- Kinetics and Mechanistic Insights into the Acetate-Assisted Dimerization of Terminal Alkynes under Ruthenium- and Acid-Promoted (RAP) Catalysis
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The mechanism of the dimerization of terminal aryl alkynes promoted by [{RuCl(μ-Cl)(η6-p-cymene)}2](1)/AcOH, under cooperative transition metal/Br?nsted acid catalysis, has been investigated with regard to (i) the activation of the d
- Salvio, Riccardo,Juliá-Hernández, Francisco,Pisciottani, Luca,Mendoza-Mero?o, Rafael,García-Granda, Santiago,Bassetti, Mauro
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- Pseudo-tetrahedral Rhodium and Iridium Complexes: Catalytic Synthesis of E-Enynes
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The reactions of the rhodium(I) and iridium(I) complexes [M(PhBP3)(C2H4)(NCMe)] (PhBP3=PhB(CH2PPh2)3?) with alkynes have resulted in the synthesis of a new family of p
- Geer, Ana M.,Julián, Alejandro,López, José A.,Ciriano, Miguel A.,Tejel, Cristina
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- A facile regio- and stereocontrolled synthesis of (Z)-1,3- enylnylstannanes via cross coupling of (E)-α-iodovinylstannanes with terminal alkynes
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Conjugated enynes bearing a stannyl group were conveniently obtained under mild condition via the cross coupling of the corresponding (E)-α- iodovinylstannanes with terminal alkynes in the presence of Pd(PPh3)4 and CuBr.
- Huang, Xian,Zhong, Ping
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- Novel and general cross-coupling reactions of alkynylzinc reagents and organotellurium compounds
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The efficient cross-coupling reactions of different alkynyl organozinc reagents with unsaturated organotellurium species catalyzed by Pd(PPh3)4/CuI and using THF/DMF systems are described. These cross-coupling reactions are general and permit the formation of new sp-sp2 carbon-carbon bonds. New reactions to reach the necessary alkynylzinc intermediates were also developed from terminal alkynes or using acetylenic tellurides as starting materials.
- Dabdoub, Miguel J.,Dabdoub, Vania B.,Marino, Joseph P.
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- Solvent-free hydrosilylation of terminal alkynes by reaction with a nonclassical ruthenium hydride pincer complex
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Upon the simple addition of substrates, the ruthenium pincer complex [Ru(tBuPNP)(H2)(H)2] [1; tBuPNP = 2,6-bis(di-tert-butylphosphinomethyl) pyridine] is an active and selective catalyst system for the hydrosilylation of terminal alkyl alkynes under mild, solvent-free conditions. The reactivity of this system for other functionalized terminal alkynes was also investigated, and we observed competing catalytic cycles that produce both alkyne dimers and dehydrogenative silylation products. Kinetic measurements for the hydrosilylation of 1-octyne show that the catalyst has an initial turnover frequency of 121 h-1 at room temperature. The stoichiometric reaction between 1 and H2SiPh2 yields [Ru(tBuPNP)(H)2(H2SiPh2)], which undergoes Si-H bond activation to yield the catalytically active species [Ru(tBuPNP)-(HSiPh2)(H)]. The reaction of 1 with phenylacetylene yielded [Ru(tBuPNP)(H)2(HC≡CPh)] and [Ru(tBuPNP)(H)(C≡CPh)-(HC≡CPh)], and we propose that the latter is the active species in the dimerization reaction.
- Conifer, Christopher,Gunanathan, Chidambaram,Rinesch, Torsten,H?lscher, Markus,Leitner, Walter
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- Influence of the gegenion in the transmetalation reaction of vinylic tellurides with higher order cyanocuprates
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Dilithium cyanocuprates R2LCu(CN)Li2 (L=2-Th, Me) react with vinylic tellurides of Z configuration, RCH=CHTeR1 to give higher order vinylic cyanocuprates, [(RCH=CH)LCu(CN)Li2]. By changing the gegenion from lithium to magnesium [R2LCu(CN)LiMgBr or R2LCu(CN)(MgBr)2] the reaction gives cross - coupling products of Z configuration, RCH=CHR2 in good yields.
- Chieffi, Andre,Comasseto, Joao V.
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- Freedom: A copper-free, oxidant-free and solvent-free palladium catalysed homocoupling reaction
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Herein, we describe a copper-free, oxidant-free, solvent-free homocoupling reaction using a palladium catalyst under mechanochemical conditions. We extended the methodology to palladium catalyst on solid support which showed a different reactivity and different product ratios from the non-supported catalyst. We were able to recycle the polymer supported catalyst for 5 cycles.
- Chen, Longrui,Lemma, Betsegaw E.,Rich, Jenna S.,Mack, James
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- An unprecedented iridium(III) catalyst for stereoselective dimerisation of terminal alkynes
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A novel iridium(III) hydride complex, IrHCl(TIMP3) (HTIMP 3, = tris[1 -(diphenylphosphino)-3-methyl-1 H-indol-2-yl]methane) was prepared and fully characterized in both the solid state and in solution. Chloride abstraction by silver
- Ciclosi, Marco,Estevan, Francisco,Lahuerta, Pascual,Passarelli, Vincenzo,Perez-Prieto, Julia,Sanau, Mercedes
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- Pseudotetrahedral rhodium(I) complexes
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A combination of four-electron donors, such as alkynes, with strongly donating and strong-field scorpionate ligands is appropriate to create pseudotetrahedral rhodium(I) environments, as found in [Rh(PhBP 3)(HCi£CPh)], which promotes Hi-C bond
- Geer, Ana M.,Julian, Alejandro,Lopez, Jose A.,Ciriano, Miguel A.,Tejel, Cristina
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- Terminal Alkyne Coupling Reactions through a Ring: Mechanistic Insights and Regiochemical Switching
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The mechanism and selectivity of terminal alkyne coupling reactions promoted by rhodium(I) complexes of NHC-based CNC pincer ligands have been investigated. Synthetic and kinetic experiments support E- and gem-enyne formation through a common reaction seq
- Storey, Caroline M.,Gyton, Matthew R.,Andrew, Rhiann E.,Chaplin, Adrian B.
