- 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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- 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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- BF3·OEt2-Promoted Propargyl Alcohol Rearrangement/[1,5]-Hydride Transfer/Cyclization Cascade Affording Tetrahydroquinolines
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An efficient BF3·OEt2-mediated propargyl alcohol rearrangement/[1,5]-hydride transfer/cyclization cascade for the synthesis of tetrahydroquinoline derivatives has been described. The substituents adjacent to triple bonds play an important role in the formation of ketones (via [1,3]-hydroxyl shift) or alkenyl fluorides which are products of formal trans-carbofluorination of internal alkynes. This method provides a rapid access to diverse heterocycles in moderate to excellent yields.
- Zhao, Shuang,Wang, Xiaoyang,Wang, Pengfei,Wang, Guangwei,Zhao, Wentao,Tang, Xiangyang,Guo, Minjie
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supporting information
p. 3990 - 3993
(2019/06/14)
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- Palladium-Catalyzed Cascade Intramolecular Cyclization and Allylation of Enynoates with Allylic Alcohols
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A Pd(II)-catalyzed mild and highly regioselective 6-endo cyclization/allylation reaction of enynoates with simple allylic alcohols has been developed. Under mild reaction conditions, the vinyl palladium species generated in situ after cyclization could insert C-C double bond of allylic alcohol through cross-coupling reaction and lead to the formation of allyl pyrone via β-OH elimination. This cascade cross-coupling reaction represents a direct and atom economic methodology for the construction of novel allyl pyrones in moderate to good yields.
- Qiu, Sheng-Qi,Ahmad, Tanveer,Xu, Yun-He,Loh, Teck-Peng
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p. 6729 - 6736
(2019/06/14)
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- Palladium-catalyzed tandem C-H functionalization/cyclization strategy for the synthesis of 5-hydroxybenzofuran derivatives
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A palladium-catalyzed benzoquinone C-H functionalization/ cyclization strategy with terminal alkynes was employed for the synthesis of some biologically relevant 2, 3-disubstituted 5-hydroxybenzofuran derivatives. The benzoquinone acts as a reactant as well as an oxidant. During the process, an additional alkyne functionality can be introduced at the C3 position of the benzofuran. Base, ligand, and external oxidant are not required in this protocol.
- Ichake, Sachin S.,Konala, Ashok,Kavala, Veerababurao,Kuo, Chun-Wei,Yao, Ching-Fa
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supporting information
p. 54 - 57
(2017/11/28)
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- A practical non-metal catalytic silicon of the amino protection of the new method (by machine translation)
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The invention relates to a high efficiency, mild organic silicon reagent carbon silicon key fracture of the new method. The method of this reaction to the alkali is cheap and easy to obtain metal catalyst, in order to common commercial solvent as a reaction solvent and a hydrogen source, in the air and in the under mild conditions can be successfully catalytic trimethyl aryl silicon reagent or aryl alkyne base silicon reagent selectively generating carbon silicon key cracking hydrogenation reaction, the substrate universality is wide, functional group compatibility outstanding. The first innovative to realize the non-transition metal catalyzed carbon silicon key breaking reaction, also overcome the traditional method requires the use of greatly excessive inorganic alkali or an expensive metal catalyst to the limitation of the silicon of the amino protection, for the laboratory preparation and industry in the production of the organosilicon group deprotection provides a completely new strategy. (by machine translation)
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Paragraph 0054; 0055
(2018/04/01)
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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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- Reaction discovery using acetylene gas as the chemical feedstock accelerated by the stop-flow micro-tubing reactor system
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Acetylene gas has been applied as a feedstock under transition-metal catalysis and photo-redox conditions to produce important chemicals including terminal alkynes, fulvenes, and fluorinated styrene compounds. The reaction discovery process was accelerated through the use of stop-flow micro-tubing reactors. This reactor prototype was developed by joining elements from both continuous micro-flow and conventional batch reactors, which was convenient and effective for gas/liquid reaction screening. Notably, the developed transformations were either inefficient or unsuccessful in conventional batch reactors. Its success relies on the unique advantages provided by this stop-flow micro-tubing reactor system.
