- Naturally occurring 5-[2-thienyl)ethynyl]thiophene-2-carbaldehyde through a short synthesis of diarylacetylenes
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Title compound and related diarylacetylenes were synthesized via a one-pot procedure starting from aryliodide and trimethylsilylacetylene.
- D'Auria
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- Asymmetric Hydrosilylation of β-Silyl Styrenes Catalyzed by a Chiral Palladium Complex
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A palladium complex coordinated with a chiral SIPHOS ligand was evaluated as an efficient catalyst for asymmetric hydrosilylation of β-silyl styrenes with trichlorosilane and 23 1,2-bis(silyl) chiral compounds were produced. Good to excellent enantioselec
- He, Yu-Han,Ji, Yang,Li, Rui,Su, Yan,Wang, Yi-Fan
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supporting information
(2022/02/10)
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- Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
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A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
- Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
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supporting information
p. 3981 - 3985
(2021/05/26)
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- Iodonium Cation-Pool Electrolysis for the Three-Component Synthesis of 1,3-Oxazoles
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The synthesis of 1,3-oxazoles from symmetrical and unsymmetrical alkynes was realized by an iodonium cation-pool electrolysis of I2 in acetonitrile with a well-defined water content. Mechanistic investigations suggest that the alkyne reacts with the acetonitrile-stabilized I+ ions, followed by a Ritter-type reaction of the solvent to a nitrilium ion, which is then attacked by water. The ring closure to the 1,3-oxazoles released molecular iodine, which was visible by the naked eye. Also, some unsymmetrical internal alkynes were tested and a regioselective formation of a single isomer was determined by two-dimensional NMR experiments.
- Sattler, Lars E.,Hilt, Gerhard
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supporting information
p. 605 - 608
(2020/12/07)
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- Cobalt-Catalyzed Hydroalkynylation of Vinylaziridines
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Transition metal-catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose the cobalt-catalyzed hydroalkynylation of vinylaziridines giving rise to both linea
- Biletskyi, Bohdan,Kong, Lingyu,Tenaglia, Alphonse,Clavier, Hervé
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supporting information
p. 2578 - 2585
(2021/03/18)
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- Synthesis, Characterization of Spirocyclic λ3-Iodanes and Their Application to Prepare 4,1-Benzoxazepine-2,5-diones and 1,3-Diynes
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Herein, a [3+2] cycloaddition of aza-oxyallylic cations with ethynylbenziodoxolones for synthesis of new λ3-iodanes containing spirocyclic 4-oxazolidinone has been developed. This cyclic λ3-iodanes display stability in air and excellent solubility in organic solvent. Using them as substrate, both the 4,1-benzoxazepine-2,5-diones and symmetrical 1,3-diynes derivatives were afforded in high yield under copper(I)-catalyzed conditions.
- Sun, Xu,Guo, Xiao-Qiang,Chen, Lian-Mei,Kang, Tai-Ran
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supporting information
p. 4312 - 4316
(2021/02/06)
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- Synthesis and Photochemical Application of Hydrofluoroolefin (HFO) Based Fluoroalkyl Building Block
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A novel fluoroalkyl iodide was synthesized on multigram scale from refrigerant gas HFO-1234yf as cheap industrial starting material in a simple, solvent-free, and easily scalable process. We demonstrated its applicability in a metal-free photocatalytic ATRA reaction to synthesize valuable fluoroalkylated vinyl iodides and proved the straightforward transformability of the products in cross-coupling chemistry to obtain conjugated systems.
- Varga, Bálint,Tóth, Balázs L.,Béke, Ferenc,Csenki, János T.,Kotschy, András,Novák, Zoltán
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supporting information
p. 4925 - 4929
(2021/07/01)
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- Frustrated Lewis pair-catalyzed double hydroarylation of alkynes with: N -substituted pyrroles
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Metal-free hydroarylation of alkynes with N-substituted pyrroles is shown to be most efficiently mediated by B(C6F5)3 to yield 12 variants of dipyrrole-alkanes, a mono-hydroarylation product and a tetrahydroarylation produ
- Guo, Jing,Cheong, Odelia,Bamford, Karlee L.,Zhou, Jiliang,Stephan, Douglas W.
