- E-Selective dimerization of phenylacetylene catalyzed by cationic tris(μ-hydroxo)diruthenium(II) complex and the mechanistic insight: The role of two ruthenium centers in catalysis
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A dinuclear complex [(Me3P)3Ru(μ-OH)3Ru(PMe3)3]+[OPh]? (1) (0.5 mol%) catalyzes E-selective dimerization of phenylacetylene, which involves the C–H bond cleavage of phenylacetyle
- Kiyota, Sayori,Soeta, Hirofumi,Komine, Nobuyuki,Komiya, Sanshiro,Hirano, Masafumi
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- Palladium-Catalyzed Decarboxylative Homodimerization of Propiolic Acids: Synthesis of 1,3-Enynes
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The 1,3-enyne product was obtained as a result of a decarboxylative homodimerization reaction when a variety aryl propiolic acids were reacted in the presence of Pd(TFA)2/i-PrPPh2 and K2CO3. It was found that aryl propiolic acids bearing an electrondonating substituent provided the desired product; however, aryl propiolic acids an bearing electron-withdrawing substituent did not give the desired product.
- Seo, Eunkyeong,Oh, Jonghoon,Lee, Sunwoo
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p. 514 - 516
(2021/02/05)
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- One-pot synthesis of α,β-unsaturated ketones through sequential alkyne dimerization/hydration reactions using the Hoveyda-Grubbs catalyst
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Herein we report a sequential one-pot alkyne dimerization/hydration protocol for the regioselective synthesis of α,β-unsaturated ketones in quantitative yields. The alkyne dimerization reactions of terminal arylacetylenes proceeded with high regioselectivity in the presence of the Hoveyda-Grubbs 2nd generation catalyst (1 mol%) and tricyclohexylphosphine (4 mol%). The hydration reactions ofin situformed 1-aryl-3-en-1-ynes proceeded very rapidly in the presence of CCl3COOH/p-TsOH·H2O, yielding the corresponding unsaturated ketones within 15 minutes in quantitative yields. Different arylacetylene derivatives were converted to the corresponding α,β-unsaturated ketones in quantitative yields (94-95%) using sequential one-pot alkyne dimerization/hydration reactions.
- ?ztürk, Bengi ?zgün,?ehito?lu, Solmaz Karabulut,A?kun, Mina,Sar?aslan, Begüm,Tunal?, Zeynep
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supporting information
p. 16689 - 16695
(2021/09/27)
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- Ligand-Controlled Diastereoselective Cobalt-Catalysed Hydroalkynylation of Terminal Alkynes to E- or Z-1,3-Enynes
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A diastereoselective hydroalkynylation of terminal alkynes to form the head-to-head dimerization products by two different cobalt-phosphine catalyst system is reported. The use of the bidentate ligand dppp and additional triphenylphosphine led to the selective formation of the (E)-1,3-enynes (E:Z>99:1) in good to excellent yields, while the tridentate ligand TriPhos led to the corresponding (Z)-1,3-enynes in moderate to good yields with excellent stereoselectivities (up to E:Z=1:99). Both pre-catalysts are easy to handle, because of their stability under atmospheric conditions. The optimized reaction conditions were identified by the Design of Experiments (DoE) approach, which has not been used before in cobalt-catalysed reaction optimisation. DoE decreased the number of required reactions to a minimum.
- Weber, Sebastian M.,Queder, Jona,Hilt, Gerhard
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supporting information
p. 12129 - 12133
(2020/09/09)
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- Syntheses of arylphosphonium salts from cyclotrimerization of terminal aryl alknyes by a ruthenium pentadienyl complex and revisiting the catalytic dimerization
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The synthesis of polyaryl phosphonium salts by cyclotrimerization of aryl alkynes is induced by a stoichiometric amount of the ruthenium η5-pentadienyl complex (η5-C5H7)(PPh3)2RuCl (1). Wit
- Chen, Chi-Ren,Lin, Ying-Chih
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p. 6408 - 6412
(2015/02/19)
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- A ruthenium-based catalytic system with switchable selectivity between cyclotrimerization and enyne metathesis/Diels-Alder reactions of terminal alkynes
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In this study, we report a practical catalytic system, [RuCl 2(p-cymene)]2/IPr (IPr: 1,3-bis(2,6 diisopropylphenyl) imidazol-2-ylidene), that can switch between cyclotrimerization and cross enyne metathesis. The cyclotrimerization reaction of phenylacetylene catalyzed by [RuCl2(p-cymene)]2 can be switched to enyne metathesis by the introduction of a sterically hindered N-heterocyclic carbene. The 1,3-diene formed during this reaction reacts with dienophiles to form the Diels-Alder adduct. A practical one-pot synthesis method, utilizing enyne metathesis/Diels-Alder reactions, was used to construct cyclic compounds in an efficient manner.
