66052-06-0Relevant academic research and scientific papers
Discovery and characterization of a novel perylenephotoreductant for the activation of aryl halides
Guo, Baodang,Huang, Shuping,Li, Jia,Li, Min,Liu, Xuanzhong,Rao, Yijian,Wu, Yawen,Yin, Huimin,Yuan, Zhenbo,Zhang, Yan
, p. 111 - 120 (2021/06/16)
To develop a photocatalyst with catalytical activity for substrates with low reactivities is always highly desired. Herein, based on the principle of structure–property relationships, we rationally designed the natural product cercosporin, the naturally occurring perylenequinonoid pigment, to develop a novel organic perylenephotoreductant, hexacetyl reduced cercosporin (HARCP), through structural manipulation. Compared with cercosporin, HARCP shows prominent electrochemical and photophysical characteristics with greatly improved photoreductive activity, fluorescence lifetime and fluorescence quantum yield. These properties allowed HARCP as a powerful photoreductant to efficiently realize a series of benchmark reactions, including photoreduction, alkoxylation and hydroxylation to construct C–H and C–O bonds using aryl halides as substrates under mild conditions, all of which have never been achieved by the same photocatalyst. Thus, this study well supports the notion that the principle between structural manipulation and photocatalytic activity is of great significance to design customized photocatalysts for photoredox chemistry.
Diaryl Ether Formation Merging Photoredox and Nickel Catalysis
Liu, Le,Nevado, Cristina
supporting information, p. 2188 - 2193 (2021/05/04)
Photoredox and Ni catalysis are combined to produce diaryl ethers under mild conditions. A broad range of aryl halides and phenol derivatives are cross-coupled in the presence of a readily available organic photocatalyst and NiBr2(dtbpy). Symmetrical diaryl ethers have also been directly obtained from aryl bromides in the presence of water. Mechanistic investigations support the involvement of Ni(0) species at the outset of the reaction and a Ni(II)/Ni(III)-photocatalyzed single electron transfer process preceding the productive C(sp2)-OAr reductive elimination.
Oxalohydrazide Ligands for Copper-Catalyzed C?O Coupling Reactions with High Turnover Numbers
Ray, Ritwika,Hartwig, John F.
supporting information, p. 8203 - 8211 (2021/03/08)
Here, we report a class of ligands based on oxalohydrazide cores and N-amino pyrrole and N-amino indole units that generates long-lived copper catalysts for couplings that form the C?O bonds in biaryl ethers. These Cu-catalyzed coupling of phenols with aryl bromides occurred with turnovers up to 8000, a value which is nearly two orders of magnitude higher than those of prior couplings to form biaryl ethers and nearly an order of magnitude higher than those of any prior copper-catalyzed coupling of aryl bromides and chlorides. This ligand also led to copper systems that catalyze the coupling of aryl chlorides with phenols and the coupling of aryl bromides and iodides with primary benzylic and aliphatic alcohols. A wide variety of functional groups including nitriles, halides, ethers, ketones, amines, esters, amides, vinylarenes, alcohols and boronic acid esters were tolerated, and reactions occurred with aryl bromides in pharmaceutically related structures.
Metal-organic layers as multifunctional two-dimensional nanomaterials for enhanced photoredox catalysis
Lan, Guangxu,Quan, Yangjian,Wang, Maolin,Nash, Geoffrey T.,You, Eric,Song, Yang,Veroneau, Samuel S.,Jiang, Xiaomin,Lin, Wenbin
supporting information, p. 15767 - 15772 (2019/10/11)
Metal-organic layers (MOLs) have recently emerged as a novel class of molecular two-dimensional (2D) materials with significant potential for catalytic applications. Herein we report the design of a new multifunctional MOL, Hf12-Ir-Ni, by laterally linking Hf12 secondary building units (SBUs) with photosensitizing Ir(DBB)[dF(CF3)ppy]2+ [DBB-Ir-F, DBB = 4,4′-di(4-benzoato)-2,2′-bipyridine; dF(CF3)ppy = 2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine] bridging ligands and vertically terminating the SBUs with catalytic Ni(MBA)Cl2 [MBA = 2-(4′-methyl-[2,2′-bipyridin]-4-yl)acetate] capping agents. Hf12-Ir-Ni was synthesized in a bottom-up approach and characterized by TEM, AFM, PXRD, TGA, NMR, ICP-MS, UV-vis, and luminescence spectroscopy. The proximity between photosensitizing Ir centers and catalytic Ni centers (~0.85 nm) in Hf12-Ir-Ni facilitates single electron transfer, leading to a 15-fold increase in photoredox reactivity. Hf12-Ir-Ni was highly effective in catalytic C-S, C-O, and C-C cross-coupling reactions with broad substrate scopes and turnover numbers of ~4500, ~1900, and ~450, respectively.