- Xue, Fei,Deng, Hongping,Xue, Chengwen,Mohamed, Dara Khairunnisa Binte,Tang, Karen Yuanting,Wu, Jie
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p. 3623 - 3627
(2017/07/11)
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- Cleavage of the Carbon–Carbon Triple Bonds of Arylacetylenes for the Synthesis of Arylnitriles without a Metal Catalyst
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Cleavage of the carbon–carbon triple bonds of alkynes was achieved, which led to the synthesis of arylnitriles under transition-metal-free conditions. A vast range of terminal alkyne substrates underwent this reaction to provide the corresponding nitriles in moderate to good yields with good functional group tolerance.
- Lin, Yuanguang,Song, Qiuling
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supporting information
p. 3056 - 3059
(2016/07/12)
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- Formal [4+ 2] reaction between 1,3-diynes and pyrroles: Gold(I)-catalyzed indole synthesis by double hydroarylation
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Indole synthesis by a gold(I)-catalyzed intermolecular formal [4+2] reaction between 1,3-diynes and pyrroles has been developed. This reaction involves the hydroarylation of 1,3-diynes with pyrroles followed by an intramolecular hydroarylation to give the 4,7-disubstituted indoles. This reaction can also be applied to the synthesis of carbazoles when indoles are used as the nucleophiles instead of pyrroles.
- Matsuda, Yuka,Naoe, Saori,Oishi, Shinya,Fujii, Nobutaka,Ohno, Hiroaki
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supporting information
p. 1463 - 1467
(2015/01/30)
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- Visible-Light-Promoted Vinylation of Tetrahydrofuran with Alkynes through Direct C-H Bond Functionalization
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(Chemical Equation Presented) Mild and direct C-H bond functionalizations and vinylations of tetrahydrofuran with alkynes have been accomplished through visible light photocatalysis, yielding a range of vinyl tetrahydrofurans under the synergistic actions of organic dye-type photocatalyst eosin Y, tert-butyl hydroperoxide (t-BuOOH), and a 45 W household lightbulb. A significant kinetic isotope effect (KIE) was recorded, which helps shed light on the mechanistic course.
- Li, Jing,Zhang, Jing,Tan, Haibo,Wang, David Zhigang
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supporting information
p. 2522 - 2525
(2015/05/27)
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- Rh(III)-catalyzed cyclization reaction of azoles with alkynes: Efficient synthesis of azole-fused-pyridines
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A Rh(III)-catalyzed cyclization of azoles with alkynes has been developed. A variety of azole-fused-pyridines were obtained in good to excellent yields and regioselectivity. Both the C5 and the C4 position of azoles were suitable for the reaction.
- Chen, Xuebing,Wu, Youzhi,Xu, Jinyi,Yao, Hequan,Lin, Aijun,Huang, Yue
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supporting information
p. 9186 - 9189
(2015/09/07)
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- Gold-Catalyzed Intermolecular Nitrene Transfer from 2H-Azirines to Ynamides: A Direct Approach to Polysubstituted Pyrroles
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(Chemical Equation Presented). An effective gold-catalyzed intermolecular nitrene transfer by the reaction of 2H-azirines and ynamides is reported, which provides highly substituted pyrroles in a straightforward manner. This transformation proceeds under mild conditions and gives the polysubstituted pyrroles in good-to-excellent yields. Preliminary results indicate that a nongold carbenoid pathway is preferred for current pyrrole synthesis.
