- Pd/Cu-Catalyzed Vinylation of Terminal Alkynes with (2-Bromoethyl)diphenylsulfonium Triflate
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The potential of (2-bromoethyl)diphenylsulfonium triflate to be a powerful vinylation reagent was determined by the Sonogashira cross-coupling reactions with terminal alkynes. The vinylation proceeded smoothly at 25 °C under Pd/Cu catalysis to afford a variety of 1- and 2-unsubstituted 1,3-enynes in moderate to excellent yields. This protocol represents the first application of (2-haloethyl)diphenylsulfonium triflate as a CH═CH2 transfer source in organic synthesis.
- Ming, Xiao-Xia,Wu, Shuai,Tian, Ze-Yu,Song, Jia-Wei,Zhang, Cheng-Pan
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p. 6795 - 6800
(2021/09/08)
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- Tertiary amines acting as Alkyl radical equivalents enabled by a P/N heteroleptic Cu(I) photosensitizer
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An unprecedented exploration of tertiary amines as alkyl radical equivalents for cross-coupling with aromatic alkynes to access allylarenes has been achieved by a P/N heteroleptic Cu(I)based photosensitizer under photoredox catalysis conditions. Mechanist
- Zheng, Limeng,Jiang, Qinfang,Bao, Hanyang,Zhou, Bingwei,Luo, Shu-Ping,Jin, Hongwei,Wu, Huayue,Liu, Yunkui
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p. 8888 - 8893
(2020/11/30)
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- SMALL MOLECULE INHIBITORS OF A PROTEIN COMPLEX
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Compositions and methods for treating thrombosis, inflammation, and atherosclerosis by administration of a compound that binds to KRIT1 to inhibit binding with HEG1.
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- Synthesis of 5H-Selenopheno[3,2-c]isochromen-5-ones Promoted by Dialkyl Diselenides and Oxone
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We describe here for the first time the synthesis of isochromenones fused to selenophenes. 5H-Selenopheno[3,2-c]isochromen-5-ones were obtained through a double intramolecular cyclization of methyl 2-(organyl-1,3-diynyl)benzoate promoted by electrophilic species of selenium generated in situ by the reaction of dialkyl diselenides with Oxone, using ethanol as solvent. The reactions were conducted satisfactorily under mild conditions, using a range of 1,3-diynes and dialkyl diselenides as substrates. A total of sixteen unprecedent 5H-selenopheno[3,2-c]isochromen-5-ones were selectively obtained in moderate to good yields (40–86%) under reflux in an open flask and in short reaction times (1.0–2.5 h). (Figure presented.).
- Goulart, Helen A.,Neto, José S. S.,Barcellos, Angelita M.,Barcellos, Thiago,Silva, Márcio S.,Alves, Diego,Jacob, Raquel G.,Lenard?o, Eder J.,Perin, Gelson
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p. 3403 - 3411
(2019/05/28)
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- Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
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4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily available reagents and can be conveniently carried out on a wide scope of substrates under mild conditions (0 °C to rt). Furthermore, the reaction is scalable for gram-scale preparation of 4-chloroisocoumarins. Additionally, 4-bromo- and 4-iodoisocoumarins can be prepared in moderate to good yields by replacing NCS with N-bromosuccinimide (NBS) and N-iodosuccinimide (NIS), respectively.
- Norseeda, Krissada,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
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p. 16222 - 16236
(2019/12/25)
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- New condensed aryl compounds and organic light-emitting diode including the same
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PURPOSE: A fused aryl compound is provided to improve low driving voltage and luminous efficiency by having excellent luminous performance while having stability. CONSTITUTION: A fused aryl compound is indicated in chemical formula 1. An organic electroluminescent device comprises an anode, a cathode, and a fused aryl compound inserted between the anode and the cathode. The fused aryl compound is comprised in an electroluminescent layer between the anode and the cathode. One or more layers selected from a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, and an electron injection layer\ are additionally comprised in between the anode and the cathode.