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- Herrmann-Beller phosphapalladacycle-catalyzed addition of alkynes to norbornadienes
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(Chemical Equation Presented) Herrmann-Beller (H-B) phosphapalladacycle selectively catalyzed the addition of terminal alkynes across one double bond of norbornadiene to afford exo5-alkynyl-bicyclo[2.2.1]hept-2-enes. The reaction shows general applicabili
- Tenaglia, Alphonse,Giordano, Laurent,Buono, Gerard
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- Bis(acetylacetonato)copper Catalyzed Cross-coupling Reaction of Alkenyldicyclohexylborane with 1-Bromo-1-alkyne or 3-Bromo-1-propene
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Bis(acetylacetonato)copper is capable of catalyzing cross-coupling reaction of alkenyldicyclohexylborane with 1-bromo-1-alkyne or 3-bromo-1-propene to give conjugated (E)-enzyme or (E)-1,4-diene in a highly stereoselective manner, respectively.
- Hoshi, Masayuki,Masuda, Yuzuru,Arase, Akira
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- Hydrocarboxylation of alkynes with formic acid over multifunctional ligand modified Pd-catalyst with co-catalytic effect
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Hydrocarboxylation of terminal alkynes with formic acid (FA) was accomplished over a multifunctional ligand (L2) modified Pd-catalyst, advantageous with 100% atom-economy, free use of CO and H2O, mild reaction conditions, and high yields (56–89%) of α,β-unsaturated carboxylic acids with 100% regioselectivity to the branched ones. The multifunctional ligand of L2 as a zwitterion salt containing the phosphino-fragment (-PPh2), Lewis acidic phosphonium cation and sulfonate group (-SO3?), was constructed on the skeleton of 1.1′-binaphthyl-2.2′-diphenyl phosphine (BINAP) upon selective quaternization by 1,3-propanesultone. It was found that L2 conferred to the Pd-catalyst the co-catalytic effect, wherein the phosphino-coordinated Pd-complex was responsible for activation of all the substrates (including CO, FA and alkyne), and the incorporated phosphonium cation was responsible for synergetic activation of FA. The 1H NMR spectroscopic analysis supported that FA was truly activated by the incorporated Lewis acidic phosphonium cation in L2 via “acid-base pair” interaction. The in situ FT-IR spectra demonstrated that, the presence of Ac2O and NaOAc additives in the catalytic amount could dramatically promote the in situ release of CO from FA, which was required to initiate the hydrocarboxylation.
- Chen, Xiao-Chao,Guo, Lin,Liu, Lei,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Xiao-Li
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p. 322 - 332
(2022/01/06)
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- Synthesis of Substituted Thiophenes through Dehydration and Heterocyclization of Alkynols
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A protocol was described for obtaining a variety of substituted thiophenes with functional potential via metal-free dehydration and sulfur cyclization of alkynols with elemental sulfur (S8) or EtOCS2K in moderate-to-good yields. The method provides the base-free generation of a trisulfur radical anion (S3?-) and its addition to alkynes as an initiator. This research broadens the applications of S3?-in the synthesis of sulfur-containing heterocycles.
- Chen, Lu,Chen, Zebin,Huang, Yubing,Ji, Xiaoliang,Li, Jiaming,Li, Jian,Li, Yibiao,Liu, Qiang,Liu, Yang
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supporting information
p. 3555 - 3566
(2022/03/14)
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- Metal-Ligand Cooperative Proton Transfer as an Efficient Trigger for Rhodium-NHC-Pyridonato Catalyzed gem-Specific Alkyne Dimerization
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The mononuclear square-planar Rh{κ2-X,N-(Xpy)}(η2-coe)(IPr) (X = O, NH, NMe, S) complexes have been synthesized from the dinuclear precursor [Rh(μ-Cl)(IPr)( η2-coe)]2 and the corresponding 2-heteroatom-pyridinate salts. The Rh-NHC-pyridinato derivatives a
- Galiana-Cameo, María,Urriolabeitia, Asier,Barrenas, Eduardo,Passarelli, Vincenzo,Pérez-Torrente, Jesús J.,Di Giuseppe, Andrea,Polo, Víctor,Castarlenas, Ricardo
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p. 7553 - 7567
(2021/06/30)
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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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- Stereo- A nd regioselective dimerization of alkynes to enynes by bimetallic syn-carbopalladation
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Enynes are important motifs in bioactive compounds. They can be synthesized by alkynea'alkyne couplings for which a number of mechanisms have been suggested depending on catalyst type and dominant product isomers. Regarding bimetallic pathways, hydrometalations and anti-carbopalladations have been discussed to account for the formation of geminally substituted and (Z)-configured enynes, respectively. Here we report a bimetallic alkynea'alkyne coupling that yields (E)-configured enynes. An unusual type of acetylide Pd bridging was found in putative catalytic intermediates which is arguably responsible for the regio- A nd stereochemical reaction outcome. Mechanistic studies suggest that a double μa'κ:η2 acetylide bridging enables a bimetallic syn-carbometalation. Interestingly, depending on the reaction conditions, it is also possible to form the geminal regioisomer as major product with the same catalyst. This regiodivergent outcome is explained by bi-versus monometallic reaction pathways.
