370-99-0Relevant articles and documents
Solvent and base dependence of copper-free palladium-catalyzed cross-couplings between terminal alkynes and arylic iodides: Development of efficient conditions for the construction of gold(III)/free-base porphyrin dimers
Ljungdahl, Thomas,Pettersson, Karin,Albinsson, Bo,Martensson, Jerker
, p. 1677 - 1687 (2006)
In this paper, our attempts to optimize the Heck alkynylation (copper-free Sonogashira) reaction are presented. An efficient copper-free coupling protocol was needed for the synthesis of gold/zinc porphyrin dimers because previous methods had failed. Prev
Estimation of the Fraction of Spin-Correlated Radical Ion Pairs in Irradiated Alkanes using Magnetosensitive Recombination Luminescence from Exciplexes Generated upon Recombination of a Probe Pair
Melnikov, Anatoly R.,Verkhovlyuk, Vladimir N.,Kalneus, Evgeny V.,Korolev, Valeri V.,Borovkov, Vsevolod I.,Sherin, Peter S.,Davydova, Maria P.,Vasilevsky, Sergei F.,Stass, Dmitri V.
, p. 239 - 267 (2017)
We suggest a convenient probe exciplex system for studies in radiation spin chemistry based on a novel acceptor-substituted diphenylacetylene, 1-(phenylethynyl)-4-(trifluoromethyl)benzene that has a very short fluorescence lifetime (a shifted to red exciplex emission band as compared to the parent system DMA-diphenylacetylene. After chemical, luminescent, radiation and spin-chemical characterization of the new system we used the magnitude of magnetic field effect in its exciplex emission band for experimental estimation of the fraction of spin-correlated radical ion pairs under X-irradiation with upper energy cutoff 40 keV in a set of 11 alkanes. For linear and branched alkanes magnetic field effects and the corresponding fractions are approximately 19-20% and 0.28, while for cyclic alkanes they are lower at 16-17% and 0.22, respectively.
On the catalytic cycle of the palladium-catalyzed cross-coupling reaction of alkynylstannane with aryl iodide
Shirakawa, Eiji,Yoshida, Hiroto,Hiyama, Tamejiro
, p. 5177 - 5180 (1997)
The coupling reaction of phenylethynyltributyltin with (4-trifluoromethyl)iodobenzene catalyzed by a Pd(0) complex coordinated by N-(2-diphenylphosphinobenzylidene)-2-phenylethylamine was found to start with oxidative addition of the tin reagent to the Pd
Kinetic analysis of aqueous-phase Pd-catalyzed, Cu-free direct arylation of terminal alkynes using a hydrophilic ligand
Domier, Ria C.,Moore, Jane N.,Shaughnessy, Kevin H.,Hartman, Ryan L.
, p. 1262 - 1271 (2013)
The engineering of reaction mixtures that ensure the solubility of inorganic salt byproducts without compromising the reactivity is a grand challenge for continuous flow manufacturing in upstream pharmaceuticals and fine chemicals process development. Aqueous cross-coupling reactions are possible solutions. We report the study of an aqueous phase Pd-catalyzed Cu-free direct arylation of an alkyne using a hydrophilic ligand towards understanding the role of water on the cross-coupling kinetics. Kinetic analyses of theoretically estimated molar flux rates and the measured reaction kinetics reveal a transition from mass transfer to kinetically controlled deprotonation and carbopalladation mechanisms. Interfacial contact areas of immiscible aqueous-organic phases control the crossover from the mass-transfer-limited to the reaction-rate-limited regime. Highly agitated batch reactors and multiphase capillary flow reactors are needed to overcome the mass transport limitations and, thus, discover the transition from the apparent reaction kinetics to the true reaction kinetics. Comparison of previously reported Density Functional Theory calculations with experimentally measured activation energies, ranging from 14.8 to 20.0 kcal/mol, elucidates the theoretical possibility of designing the aqueous phase C-C cross-coupling reaction with similar reactivity as purely organic reactions. Although ambiguity remains concerning which reaction step is rate-determining in either the deprotonation or the carbopalladation mechanism, our discovery undergirds that one mechanism or the other could dominate in aqueous designed direct arylations.
Lipids as versatile solvents for chemical synthesis
Bayer, Annette,Gevorgyan, Ashot,Hopmann, Kathrin H.
supporting information, p. 7219 - 7227 (2021/09/28)
Development of safe, renewable, cheap and versatile solvents is a longstanding challenge in chemistry. We show here that vegetable oils and related systems can become prominent solvents for organic synthesis. Suzuki-Miyaura, Hiyama, Stille, Sonogashira and Heck cross-couplings proceed with quantitative yields in a range of vegetable oils, fish oil, butter and waxes used as solvents. Appropriate methodologies for high-throughput screening and sustainable isolation techniques applicable for vegetable oils and related lipids are presented.
Simple and efficient diaryl alkyne synthesis method
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Paragraph 0026; 0029-0031, (2021/04/14)
The embodiment of the invention discloses a simple and efficient diaryl alkyne synthesis method. The method comprises the steps of by taking arylmethylbenzotriazole and aromatic aldehyde as raw materials, carrying out addition and double-beta-elimination reaction under the action of bis (trimethylsilyl) amino salt MN (SiMe3) 2 to synthesize diaryl alkyne by a one-pot method. The raw materials and chemical reagents used in the method are easy to obtain, the reaction conditions are mild, the operation is simple, the substrate universality is good, the product yield is high, and the method is a simple and efficient diaryl alkyne synthesis method.
Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
supporting information, p. 15396 - 15405 (2021/10/12)
In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
Li, Qing-Han,Wu, Chuan
supporting information, (2021/08/25)
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or aryltitanium substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives.
Decarbonylative Sonogashira Cross-Coupling of Carboxylic Acids
Liu, Chengwei,Szostak, Michal
supporting information, p. 4726 - 4730 (2021/06/28)
Decarbonylative Sonogashira cross-coupling of carboxylic acids by palladium catalysis is presented. The carboxylic acid is activated in situ by the formation of a mixed anhydride and further decarbonylates using the Pd(OAc)2/Xantphos system to provide an aryl-Pd intermediate, which is intercepted by alkynes to access the traditional Pd(0)/(II) cycle using carboxylic acids as ubiquitous and orthogonal electrophilic cross-coupling partners. The methodology efficiently constructs new C(sp2)-C(sp) bonds and can be applied to the derivatization of pharmaceuticals. Mechanistic studies give support to decarbonylation preceding transmetalation in this process.
Facile one-pot synthesis of diarylacetylenes from arylaldehydes: Via an addition-double elimination process
Chen, Jianyang,Zhang, Xuan,Wu, Jiajun,Wang, Rui,Lei, Chunlin,An, Yanan
, p. 4701 - 4705 (2021/06/11)
A practical one-pot protocol has been developed to synthesize diarylacetylenes from arylaldehydes by treatment with 1-(arylmethyl)benzotriazoles and LiN(SiMe3)2. The reaction proceeded through imine formation, Mannich-type addition and double elimination to deliver products in up to 99% yields with broad substrate scope. In addition, gram-scale synthesis of 1-bromo-4-(phenylethynyl)benzene has been demonstrated.