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- Gold(i)-catalyzed Nicholas reaction with aromatic molecules utilizing a bifunctional propargyl dicobalt hexacarbonyl complex
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A benchtop-stable reagent for the catalytic Nicholas reaction was developed. By combining a propargyl dicobalt hexacarbonyl cluster with an ortho-alkynylbenzoate unit and a fluorous tag, introduction of a propargyl hexacarbonyl complex on various aromatic compounds having acid- or base-sensitive functional groups becomes possible by using a gold(i) catalyst. In addition, the presence of a fluorous tag facilitates convenient separation of the target products from byproducts.
- Okamura, Toshitaka,Fujiki, Shogo,Iwabuchi, Yoshiharu,Kanoh, Naoki
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p. 8522 - 8526
(2019/10/02)
-
- COMPLEX COMPOUND, METHOD FOR PRODUCING COMPOUND HAVING CARBON-CARBON TRIPLE BOND, METHOD FOR PRODUCING INTERMEDIATE IN THE METHOD, AND KIT FOR USE IN THESE METHODS
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PROBLEM TO BE SOLVED: To provide a method for introducing a dicobalt cationic complex into a raw material compound under a milder condition, and a novel compound useful for conducting a method for introducing a carbon-carbon triple bond such as a propargyl group into the raw material compound. SOLUTION: The present invention provides a dicobalt cationic complex compound represented by the formula 23a or a salt thereof. Using the compound makes it possible to introduce a C3 dicobalt cationic complex portion into methoxy naphthalene or the like, and further, removing Co makes it possible to introduce a propargyl group. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPO&INPIT
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- Configurationally Stabilized Analogs of M. ulcerans Exotoxins Mycolactones A and B Reveal the Importance of Side Chain Geometry for Mycolactone Virulence
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Mycolactones A/B (1a/b) are exotoxins of Mycobacterium ulcerans that are the molecular cause of Buruli ulcer. 1a/b represent a rapidly equilibrating mixture of Z/E isomers about the C4′=C5′ double bond of the C5-side chain. Here, we describe the syntheses
- Gehringer, Matthias,M?der, Patrick,Gersbach, Philipp,Pfeiffer, Bernhard,Scherr, Nicole,Dangy, Jean-Pierre,Pluschke, Gerd,Altmann, Karl-Heinz
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supporting information
p. 5853 - 5857
(2019/08/26)
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- Divergent Syntheses of (Z)-3-Alkylideneisobenzofuran-1(3 H)-ones and 1 H-Isochromen-1-ones by Copper-Catalyzed Cycloisomerization of 2-Alkynylbenzoic Acids in Ionic Liquids
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The cycloisomerization of readily available 2-alkynylbenzoic acids 1 in ionic liquids (ILs) as recyclable reaction media has been studied under the catalytic action of CuCl2. With substrates bearing an aryl group on the triple bond, a mixture o
- Mancuso, Raffaella,Pomelli, Christian S.,Chiappetta, Piera,Gioia, Katia F.,Maner, Asif,Marino, Nadia,Veltri, Lucia,Chiappe, Cinzia,Gabriele, Bartolo
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p. 6673 - 6680
(2018/06/01)
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- PROCESS FOR HYDROCYANATION OF TERMINAL ALKYNES
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The present invention refers to a process for a Rh-catalyzed Anti-Markovnikov hydrocyanation of terminal alkynes which process discloses, for the first time, the highly stereo- and regio-selective hydrocyanation of terminal alkynes to furnish E- configured alkenyl nitriles and the catalyst used in the present process.
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Page/Page column 20
(2018/12/13)
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- Photophysical and theoretical studies of diphenylacetylene derivatives with restricted rotation
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Diphenylacetylene derivatives containing electron-donor (amino) and electron-acceptor (ester) groups in 2,2′ or 3,2′ positions in phenyl rings were synthesized to study the effects of intramolecular charge transfer and stiffening of the conformation by in
- Szyszkowska, Ma?gorzata,Czaplewski, Cezary,Wiczk, Wies?aw
-
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- HEPATITIS B CORE PROTEIN MODULATORS
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The present disclosure provides, in part, compounds having allosteric effector properties against Hepatitis B virus Cp. Also provided herein are methods of treating viral infections, such as hepatitis B, comprising administering to a patient in need thereof a disclosed compound.
