- Intramolecular One-Carbon Homologation of Unstrained Ketones via C-C Activation-Enabled 1,1-Insertion of Alkenes
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Here, we describe the development of a Rh-catalyzed intramolecular one-carbon homologation of unstrained aryl ketones through a formal 1,1-insertion process of olefins, enabled by temporary directing group (TDG)-aided C-C activation. The reaction provides a distinct approach to access various substituted 1-indanones. Computational mechanistic studies reveal that the formal 1,1-insertion is realized by a selective C(sp2)-C(sp3) activation and turnover limiting 2,1-insertion into the alkene, followed by a facile β-H elimination and reinsertion process.
- Huang, Jiangkun,Zhang, Rui,Wu, Xiuli,Dong, Guangbin,Xia, Ying
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p. 2436 - 2440
(2022/04/07)
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- Zinc salt-catalyzed reduction of α-aryl imino esters, diketones and phenylacetylenes with water as hydrogen source
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The zinc salt-catalyzed reduction of α-aryl imino esters, diketones and phenylacetylenes with water as hydrogen source and zinc as reductant was successfully conducted. The presented method provides a low-cost, environmentally friendly and practical preparation of α-aryl amino esters, α-hydroxyketones and phenylethylenes. By using D2O as deuterium source, the corresponding products were obtained in high efficiency with excellent deuterium incorporation rate, which gives a cheap and safe tool for access to valuable deuterium-labelled compounds. This journal is
- Shen, Guoli,Liu, Haojie,Chen, Jingchao,He, Zhenxiu,Zhou, Yongyun,Wang, Lin,Luo, Yang,Su, Zhimin,Fan, Baomin
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supporting information
p. 3601 - 3610
(2021/05/04)
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- Rhodium-Catalyzed Hydrocarboxylation of Olefins with Carbon Dioxide
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The catalytic hydrocarboxylation of styrenes derivatives and α,β-unsaturated carbonyl compounds with CO2(101.3 kPa) in the presence of an air-stable rhodium catalyst was explored. The combination of [RhCl(cod)]2(cod = cyclooctadiene) as a catalyst and diethylzinc as a hydride source allowed for effective hydrocarboxylation and provided the corresponding α-aryl carboxylic acids in moderate to excellent yields. In this catalytic process with carbon dioxide, intervention of the RhI–H species, which could be generated from the RhIcatalyst and diethylzinc, was clarified. Significantly, the catalytic asymmetric hydrocarboxylation of α,β-unsaturated esters with carbon dioxide was also performed by employing a cationic rhodium complex possessing (S)-(–)-4,4′-bi-1,3-benzodioxole-5,5′-diylbis(diphenylphosphine) [(S)-SEGPHOS] as a chiral diphosphine ligand. A plausible model for asymmetric induction was proposed by determination of the absolute configuration of the product.
- Kawashima, Shingo,Aikawa, Kohsuke,Mikami, Koichi
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p. 3166 - 3170
(2016/07/19)
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- Dihydrobiphenylenes through ruthenium-catalyzed [2+2+2] cycloadditions of ortho-alkenylarylacetylenes with alkynes
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A new synthetic route to dihydrobiphenylenes has been developed. The process involves a mild RuII-catalyzed [2+2+2] dimerization of ortho-alkenylarylacetylenes or its more versatile variant, the Ru-catalyzed [2+2+2] cycloaddition of ortho-ethynylstyrenes with alkynes. Mechanistic aspects of this [2+2+2] cycloaddition are discussed. A new synthetic route to dihydrobiphenylenes involves a mild RuII-catalyzed [2+2+2] dimerization of ortho-alkenylarylacetylenes or its more versatile variant, the Ru-catalyzed [2+2+2] cycloaddition of ortho-ethynylstyrenes with alkynes. The mechanistic aspects of this [2+2+2] cycloaddition are also discussed. Copyright
- Garcia-Rubin, Silvia,Gonzalez-Rodriguez, Carlos,Garcia-Yebra, Cristina,Varela, Jesus A.,Esteruelas, Miguel A.,Saa, Carlos
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p. 1841 - 1844
(2014/03/21)
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- One-pot Suzuki/Heck sequence for the synthesis of (E)-stilbenes featuring a recyclable silica-supported palladium catalyst via a multi-component reaction in 1,3-propanediol
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The synthesis of (E)-stilbenes was performed following a one-pot Suzuki/Heck sequence through the use of potassium vinyltrifluoroborate. The combination of heterogeneous palladium/silica (Pd/SiO2) catalyst with potassium phosphate monohydrate (K3PO4?H 2O) as base resulted in useful to good isolated yields regardless of the ortho-, meta- or para-substitution of the aryl halides employed. In a sustainable approach, we found that bio-sourced 1,3- propanediol could advantageously replace N-methylpyrrolidone (NMP) as similar yields were obtained. Moreover, the reactivity gap between aryl iodides and bromides resulting from the use of 1,3-propanediol allowed an efficient multi-component approach toward the synthesis of (E)-stilbenes. Furthermore, this heterogeneous catalyst was found to be extremely robust despite the use of aerobic conditions and was successfully re-used over several cycles.