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supporting information
p. 1855 - 1858
(2020/02/22)
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- Copper-Catalyzed Ring Opening of [1.1.1]Propellane with Alkynes: Synthesis of Exocyclic Allenic Cyclobutanes
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Despite the long history and interesting properties of propellanes, these compounds still have tremendous potential to be exploited in synthetic organic chemistry. Herein we disclose an experimentally simple procedure to achieve cyclobutane-containing allenes and alkynes through a copper-catalyzed ring opening of [1.1.1]propellane and subsequent reaction with ethynes.
- Lasányi, Dániel,Tolnai, Gergely L.
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supporting information
p. 10057 - 10062
(2019/12/24)
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- Palladium catalysed regio- and stereoselective synthesis of (E)-4-aryl-1,3-bis(trimethylsilyl)but-3-en-1-ynes
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A practical and general synthetic approach to a series of 4-aryl-but-3-en-1-ynes is described. In the presence of palladium complexes a variety of aryl bromides (or iodides) undergo coupling with two equivalents of trimethylsilylacetylene with the formati
- Rogalski, Szymon,Kubicki, Maciej,Pietraszuk, Cezary
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p. 6192 - 6198
(2018/09/17)
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- Au-Catalyzed Intermolecular [2+2] Cycloadditions between Chloroalkynes and Unactivated Alkenes
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The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.
- Bai, Yu-Bin,Luo, Zaigang,Wang, Yuguang,Gao, Jin-Ming,Zhang, Liming
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supporting information
p. 5860 - 5865
(2018/05/14)
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- Blue-shifted aggregation-induced emission of siloles by simple structural modification and their application as nitro explosive chemosensors
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To induce blue-shifted emission of siloles, two tolyl-substituted derivatives-1,1-diphenyl-2,3,4,5-tetra(m-tolyl)-1H-silole (m-TS) and 1,1-diphenyl-2,3,4,5-tetra(o-tolyl)-1H-silole (o-TS)-were prepared, and their photophysical properties were compared with those of a reference compound, hexaphenylsilole (HPS). By substituting methyl groups at ortho positions of peripheral tetraphenyl rings on the silacyclopentadiene ring, intramolecular rotations could be successfully controlled and the photophysical properties were varied, while substituting methyl groups at meta positions showed similar photophysical properties compared with the case of HPS. That is, simple structural modification at the ortho position significantly affects the geometry and the photophysical properties of silole, which leads to blue-shifted emission. Finally, two tolyl-substituted siloles and HPS were employed as chemosensors for the detection of nitro explosives, and o-TS showed the highest sensing ability.
- Lee, Jiwon,Park, Yoona,Jung, Joori,Han, Won-Sik
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p. 1495 - 1501
(2017/10/19)
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- Fluoroform-Derived CuCF3 for Trifluoromethylation of Terminal and TMS-Protected Alkynes
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An efficient trifluoromethylation reaction of alkynes using a fluoroform-derived CuCF3 reagent is described. The CF3 source is the inexpensive industrial waste fluoroform (CF3H). The air-stable CuCF3 reagent can be prepared in large quantities and is convenient to use. Synthetically useful trifluoromethylated alkynes containing a wide range of functional groups were successfully synthesized under mild conditions. Both terminal and TMS-protected alkynes gave the products in one step. The beneficial effect of a diamine ligand tetramethylethylenediamine (TMEDA) with the fluoroform-derived CuCF3 reagent was also demonstrated.