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- Rh-Catalyzed Anti-Markovnikov Hydrocyanation of Terminal Alkynes
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We report the first highly stereo- and regioselective hydrocyanation of terminal alkynes to furnish E-configured alkenyl nitriles. Acrylonitriles can be accessed on gram scale with broad substrate scope and functional group tolerance. The hydrocyanation reaction employs acetone cyanohydrin as a practical alternative to HCN gas.
- Ye, Fei,Chen, Junting,Ritter, Tobias
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p. 7184 - 7187
(2017/06/05)
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- Hydroiodination-Triggered Cascade Reaction with I2/PPh3/H2O: Metal-Free Access to 3-Substituted Phthalides from 2-Alkynylbenzoates
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Phthalide is an important scaffold found in several biologically active compounds. Therefore, effective methods for the synthesis of phthalides are strongly desired. Herein, we describe the metal-free synthesis of 3-substituted phthalides by the reductive hydroiodination of 2-alkynylbenzoates through an I2/PPh3/H2O-triggered cascade reaction. A variety of 3-substituted phthalides were synthesized in excellent yields by a one-pot reaction involving four processes: desilylation, hydroiodination, cyclization, and reduction.
- Kawaguchi, Shin-Ichi,Nakamura, Kentaro,Yamaguchi, Kotaro,Sato, Yuki,Gonda, Yuhei,Nishioka, Masaaki,Sonoda, Motohiro,Nomoto, Akihiro,Ogawa, Akiya
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p. 5343 - 5346
(2017/09/06)
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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)
- -
-
Paragraph 0078; 0079
(2018/04/01)
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- Cobalt-Catalyzed Bis-alkynylation of Amides via Double C-H Bond Activation
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The first example of cobalt-catalyzed selective bis-alkynylation of amides via double C-H bond activation with the directing assistance of a removable bidentate auxiliary is reported. The developed alkynylation strategy is simple, efficient, and tolerant
- Landge, Vinod G.,Jaiswal, Garima,Balaraman, Ekambaram
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p. 812 - 815
(2016/03/01)
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- Nickel-catalyzed direct alkynylation of C(sp2)-H bonds of amides: An "inverse Sonogashira strategy" to ortho-alkynylbenzoic acids
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Nickel-catalyzed direct alkynylation of C(sp2)-H bonds of amides using commercially available, inexpensive 8-aminoquinoline as a removable bidentate directing group is described. The present ortho-alkynylation has a broad substrate scope, funct
- Landge, Vinod G.,Shewale, Chinmay H.,Jaiswal, Garima,Sahoo, Manoj K.,Midya, Siba P.,Balaraman, Ekambaram
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p. 1946 - 1951
(2016/04/05)
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- Catalyst-Free Synthesis of Borylated Lactones from Esters via Electrophilic Oxyboration
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A catalyst-free oxyboration reaction of alkynes is developed. The resulting borylated isocoumarins and 2-pyrones are isolated as boronic acids, pinacolboronate esters, or potassium organotrifluoroborate salts, providing a variety of bench-stable organobor
- Faizi, Darius J.,Issaian, Adena,Davis, Ashlee J.,Blum, Suzanne A.
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p. 2126 - 2129
(2016/03/05)
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- Catalyst-Free Formal Thioboration to Synthesize Borylated Benzothiophenes and Dihydrothiophenes
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The first ring-forming thioboration reaction of C?C π bonds is reported. This catalyst-free method proceeds in the presence of a commercially available external electrophilic boron source (B-chlorocatecholborane) in good to high yields. The method is scalable and tolerates a variety of functional groups that are intolerant of other major borylation methods. The resulting borylated benzothiophenes participate in a variety of in situ derivatization reactions, showcasing that these borylated intermediates do not need to be isolated prior to downstream functionalization. This methodology has been extended to the synthesis of borylated dihydrothiophenes. Mechanistic experiments suggest that the operative mechanistic pathway is through boron-induced activation of the alkyne followed by electrophilic cyclization, as opposed to S?B σ bond formation, providing a mechanistically distinct pathway to the thioboration of C?C π bonds.
