene to the catalyst is 1:(0.03-0.5). The method has the advantages of mild reaction conditions, lower solvent consumption, high yield, low cost, small environmental pollution, recyclable solvent without further treatment after use and short reaction time, is simple to operate, and is very suitable for large-scale industrial production.
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Paragraph 0015; 0016; 0017; 0018; 0019; 0020
(2016/12/01)
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- Ionic liquid [bmim]Br assisted chemoselective benzylic [Formula presented] oxidations using tert-butyl hydroperoxide
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A mild and efficient, ionic-liquid-assisted green protocol for the chemoselective oxygenation of benzylic C-H bonds to corresponding ketones using ionic liquid [bmim]Br with tert-butyl hydroperoxide has been developed. The method reported in this paper has the advantages of [bmim]Br acting as recyclable solvent and reagent. The usage of additives such as acids or bases and metal salts is not required. The developed strategy is further extended to oxidation of secondary alcohols to respective ketones under similar optimized reaction conditions.
- Naidu, Shivaji,Reddy, Sabbasani Rajasekhara
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p. 441 - 445
(2016/07/27)
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- NHC-Catalyzed Benzylic Csp3–H Bond Activation of Alkylarenes and N-Benzylamines for the Synthesis of 3H-Quinazolin-4-ones: Experimental and Theoretical Study
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An N-heterocyclic carbene catalyzed benzylic Csp3–H bond activation of alkylarenes and N-benzylamines under metal-free conditions was developed. This organocatalyzed oxidative transformation afforded the corresponding carbonyl derivatives in good to excellent yields. A variety of alkylarenes and N-benzylamines were tolerated under the optimized reaction conditions. The established method was further extended to the synthesis of biologically important 3H-quinazolin-4-ones in good yields. For example, NPS 53574, a potent calcium receptor antagonist, was successfully synthesized by using this oxidative protocol. DFT studies show that the benzylic C–H bond activation proceeds through the nucleophilic attack of the free carbene on the benzylic carbon atom.
- Alanthadka, Anitha,Devi, E. Sankari,Nagarajan, Subbiah,Sridharan, Vellaisamy,Suvitha, Ambigapathy,Maheswari, C. Uma
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supporting information
p. 4872 - 4880
(2016/10/13)
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- Expeditious Assembly of Fluorenones through Domino Reactions of Benzoyl Chlorides with Arylboronic Acids Catalyzed by ONO Pincer-like Palladium(II) Complexes
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A new set of palladium(II) complexes featuring ONO pincer-type ligands were synthesized and utilized as efficient homogeneous catalysts for the domino reactions of benzoyl chlorides with arylboronic acids to yield a library of fluorenones. The titled reaction proceeded smoothly in H2O/MeOH media at a low catalyst loading (0.1 mol %) under mild reaction conditions in an open flask, and the catalyst could be reused over six consecutive runs. To validate the currently developed methodology for industrial-level applications, a gram-scale synthesis was done. Advantageously, the present protocol does not require any external oxidant, additives, or phase-transfer agents.
- Vignesh, Arumugam,Kaminsky, Werner,Dharmaraj, Nallasamy
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p. 3207 - 3212
(2016/10/24)
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- Chelation-assisted Pd-catalysed ortho-selective oxidative C-H/C-H cross-coupling of aromatic carboxylic acids with arenes and intramolecular Friedel-Crafts acylation: One-pot formation of fluorenones
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Pd-Catalysed ortho-selective oxidative C-H/C-H cross-coupling of aromatic carboxylic acids with arenes and subsequent intramolecular Friedel-Crafts acylation has been accomplished for the first time through a chelation-assisted C-H activation strategy. Starting from the readily available substrates, a variety of fluorenone derivatives are obtained in one pot. The direct use of naturally occurring carboxylic acid functionalities as directing groups avoids unnecessary steps for installation and removal of an extra directing group.