- Pfeffer, Camilla,Wannenmacher, Nick,Frey, Wolfgang,Peters, René
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p. 5496 - 5505
(2021/05/31)
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- Calix[4]trap: A Bioinspired Host Equipped with Dual Selection Mechanisms
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Regulation of recognition events evolving in time and space is vital for living organisms. During evolution, organisms have developed distinct and orthogonal mechanisms to achieve selective recognition, avoiding mutual interference. Although the merging of multiple selection mechanisms into a single artificial host may lead to a more adaptable recognition system with unparalleled selectivity, successful implementation of this strategy is rare. Inspired by the intriguing structures and recognition properties of two well-known biological ion binders - valinomycin and K+ channels - we herein report a series of hosts equipped with dual guest selection mechanisms. These hosts simultaneously possess a preorganized binding cavity and a confined ion translocation tunnel, which are crucial to the record-setting K+/Na+ selectivity and versatile capabilities to discriminate against a wide range of ion pairs, such as K+/Rb+, K+/Ba2+, and Rb+/Cs+. Mechanistic studies verify that the host's portal is capable of discriminating cations by their size, enabling varied ion uptake rates. The confined tunnel bearing consecutive binding sites promotes complete desolvation of ions during their inclusion into the buried cavity, mimicking the ion translocation within ion channels. Our results demonstrate that the capability to manipulate guest recognition both in equilibrium and out-of-equilibrium states allows the host to effectively discriminate diverse guests via distinct mechanisms. The strategy to merge orthogonal selection mechanisms paves a new avenue to creating more robust hosts that may function in complex biological environments where many recognition events occur concurrently.
- Xu, Zhenchuang,Fang, Nie,Zhao, Yanchuan
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supporting information
p. 3162 - 3168
(2021/03/08)
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- Palladium-Catalyzed Modular and Enantioselective cis-Difunctionalization of 1,3-Enynes with Imines and Boronic Reagents
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Here we report that a palladium(0) complex can mediate the unprecedented intermolecular coupling reaction of 1,3-enynes and N-sulfonylimines regio- and stereoselectively, and the resultant palladium(II) species undergo a cascade Suzuki reaction with organ
- He, Qing,Zhu, Lei,Yang, Zhen-Hong,Zhu, Bo,Ouyang, Qin,Du, Wei,Chen, Ying-Chun
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supporting information
p. 17989 - 17994
(2021/11/10)
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- Variation on the π-Acceptor Ligand within a RhI?N-Heterocyclic Carbene Framework: Divergent Catalytic Outcomes for Phenylacetylene-Methanol Transformations
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A series of neutral and cationic rhodium complexes bearing IPr {IPr=1,3-bis-(2,6-diisopropylphenyl)imidazolin-2-carbene} and π-acceptor ligands are reported. Cationic species [Rh(η4-cod)(IPr)(NCCH3)]+ and [Rh(CO)(IPr)(L)2]+ (L=pyridine, CH3CN) were obtained by chlorido abstraction in suitable complexes, whereas the cod-CO derivative [Rh(η4-cod)(IPr)(CO)]+ was formed by the carbonylation of [Rh(η4-cod)(IPr)(NCCH3)]+. Alternatively, neutral derivatives of type RhCl(IPr)(L)2 {L=tBuNC or P(OMe)3} can be accessed from [Rh(μ-Cl)(η2-coe)(IPr)]2. In addition, the mononuclear species Rh(CN)(η4-cod)(IPr) was prepared by cyanide-chlorido anion exchange, which after carbonylation afforded the unusual trinuclear compound [Rh{1κC,2κN-(CN)}(CO)(IPr)]3. Divergent catalytic outcomes in the phenylacetylene-methanol transformations have been observed. Thus, enol ethers, arisen from hydroalkoxylation of the alkyne, were obtained with neutral Rh?CO catalyst precursors whereas dienol ethers were formed with cationic catalysts. Variable amounts of alkyne dimerization, cyclotrimerization or polymerization products were obtained in the absence of a strong π-acceptor ligand on the catalyst.
- Galiana-Cameo, María,Passarelli, Vincenzo,Pérez-Torrente, Jesús J.,Di Giuseppe, Andrea,Castarlenas, Ricardo
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p. 2947 - 2957
(2021/07/16)
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- Ru-catalyzed (E)-specific ortho-C-H alkenylation of arenecarboxylic acids by coupling with alkenyl bromides
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In the presence of [p-cymene)RuCl2]2, (E)-configured alkenyl bromides couple with aromatic carboxylates to form ortho-vinylbenzoic acids. This C-H vinylation proceeds in high yields without any activating phosphine ligands and has an excellent functional group tolerance. Starting from commonly available (E/Z)-mixtures of alkenyl bromides, (E)-configured vinyl arenes or dienes are formed exclusively. Mechanistic studies show that this selectivity is achieved because the (E)-configured alkenyl bromides undergo a smooth coupling, whereas the (Z)-isomers are rapidly eliminated with the formation of alkynes.