Semiheterogeneous Dual Nickel/Photocatalytic (Thio)etherification Using Carbon Nitrides
Cavedon, Cristian,Madani, Amiera,Seeberger, Peter H.,Pieber, Bartholom?us
supporting information, p. 5331 - 5334 (2019/07/08)
A carbon nitride material can be combined with homogeneous nickel catalysts for light-mediated cross-couplings of aryl bromides with alcohols under mild conditions. The metal-free heterogeneous semiconductor is fully recyclable and couples a broad range of electron-poor aryl bromides with primary and secondary alcohols as well as water. The application for intramolecular reactions and the synthesis of active pharmaceutical ingredients was demonstrated. The catalytic protocol is applicable for the coupling of aryl iodides with thiols as well.
Variation in hydrophobic chain length of co-adsorbents to improve dye-sensitized solar cell performance
Da Silva, Luciano,Freeman, Harold
, p. 16771 - 16778 (2019/08/12)
Three compounds based on the phenyltetrazole system, 5-(4-hydroxyphenyl)tetrazole (LTz-1), 5-(4-methoxyphenyl)tetrazole (LTz-2) and 5-(4-hexyloxyphenyl)tetrazole (LTz-3), were synthesized and characterized as co-adsorbents in dye-sensitized solar cells (DSSCs). The effects of hydrophobic chain length of the co-adsorbent and the effects of tetrazole anchoring group on the properties of DSSCs containing the previously reported dye HD-2 were compared with the benchmark deoxycholic acid (DCA). The charge-transfer resistance of the dye/TiO2 interface followed the order HD-2-DCA > HD-2-LTz-2 > HD-2-LTz-3 > HD-2-LTz-1. However, the Voc of the dye HD-2 with co-adsorbent DCA was 0.66 V, for the dye HD-2 with co-adsorbent LTz-1, it was 0.70 V, for the dye HD-2 with co-adsorbent LTz-2, it was 0.68 V and for the dye HD-2 with co-adsorbent LTz-3, it was 0.67 V. Co-adsorbents LTz-1, LTz-2 and LTz-3 achieved a mean solar-to-power conversion efficiency (%η), for the three devices, of 8.29, 7.63 and 8.49, respectively, compared to 7.76 for DCA under the same experimental device conditions. For the LTz-3 co-adsorbent, the results can be attributed to the repellent effect of the long alkyl chain. For LTz-1 and LTz-2 co-adsorbents, it is possible that the more compact layer formed improves electron-injection efficiency into TiO2.
Copper-catalyzed reduction of alkyl triflates and iodides: An efficient method for the deoxygenation of primary and secondary alcohols
Dang, Hester,Cox, Nick,Lalic, Gojko
, p. 752 - 756 (2014/01/23)
We describe an effective method for catalytic reduction of 1°alkyl sulfonates, and 1°and 2°iodides in the presence of a wide range of functional groups. This Cu-catalyzed reaction provides a means for the effective deoxygenation of alcohols, as demonstrated by the highly selective reduction of 1°alcohols using a triflation/reduction sequence. A preliminary study of the reaction mechanism suggests that the reduction does not involve free-radical intermediates. Primarily reduced: The copper-catalyzed reduction of 1°alkyl sulfonates, and 1°and 2°iodides, which is effective in the presence of a wide range of functional groups, provides a means for the effective deoxygenation of alcohols. A preliminary study of the reaction mechanism suggests that the reduction does not involve free-radical intermediates. Copyright
NHC-copper hydrides as chemoselective reducing agents: Catalytic reduction of alkynes, alkyl triflates, and alkyl halides
Cox, Nick,Dang, Hester,Whittaker, Aaron M.,Lalic, Gojko
, p. 4219 - 4231 (2014/06/09)
The NHC-copper-catalyzed Z-selective semi-reduction of terminal and internal alkynes, as well as the NHC-copper-catalyzed reduction of primary alkyl triflates and primary and secondary alkyl iodides and bromides are described. The high chemoselectivity demonstrated in these examples illustrates the mild nature of copper hydride complexes as reducing agents, which have applications in synthetic chemistry beyond their traditional role in the reduction of activated alkenes and carbonyl compounds.
AMINE COMPOUNDS HAVING ANTI-INFLAMMATORY, ANTIFUNGAL, ANTIPARASITIC AND ANTICANCER ACTIVITY
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Page/Page column 126-127, (2014/08/19)
Amine compounds having activity against inflammation, fungi, unicellular parasitic microorganisms, and cancer are described. The compounds contain a monocyclic, bicyclic, or tricyclic aromatic ring having one, two, or three ring nitrogen atoms.
COMPOUND, COMPOSITION AND THIN FILM
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Page/Page column 40-41, (2010/10/20)
A liquid-crystalline compound of the following formula:wherein Y11, Y12 and Y13 are methine or N; L1, L2 and L3 are single bond or divalent group; H1, H2 and H3/