- He, Lisi,Tsui, Gavin Chit
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supporting information
p. 2800 - 2803
(2016/07/06)
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- Aerobic oxidation in nanomicelles of aryl alkynes, in water at room temperature
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On the basis of the far higher solubility of oxygen gas inside the hydrocarbon core of nanomicelles, metal and peroxide free aerobic oxidation of aryl alkynes to β-ketosulfones has been achieved in water at room temperature. Many examples are offered that illustrate broad functional group tolerance. The overall process is environmentally friendly, documented by the associated low E Factors. It's all happenin' in the micelle! The highly preferential dissolution of oxygen gas within the lipophilic cores inside nanomicelles leads to efficient trapping of in situ generated vinyl radicals. These intermediate radicals, derived from arylalkynes and sulfinic acids, lead to β-ketosulfone products, formed under especially mild and green conditions: no metals, no heating or cooling, recyclable aqueous media, and low E Factors.
- Handa, Sachin,Fennewald, James C.,Lipshutz, Bruce H.
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supporting information
p. 3432 - 3435
(2014/04/03)
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- Reactivity switch enabled by counterion: Highly chemoselective dimerization and hydration of terminal alkynes
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A counterion-controlled reactivity tuning in Pd-catalyzed highly chemoselective and regioselective dimerization and hydration of terminal alkynes is reported. The use of acetate as counterion favors the formation of an alkenyl alkynyl palladium intermediate which forms hitherto less reported 1,3-diaryl-substituted conjugated enynes after reductive elimination. Using chloride, which is a better leaving group, leads to anion exchange on the alkenylpalladium intermediate with hydroxide which after reductive elimination and tautomerization delivered the hydration products.
- Xu, Caixia,Du, Weiyuan,Zeng, Yi,Dai, Bin,Guo, Hao
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supporting information
p. 948 - 951
(2014/03/21)
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- Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira-Glaser cyclization sequence
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2,5-Di(hetero)arylfurans are readily accessible in a pseudo five-component reaction via a Sonogashira-Glaser coupling sequence followed by a superbase-mediated (KOH/DMSO) cyclization in a consecutive one-pot fashion. Besides the straightforward synthesis of natural products and biologically active molecules all representatives are particularly interesting due to their bright blue luminescence with remarkably high quantum yields. The electronic structure of the title compounds is additionally studied with DFT computations.
- Klukas, Fabian,Grunwald, Alexander,Menschel, Franziska,Mueller, Thomas J. J.
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supporting information
p. 672 - 679
(2014/04/17)
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- Pseudo five-component synthesis of 3-(hetero)arylmethyl-2,5-di(hetero)-aryl-substituted thiophenes via sonogashira-glaser cyclization sequence
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The Sonogashira-Glaser sequence combined with a microwave-assisted cyclization is a powerful tool to synthesize unsymmetrically substituted conjugated thiophenes. A variety of 3-(hetero)arylmethyl-2,5-di(hetero)aryl-substituted thiophenes could be synthesized in moderate to excellent yields using a single Pd/Cu catalyst system. The presented method is strikingly simple to perform using commercially available starting materials. The obtained trisubstituted oligothiophene derivatives are interesting molecules for materials science.
- Klukas, Fabian,Perkampus, J?rg,Urselmann, Dominik,Müller, Thomas J. J.
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p. 3415 - 3422
(2015/02/02)
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- Mn-catalyzed aromatic C-H alkenylation with terminal alkynes
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The first manganese-catalyzed aromatic C-H alkenylation with terminal alkynes is described. The procedure features an operationally simple catalyst system containing commercially available MnBr(CO)5 and dicyclohexylamine (Cy2NH). The reaction occurs readily in a highly chemo-, regio-, and stereoselective manner delivering anti-Markovnikov E-configured olefins in high yields. Experimental study and DFT calculations reveal that (1) the reaction is initiated by a C-H activation step via the cooperation of manganese and base; (2) manganacycle and alkynylmanganese species are the key reaction intermediates; and (3) the ligand-to-ligand H-transfer and alkynyl-assisted C-H activation are the key steps rendering the reaction catalytic in manganese.