- Belitz, Florian,Goo?en, Lukas J.,Hu, Zhiyong,Papp, Florian,Zhang, Guodong
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supporting information
p. 3541 - 3545
(2021/05/31)
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- Regioselective Access to 3-Ethylideneflavanones via Rhodium(I)-Catalyzed 1,3-Enyne Hydroacylation/Annulation Cascades
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The highly efficient synthesis of 3-ethylideneflavanones through sequential rhodium(I)-catalyzed hydroacylation of terminal aryl-substituted 1,3-enynes with chelating aldehydes and annulation is described. This straightforward protocol highlights an unprecedented C3-regioselective hydroacylation of 1,3-enynes, excellent functional group compatibility, and complete atom economy. (Figure presented.).
- Chang, Zhi-Xin,Li, Fu-Rong,Xia, Chengcai,Li, Fei,Li, Hong-Shuang
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supporting information
p. 1722 - 1726
(2021/02/20)
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- Ruthenium-Catalyzed E-Selective Partial Hydrogenation of Alkynes under Transfer-Hydrogenation Conditions using Paraformaldehyde as Hydrogen Source
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E-alkenes were synthesized with up to 100 % E/Z selectivity via ruthenium-catalyzed partial hydrogenation of different aliphatic and aromatic alkynes under transfer-hydrogenation conditions. Paraformaldehyde as a safe, cheap and easily available solid hydrogen carrier was used for the first time as hydrogen source in the presence of water for transfer-hydrogenation of alkynes. Optimization reactions showed the best results for the commercially available binuclear [Ru(p-cymene)Cl2]2 complex as pre-catalyst in combination with 2,2-bis(diphenylphosphino)-1,1-binaphthyl (BINAP) as ligand (1 : 1 ratio per Ru monomer to ligand). Mechanistic investigations showed that the origin of E-selectivity in this reaction is the fast Z to E isomerization of the formed alkenes. Mild reaction conditions plus the use of cheap, easily available and safe materials as well as simple setup and inexpensive catalyst turn this protocol into a feasible and promising stereo complementary procedure to the well-known Z-selective Lindlar reduction in late-stage syntheses. This procedure can also be used for the production of deuterated alkenes simply using d2-paraformaldehyde and D2O mixtures.
- Fetzer, Marcus N. A.,Tavakoli, Ghazal,Klein, Axel,Prechtl, Martin H. G.
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p. 1317 - 1325
(2021/02/11)
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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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- Palladium-catalyzed decarbonylative sonogashira coupling of terminal alkynes with carboxylic acids
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A direct decarbonylative Sonogashira coupling of terminal alkynes with carboxylic acids was achieved through palladium catalysis. This reaction did not use overstoichiometric oxidants, thus overcoming the homocoupling issue of terminal alkynes. Under the reaction conditions, a wide range of carboxylic acids including those bioactive ones could couple readily with various terminal alkynes, thus providing a relative general method for preparing internal alkynes.
- Chen, Tieqiao,Huang, Tianzeng,Li, Chunya,Li, Wenhui,Li, Xinyi,Li, Zhaohui,Liu, Long,Tang, Zhi,Zhang, Tao
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supporting information
p. 3304 - 3309
(2021/05/31)
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- Manganese-catalysed divergent silylation of alkenes
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Transition-metal-catalysed, redox-neutral dehydrosilylation of alkenes is a long-standing challenge in organic synthesis, with current methods suffering from low selectivity and narrow scope. In this study, we report a general and simple method for the manganese-catalysed dehydrosilylation and hydrosilylation of alkenes, with Mn2(CO)10 as a catalyst precursor, by using a ligand-tuned metalloradical reactivity strategy. This enables versatility and controllable selectivity with a 1:1 ratio of alkenes and silanes, and the synthetic robustness and practicality of this method are demonstrated using complex alkenes and light olefins. The selectivity of the reaction has been studied using density functional theory calculations, showing the use of an iPrPNP ligand to favour dehydrosilylation, while a JackiePhos ligand favours hydrosilylation. The reaction is redox-neutral and atom-economical, exhibits a broad substrate scope and excellent functional group tolerance, and is suitable for various synthetic applications on a gram scale. [Figure not available: see fulltext.].
