- One-step synthesis of novel flavylium salts containing alkyl side chains in their 3-, 4′-, 5- or 6-positions and their photophysical properties in micellar media
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A one-step preparation of several flavylium salts containing alkyl side chains in their 3-, 4′-, 5- or 6-positions is described. Flavylium salts with alkyl side chains in positions 3 or 4′ were isolated from reactions between 2,4-dihydroxybenzaldehyde and
- Fernandes, Ana C.,Romao, Carlos C.,Rosa, Carla P.,Vieira, Vera P.,Lopes, Antonio,Silva, Palmira F.,Macanita, Antonio L.
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- Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
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Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
- Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
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supporting information
p. 10632 - 10636
(2021/04/09)
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- Preparation of Alkyl Indium Reagents by Iodine-Catalyzed Direct Indium Insertion and Their Applications in Cross-Coupling Reactions
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An efficient method for the synthesis of alkyl indium reagent by means of an iodine-catalyzed direct indium insertion into alkyl iodide in THF is reported. The thus-generated alkyl indium reagents effectively underwent Pd-catalyzed cross-coupling reactions with various aryl halides, exhibiting good compatibility to a variety of sensitive functional groups. By replacing THF with DMA and using 0.75 equiv of iodine, less reactive alkyl bromide could be used as substrate for indium insertion with equal ease.
- Zhi, Man-Ling,Chen, Bing-Zhi,Deng, Wei,Chu, Xue-Qiang,Loh, Teck-Peng,Shen, Zhi-Liang
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p. 3017 - 3023
(2019/02/26)
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- Cesium carbonate-catalyzed indium insertion into alkyl iodides and their synthetic utilities in cross-coupling reactions
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A catalytic amount of cesium carbonate (10?mol%) was found to be capable of effectively catalyzing the insertion of indium powder into alkyl iodides. The thus-generated alkyl indium reagents could readily undergo palladium-catalyzed cross-coupling reactions with a wide variety of aryl halides, showing compatibility to a range of important functional groups.
- Feng, Xue-Xin,Wu, Zhen,Wang, Qing-Dong,Chen, Bing-Zhi,Rao, Weidong,Yang, Jin-Ming,Shen, Zhi-Liang
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- Copper(II)-catalyzed preparation of alkylindium compounds and applications in cross-coupling reactions both in aqueous media
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An efficient water-based method for the synthesis of alkylindium compound in the presence of a catalytic amount of cheap and readily available CuSO4·5H2O (10 mol%) was developed. The thus-generated alkylindium compounds effectively underwent palladium-catalyzed cross-coupling reactions with a myriad of aryl halides in aqueous media, leading to the cross-coupled products in modest to high yields. The mildness of the formed alkyl organometallics allowed the tolerance to various important functional groups incorporated in both substrates of alkyl iodides and aryl halides.
- Wang, Peng,Chen, Bing-Zhi,Guo, Yi-Cong,Rao, Weidong,Shen, Zhi-Liang
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supporting information
(2019/11/11)
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- Cobalt(II)-catalyzed preparation of alkylindium reagents and applications in cross-coupling with aryl halides
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The direct insertion of indium powder into alkyl iodides was found to be efficiently catalyzed by a catalytic amount of cobalt(II) bromide (10 mol%). Upon subjection of the thus-formed alkylindium compounds to palladium-catalyzed cross-coupling reactions with a wide range of aryl halides, a series of cross-coupled products could be obtained in moderate to good yields with the tolerance to many important functional groups.
- Wang, Peng,Song, Xuan-Di,Chen, Bing-Zhi,Rao, Weidong,Shen, Zhi-Liang
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- Synthesis of Alkyl Indium Reagents by Using Unactivated Alkyl Chlorides and Their Applications in Palladium-Catalyzed Cross-Coupling Reactions with Aryl Halides
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An efficient method for the preparation of alkyl indium reagents by using unactivated and cheap alkyl chlorides as substrates in the presence of indium and LiI was developed. The thus-formed alkyl indium species effectively underwent palladium-catalyzed cross-coupling reactions with aryl halides with wide functional group tolerance.