- Zhu, Lei,Yu, Yinghua,Mao, Zhifeng,Huang, Xueliang
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supporting information
p. 30 - 33
(2015/07/28)
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- "quick and click" assembly of functionalised indole rings via metal-promoted cyclative tandem reactions
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An efficient and convenient synthesis of a variety of decorated indoles using a three-component tandem metal-catalysed process is described. We propose here a new "synthetic kit" that allows for the "quick and click" assembly of indole rings using readily available, and inexpensive starting materials under environmentally friendly reaction conditions. This journal is
- Capitta, Francesca,De Luca, Lidia,Porcheddu, Andrea
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p. 59297 - 59301
(2015/02/19)
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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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- 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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- Aerobic oxynitration of alkynes with tBuONO and TEMPO
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An efficient method for stereoselective nitroaminoxylation of alkyne has been reported. The reaction enjoys a broad substrate scope, good functional group tolerance, and high yields. Synthetically useful α-nitroketones can be accessed through these products in a single step.
- Dutta, Uttam,Maity, Soham,Kancherla, Rajesh,Maiti, Debabrata
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supporting information
p. 6302 - 6305
(2015/02/19)
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- ARYL-SUBSTITUTED IMIDAZOLES
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The compounds of the invention are antagonists of MDM2 and MDMX, with excellent specificity for MDM2 and MDMX over other proteins, and with selective binding affinity to MDMX over MDM2. The compounds can therefore regulate p53 activity and treat a variety of cancers. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
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Page/Page column 52
(2012/04/17)
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- A novel and efficient synthesis of terminal arylacetylenes via Sonogashira coupling reactions catalysed by MCM-41-supported bidentate phosphine palladium(0) complex
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A variety of terminal arylacetylenes have been conveniently synthesised in good to high yields via Sonogashira coupling of aryl iodides with (trimethylsilyl)acetylene catalysed by a MCM-41-supported bidentate phosphine palladium(0) complex, followed by desilylation. The polymeric palladium catalyst can be reused many times without any decrease in activity.
- Wang, Yue,Huang, Bin,Sheng, Shouri,Cai, Mingzhong
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p. 728 - 732
(2008/09/20)
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- Novel 3-phenylprop-2-ynylamines as inhibitors of mammalian squalene epoxidase.
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The synthesis of a novel series of 3-phenylprop-2-ynylamines as selective mammalian squalene epoxidase inhibitors is described. Structure activity relationship studies led to the discovery of compound 19, 1-[3-(3,5-dichlorophenyl)-prop-2-ynyl]-3- methylpiperidine hydrochloride with an IC50 of 2.8 +/- 0.6 microM against rat liver squalene epoxidase. Against 23 strains of fungal squalene epoxidase compound 19 was found to be inactive.
- Musso, David L,Clarke, Morris J,Kelley, James L,Boswell, G Evan,Chen, Grace
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p. 498 - 506
(2007/10/03)
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- Substituted indoles and their use as integrin antagonists
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The present invention relates to novel substituted indole compounds that are antagonists of alpha V (αv) integrins, for example αvβ3 and αvβ5 integrins, their pharmaceutically acceptable salts, and pharmaceutical compositions thereof. The compounds may be used in the treatment of pathological conditions mediated by αvβ3 and αvβ5 integrins, including such conditions as tumor growth, metastasis, restenosis, osteoporosis, inflammation, macular degeneration, diabetic retinopathy, and rheumatoid arthritis. The compounds have the general formula: where R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, D, X, W, a, m, n, i, j, k and v are defined herein.
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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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- Ultraviolet photochemistry of diacetylene: Reactions with benzene and toluene
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The reactions of metastable diacetylene with benzene and toluene are explored using a molecular beam pump-probe time-of-flight mass spectrometer. Diacetylene is laser-excited to the 210610 band of the 1Δu←X1Σ+g transition, whereupon rapid intersystem crossing occurs to the lowest triplet states. The triplet state diacetylene then reacts with either benzene or toluene as the gas mixture traverses a short reaction tube (approximately 20 μs). The reactions are quenched as the gas mixture expands into the ion source region of a time-of-flight mass spectrometer where the primary photoproducts are detected using vacuum ultraviolet (VUV) photoionization or resonant two-photon ionization (R2PI). The major products from the reaction of diacetylene and benzene have molecular formulas C8H6 and C10H6, and are identified as phenylacetylene and phenyldiacetylene using R2PI spectroscopy. The major products from metastable diacetylene's reaction with toluene are C9H8 and C11H8. The C9H8 product is confirmed as a mixture of o-, m-, and p-ethynyltoluene, with the ortho product dominating. Mechanisms for the formation of the above products are proposed based on deuterium substitution studies of the reactions. The potential importance of these reactions is discussed as they relate to hydrocarbon growth in sooting flames.