- Dong, Jie,Yuan, Xiang-Ai,Yan, Zhongfei,Mu, Liying,Ma, Junyang,Zhu, Chengjian,Xie, Jin
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p. 182 - 190
(2020/12/17)
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- Rhodium(I)-NHC Complexes Bearing Bidentate Bis-Heteroatomic Acidato Ligands as gem-Selective Catalysts for Alkyne Dimerization
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A series of Rh(κ2-BHetA)(η2-coe)(IPr) complexes bearing 1,3-bis-hetereoatomic acidato ligands (BHetA) including carboxylato (O,O), thioacetato (O,S), amidato (O,N), thioamidato (N,S), and amidinato (N,N), have been prepared by reacti
- Galiana-Cameo, María,Borraz, Marina,Zelenkova, Yaroslava,Passarelli, Vincenzo,Lahoz, Fernando J.,Pérez-Torrente, Jesús J.,Oro, Luis A.,Di Giuseppe, Andrea,Castarlenas, Ricardo
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supporting information
p. 9598 - 9608
(2020/07/13)
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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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- Bulky Diphosphine Acetate Ruthenium Complexes: Synthesis and Catalytic Activity in Ketone Transfer Hydrogenation and Alkyne Dimerization
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Several mononuclear ruthenium complexes containing bulky diphosphines have been easily prepared from acetate ruthenium precursors. The cyclohexyl complex [Ru(n 2-OAc)2(DCyPF)] (1-cy; DCyPF = 1,1′-bis(dicyclohexylphosphino)ferrocene) is synthesized from [R
- Ballico, Maurizio,Zuccaccia, Daniele,Figliolia, Rosario,Baratta, Walter
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p. 3180 - 3193
(2020/09/15)
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- Z-Selective Alkyne Functionalization Catalyzed by a trans-Dihydride N-Heterocyclic Carbene (NHC) Iron Complex
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The Z-selective functionalization of terminal alkynes is a useful transformation in organic chemistry and mainly catalyzed by noble metals. Here, we present the Z-selective hydroboration of terminal alkynes catalyzed by a stable trans-dihydride iron compl
- De Ruiter, Graham,Fridman, Natalia,Garhwal, Subhash
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supporting information
p. 13817 - 13821
(2020/10/09)
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- Diorganyl tellurides as substrates in Sonogashira coupling reactions under mild conditions
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A new method of Sonogashira coupling reactions between diorganyl tellurides and terminal alkynes is reported. The coupling reactions are performed using Pd(dppf)Cl2 as a catalyst, CuI as a co-catalyst in the presence of K2CO3 in DMSO. The reactions are carried out at room temperature and completed within 2 h when phenyl acetylene is used as a terminal alkyne. For aliphatic terminal alkynes, such as 1-hexyne and 1-octyne, an elevated temperature and longer reaction time are needed for the completion of the reactions. This process results in good yields of Sonogashira coupling products which is applicable for diaryl, divinyl and dialkynyl tellurides but not applicable for dialkyl tellurides.
- Zhang, Shaozhong,Ailneni, Chandra,Al-Mohammed Baqer, Osamah,Lolla, Mahati,Mannava, Bala Bharathi,Siraswal, Parvinlal,Yen, Changchi,Jin, Jin
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supporting information
p. 217 - 225
(2019/11/22)
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- Ruthenium-Catalyzed trans-Hydroalkynylation and trans-Chloroalkynylation of Internal Alkynes
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[Cp*RuCl]4 catalyzes the addition of iPr3SiCCX (X = H, Cl) across internal alkynes with formation of 1,3-enyne or 1-chloro-1,3-enyne derivatives, respectively; the reaction follows an unorthodox trans-addition mode. The well-balanced affinities of the different reaction partners to the ruthenium catalyst ensure that crossed addition prevails over homodimerization of the individual components, as can be deduced from spectroscopic and crystallographic data of various intermediates; this includes a dinuclear complex in which an internal alkyne bridges two [Cp*RuCl] fragments.
- Barsu, Nagaraju,Leutzsch, Markus,Fürstner, Alois
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supporting information
p. 18746 - 18752
(2020/11/13)
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- Transition-metal-free variant of Glaser- and Cadiot-Chodkiewicz-type Coupling: Benign access to diverse 1,3-diynes and related molecules
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Efficient and transition-metal-free transformations towards the synthesis of 1,3-diynes have been described from their corresponding terminal acetylenes or 1,1-dibromo-1-alkenes. The efficiency of molecular iodine as catalyst in aqueous medium, driven the transformation to afford 1,3-diynes in moderate to good yields. The developed reaction conditions revealed appreciable functional group tolerance in aqueous medium. Further, the scope of the transition-metal-free approach for the synthesis of 1,3-enynes has been investigated using terminal alkynes as easy available precursors.
- Kaldhi, Dhananjaya,Vodnala, Nagaraju,Gujjarappa, Raghuram,Kabi, Arup K.,Nayak, Subhashree,Malakar, Chandi C.
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supporting information
(2020/03/13)
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- Coordination chemistry of H-spirophosphorane ligands towards pentacarbonylchlororhenium(I) – synthesis, structure and catalytic activity of complexes
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Synthesis of a group of carbonyl rhenium coordination compounds with hydrospirophosphorane ligands was carried out and described. Different symmetrical HP(OCH2CH2NH)2L1, HP(OCH2CMe2NH)2L2,
- Skar?yńska, Anna,Siczek, Mi?osz,Gawryszewska, Paula,Chaczko, Karolina
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- Pd-Senphos Catalyzed trans-Selective Cyanoboration of 1,3-Enynes
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The first trans-selective cyanoboration reaction of an alkyne, specifically a 1,3-enyne, is described. The reported palladium-catalyzed cyanoboration of 1,3-enynes is site-, regio-, and diastereoselective, and is uniquely enabled by the 1,4-azaborine-based Senphos ligand structure. Tetra-substituted alkenyl nitriles are obtained providing useful boron-dienenitrile building blocks that can be further functionalized. The utility of our method has been demonstrated with the synthesis of Satigrel, an anti-platelet aggregating agent.
- Li, Bo,Liu, Shih-Yuan,Zhang, Yuanzhe
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supporting information
p. 15928 - 15932
(2020/07/24)
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- Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
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Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.
- Chen, Qiang,Fu, Liyan,Nishihara, Yasushi
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supporting information
p. 7977 - 7980
(2020/09/09)
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- Nickel-Catalyzed Allylmethylation of Alkynes with Allylic Alcohols and AlMe3: Facile Access to Skipped Dienes and Trienes
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We present herein an unprecedented allylative dicarbofunctionalization of alkynes with allylic alcohols. This simple catalytic procedure utilizes commercially available Ni(COD)2, triphenylphosphine, and inexpensive reagents, and delivers valuable skipped dienes and trienes with an all-carbon tetrasubstituted alkene unit in a highly stereoselective fashion. Preliminary mechanistic studies support the reaction pathway of allylnickelation followed by transmetalation in this dicarbofunctionalization of alkynes.