- Zhou, Bingwei,Chen, Hui,Wang, Congyang
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supporting information
p. 1264 - 1267
(2013/03/14)
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- A guide to sonogashira cross-coupling reactions: The influence of substituents in aryl bromides, acetylenes, and phosphines
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The conversion-time data for 168 different Pd/Cu-catalyzed Sonogashira cross-coupling reactions of five arylacetylenes (phenylacetylene; 1-ethynyl-2-ethylbenzene; 1-ethynyl-2,4,6-R3-benzene (R = Me, Et, i-Pr)) and Me3SiCCH with seven
- Schilz, Marc,Plenio, Herbert
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experimental part
p. 2798 - 2807
(2012/05/05)
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- Efficient approach to 1,2-diazepines via formal diazomethylene insertion into the C-C bond of cyclobutenones
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Efficient monocyclic 1,2-diazepine formation via a tandem electrocyclization reaction of cyclobutenones with lithiodiazoacetate is demonstrated. The reaction proceeds through an oxy anion-accelerated 4π-ring opening of cyclobutene followed by an 8π-ring closure of the resultant oxy anion-substituted diazo-diene under mild conditions to furnish a 1,2-diazepine via formal diazomethylene insertion into the C-C bond of cyclobutenone.
- Sugimoto, Kenji,Hayashi, Rie,Nemoto, Hideo,Toyooka, Naoki,Matsuya, Yuji
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supporting information; experimental part
p. 3510 - 3513
(2012/07/31)
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- Regioselective, stereoselective, and conformationally controlled synthesis of(η4-tetraarylcyclobutadiene)(η5- carbomethoxycyclopentadienyl)cobalt metallocenes
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The Friedel - Crafts reaction of (η4- tetraphenylcyclobutadiene)(η5-carbomethoxycyclopentadienyl) cobalt with acid chlorides/aluminum chloride resulted exclusively in para-phenyl acylation. Both monoacylated (1.1 equiv of RCOCl/AlCl
- Cassar, Doyle J.,Nagaradja, Elisabeth,Butler, David C. D.,Villemin, Didier,Richards, Christopher J.
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supporting information; experimental part
p. 894 - 897
(2012/03/26)
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- One-pot click synthesis of 1N-alkyl-4-aryl-1,2,3-triazoles from protected arylalkynes and alkyl bromides
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1N-Alkyl-4-aryl-1,2,3-triazoles have been prepared through a multicomponent one-pot protocol from the corresponding (arylethynyl)trimethylsilanes and alkyl bromides. In situ alkyl azide formation and alkyne deprotection followed by copper(I)-catalyzed click cycloaddition afforded the desired 1,4-disubstituted 1,2,3-triazoles in generally good to excellent yield, with only minor observation of the undesired 1,5-regioisomeric cycloadduct. The protocol eliminates the need to use reactive organic azides and terminal alkynes. Georg Thieme Verlag Stuttgart. New York.
- Ladouceur, Sebastien,Soliman, Ahmed M.,Zysman-Colman, Eli
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body text
p. 3604 - 3611
(2011/12/16)
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- Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira-Glaser cyclization sequence
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Based upon a consecutive one-pot Sonogashira-Glaser coupling-cyclization sequence a variety of 2,5-di(hetero)arylthiophenes were synthesized in moderate to good yields. A single Pd/Cu-catalyst system, without further catalyst addition, and easily available, stable starting materials were used, resulting in a concise and highly efficient route for the synthesis of the title compounds. This novel pseudo five-component synthesis starting from iodo(hetero)arenes is particularly suitable as a direct access to well-defined thiophene oligomers, which are of peculiar interest in materials science.
- Urselmann, Dominik,Antovic, Dragutin,Mueller, Thomas J. J.
