88768-84-7Relevant articles and documents
Enantioselective Inverse Electron Demand (3 + 2) Cycloaddition of Palladium-Oxyallyl Enabled by a Hydrogen-Bond-Donating Ligand
Zheng, Yin,Qin, Tianzhu,Zi, Weiwei
, p. 1038 - 1045 (2021/01/25)
Cycloaddition reactions between oxyallyl cations and alkenes are important transformations for the construction of ring systems. Although (4 + 3) cycloaddition reactions of oxyallyl cations are well-developed, (3 + 2) cycloadditions remain rare, and an as
Controlled Cyclopolymerization of 1,5-Hexadiynes to Give Narrow Band Gap Conjugated Polyacetylenes Containing Highly Strained Cyclobutenes
Kang, Cheol,Jung, Kijung,Ahn, Sojeong,Choi, Tae-Lim
, p. 17140 - 17146 (2020/10/09)
For decades, cyclopolymerization of α,ω-diyne derivatives has been an effective method to synthesize various soluble polyacetylenes containing five- to seven-membered rings in the backbone. However, cyclopolymerization to form four-membered carbocycles was considered impossible due to their exceptionally high ring strain (～30 kcal/mol). Herein, we demonstrate the successful cyclopolymerization of rationally designed 1,5-hexadiyne derivatives to afford various polyacetylenes containing highly strained cyclobutenes in each repeat unit. After screening, Ru catalysts containing bulky diisopropylphenyl groups promoted challenging four-membered ring cyclization efficiently from various monomers, enabling the synthesis of high molecular weight (up to 40 kDa) polyacetylenes in a controlled manner. Furthermore, living polymerization allowed for block copolymer synthesis by combining with ring-opening metathesis polymerization as well as block copolymerization of two different 1,5-hexadiyne monomers to give a fully conjugated polyacetylene. These new polymers unexpectedly showed much narrower band gaps than conventional substituted polyacetylenes by >0.2 eV. Interestingly, computational studies showed much smaller bond length alternation in the conjugated backbone containing cyclobutenes, resulting in highly delocalized πelectrons along the polymer chain and lower band gaps.
A facile access to 4-substituted-2-naphthols via a tandem Friedel-Crafts reaction: A β-chlorovinyl ketone pathway
Kim, Hun Young,Oh, Kyungsoo
supporting information, p. 5934 - 5936 (2015/01/08)
A one-pot synthesis of 2-naphthol derivatives is accomplished using a tandem Friedel-Crafts reaction sequence. The developed methodology allows for a concomitant construction of up to three C-C bonds between readily available alkynes and phenylacetyl chloride derivatives by an intermolecular Friedel-Crafts acylation of alkynes followed by an intramolecular Friedel-Crafts alkylation of β-chlorovinyl ketone intermediates.
Transition-metal-free approach to 4-ethynylpyrimidines via alkenynones
Golubev, Pavel R.,Pankova, Alena S.,Kuznetsov, Mikhail A.
, p. 3614 - 3621 (2014/06/23)
A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4- yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%. Copyright
Synthesis of [2-(Trimethylsilyl)ethynyl]pyrazoles based on bis(trimethylsilyl)acetylene and arylacetyl chlorides
Pankova, Alena S.,Golubev, Pavel R.,Kuznetsov, Mikhail A.,Ananyev, Ivan V.
, p. 5965 - 5971,7 (2020/09/02)
A practical approach to the synthesis of [2-(trimethylsilyl)ethynyl] pyrazoles was developed through condensation of hydrazines with enynones that are easily accessible frombis(trimethylsilyl)acetylene and arylacetyl chlorides. Optimized conditions for reactions with monoarylhydrazines permit the chemoselective formation of 5-alkynylpyrazoles in high yields (48-94 %). When monoalkylhydrazines or the parent hydrazine is used, mixtures of 3- and 5-alkynylpyrazoles are formed in 73-79 % yields. The method uses inexpensive starting materials and can be applied to a variety of substrates, which makes it convenient for the synthesis of alkynylpyrazoles. A three-step method for the synthesis of 5-alkynylpyrazoles through a transformation of bis(trimethylsilyl) acetylene to enynones followed by their condensation with hydrazines is described. The chemoselectivity of the last stage is discussed.