- Robinson, Allison G.,Winter, Paul R.,Ramos, Christopher,Zwier, Timothy S.
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p. 10312 - 10320
(2007/10/03)
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- Synthesis and Electrochemical Properties of 4-Phenyl-1-buten-3-yne-1,1,2-tricarbonitriles and Tricyanoacrylates
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The reaction of phenylacetylenes 4a-h copper(I) acetate (5) and TCNE (tetracyanoethylene) in THF/acetonitrile gave 4-phenyl-1-buten-3-yne-1,1,2-tricarbonitriles 6a-h. 4i did not react to give 6i.The phenylacetylenes 4b-i were prepared by a two-step synthesis starting from the corresponding phenyl halides 1b-i.The tricyanoacrylates 8 were synthesised from the corresponding cyanoacetates 7, TCNE and catalytic amounts of pyridine in THF. - Cyclovoltammetric investigations showed that the butenynes 6 and the tricyanoacrylates 8 are strong electron acceptors which can be easily reduced.The radical anions 6.- are unstable in acetonitrile and react irreversibly with 6 to give oligomeric anions 6.-n.Only 4-(2,4,6-trimethoxyphenyl)-1-buten-3-yne-1,1,2-tricarbonitrile (6h) is reduced to a radical anion 6h.- which associates with 6h in a reversible follow-up process to form a dimeric anion 6h2.-.By contrast, the tricyanoacrylates 8 can be reversibly reduced to their respective radical anions and dianions. - Keywords: Cyano compounds, conjugated / Phenylacetylenes / Radical anions / Electrochemistry
- Dulog, Lothar,Koerner, Bernd,Heinze, Juergen,Yang, Jianjun
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p. 1663 - 1672
(2007/10/02)
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- Gas-Phase Reactions of Charged Electrophiles with Styrene and Phenylacetylene
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The reactions of styrene and phenylacetylene toward charged electrophiles have been studied in the gas phase by a radiolytic technique, supported by chemical ionization mass spectrometry.The two substrates undergo a methylation reaction by Me2F(1+) both at the ring and at the side chain, at variance with the side-chain electrophilic attack prevailing in condensed phase.The nitrating (MeONO2)H(1+) ion selectively nitrates the orto position of styrene, an unprecedented ring nitration on this substrate.The formation of neutral isomeric products is determined by the efficiency of deprotonation of their ionic precursors and is sensitive interalia to the presence of oxygen nucleophiles.The overall reactivity pattern is rationalized in terms of preferential electrostatic interactions between the reactants in a preliminary collision complex, whereby an incoming ROH molecule can simulate a "solvating" environment, shifting the reactivity in the direction observed in solution.
- Crestoni, Maria Elisa,Fornarini, Simonetta
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p. 6008 - 6014
(2007/10/02)
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- Choix des methodes pour la synthese univoque de carbures acetyleniques. Troisieme partie : Arylacetylenes et aryl-1 alcynes-1
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The range of applicability of six syntheses of pure alkynes with one aryl group has been defined; a short review of other possible procedures is included.We have specified the best method to obtain selectively the alkynes Ar-CCH and Ar-CC-R, according to the nature of the substituents of the aryl group and according to the developed structure of the R group.It is thus possible to recommend with the largest probability of success the method to obtain, in homogenous series, alkynes corresponding to still more complicated structures.
- Mesnard, Danielle,Bernadou, Francoise,Miginiac, Leone
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p. 3216 - 3245
(2007/10/02)
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