- Karabulut, Solmaz,Sariaslan, Begüm,?ztürk, Bengi ?zgün
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- A practical ruthenium based catalytic system bearing a switchable selectivity between the dimerization and cyclotrimerization reactions of alkynes
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In this study, a practical and inexpensive switchable catalytic system (cyclotrimerization vs. dimerization), [RuCl2(p-cymene)] 2/PR3 has been developed for the catalytic dimerization of terminal alkynes. Bulky and basic phosphine derivatives, PCy3 and P(i-Pr)3, were used with [RuCl2(p-cymene)] 2 and excess of terminal alkyne to in situ formation of vinylidenic intermediates which are active towards dimerization reactions. Effect of phosphine/ruthenium ratio has been investigated. A solvent study was carried out and toluene was found to be the most versatile solvent for both cyclotrimerization and dimerization reactions. A set of aryl and alkyl acetylenes were chosen as substrates to investigate the effect of the nature of the substrates on alkyne dimerization reactions catalyzed by [RuCl 2(p-cymene)]2/PR3. In conclusion, we have shown that [RuCl2(p-cymene)]2/PCy3 can be used as a practical and inexpensive catalytic system which has a switchable selectivity towards cyclotrimerization and dimerization reactions. Best results in means of regioselectivity and yield were observed by using arylacetylene derivatives in these reactions. This catalytic system emerges as an economical method for the transformation of arylacetylenes to corresponding enyne and arene derivatives in excellent yields and selectivity.
- ?ztürk, Bengi ?zgün,Karabulut, Solmaz,Imamoglu, Yavuz
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experimental part
p. 214 - 222
(2012/09/08)
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- Zirconium catalyzed alkyne dimerization for selective Z-enyne synthesis
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The regioselective head-to-head dimerization of alkynes is catalyzed by a dibenzyl tethered bis(ureate) zirconium precatalyst with aniline as an additive. This system also gives outstanding stereoselectivity to furnish Z-enynes in high yields. A dinuclear
- Platel, Rachel H.,Schafer, Laurel L.
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supporting information
p. 10609 - 10611,3
(2020/09/02)
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- Rh- and Ru-complex-catalyzed dimerization of arylethynes Rylethynes in aqueous environment
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Complexes [RhCl(PPh3)3] and [Ru(CHPh)Cl 2(PCy3)2] efficiently catalyzed the dimerization of arylethynes to the corresponding 1,4-substituted enynes in aqueous environment in the presence of sodium dodecyl sulfate. The Rh catalyst exhibited almost exclusive preference for the formation of £-isomers, the Ru one exhibits strong preference for the formation of Z-isomers.
- Novak, Petr,Kotora, Martin
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experimental part
p. 433 - 442
(2009/07/17)
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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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- Rare-earth silylamide-catalyzed selective dimerization of terminal alkynes and subsequent hydrophosphination in one pot
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Rare-earth silylamides, Ln[N(SiMe3)2]3 (Ln = Y, La, Sm), catalyzed regio- and stereoselective dimerization of terminal alkynes in the presence of amine additives to give conjugated enynes in high yields. The additives play
- Komeyama, Kimihiro,Kawabata, Tomonori,Takehira, Katsuomi,Takaki, Ken
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p. 7260 - 7266
(2007/10/03)
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- Novel regio- and stereoselective dimerization of terminal alkynes catalyzed by rare-earth silylamide
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Rare-earth silylamide complex, Y[N(SiMe3)2] 3, was found to exhibit good catalyst activities for regio- and stereoselective dimerization of terminal aliphatic and aromatic alkynes in the presence of amine additives. Thus,
- Komeyama, Kimihiro,Takehira, Katsuomi,Takaki, Ken
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p. 1062 - 1066
(2007/10/03)
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- Dimerization of terminal alkynes catalyzed by indenyl ruthenium(II) complexes
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The indenyl ruthenium complexes [Ru(η5-C9H7)X(dppm)] (X=H, 1; C?CPh, 2; (E)-CH=CHPh, 3), [Ru(η5-C9H7)X(PPh3)2] (X=H, 4; C?CPh, 5), [Ru(η5-C9Hsub
- Bassetti, Mauro,Marini, Silvia,Tortorella, Francesco,Cadierno, Victorio,Díez, Josefina,Gamasa, M. Pilar,Gimeno, José
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p. 292 - 298
(2007/10/03)
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