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supporting information; experimental part
p. 1499 - 1503
(2011/12/22)
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- One-pot procedure for the synthesis of unsymmetrical diarylalkynes
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Unsymmetrical diarylalkynes are accessible by a one-pot procedure from two different aryl halides and (trimethylsilyl)acetylene. The three-component coupling is initialized by a Pd/Cu-catalyzed Sonogashira coupling of an aryl halide with (trimethylsilyl)a
- Severin, Rene,Reimer, Jessica,Doye, Sven
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supporting information; experimental part
p. 3518 - 3521
(2010/07/17)
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- One-pot three-step synthesis of 1,2,3-triazoles by copper-catalyzed cycloaddition of azides with alkynes formed by a Sonogashira cross-coupling and desilylation
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A microwave-assisted, one-pot, three-step Sonogashira cross-coupling- desilylation-cycloaddition sequence was developed for the convenient preparation of 1,4-disubstituted 1,2,3-triazoles starting from a range of halides, acyl chlorides, ethynyltrimethyls
- Friscourt, Frederic,Boons, Geert-Jan
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supporting information; experimental part
p. 4936 - 4939
(2010/12/25)
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- Photochemical behavior of (diphosphine)(η2-tolane)Pt 0 complexes. Part A: Experimental considerations in solution and in the solid state
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A series of various (diphosphine)(η2-tolane)Pt0 complexes exhibiting manifold substitution pattern of the tolane ligand (5a-g) and different rigid diphosphines defining various bite angles at the Pt center (9a-b) have been synthesized. All compounds were isolated and characterized by means of spectroscopic methods and additionally by X-ray structure determination (5a-e, 9a-b). In view of potential Caryl-Cethynyl bond activation, we investigated their photochemical behavior in the solid state as well as in solution by irradiating with sunlight. The reactivity towards C aryl-Cethynyl bond activation in the crystalline state and in solution is discussed in relation to substituents attached to the tolane ligand and on the extent of the torsion of its phenyl rings. Complexes 5a-c and 9a either bearing electron withdrawing bromides or possessing a large dihedral angle of the phenyl rings, showed selective oxidative addition of the C aryl-Cethynyl bond to the Pt center in the solid state, yielding complexes 6a-c and 10a, respectively. In contrast, 5d-f and 9b proved to be unreactive under similar conditions because of their electron donating methoxy groups as well as the reduced twisting of their phenyl or pyridyl moieties of the tolane ligands. Irradiation of complexes 5a and 5b with sunlight in solution revealed the formation of the appropriate C-Br activated compounds 7a and 7b along with 6a and 6b in a 1:1 mixture. The observed photochemical Caryl-Cethynyl bond activation is reversible under thermal conditions, regaining the appropriate Pt0 complexes by reductive elimination.
- Weisheit, Thomas,Escudero, Danie,Petzold, Holm,Goerls, Helmar,Gonzalez, Leticia,Weigand, Wolfgang
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experimental part
p. 9493 - 9504
(2011/01/11)
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- Neopentylphosphines as effective ligands in palladium-catalyzed cross-couplings of aryl bromides and chlorides
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The use of neopentylphosphine ligands in the palladium-catalyzed Suzuki, Sonogashira, Heck, and Hartwig-Buchwald couplings of aryl bromides and chlorides are reported. Di-tert-butylneopentylphosphine (DTBNpP) provided highly active catalysts for the coupling of aryl bromides at mild temperatures. Trineopentylphosphine, an air-stable trialkylphosphine, gave inactive catalysts at room temperature, but showed good activity in the H-B amination of aryl chlorides at elevated temperatures.
- Hill, Lensey L.,Smith, Joanna M.,Brown, William S.,Moore, Lucas R.,Guevera, Paul,Pair, Emily S.,Porter, Jake,Chou, Joe,Wolterman, Christopher J.,Craciun, Raluca,Dixon, David A.,Shaughnessy, Kevin H.