- Chen, Bing-Zhi,Zhi, Man-Ling,Wang, Chuang-Xin,Chu, Xue-Qiang,Shen, Zhi-Liang,Loh, Teck-Peng
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supporting information
p. 1902 - 1905
(2018/04/16)
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- Study on the design, synthesis and structure-activity relationships of new thiosemicarbazone compounds as tyrosinase inhibitors
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52 Structure-based thiosemicarbazone compounds bearing various substituted-lipophilic part, including substituted-benzaldehyde, substituted-phenylalkan-1-one and their biphenyl-type thiosemicarbazone analogs, were designed, synthesized and evaluated as new tyrosinase inhibitors. The results demonstrated that 22 compounds have potent inhibitory activities against tyrosinase with the IC50 value of lower than 1.0 μM. On the basis of the obtained experimental data, the structure-activity relationships (SARs) were rationally derived. Besides, the inhibition mechanism and the inhibitory kinetics of selected compounds 3d and 6e were investigated, revealing that such type of compounds were belonged to the reversible and competitive tyrosinase inhibitors. To verify the safety of these developed thiosemicarbazone compounds, four randomly selected compounds 3d, 4e, 6a and 9a were also tested in 293T cell line for the evaluation of the cytotoxicity. Interestingly, all these compounds almost did not perform any toxicity to 293T cells even at a high concentration of 1000 μmol/L. Taken together, these results suggested that such compounds could serve as the highly efficient and more safe candidates for the treatment of tyrosinase-related disorders.
- Song, Senchuan,You, Ao,Chen, Zhiyong,Zhu, Guoxun,Wen, Huan,Song, Huacan,Yi, Wei
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p. 815 - 825
(2017/09/05)
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- Phenol Derivatives as Coupling Partners with Alkylsilicates in Photoredox/Nickel Dual Catalysis
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Photoredox/nickel dual catalysis via single electron transmetalation allows coupling of Csp3-Csp2 hybridized centers under mild conditions. A procedure for the coupling of electron-deficient aryl triflates, -tosylates, and -mesylates with alkylbis(catecholato)silicates is presented. This method represents the first example of the use of phenol derivatives as electrophilic coupling partners in photoredox/nickel dual catalysis.
- Patel, Niki R.,Molander, Gary A.
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supporting information
p. 7271 - 7275
(2016/08/30)
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- Regio-specific polyacetylenes synthesized from anionic polymerizations of template monomers
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Substituted polyacetylenes with alkylphenyl side groups and head-to-head regioregularity were prepared through anionic living polymerization of template monomers and subsequent dehydrogenation process. The template monomers have the structure of 2, 3-disubstituted-1, 3-butadienes prepared by palladium-catalyzed Kumada coupling of the corresponding vinyl bromides. Anionic polymerizations of the template monomers produced narrow disperse substituted polybutadiene precursors with exclusive 1, 4-enchainment. The precursors were converted into soluble polyacetylene derivatives via two methods, e.g., bromination followed by elimination of HBr, and direct dehydrogenation by 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ), both resulting in dark colored products with significant red shift in UV spectra. The obtained head-to-head polyacetylene derivatives exhibited highly thermal stability, possibly due to trans-rich and/or head-to-head chain configurations. The microstructures of the poly(2, 3-dialkylphenyl butadiene) precursors were analyzed in detail using NMR spectroscopy with regard to the solvent effect during polymerization. Block copolymers containing substituted polyacetylene segments were prepared through sequential anionic polymerization of different monomers, followed by dehydrogenation transformation. The present synthesis may serve as a new strategy for tailoring molecular structures of polyacetylene-based polymers by virtue of anionic living polymerization techniques.
- Zhang, Yang,Li, Jia,Li, Xiaohong,He, Junpo
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p. 6260 - 6269
(2015/02/19)
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- Small molecule suppression of carbapenem resistance in ndm-1 producing klebsiella pneumoniae
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The already considerable global public health threat of multidrug-resistant Gram-negative bacteria has become even more of a concern following the emergence of New Delhi metallo-β-lactamase (NDM-1) producing strains of Klebsiella pneumoniae and other Gram-negative bacteria. As an alternative approach to the traditional development of new bactericidal entities, we have identified a 2-aminoimidazole-derived small molecule that acts as an antibiotic adjuvant and is able to suppress resistance of a NDM-1 producing strain of K. pneumoniae to imipenem and meropenem, in addition to suppressing resistance of other β-lactam nonsusceptible K. pneumoniae strains. The small molecule is able to lower carbapenem minimum inhibitory concentrations by up to 16-fold, while exhibiting little bactericidal activity itself.