- Faizi, Darius J.,Davis, Ashlee J.,Meany, Fiach B.,Blum, Suzanne A.
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p. 14286 - 14290
(2016/11/11)
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- Contrasting Frustrated Lewis Pair Reactivity with Selenium- and Boron-Based Lewis Acids
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The activation of π-bonds in diynyl esters has been investigated by using soft and hard Lewis acids. In the case of the soft selenium Lewis acid PhSeCl, sequential activation of the alkyne bonds leads initially to an isocoumarin (1 equiv PhSeCl) and then
- Wilkins, Lewis C.,Günther, Benjamin A. R.,Walther, Melanie,Lawson, James R.,Wirth, Thomas,Melen, Rebecca L.
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p. 11292 - 11295
(2016/10/13)
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- PhI(OCOCF3)2-Mediated Cyclization of o -(1-Alkynyl)benzamides: Metal-Free Synthesis of 3-Hydroxy-2,3-dihydroisoquinoline-1,4-dione
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The synthesis of an undocumented skeleton of 3-hydroxy-2,3-dihydroisoquinoline-1,4-diones has been discovered and reported. The reaction consists of an intramolecular cyclization of o-(1-alkynyl)benzamides in MeCN/H2O, mediated by metal-free, h
- Yang, Chao,Zhang, Xiang,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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p. 5320 - 5328
(2015/05/27)
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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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p. 2522 - 2525
(2015/05/27)
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- Regiocontrolled palladium-catalyzed arylative cyclizations of alkynols
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Tuning the reactivity of arylpalladium intermediates enables control of catalytic arylative 5-exo and 6-endo cyclizations of alkynols. The two modes of cyclizations represent a rare example of controllable, regioselective difunctionalization of alkynes. T
- Fujino, Daishi,Yorimitsu, Hideki,Osuka, Atsuhiro
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supporting information
p. 6255 - 6258
(2014/05/20)
-
- A Lewis acid-mediated conformational switch
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Molecules that change conformation in response to a stimulus have numerous uses, such as artificial chemoreceptors, novel drug delivery strategies and liquid crystal technology. Here we describe the design, synthesis and conformational behaviour of an iso
- Knipe, Peter C.,Lingard, Hannah,Jones, Ian M.,Thompson, Sam,Hamilton, Andrew D.
-
supporting information
p. 7937 - 7941
(2015/01/08)
-
- K3PO4-KOH mixture as efficient reagent for the deprotection of 4-aryl-2-methyl-3-butyn-2-ols to terminal acetylenes
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A mixture of potassium hydroxide and potassium phosphate was found to be an active reagent mixture for the cleavage of 2-hydroxypropyl-protected acetylenes. The reaction was performed in toluene at reflux temperature and gave terminal acetylenes in good to excellent yields within very short periods of time. Numerous other functional groups are tolerated. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for full experimental and spectral details.
- Smeyanov, Alexey,Schmidt, Andreas
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supporting information
p. 2809 - 2816
(2013/08/23)
-
- A reaction-based sensing scheme for gold species: Introduction of a (2-ethynyl)benzoate reactive moiety
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To alleviate side reactions identified in an N-propargyl-rhodamine lactam sensing system, we devised the novel reaction-based sensing scheme for gold species based on the alkynophilicity. A fluorescein (2-ethynyl)benzoate underwent Au(III)-promoted ester
- Seo, Hyewon,Jun, Mi Eun,Ahn, Kyo Han,Egorova, Olga A.,Lee, Kyung-Ha,Kim, Kyong-Tai
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p. 5062 - 5065,4
(2012/12/13)
-
- Designed molecular switches: Controlling the conformation of benzamido-diphenylacetylenes
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With the goal of creating a molecular switch, the hydrogen-bonded diphenylacetylene structure has been modified such that an equilibrium now exists between two intramolecular H-bonded states. Through X-ray crystallography and 1H NMR analysis it
- Jones, Ian M.,Hamilton, Andrew D.