- Li, Jincan,Li, Wanfang,Yu, Shun,Zhao, Yu
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supporting information
p. 14404 - 14408
(2020/07/04)
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- Terminal Phosphido Complexes of the Ru(n5-Cp?) Fragment
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In situ generation of the five-coordinate complex Ru(n5-Cp?)(PR2)(PPh3) (2), via dehydrohalogenation of Ru(n5-Cp?)Cl(PR2H)(PPh3), has allowed its reactivity toward a range of small molecules to be compared with that of its well-studied analogue Ru(n5-indenyl)(PR2)(PPh3) (1), in a study designed to assess the likelihood of variable hapticity in the chemistry of complex 1. Reactions of 2 with hydrogen, carbon monoxide, phenylacetylene, ethylene, acrylonitrile, and 1-hexene demonstrate enhanced nucleophilicity/basicity of the terminal phosphido ligand in 2 relative to that in complex 1. Complex 2 also exhibits greater lability of the PPh3 ligand, leading to substitutional product mixtures that were not observed for 1. Both of these features are consistent with the more electron-rich and sterically imposing nature of the Cp? ligand in 2 relative to the indenyl ligand in 1. Nevertheless, the fundamental transformations of the phosphido ligand are comparable for the two complexes. This suggests that variable hapticity does not play a role in reactions of indenyl complex 1, since n5-n3 shifts are unlikely to occur for Cp? complex 2. The implications of these reactivity studies for the design of highly active, yet stable, ruthenium half-sandwich catalysts for hydrophosphination are discussed.
- Yang, Jin,Langis-Barsetti, Sophie,Parkin, Hayley C.,McDonald, Robert,Rosenberg, Lisa
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- A K-arylacetylide complex for catalytic terminal alkyne functionalization using KO: TBu as a precatalyst
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Herein we report a transition metal free catalytic terminal alkyne functionalization across the C-X triple bond (X = CH and N) with E-selective homo (alkyne-alkyne) and head-to-tail selective hetero (alkyne-nitrile) dimerization. A series of stoichiometric reactions enabled us to crystallize a reactive organometallic intermediate K-arylacetylide complex which was characterized by X-ray crystallography, indicating that an ionic mechanism is operative.
- Ahmed, Jasimuddin,Swain, Asim Kumar,Das, Arpan,Govindarajan,Bhunia, Mrinal,Mandal, Swadhin K.
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supporting information
p. 13860 - 13863
(2019/11/21)
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- Cobalt-Catalyzed Regio- and Stereoselective Hydrosilylation of 1,3-Diynes to Access Silyl-Functionalized 1,3-Enynes
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A regio- and stereoselective hydrosilylation of 1,3-diynes has been developed relying on catalysts generated from bench-stable Co(acac)2 and dppp ligand. A variety of symmetrical and unsymmetrical 1,3-diynes undergo this transformation, yieldin
- Sang, Hui Leng,Hu, Yongyi,Ge, Shaozhong
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p. 5234 - 5237
(2019/07/04)
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- Carboxylic acid addition to terminal alkynes utilizing ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica: A highly reusable and air compatible catalytic system
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In this study, the performance of ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica gel was tested on carboxylic acid addition reactions to terminal alkynes using a variety of carboxylic acid derivatives under air atmosphere. The catalytic system was found to be compatible with air atmosphere and can tolerate even non-degassed solvents. The reaction parameters such as temperature, substrate/catalyst ratio and the effect of carboxylic acid on the selectivity and yield of the reaction were investigated in details. The reaction of arylacetylenes with acetic acid yielded the corresponding E-isomer with conversion values up to 99% with a catalytic loading of 1% Ru. The reusability of the catalyst was tested using acetic acid/benzoic acid and phenylacetylene in toluene at 85 °C under air atmosphere. The catalyst was found to be highly reusable and maintained its activity up to 11th run, reaching a conversion value of 83% with minimum ruthenium leaching.
- ?ztürk, Bengi ?zgün,Gürcü, Didar,?ehito?lu, Solmaz Karabulut
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- The photoisomerization of: Cis, trans -1,2-dideuterio-1,4-diphenyl-1,3-butadiene in solution. No bicycle-pedal
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cis,trans-1,2-Dideuterio-1,4-diphenyl-1,3-butadiene (ct-DPBd2) was synthesized and its cis-trans photoisomerization in cyclohexane-d12 (C6D12) at room temperature was monitored by 1H NMR spectroscopy. The results reveal formation of only trans,trans-1,2-dideuterio-1,4-diphenyl-1,3-butadiene (tt-DPBd2). The failure to detect formation of trans,cis-1,2-dideuterio-1,4-diphenyl-1,3-butadiene (tc-DPBd2) eliminates the possibility that an identity bicycle pedal process contributes to inefficiency in the cis-trans photoisomerization of cis,trans-1,4-diphenyl-1,3-butadiene (ct-DPB).