- Joucla, Lionel,Cusati, Giuseppe,Pinel, Catherine,Djakovitch, Laurent
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scheme or table
p. 1993 - 2001
(2010/10/20)
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- Low pressure vinylation of aryl and vinyl halides via Heck-Mizoroki reactions using ethylene
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Aryl bromides and iodides in the presence of catalytic amounts of a palladacycle derived from acetophenone oxime and 2 equiv of potassium acetate react with ethylene under ambient pressure (15-30 psi) to give the corresponding vinylarenes. The reactions work with both electron-deficient and electron-rich aryl compounds and tolerate wide variety of common functional groups. Vinyl bromides lead to 1,3-dienes in moderate yields.
- Smith, Craig R.,RajanBabu
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supporting information; experimental part
p. 1102 - 1110
(2010/03/25)
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- NOVEL PYRROLE DERIVATIVE HAVING UREIDE GROUP AND AMINOCARBONYL GROUP AS SUBSTITUENTS
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Objects of the present invention are to study on the synthesis of a novel pyrrole derivative having a ureido group and an aminocarbonyl group as substituents or a salt thereof, to find a pharmacological effect of the derivative or a salt thereof, and to f
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Page/Page column 36
(2009/12/05)
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- Acids direct 2-styrylcyclobutanone into two distinctly different reaction pathways
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(Chemical Equation Presented) Two structurally distinct carbocycles were selectively obtained by the reactions of 2-(o-styryl)cyclobutanones promoted by ytterbium salts. Treatment of the cyclobutanones with YbCl3 in 1,4-dioxane at 100°C afforde
- Murakami, Masahiro,Kadowaki, Sho,Fujimoto, Atsushi,Ishibashi, Mitsuru,Matsuda, Takanori
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p. 2059 - 2061
(2007/10/03)
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- Suzuki cross-coupling reactions between alkenylboronic acids and aryl bromides catalysed by a tetraphosphane-palladium catalyst
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A range of alkenylboronic acids undergo Suzuki cross-coupling with aryl bromides in good yields in the presence of [PdCl(C3H 5)]2/cis,cis,cis-1,2,3,4-tetrakis[(diphenylphosphanyl) methyl]cyclopentane as a catalyst. A wide variety of 1-arylprop-1-enes, 2-arylprop-1-enes, 2-arylbut-1-enes and 1,1-diarylethylene or styrene derivatives have been prepared. Moreover, the reaction tolerates several functions, such as acetyl, formyl, nitrile or nitro. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Peyroux, Eugenie,Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1075 - 1082
(2007/10/03)
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- Method for producing vinyl oxime-ethers
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In the process for the preparation of vinyloxime ethers of the formula I by reacting an oxime with an alkyne where R1and R2are identical or different and are alkyl or aryl radicals, R3is hydrogen, an alkyl or aryl radical,
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- Nickel-catalysed cross-coupling reactions of aryl halides with organostannanes
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A triphenylphosphine-nickel complex is found to be an active catalyst for the cross-coupling reactions of various types of aryl halides, including unactivated aryl chlorides, with alkynyl-, alkenyl- and allyl-stannanes to give the corresponding coupled products in high yields.
- Shirakawa, Eiji,Yamasaki, Kenji,Hiyama, Tamejiro
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p. 2449 - 2450
(2007/10/03)
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- Palladium Catalysis in Cephalosporin Chemistry: General Methodology for the Synthesis of Cephem Side Chains
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We describe in full the palladium-catalyzed coupling of 3-(triflyloxy)cephems with organotin compounds, leading to the synthesis of 3-alkenyl-, 3-alkynyl-, and 3-arylcephems under exceptionally mild conditions.While this approach was not satisfactory for
- Farina, Vittorio,Baker, Stephen R.,Benigni, Daniel A.,Hauck, Sheila I.,Sapino, Chester
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p. 5833 - 5847
(2007/10/02)
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