-
supporting information; experimental part
p. 3651 - 3653
(2010/10/03)
-
- Pyrrole-cored push-pull single chromophore
-
We report a straightforward synthesis toward pyrrole-cored push-pull single chromophore in which the electron-donating (D) units are pyrrole groups and electron-withdrawing (A) moieties are diketone groups. Optical and electrochemical properties of the no
- Yang, Changduk
-
scheme or table
p. 2007 - 2009
(2010/06/14)
-
- Competition studies in alkyne electrophilic cyclization reactions
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The relative reactivity of various functional groups toward alkyne electrophilic cyclization reactions has been studied. The required diarylalkynes have been prepared by consecutive Sonogashira reactions of appropriately substituted aryl halides and competitive cyclizations have been performed using I2, ICl, NBS and PhSeCl as electrophiles. The results indicate that the nucleophilicity of the competing functional groups, polarization of the alkyne triple bond, and the cationic nature of the intermediate are the most important factors in determining the outcome of these reactions.
- Mehta, Saurabh,Waldo, Jesse P.,Larock, Richard C.
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supporting information; experimental part
p. 1141 - 1147
(2009/07/11)
-
- Halocyclization of methyl 2-alkynylbenzoates to isocoumarins using cupric halides
-
Treatment of methyl 2-alkynylbenzoates with two to three equivalents of CuX2 (X = Cl or Br) in refluxing acetonitrile gave isocoumarins 2 in good to excellent chemical yields.
- Chin, Ling-Yu,Lee, Chia-Ying,Lo, Yu-Hsiang,Wu, Ming-Jung
-
body text
p. 643 - 648
(2009/05/11)
-
- Palladium-catalyzed cyclization of enediynes to benzopyranones
-
Treatment of methyl 2-[6-substituted-3(Z)-hexen-1,5-diynyl]benzoates (1) with five mol% of palladium chloride and three equivalents of cupric chloride in refluxing acetonitrile gave dibenzo[b,d]pyran-6-ones (2) in modest to good yields.
- Chang, Wei-Ren,Lo, Yu-Hsiang,Lee, Chia-Ying,Wu, Ming-Jung
-
body text
p. 1248 - 1252
(2009/06/25)
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- Cycloisomerization of γ- and δ-acetylenic acids catalyzed by gold(I) chloride
-
We have developed a gold(I)-catalyzed intramolecular cyclization of γ- and δ-alkyne acids in mild conditions yielding various alkylidene lactones. Whereas a slight electronic effect of the R group was observed on the regioselectivity, bulky substituents o
- Marchal, Estelle,Uriac, Philippe,Legouin, Béatrice,Toupet, Lo?c,Weghe, Pierre van de
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p. 9979 - 9990
(2008/02/13)
-
- COMPOUNDS AND METHODS FOR MODULATING FXR
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Compounds of formula (I) wherein variables are as defined herein and their pharmaceutical compositions and methods of use are disclosed as useful for treating dyslipidemia and related diseases.
