- A highly selective synthesis of 1,1'-Bi-2-naphthol by oxidative coupling of naphthol on mesoporous Fe,Cu/MCM-41 aluminosilicates
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The oxidative coupling of 2-naphtol to 2,2'-dihydroxy-1,1'-binaphthyl (binaphthol) by air or oxygen has been carried out in the presence of Cu2+- and Fe3+-doped MCM-41 aluminosilicate as catalyst. Fe-exchanged MCM-41 was found to be a very efficient catalyst; excellent mass balances (> 95%) with almost total conversion and selectivity to binaphthol were achieved. The same reaction has also been carried out on Cu2+- and Fe3+-Y zeolites. Taking into account the relative dimensions of binaphthol and the catalyst pores, molecular modeling predicts that binaphthol can be accommodated inside the zeolite Y supercages (1.3 nm), but it cannot diffuse outside the zeolite cavities through the smaller pore apertures (0.74 nm). This prediction has been confirmed by dissolving a Y zeolite after the reaction, whereby unextractable binaphthol entrapped within the cavities was recovered. Variable amounts of two secondary by-products have also been detected, and their structure assigned to (2,8');(8,2')-dioxo-1,1'-binaphthyl and bisnaphthofuran based on analytical and spectroscopic data. Their percentage is particularly high when alumina-supported CuSO4 is used as the catalyst.
- Armengol, Elvira,Corma, Avelino,Garcia, Hermenegildo,Primo, Jaime
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- Charge-transfer complexes of PXX (PXX = 6, 12-dioxaanthanthrene). The formal charge and molecular geometry
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Three kinds of charge-transfer (CT) complexes of PXX (PXX = 6, 12-dioxaanthanthrene) have been newly prepared and structurally characterized. In the 1:2 CT complex with TNP (TNP = 2,4,6-trinitrophenol), PXX is practically neutral. In the semiconducting partially oxidized salt with I3, the PXX molecules form a trimer and each PXX is formally oxidized by e/3. In the 3:2 salt with [Ni(mnt)2]- (mnt = maleonitriledithiolate), the PXX molecules again form a trimer unit and each PXX is formally oxidized by 2e/3. Together with the structural data obtained from the PXX single component crystal, the molecular geometry change by the formal charge on PXX has been examined. A noticeable change has been found in the aromatic ring framework, which is consistent with the distribution of the HOMO coefficients obtained from the extended Hueckel calculation.
- Asari,Kobayashi,Naito,Inabe
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- A peri-Xanthenoxanthene Centered Columnar-Stacking Organic Semiconductor for Efficient, Photothermally Stable Perovskite Solar Cells
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Modulating the structure and property of hole-transporting organic semiconductors is of paramount importance for high-efficiency and stable perovskite solar cells (PSCs). This work reports a low-cost peri-xanthenoxanthene based small-molecule P1, which is
- Xu, Niansheng,Li, Yang,Wu, Ruihan,Zhu, Rui,Zhang, Jidong,Zakeeruddin, Shaik M.,Li, Hanying,Li, Ze-Sheng,Gr?tzel, Michael,Wang, Peng
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- Cu-Catalyzed Aerobic Oxidative C-H/C-O Cyclization of 2,2′-Binaphthols: Practical Synthesis of PXX Derivatives
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Cu-catalyzed C-H/C-O cyclization of 2,2′-binaphthol, using air as an oxidant, was developed. C-H functionalization of binaphthols occurred at the 8,8′-position to form peri-xanthenoxanthenes that exhibit high charge-carrier mobility. The reaction can tole
- Kamei, Toshiyuki,Uryu, Mizuho,Shimada, Toyoshi
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- Tandem Living Insertion and Controlled Radical Polymerization for Polyolefin–Polyvinyl Block Copolymers
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Practical synthesis of polyolefin–polyvinyl block copolymers remains a challenge for transition-metal catalyzed polymerizations. Common approaches functionalize polyolefins for post-radical polymerization via insertion methods, yet sacrifice the livingness of the olefin polymerization. This work identifies an orthogonal radical/spin coupling technique which affords tandem living insertion and controlled radical polymerization. The broad tolerance of this coupling technique has been demonstrated for diverse radical/spin traps such as 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO), 1-oxyl-(2,2,6,6-tetramethylpiperidine) -4-yl-α-bromoisobutyrate (TEMPO-Br), and N-tert-butyl-α-phenylnitrone (PBN). Subsequent controlled radical polymerization is demonstrated with nitroxide-mediated polymerization (NMP) and atom transfer radical polymerization (ATRP), yielding polyolefin–polyvinyl di- and triblock copolymers (?1.3) with acrylic, vinylic and styrenic segments. These findings highlight radical trapping as an approach to expand the scope of polyolefin-functionalization techniques to access polyolefin macroinitiators.
- Dau, Huong,Harth, Eva,Keyes, Anthony,Matyjaszewski, Krzysztof
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supporting information
(2022/01/19)
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- peri-Xanthenoxanthene (PXX): a Versatile Organic Photocatalyst in Organic Synthesis
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Recent years have witnessed a continuous development of photocatalysts to satisfy the growing demand of photophysical and redox properties in photoredox catalysis, with complex structures or alternative strategies devised to access highly reducing or oxidising systems. We report herein the use of peri-xanthenoxanthene (PXX), a simple and inexpensive dye, as an efficient photocatalyst. Its highly reducing excited state allows activation of a wide range of substrates, thus triggering useful radical reactions. Benchmark transformations such as the addition of organic radicals, generated by photoreduction of organic halides, to radical traps are initially demonstrated. More complex dual catalytic manifolds are also shown to be accessible: the β-arylation of cyclic ketones is successful when using a secondary amine as organocatalyst, while cross-coupling reactions of aryl halides with amines and thiols are obtained when using a Ni co-catalyst. Application to the efficient two-step synthesis of the expensive fluoro-tetrahydro-1H-pyrido[4,3-b]indole, a crucial synthetic intermediate for the investigational drug setipiprant, has been also demonstrated. (Figure presented.).
- Pezzetta, Cristofer,Folli, Andrea,Matuszewska, Oliwia,Murphy, Damien,Davidson, Robert W. M.,Bonifazi, Davide
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supporting information
p. 4740 - 4753
(2021/04/09)
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- Preparation method of reactive fluorescent probe for rapid hydrazine detection
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The invention discloses a preparation method of a reactive fluorescent probe for rapid hydrazine detection, and relates to the field of fluorescent probes. The method comprises the steps: adding powdery 2-naphthol into an aqueous solution of FeCl3.6H2O to
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Paragraph 0032
(2021/11/06)
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- Preparation method and application of peri-xanthenoxanthene
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The invention discloses a preparation method and application of a peri-xanthenoxanthene compound. The preparation method of the peri-xanthenoxanthene comprises the following steps: (1) oxidizing binaphthol under the action of a copper amine complex to obtain dibenzo[a, kl] xanthene; (2) heating the dibenzo[a, kl] xanthenes to obtain the peri-xanthenoxanthene. The invention also discloses application of the peri-xanthenoxanthene in preparation of an antitumor drug. The invention provides a novel synthesis method of preparing the peri-xanthenoxanthene compound, and the reaction conditions are mild, and the product purity is high; the obtained compound is relatively high in antitumor activity and has a relatively good prospect in preparation of the antitumor drug.
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Paragraph 0047; 0049
(2019/05/08)
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