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p. 6920 - 6934
(2008/09/21)
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- Synthesis and rearrangement of dewar benzenes into biaryls: Experimental evidence for conrotatory ring opening
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Rearrangement of aryl-substituted Dewar benzenes into the corresponding biaryls may serve as an alternative pathway for synthesis of sterically hindered biaryls. The kinetic data obtained from thermal rearrangements of Dewar benzenes provide experimental
- Jankova, Stepanka,Dracinsky, Martin,Cisarova, Ivana,Kotora, Martin
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- Ru-catalyzed intermolecular [3+2+1] cycloaddition of α,β- unsaturated ketones with silylacetylenes and carbon monoxide leading to α-pyrones
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Ruthenium catalyzes a carbonylative [3+2+1] cycloaddition, using silylacetylenes, α,β-unsaturated ketones, and CO as the starting materials, providing the new method for the synthesis of tetrasubstituted α-pyrones. In this reaction, the carbonyl group and
- Fukuyama, Takahide,Higashibeppu, Yuki,Yamaura, Ryo,Ryu, Ilhyong
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p. 587 - 589
(2008/02/02)
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- 7H-PYRIDO[3,4-D]PYRIMIDIN-8-ONES, THEIR MANUFACTURE AND USE AS PROTEIN KINASE INHIBITORS
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Objects of the present invention are the compounds of formula (I) their pharmaceutically acceptable salts, enantiomeric forms, diastereoisomers and racemates, the preparation of the above compounds, medicaments containing them and their manufacture, as we
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Page/Page column 31-32
(2008/06/13)
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- Poly(norbornene)-supported N-heterocyclic carbenes as ligands in catalysis
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In this contribution, we present the synthesis of norbornene-supported N-heterocyclic (NHC) carbenes. These functionalized norbornenes were polymerized via ring-opening metathesis polymerization in a controlled fashion either before or after metalation with a variety of palladium and ruthenium precursors resulting in the formation of polymer-supported NHC-based metal catalysts. The activities of the palladium-based catalysts in the Suzuki-Miyaura, Sonogashira and Heck coupling reactions were studied in detail. In all cases, the polymeric catalysts demonstrated the same activity as their small molecule analogues. Furthermore, we carried out preliminary investigations into the stability of these catalysts using poisoning studies. A clear dependence of the stability of the polymer-supported catalysts on their palladium precursor was observed with palladium acetate-based polymeric NHC catalysts being the most stable. Finally, we have studied the reactivity of our supported NHC ruthenium complexes as catalysts for ring-closing metathesis. Again, in all cases good conversions were observed with comparable activities to other supported NHC-ruthenium catalysts. Lastly, we were able to remove the ruthenium catalysts from the solution quantitatively demonstrating the possibility of metal removal.
- Sommer, William J.,Weck, Marcus
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p. 2101 - 2113
(2007/10/03)
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- Formation of new alkynyl(phenyl)iodonium salts and their use in the synthesis of phenylsulfonyl indenes and acetylenes http://www.mdpi.org
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The preparation of phenylsulfonyl indene derivatives and phenylsulfonyl-acetylenes from readily available alkynyl(phenyl)iodonium tetrafluoroborates and triflates was investigated using phenylsulfinate as nucleophile.
- Koumbis, Alexandros E.,Kyzas, Christos M.,Savva, Antri,Varvoglis, Anastasios
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p. 1340 - 1350
(2007/10/03)
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- Synthesis of sterically hindered biaryls by Zr-mediated Co-cyclotrimerization of alkynes
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Treatment of zirconacyclopentadienes with ortho-substituted arylpropynoates in the presence of stoichiometric amounts of CuCl or NiBr 2(PPh3)2 represents a novel approach to the synthesis of biaryls, formed in good yields. The CuCl-mediated reaction proceeded through two reaction mechanisms, also affording Dewar benzenes together with the corresponding biaryls Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Dufkova, Lenka,Kotora, Martin,Cisarova, Ivana
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p. 2491 - 2499
(2007/10/03)
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- (Z)-Selective cross-dimerization of arylacetylenes with silylacetylenes catalyzed by vinylideneruthenium complexes
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The vinylideneruthenium(II) complexes bearing bulky and basic tertiary phosphine ligands, RuCl2(=C=CHPh)L2 (L = PPr i3, PCy3), serves as a good catalyst precursor for (Z)-selective cross-dimerization between arylacetylenes and silylacetylenes in the presence of N-methylpyrrolidine. The Royal Society of Chemistry 2005.
- Katayama, Hiroyuki,Yari, Hiroshi,Tanaka, Masaki,Ozawa, Fumiyuki
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p. 4336 - 4338
(2008/02/08)
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- ANTIBACTERIAL BENZOIC ACID DERIVATIVES
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The invention provides antimicrobial agents and methods of using the agents for sterilization, sanitation, antisepsis, disinfection, and treatment of infections in mammals.