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- New 2,4-Diamino-5-(2′,5′-substituted benzyl)pyrimidines as Potential Drugs against Opportunistic Infections of AIDS and Other Immune Disorders. Synthesis and Species-Dependent Antifolate Activity
-
In a continuing effort to design small-molecule inhibitors of dihydrofolate reductase (DHFR) that combine the enzyme-binding selectivity of 2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl)-pyrimidine (trimethoprim, TMP) with the potency of 2,4-diamino-5-methyl-6-(2′ ,5′-dimethoxybenzyl)pyrido[2,3-d]pyrimidine (piritrexim, PTX), seven previously undescribed 2,4-diamino-5-[2′-methoxy-5′-(substituted benzyl)]pyrimidines were synthesized in which the substituent at the 5′-position was a carboxyphenyl group linked to the benzyl moiety by a bridge of two or four atoms in length. The new analogues were all obtained from 2,4-diamino-5-(5′-iodo-2′-methoxybenzyl)pyrimidine via a Sonogashira reaction, followed, where appropriate, by catalytic hydrogenation. The new analogues were tested as inhibitors of DHFR from Pneumocystis carinii (Pc), Toxoplasma gondii (Tg), and Mycobacterium avium (Ma), three life-threatening pathogens often found in AIDS patients and individuals whose immune system is impaired as a result of treatment with immunosuppressive chemotherapy or radiation. The selectivity index (SI) of each compound was obtained by dividing its 50% inhibitory concentration (IC50) against Pc, Tg, or Ma DHFR by its IC50 against rat DHFR. 2,4-Diamino-[2′-methoxy-5′-(3-carboxyphenyl)-ethynylbenzyl] pyrimidine (28), with an IC50 of 23 nM and an SI of 28 in the Pc DHFR assay, had about the same potency as PTX and was 520 times more potent than TMP. As an inhibitor of Tg DHFR, 28 had an IC50 of 5.5 nM (510-fold lower than that of TMP and similar to that of PTX) and an SI value of 120 (2-fold better than TMP and vastly superior to PTX). Against Ma DHFR, 28 had IC50 and SI values of 1.5 nM and 430, respectively, compared with 300 nM and 610 for TMP. Although it had 2.5-fold lower potency than 28 against Ma DHFR (IC50 = 3.7 nM) and was substantially weaker against Pc and Tg DHFR, 2,4-diamino-[2′-methoxy-5′ -(4-carboxyphenyl)ethynylbenzyl]pyrimidine (29), with the carboxy group at the para rather than the meta position, displayed 2200-fold selectivity against the Ma enzyme and was the most selective 2,4-diamino-5-(5′-substituted benzyl)pyrimidine inhibitor of this enzyme we have encountered to date. Additional bioassay data for these compounds are also reported.
- Rosowsky, Andre,Forsch, Ronald A.,Sibley, Carol Hopkins,Inderlied, Clark B.,Queener, Sherry F.
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p. 1475 - 1486
(2007/10/03)
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- One-pot synthesis of monosubstituted aryl(hetaryl)acetylenes by direct introduction of the C≡CH residue into arenes and hetarenes
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A convenient one-pot synthesis of aryl(hetaryl)acetylenes by cross-coupling of aryl(hetaryl)iodides with acetylene in presence of PdCl2(Ph 3)2, CuI and K2CO3 in DMF has been developed.
- Vasilevsky, Sergei F.,Klyatskaya, Svetlana V.,Elguero, José
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p. 6685 - 6688
(2007/10/03)
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- Cyclopentadienones as intermediates for the synthesis of highly functionalized biaryls
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A new approach to the synthesis of substituted biaryls, via Diels-Alder reaction between cyclopentadienones and arylacetylenes, is described.
- Pearson, Anthony J.,Kim, Jin Bum
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p. 8525 - 8527
(2007/10/03)
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- Copper(I) mediated intramolecular cyclization of 2-(2-amino-phenylethynyl)benzoic and [2-(2-aminophenylethynyl)phenyl]acetic acid esters: A new synthetic step towards isoindolo[2,1-a]indoles and 5H-indolo[2,1-a]isoquinolines
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We describe herein parallel synthetic routes to isoindolo[2,1-a]indoles and 5H-indolo[2,1-a]isoquinolines from 2-(2-aminophenylethynyl)benzoic acid esters and [2-(2-aminophenylethynyl)phenyl]acetic acid esters, respectively.
- Reboredo, Francisco J.,Treus, Mónica,Estévez, Juan C.,Castedo, Luis,Estévez, Ramón J.