- Sun, Denan,Li, Bijin,Lan, Jingbo,Huang, Quan,You, Jingsong
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supporting information
p. 3635 - 3638
(2016/03/05)
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- Metal-free oxidation of secondary benzylic alcohols using aqueous TBHP
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We report a simple, yet efficient metal-free oxidation of secondary benzylic alcohols in the presence of t-butyl hydroperoxide (70% TBHP) with high yields of up to 98%. This type of reaction can be carried out using a wide variety of substrates, requires no other organic solvent, and proves to be tolerant toward a variety of different functional groups.
- Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
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supporting information
p. 1747 - 1758
(2016/10/30)
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- Four alkoxohexavanadate-based pd-polyoxovanadates as robust heterogeneous catalysts for oxidation of benzyl-alkanes
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Four alkoxohexavanadate-based Pd-POVs [Pd(dpa)(acac)]2[V6O13(OMe)6] (1), [Pd(dpa)(acac)]2[V6O11(OMe)8] (2), [Pd(dpa)(acac)]2[V6O11(OMe)8]·H2O (3), and [Pd(DMAP)2(acac)]2[V6O11(OMe)8]·H2O (4) (POV = polyoxovanadate; dpa = 2,2′-dipyridine amine; DMAP = 4-dimethylaminopyridine; acac = acetylacetone anion) have been synthesized and fully characterized by single crystal X-ray diffraction and powder X-ray diffraction analyses, Fourier transform infrared spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In 1-4, Pd complexes and hexavanadate anions are assembled through electrostatic interactions. Interestingly, the [V6O11(OMe)8]2- cores in 2 and 3 are a pair of isomers that can be isolated by controlling crystallization temperature. Moreover, to the best of our knowledge, the {V6} core in 3 represents a new octamethoxyhexavanadates cluster. It is notable that compounds 1-4 exhibit excellent heterogeneous catalytic performance in the oxidation of benzyl-alkanes with t-butylhydroperoxide as oxidant. Among them, the catalytic activity of 1 (conv. and selec. up to 99%, respectively) outperforms others and can be reused without losing its activity.
- Li, Ji-Kun,Huang, Xian-Qiang,Yang, Song,Ma, Hong-Wei,Chi, Ying-Nan,Hu, Chang-Wen
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supporting information
p. 1454 - 1461
(2015/04/21)
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- Coordination polymers based on substituted terpyridine ligands: synthesis, structural diversity, and highly efficient and selective catalytic oxidation of benzylic c-h bonds
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Reaction of two related rigid terpyridine ligands, 4′-(4-cyanophenyl)-4,2′:6′,4-terpyridine (L1) and its derivative, 4′-(4-carboxyphenyl)-4,2′:6′,4-terpyridine (L2), with transition metal ions (Co2+ or Cu2+/Cu+), afforded four novel coordination compounds: Co(L1)Cl2 (1), Co3(L1)3Cl6 (2), CuI9(L1)4.5(CN)9 (3), and [CuII3(L2)6(H2O)6]·4H2O (4). Crystal structure analysis reveals that 1 is comprised of single-stranded 21 helical chains, and weak interactions involving C-H···Cl weak hydrogen bonding and stacking interactions exist in the structure. The structure of 2 is comprised of 32 helices, which is compared with the structure of compound 1. 3 shows a three-dimensional (3D) 4-fold interpenetration structure. 4 exhibits a one-dimensional gridlike belt structure, which further builds 3D supramolecular architecture via stacking interactions. These novel coordination compounds show exceptional catalytic activity for the oxidation of benzylic C-H bonds. Notably, compound 4 shows the best catalytic properties for the oxidation of benzylic hydrocarbons up to 99% conversion and 99% selectivity.
- Xi, Yaru,Wei, Wei,Xu, Yanqing,Huang, Xianqiang,Zhang, Fanzhou,Hu, Changwen
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p. 2695 - 2702
(2015/06/16)
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- Synthesis of fluorenones through rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids
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An efficient approach to the synthesis of fluorenones via the rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids was developed. Using this procedure, fluorenones with various substituents can be synthesized in good to high yields. This work marks the first recorded use of catalytic intramolecular acylation to synthesize fluorenones.