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- Homogeneous catalysts supported on soluble polymers: Biphasic Sonogashira coupling of aryl halides and acetylenes using MeOPEG-bound phosphine - Palladium catalysts for efficient catalyst recycling
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The Sonogashira coupling of various aryl bromides and iodides with different acetylenes was studied under biphasic conditions with soluble, polymer-modified catalysts to allow the efficient recycling of the homogeneous catalyst. For this purpose, several
- Koellhofer, Axel,Plenio, Herbert
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p. 1416 - 1425
(2007/10/03)
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- A comparison of linear optical properties and redox properties in chalcogenopyrylium dyes bearing ortho-substituted aryl substituents and tert-butyl substituents
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A series of thiapyrylium pentamethine dyes (4 and 12-15) bearing 2,2′-di-tert-butyl-6,6′-diphenyl, 2,2′-di-tert-butyl-6,6′-bis(2,6-dimethylphenyl), 2,2′-di-tert-butyl-6,6′-bis(2-methylphenyl), 2,2′,6,6′-tetrakis(2,6-dimethylphenyl), and 2,2′,6,6′-tetrakis(2-methylphenyl) substituents, respectively, were prepared and their linear optical properties and electrochemical redox properties were measured and compared to thiapyrylium pentamethine dyes 3 and 5. The tert-butyl and 2,6-dimethylphenyl substituents give nearly identical chromophores with respect to values of λmax, molar extinction coefficients (ε), bandwidths at half-height (ν1/2), and lack of absorption in the visible spectrum. The 2-methylphenyl substituent imparts linear optical properties that are intermediate between those of the tert-butyl and phenyl substituents. The 2,6-dimethylphenyl and 2-methylphenyl substituents impart greater oxidative stability based on anodic shifts in oxidation potential.
- Panda, Jagannath,Virkler, Peter R.,Detty, Michael R.
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p. 1804 - 1809
(2007/10/03)
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- Palladium-catalyzed carbon-carbon coupling reactions using aryl Grignards
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Coupling reactions using Pd(PPh3)4 were investigated with a number of electron donating and electron withdrawing substituents. High yields were obtained with both types of substituents. In competitive reactions the electron-withdrawi
- Gottardo, Christine,Aguirre, Andrea
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p. 7091 - 7094
(2007/10/03)
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- Formation of benzo[b]fluorenes and the benzo[a]fluorene core of the fluostatins by cyclization of diaryldiynones.
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[figure: see text] Thermal cyclization of 1-[2-(trimethylsilylethynyl)phenyl]-3-arylpropinones was expected to give benzo[b]fluorenones. However, benzo[a]-fluorenones were also formed as a result of a new rearrangement. These tetracycles possess the core structure of the fluostatins and isoprekinamycin.
- Atienza,Mateo,de Frutos,Echavarren
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p. 153 - 155
(2007/10/03)
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- Intramolecular aminopalladation and cross coupling of acetylenic amines
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Stereodefined 2-alkylidene-pyrrolidines and -piperidine were synthesized by treatment of an acetylenic amines with n-BuLi followed by addition of catalytic amount of Pd(OAc)2 and PPh3 in THF and 3 equiv of an organic halide.
- Luo, Fen-Tair,Wang, Ren-Tzong
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p. 6835 - 6838
(2007/10/02)
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- PALLADIUM-CATALYSED REDUCTIVE ADDITION OF ARYL IODIDES TO ARYL AND ALKYLETHYNYLSILANES: A STEREO AND REGIOSELECTIVE ROUTE TO FUNCTIONALIZED 2,2-DISUBSTITUTED VINYLSILANES
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Aryl and alkylethynylsilanes are converted into 2,2-disubstituted vinylsilanes containing various common functional groups in the presence of aryl iodides, a palladium catalyst, formic acid, and a tertiary or secondary amine with high stereoselectivity an
- Arcadi, A.,Cacchi, S.,Marinelli, F.
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p. 6397 - 6400
(2007/10/02)
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