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p. 1603 - 1606
(2007/10/03)
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- Solid-phase synthesis of an A-B loop mimetic of the Cε3 domain of human IgE: Macrocyclization by Sonogashira coupling
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The solid-phase synthesis of a cyclic peptide containing the 21-residue epitope found in the A-B loop of the Cε3 domain of human immunoglobulin E has been carried out. The key macrocyclization step to form the 65-membered ring is achieved in ~15% yield vi
- Spivey, Alan C.,McKendrick, John,Srikaran, Ratnasothy,Helm, Birgit A.
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p. 1843 - 1851
(2007/10/03)
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- Synthesis of 3-arylisocoumarins, including thunberginols A and B, unsymmetrical 3,4-disubstituted isocoumarins, and 3-ylidenephthalides via iodolactonization of methyl 2-ynylbenzoates or the corresponding carboxylic acids
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3-Aryl-4-iodoisocoumarins, which were readily and efficiently prepared by regioselective iodolactonization of methyl 2-ynylbenzoates or the corresponding carboxylic acids, were used as precursors either to 3-arylisocoumarins, including naturally-occurring
- Rossi, Renzo,Carpita, Adriano,Bellina, Fabio,Stabile, Paolo,Mannina, Luisa
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p. 2067 - 2081
(2007/10/03)
-
- Hydrogen Bond-Stabilized Helix Formation of a m-Phenylene Ethynylene Oligomer
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(Matrix Presented) Incorporation of a single hydrogen bonded β-turn mimic in the backbone of a m-phenylene ethynylene oligomer is shown to affect the thermodynamic properties of the folding reaction. Oligomers 1 and 2 both undergo solvophobic helix formation, but hydrogen bonded oligomer 1 was found to form a more stable helix with a higher tolerance to solvent denaturation than isomeric, non-hydrogen bonded oligomer 2.
- Cary, Jennifer M.,Moore, Jeffrey S.
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p. 4663 - 4666
(2007/10/03)
-
- Coupling reactions of ortho-substituted aryl halides with alkynes. The synthesis of functionalized 1-naphthyl-, 1-(1-naphthyl)-2-phenyl-, and 1,2- bis(1-naphthyl)acetylenes
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Coupling of 2-functionalized 1-naphthyl halides with gaseous acetylene, (trialkylsilyl)acetylenes, and aryl acetylenes under Pd(PPh3)4 or Pd(PPh3)4/CuI catalysis has been investigated to prepare 1-naphthyl-, 1-
- Stara, Irena G.,Stary, Ivo,Kollarovic, Adrian,Teply, Filip,Saman, David,Fiedler, Pavel
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p. 11209 - 11234
(2007/10/03)
-
- Rhodium Carbenoid Mediated Cyclizations of o-Alkynyl-Substituted α-Diazoacetophenones
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o-Alkynyl-substituted α-diazoacetophenones undergo facile cyclization to indenone derivatives upon treatment with catalytic quantities of Rh(II) carboxylates.A variety of structural influences were encountered by varying the nature of the substituent group attached to the alkyne carbon atom.The cyclization reaction involves addition of a rhodium stabilized carbenoid onto the acetylenic ?-bond to generate a vinyl carbenoid.The vinyl carbenoid was found to undergo both CH and CC migration as well as δ-CH insertion into the alkyl backbone.Different catalysts were shown to result in significant variation in the product ratios for these reactions.Treatment of o-(5-(allyloxy)-1-pentynyl)-α-diazoacetophenone with rhodium(II) mandelate afforded 2-(2-propen-1-yl)-2-(1-oxo-1H-indenyl)-2,3,4,5-tetrahydrofuran in high yield.The formation of this compound involves initial formation of a vinyl carbenoid which reacts with the neighboring oxygen atom to give an oxonium ylide which subsequently undergoes a 2,3-sigmatropic rearrangement.When 2-ethynyl-α-diazoacetophenone is used, only products derived from 6-endo closure are observed.Substituted o-alkynyl α-diazoacetophenones give products derived from 5-exo cyclization.The mode of ring closure is controlled by both steric and electronic factors.
- Padwa, Albert,Krumpe, Keith E.,Kassir, Jamal M.
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p. 4940 - 4948
(2007/10/02)
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