Synthesis of α,β-diketotriazoles by aerobic copper-catalyzed oxygenation with triazole as an intramolecular assisting group
Menendez, Christophe,Gau, Sylvain,Ladeira, Sonia,Lherbet, Christian,Baltas, Michel
scheme or table, p. 409 - 416 (2012/02/04)
The catalytic oxidation of α-ketotriazoles to α,β- diketotriazoles was performed with CuCl2 or CuI/2,9-dimethyl-1,10- phenanthroline in air at 80 °C in good yields. Studies showed that the triazole group participates in complexation to the copper and favors oxidation. Copyright
Synthesis and biological activities of triazole derivatives as inhibitors of InhA and antituberculosis agents
Menendez, Christophe,Gau, Sylvain,Lherbet, Christian,Rodriguez, Frédéric,Inard, Cyril,Pasca, Maria Rosalia,Baltas, Michel
, p. 5524 - 5531 (2011/12/15)
InhA, the enoyl reductase from the mycobacterial type II fatty acid biosynthesis pathway, is a target for the development of novel drugs against tuberculosis. We exploited copper-catalyzed [3+2] cycloaddition between alkynes and different azides to afford 1,4-disubstituted triazole or α-ketotriazole derivatives. Several compounds bearing a lipophilic chain mimicking the substrate were able to inhibit InhA. Among them, 1-dodecyl-4-phenethyl-1H-1,2,3-triazole displayed a minimum inhibitory concentration inferior to 2 μg/mL against Mycobacterium tuberculosis H37Rv.
Synthesis and structure-activity relationships of 3-[(2-methyl-1,3-thiazol- 4-yl)ethynyl]pyridine analogues as potent, noncompetitive metabotropic glutamate receptor subtype 5 antagonists; search for cocaine medications
Iso, Yasuyoshi,Grajkowska, Ewa,Wroblewski, Jarda T.,Davis, Jared,Goeders, Nicholas E.,Johnson, Kenneth M.,Sanker, Subramaniam,Roth, Bryan L.,Tueckmantel, Werner,Kozikowski, Alan P.
, p. 1080 - 1100 (2007/10/03)
Recent genetic and pharmacological studies have suggested that the metabotropic glutamate receptor subtype 5 (mGluR5) may represent a druggable target in identifying new therapeutics for the treatment of various central nervous system disorders including drug abuse. In particular, considerable attention in the mGluR5 field has been devoted to identifying ligands that bind to the allosteric modulatory site, distinct from the site for the primary agonist glutamate. Both 2-methyl-6-(phenylethynyl)pyridine (MPEP) and its analogue 3-[(2-methyl-4-thiazolyl)ethynyl]pyridine (MTEP) have been shown to be selective and potent noncompetitive antagonists of mGluR5. Because of results presented in this study showing that MTEP prevents the reinstatement of cocaine self-administration caused by the presentation of environmental cues previously associated with cocaine availability, we have prepared a series of analogues of MTEP with the aim of gaining a better understanding of the structural features relevant to its antagonist potency and with the ultimate aim of investigating the effects of such compounds in blunting the self-administration of cocaine. These efforts have led to the identification of compounds showing higher potency as mGluR5 antagonists than either MPEP or MTEP. Two compounds 19 and 59 exhibited functional activity as mGluR5 antagonists that are 490 and 230 times, respectively, better than that of MTEP.
Practical asymmetric approach to medium-sized carbocycles based on the combination of two Ru-catalyzed transformations and a lewis acid-induced cyclization
López, Fernando,Castedo, Luis,Mascare?as, José L.
, p. 287 - 290 (2007/10/03)
(Chemical Equation Presented) Ruthenium-catalyzed coupling of allyl ethyl ether to optically active 1-trimethylsilyl-1-alkyn-3-ols, followed by in situ ketalization and Lewis-acid-induced cyclization, affords enantiomerically pure 1,5-oxygen-bridged eight
LITHIATED 2-ALKYNYL-1,3-DIOXANES AS FULLY OXYGENATED ACYL-ANION EQUIVALENTS: SYNTHESIS OF 1-ALKYNYL KETONES
Kruithof, Klaas J. H.,Schmitz, Robert F.,Klumpp, Gerhard W.
, p. 3073 - 3082 (2007/10/02)
2-Lithio-2-(trimethylsilylethynyl)-1,3-dioxane 3 is prepared from 2-(trimethylsilylethynyl)-1,3-dioxane with n-BuLi.Alkylation of 3 produces propargylic ketals 2 exclusively.Reaction with group IV-B chlorotrimethylmetalanes gives both propargylic products 2 and allenes 6 depending on the solvent used.Desilylation of 2 as well as hydrolysis to the alkynyl ketones 1 can be carried out under mild conditions.The first 1-alkynyl stannyl ketone has been prepared in this way.Formation of 2-lithio-2-(3,3-dimethyl-1-butynyl)-1,3-dioxane 10 requires t-BuLi.With various electrophiles 10 yields propargylic products and/or allenes in ratios depending on the solvent used.