- Saltiel, Jack,Redwood, Christopher E.,Ratheesh Kumar
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p. 2174 - 2179
(2019/09/18)
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- Dihalogen-bridged NHC-palladium(i) dimers: Synthesis, characterisation and applications in cross-coupling reactions
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A di-iodo-bridged PdI dimer bearing an N-heterocyclic carbene ligand was made accessible via the reduction of [(IPr)PdI2]2 in basic methanol solution. The structural features of [(IPr)PdI]2 were explored by single-crystal X-ray analysis. It was found to be a convenient one-component precatalyst with high activity in Suzuki-Miyaura, Buchwald-Hartwig, and Sonogashira reactions.
- Pirkl, Nico,Del Grosso, Alessandro,Mallick, Bert,Doppiu, Angelino,Goo?en, Lukas J.
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supporting information
p. 5275 - 5278
(2019/05/08)
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- Photochemical Cobalt-Catalyzed Hydroalkynylation to Form 1,3-Enynes
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A photochemical hydroalkynylation is reported employing a metallaphotoredox approach using cobalt catalysis and an organic dye, 4CzIPN. The protocol enables catalysis without the need for stoichiometric metal reductants, normally needed to convert higher
- Grenier-Petel, Jean-Christophe,Collins, Shawn K.
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p. 3213 - 3218
(2019/04/13)
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- Sequential Transformation of Terminal Alkynes to 1,3-Dienes by a Cooperative Cobalt Pyridonate Catalyst
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We describe the cobalt(II) catalyst 1 bearing a phosphinopyridonate ligand for sequential transformation of aryl terminal alkynes to (E,Z)-1,3-dienes with excellent stereoselectivity. By cooperative metal-ligand reactivity, 1 reacts readily with the termi
- Zhuang, Xuewen,Chen, Jia-Yi,Yang, Zhuoyi,Jia, Mengjing,Wu, Chengjuan,Liao, Rong-Zhen,Tung, Chen-Ho,Wang, Wenguang
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supporting information
p. 3752 - 3759
(2019/11/13)
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- Regio- and Stereoselective Synthesis of 2-Hydroxymethyl-1,3-enynes by Rhodium-Catalyzed Decarboxylative C?C Coupling
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A regio- and stereoselective protocol for rhodium(I)-catalyzed decarboxylative C?C coupling between propiolic acids and propargyl alcohols has been achieved. This efficient catalytic approach could facilitate the preparation of a diversity of synthetically valuable 2-hydroxymethyl-1,3-enynes with high Z-stereoselectivity. Notably, non-terminal alkynes were smoothly transformed into the target products that show intriguing synthetic utility. (Figure presented.).
- Lu, Shi-Chao,Chang, Zhi-Xin,Xiao, Yu-Liang,Li, Hong-Shuang
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supporting information
p. 4831 - 4836
(2019/10/28)
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- A polystyrene supported [PdCl-(SeCSe)] complex: A novel, reusable and robust heterogeneous catalyst for the Sonogashira synthesis of 1,2-disubstituted alkynes and 1,3-enynes
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3,5-Bis((phenylselanyl)methyl)phenol has been synthesized as a novel SeCSe pincer type pre-ligand from commercially available 5-hydroxy isophthalic acid through a multistep synthesis. Then, a polystyrene-supported SeCSe pincer ligand and its corresponding palladium complex were prepared and characterized using different techniques including FT-IR, SEM/EDX, TG/DTG, and XPS. The amount of palladium incorporated into the polymer matrix as determined by ICP analysis was obtained to be 3.64 wt% (0.34 mmol g-1). The PS[PdCl-SeCSe] catalytic activity has been evaluated in the Sonogashira coupling of diverse aryl halides with aromatic and aliphatic terminal alkynes. It was also noted that less reactive and inexpensive aryl bromides and aryl chlorides have been successfully cross-coupled with terminal alkynes using low catalyst loading. Moreover, the developed methodology is effective for the stereoselective preparation of substituted 1,3-enynes.
- Mohammadi, Elmira,Movassagh, Barahman
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supporting information
p. 11471 - 11479
(2018/07/25)
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- One-Pot Conversion of Aldehydes and Ketones into 1-Substituted and 1,4-Disubstituted 1,3-Enynes
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Sequential treatment of 2,3-dichloropropene with magnesium and n -BuLi generates the operational equivalent of 1,3-dilithiopropyne, which upon treatment with aldehydes or ketones, produces the corresponding alkoxy lithium acetylide intermediates. Reaction of this alkoxide with tosyl chloride, and t -BuLi produces 1-substituted, or 1,1-disubstituted 1,3-enynes in a one-pot reaction. When this lithium acetylide intermediates, obtained by this procedure, were used to perform palladium-catalyzed cross-coupling reactions, followed by addition of thionyl chloride and pyridine, 1,4-disubstituted or 1,1,4-trisubstituted 1,3-enynes were obtained in a one-pot protocol.
- Cabezas, Jorge A.,Poveda, Rebeca R.,Brenes, José A.
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p. 3307 - 3321
(2018/09/04)
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- Enol Ester Synthesis via Cobalt-Catalyzed Regio- and Stereoselective Addition of Carboxylic Acids to Alkynes
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A cobalt-catalyzed highly regio- and stereoselective hydro-oxycarbonylation of alkynes is reported. Both terminal and internal alkynes can react with carboxylic acids to afford enol esters in high yields. The catalyst generated from Co(BF4)2, tridentate phosphine ligand L5, and zinc in situ exhibits much higher reactivity than the corresponding cobalt/diphosphine complex.