- Worthington, Roberta J.,Bunders, Cynthia A.,Reed, Catherine S.,Melander, Christian
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supporting information; experimental part
p. 357 - 361
(2012/07/01)
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- Novel diamides of 2,2′-dipyridyl-6,6′-dicarboxylic acid: Synthesis, coordination properties, and possibilities of use in electrochemical sensors and liquid extraction
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The procedure was proposed for the synthesis of various dipyridyldiamides. Their various properties in the series of rare-earth elements were studied. The possibility to use the synthe-sized compounds in polymer membranes of electrochemical sensors for th
- Kirsanov,Borisova,Reshetova,Ivanov,Korotkov,Eliseev,Alyapyshev, M. Yu.,Spiridonov,Legin,Vlasov, Yu. G.,Babain
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p. 881 - 890
(2013/04/10)
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- Ferrocenyl iminophosphine ligands in Pd-catalysed Suzuki couplings
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A mixture of Pd2(dba)3/{η-C5H 4CHN[CH(CH3)(Nap)]}Fe[η-C5H 4P(tBu)2] efficiently catalyzes the Suzuki reactions of a variety of bulky aryl halides and aryl- and alkyl-boronic acids, affording the desired cross-coupling biaryl products in quantitative isolated yields under mild conditions and at low (1 × 10-6-1 mol%) Pd loadings. Spectroscopic (NMR & ESI) analysis of the mixture of Pd 2(dba)3, the hybrid [P,N] ligands, and aryl halides revealed different structural forms of oxidative addition products that are dependent on the substituent on the imino nitrogen.
- Teo, Shihui,Weng, Zhiqiang,Hor, T.S. Andy
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experimental part
p. 2928 - 2934
(2011/08/05)
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- Direct synthesis of water-tolerant alkyl indium reagents and their application in palladium-catalyzed couplings with aryl halides
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A direct result: Alkyl indium reagents are synthesized by the insertion of indium into alkyl halide mediated by CuCl. The synthetic utility of these reagents is demonstrated by their palladium-catalyzed coupling with aryl halides (see scheme). The reagents are compatible with various functional groups, and this makes the protocol generally useful in organic synthesis. DMA=N,N-dimethylacetamide, TBS=tert-butyldimethylsilyl.
- Shen, Zhi-Liang,Goh, Kelvin Kau Kiat,Yang, Yong-Sheng,Lai, Yin-Chang,Wong, Colin Hong An,Cheong, Hao-Lun,Loh, Teck-Peng
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supporting information; experimental part
p. 511 - 514
(2011/03/17)
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- Syndiospecific synthesis of longer p-n-alkyl-substituted polystyrenes using monocyclopentadienyl-type titanium catalysts
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Substituted styrenes with linear alkyl substituents (C6 to C12) at the para position on the ring were synthesized and polymerized using the (Me)5CpTi(OMe)3/MAO catalytic system. Increased polymerization activiti
- Quirk, Roderic P.,Ok, Myung-Ahn
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p. 3976 - 3982
(2007/10/03)
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- Synthesis of quaternary alkylammonium sulfobetaines
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A series of quaternary alkylammonium sulfobetaines of general formula RN+(CH3)2(CH2)nSO 3-, where n = 2-4, have been synthesised by reacting the corresponding N,N-dimethylamines with either sodium 2-chloroethanesulfonate (n = 2), 1,3-propane-sultone (n = 3), or 1,4-butanesultone (n = 4). Full details of the preparation of the required N,N-dimethylamines are reported.
- Ward, Robert S.,Davies, Joanna,Hodges, Geoffrey,Roberts, David W.