- Fukuyama, Takahide,Maetani, Shinji,Miyagawa, Kazusa,Ryu, Ilhyong
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p. 3216 - 3219
(2014/07/08)
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- Novel tri-carbazole modified fluorene host material for highly efficient solution-processed blue and green electrophosphorescent devices
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A series of novel solution-processable small-molecule host materials: 2DPF-TCz, 2SBF-TCz, 27DPF-TCz, and 27SBF-TCz comprising a fluorene monomer as the rigid core and tri-carbazole as the periphery have been designed and synthesized, and their optical, electrochemical, and thermal properties have been fully characterized. The host materials exhibit high glass-transition temperatures (231-310 °C) and high triplet energy levels (2.61-2.73 eV). High-quality amorphous thin films can be obtained by spin-coating the host materials from solutions. It is found that the HOMO level of the host materials can be tuned by linking the tri-carbazole unit to the 2,7 positions of the fluorine core, resulting in appropriate HOMO energy levels (-5.36 to -5.23 eV) for improved hole-injection in the device. Solution-processed blue and green electrophosphorescent devices bases on the developed host materials exhibit high efficiencies of 21.2 and 34.8 cd A-1, respectively.
- Tang, Jinan,Chen, Yuanshen,Cong, Lei,Lin, Baoping,Sun, Yueming
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p. 3847 - 3853
(2014/06/09)
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- Novel blue luminescent materials for organic light-emitting diodes based on C9-fluorenyl anthracenes
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A series of twisted fluorenyl anthracenes linked by a rigid sp 3-hybridized carbon atom, containing an end-capping aryl substituent at either the C2-position of fluorene or at the C10-position of anthracene, have been synthesized and characterized. These materials exhibited good thermal stabilities and amorphous properties. Theoretical calculations and X-ray diffraction studies revealed that the six blue emitters possess non-coplanar structures to suppress intermolecular interactions. The relationship between the chemical structures with different end-capping groups and the electroluminescent properties has been investigated. Organic light-emitting diodes utilizing 9-(2-phenyl-9H-fluoren-9-yl) anthracene as the emitter exhibited deep-blue emissions CIE x, y (0.166, 0.153) with a current efficiency of 1.47 cd/A, external quantum efficiency of 1.84% at 20 mA/cm2 and a maximum brightness of 3013 cd/m2 at 11 V. It was found that the introduction of the aryl substituents to the C2 position of fluorene could improve the performance of OLEDs based on C9-fluorenyl anthracenes.
- Wan, Wen,Du, Heliang,Wang, Jing,Le, Yuping,Jiang, Haizhen,Chen, Hua,Zhu, Shizheng,Hao, Jian
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p. 642 - 652
(2013/03/13)
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- Aerobic oxidation of 9H-fluorenes to 9-fluorenones using mono-/multilayer graphene-supported alkaline catalyst
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The synthesis of 9-fluorenone derivatives has been achieved in high yield and with high purity by aerobic oxidation of 9H-fluorenes at room temperature in the presence of a graphene-supported KOH composite that acts as a catalyst in N,N-dimethylformamide. The new protocol involves very simple work-up procedures, and the solvent and the catalyst can be recycled and reused. A scaled-up preparative study employing this method was also conducted and showed its advantages of being both cost-effective and environmentally friendly, and has potential for application in industrial processes. Copyright
- Zhang, Xin,Ji, Xuan,Su, Ruifei,Weeks, Brandon L.,Zhang, Zhao,Deng, Songlu
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p. 703 - 711
(2013/07/26)
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- New fluorenone-containing organic photosensitizers for dye-sensitized solar cells
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Four new organic dyes (F1-F4) comprising the triarylamine or fluorene unit as an electron-donating group, a less commonly used fluorenone spacer and a cyanoacrylic acid as the anchoring group in the molecular framework were synthesized, characterized and utilized in dye-sensitized solar cells (DSSCs). Their absorption, photoluminescence, electrochemical and photovoltaic properties were fully investigated in detail. Electrochemical data indicate that the tuning of the HOMO and LUMO energy levels can be conveniently accomplished by alternating the donor moiety. The photovoltaic performance can be increased by adding an electron-donating triarylamine or fluorene unit next to the fluorenone ring or increasing the number of thienyl ring next to the cyanoacrylic acid group, which is consistent with the results from electrochemical impedance spectroscopy. The maximal monochromatic incident photon-to-current conversion efficiency (IPCE) can reach up to 80% for DSSC devices based on F4 with the overall light to electricity conversion efficiency up to 4.71% (Voc = 565 mV, Jsc = 11.71 mA cm-2 and FF = 0.71) under AM 1.5 irradiation (100 mW cm-2).
- Lai, Lai-Fan,Qin, Chuanjiang,Chui, Chung-Hin,Islam, Ashraful,Han, Liyuan,Ho, Cheuk-Lam,Wong, Wai-Yeung
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p. 428 - 436
(2013/07/27)
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- Novel syntheses of fluorenones via nitrile-directed palladium-catalyzed C-H and dual C-H bond activation
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Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
- Wan, Jung-Chih,Huang, Jun-Min,Jhan, Yu-Huei,Hsieh, Jen-Chieh
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p. 2742 - 2745
(2013/07/19)
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- Cross dehydrogenative coupling via base-promoted homolytic aromatic substitution (BHAS): Synthesis of fluorenones and xanthones
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Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant. Initiation of the radical chain reaction is best achieved with small amounts of FeCp2 (0.1 or 1 mol %).
- Wertz, Sebastian,Leifert, Dirk,Studer, Armido
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p. 928 - 931
(2013/03/28)
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- QUINOXALINE DERIVATIVES AND ORGANIC LIGHT-EMITTING DIODES COMPRISING THE SAME
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A quinoxaline derivative represented by Formula (I) of or Formula (II) of is provided. In Formula (I) or (II), R1, R2, R3 and R4 are, independently, hydrogen, halogen, methyl, ethyl, propyl, butyl, aryl or heteroaryl, for example phenyl, furyl, thienyl, pyridyl, pyrimidyl, benzothiazolyl or benzoimidazolyl. The disclosure also provides an organic light-emitting diode including the quinoxaline derivative.
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Page/Page column 6-7
(2012/12/14)
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- Synthesis, characterization, physical properties, and applications of highly fluorescent pyrene-functionalized 9,9-bis(4-diarylaminophenyl)fluorene in organic light-emitting diodes
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A new, highly fluorescent pyrene-functionalized 9,9-bis(4- diarylaminophenyl)fluorene, namely PTF, was synthesized and characterized. This material is an amorphous molecular glass with notably high Tg, is electrochemically stable, and exhibits strong blue emission both in solution and solid state. It shows promising ability as a solution processed blue emitter and hole-transporter for OLEDs. High-efficiency sky-blue and Alq3-based green devices with luminance efficiencies of 1.13 and 4.08 cd/A are achieved, respectively. 2012 Elsevier Ltd. All rights reserved.
- Prachumrak, Narid,Thangthong, A-Monrat,Tarsang, Ruangchai,Keawin, Tinnagon,Jungsuttiwong, Siriporn,Sudyoadsuk, Taweesak,Promarak, Vinich
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p. 5492 - 5496
(2012/11/07)
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- Pd-catalyzed multiple C-H functionalization to construct biologically active compounds from aryl aldoxime ethers with arenes
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Functional fluorenones: Aromatic aldoxime ethers react with unactivated arenes catalyzed by palladium complexes to give biologically active fluoren-9-ones (see scheme). Multiple C-H bond activation and an oxidative cyclization are involved in the reaction.
- Thirunavukkarasu, Vedhagiri S.,Cheng, Chien-Hong
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supporting information; experimental part
p. 14723 - 14726
(2012/02/01)
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