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p. 2431 - 2439
(2007/10/03)
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- Palladium-Catalyzed Cross-Coupling Reaction of Alkyltrifluorosilanes with Aryl Halides
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A cross-coupling reaction of alkyltrifluorosilanes with aryl halides was achieved using a catalytic amount of tetrakis-(triphenylphosphine)palladium(0) and excess of tetrabutylammonium fluoride (TBAF) at 100°C with high chemoselectitvity. Functional groups like nitro, ketone carbonyl, and formyl tolerated the coupling conditions. Because potassium(18-crown-6) alkyltetrafluorosilicates also underwent a cross-coupling reaction in the presence of an additional molar amount of TBAF, the active species of the coupling reaction was assumed to be pentacoordinate silicates. TBAF in excess was considered to be required for trapping the tetrafluorosilane produced in the catalytic cycle of the cross-coupling reaction.
- Matsuhashi, Hayao,Asai, Satoshi,Hirabayashi, Kazunori,Hatanaka, Yasuo,Mori, Atsunori,Hiyama, Tamejiro
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p. 437 - 444
(2007/10/03)
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- Palladium catalyzed cross-coupling reaction of functionalized alkyltrifluorosilanes with aryl halides
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A variety of alkyltrifluorosilanes were found to couple with aryl halides in the presence of Pd(PPh3)4 catalyst and tetrabutylammonium fluoride (TBAF) to give the corresponding cross-coupled products in moderate to good yields.
- Matsuhashi, Hayao,Kuroboshi, Manabu,Hatanaka, Yasuo,Hiyama, Tamejiro
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p. 6507 - 6510
(2007/10/02)
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- Nouveaux diamino-3,4 phenylalcanes et leur transformation en benzimidazolemethanethiols-2
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We report five o-phenylenediamines which are substituted by an aliphatic chain containing n carbon atoms (n = 4, 6, 8, 10, 12).We describe a well adapted general synthetic method using Schmidt's reaction.The diamines were then transformed into 2-benzimidazolemethanethiols and their related S-methyl derivatives which structures were checked by (1)H NMR.
- Krati, Noureddine,Roizard, Denis,Brembilla, Alain,Lochon, Pierre
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p. 443 - 448
(2007/10/02)
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- The Synthesis of 3-Aryl-6-alkylpyridazines
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Nine compounds of general structure R-X-Y-R' where X is a para-disubstituted phenyl ring and Y is a 3,6-disubstituted-pyridazine ring were synthesized.These can be used as liquid crystal dopents.A general procedure for their synthesis was developed.N-Alkyl benzene and ethyl butyrylacetate were used as starting materials.The purification of reaction intermediates was not necessary if preparative hplc was used to purify the final products.Very pure materials were obtained with good yield.Their structure was confirmed by carbon 13 nmr.
- Liang, Jason
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p. 1297 - 1299
(2007/10/02)
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- Multiple Melting Behaviour in Square-planar trans-Bis-(1-p-n-alkylphenylbutane-1,3-dionato)copper(II) - The Effect of Alkyl Chain Length
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The title complexes having different n-alkyl groups from methyl to dodecyl have synthesized.All these complexes exhibit solid polymorphism.The number of polymorphs depends on the length of the alkyl chain: two for n (the number of carbon atoms) = 0-2, three for n = 3-5 and 12, and four for n = 6-11, respectively.Each polymorphic form except those with the highest m.p.s. exhibits multiple melting behaviour: double melting for n = 0-5,8, and 12, and triple melting for n = 6-11 except 8.The m.p.s. of the complexes with alkyl groups of odd carbon atoms are higher than those with even atoms, while the respective ligand solids show the opposit e even-odd effect in their m.p.s.
- Ohta, Kazuchika,Jiang, Guang-Jie,Yokoyama, Masaaki,Kusabayashi, Shigekazu,Mikawa, Hiroshi
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p. 283 - 294
(2007/10/02)
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- Study of the Influence of Molecular Length on the Characteristics of the Ordered Smectic Phase.
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Study of DTA and X-rays of p-phenyl-benzylidene-p'-alkylanilines of mesomorphic phases demonstrates the predominant role of the aliphatic chain length. In effect, it governs the appearance of the different phases; the correlation between layers decreases for greater chain lengths. The nonlinear variations of SmB layer thickness for these compounds shows clearly the importance of steric effects coupled with the molecular length with respect to the dipolar effect.
- Benattar,Levelut,Strzelecki
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p. 1233 - 1240
(2007/10/05)
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