- Chen, Jia-Feng,Li, Changkun
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supporting information
p. 6719 - 6724
(2018/11/21)
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- Selective dimerization of terminal acetylenes in the presence of PEPPSI precatalysts and relative chloro- and hydroxo-bridged N-heterocyclic carbene palladium dimers
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Highly regio- and stereoselective dimerization of terminal acetylenes occurs in the presence of [PdCl2(IPr)(3-chloropyridine)], other members of the family of PEPPSI precatalysts and the structurally related N-heterocyclic carbene palladium dim
- Ostrowska, Sylwia,Szymaszek, Natalia,Pietraszuk, Cezary
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- 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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p. 419 - 428
(2016/12/16)
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- A copper (I or II)/diethylphosphite catalytic system for base-free additive dimerization of alkynes
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Copper (I) or copper (II) salts and oxides promote regioselective head-to-head additive dimerization of aromatic and aliphatic terminal alkynes in the presence a catalytic amount of diethylphosphite. The reaction proceeds under ambient conditions without
- Trostyanskaya, Inna G.,Beletskaya, Irina P.
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supporting information
p. 148 - 153
(2016/12/23)
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- Synthesis and biological evaluation of the ascidian blood-pigment halocyamine A
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Synthesis of the antimicrobial marine natural product halocyamine A has been achieved utilizing a combination of Sonogashira coupling, ruthenium complex/ytterbium triflate catalyzed hydroamidation and solid-phase peptide synthesis (SPPS) chemistry. The sy
- Fong, Hugo K. H.,Brunel, Jean Michel,Longeon, Arlette,Bourguet-Kondracki, Marie-Lise,Barker, David,Copp, Brent R.
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p. 6194 - 6204
(2017/08/02)
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- Stable, Yet Highly Reactive Nonclassical Iron(II) Polyhydride Pincer Complexes: Z-Selective Dimerization and Hydroboration of Terminal Alkynes
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The synthesis, characterization, and catalytic activity of nonclassical iron(II) polyhydride complexes containing tridentate PNP pincer-type ligands is described. These compounds of the general formula [Fe(PNP)(H)2(η2-H2)]
- Gorgas, Nikolaus,Alves, Luis G.,St?ger, Berthold,Martins, Ana M.,Veiros, Luis F.,Kirchner, Karl
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supporting information
p. 8130 - 8133
(2017/06/27)
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- Copper(I)-catalyzed stereoselective hydrogenation of 1,3-diynes and enynes
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A stereoselective hydrogenation of 1,3-diynes with an air-stable copper(I)/N-heterocyclic carbene complex, [IPrCuOH], has been developed. The corresponding products, 1,3-dienes, are obtained in a stereoselective manner depending on their substitution pattern: Diaryl-diynes yield E,E-1,3-dienes, whereas dialkyl-diynes are converted to the corresponding Z,Z-1,3-dienes. Hydrogenation and deuteration experiments with enynes indicate that these are competent reaction intermediates in the hydrogenation of diynes.
- Thiel, Niklas O.,Kemper, Sebastian,Teichert, Johannes F.
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p. 5023 - 5028
(2017/07/27)
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- Synthesis, characterization and catalytic application of some novel PNP-Ni(II) complexes: Regio-selective [2+2+2] cycloaddition reaction of alkyne
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Some novel Ni(II) complexes of PN(H)PPh, PN(Me)PiPr and PN(Me)PtBu ligands have been synthesized and characterized using standard analytical and spectroscopic methods such as 1H NMR, 31P NMR, elemental analysis, ESI-MS, UV-Visible spectroscopy and single-crystal X-ray crystallography. In the presence of silver triflate, complex [PN(H)PPhNiBr]2NiBr4 (5) activated the C?Cl bond of dichloromethane at room temperature and afford complex [PN(H)PPhNiCl]OTf (6). We have also performed alkyne [2+2+2] cycloaddition reaction using Ni(II) complexes and observed high regioselectivity of the products. The observed selectivity is well correlating with the electronic feature of alkynes. The [2+2+2] cycloaddition of electron rich alkynes produced 1,3,5-substituted benzene derivatives as a major product whereas the electron deficient alkynes produced 1,2,4-substituted benzene derivatives as a major product.
- Tamizmani, Masilamani,Sivasankar, Chinnappan
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- Platinum Complexes Bearing Bulky N-Heterocyclic Carbene Ligands as Efficient Catalysts for the Fully Selective Dimerization of Terminal Alkynes
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New platinum(0) complexes of the general formula [(NHC)Pt(dvtms)] (dvtms=1,3-divinyltetramethyldisiloxane) containing bulky N-heterocyclic carbene (NHC) ligands were prepared, characterized, and found to be catalytically active in the fully regio- and ste
- ?ak, Patrycja,Bo?t, Ma?gorzata,Lorkowski, Jan,Kubicki, Maciej,Pietraszuk, Cezary
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p. 3627 - 3631
(2017/09/06)
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- Synthesis of α-pyrones by catalytic oxidative coupling of terminal alkynes and carbon dioxide
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The use of the complex [(dippe)Ni(μ-H)]2(1) as a catalyst precursor (10?mol%) in the presence of a variety of terminal alkynes and CO2allowed the production of substituted α–pyrones. This reaction occurs using relatively mild conditions (50?°C, 150 psi of CO2) with good to modest yields, depending on the nature of the substituents in the corresponding alkyne. The produced α–pyrones were characterized by different analytical methods and spectroscopic techniques.
- Oliveros-Cruz, Saray,Arévalo, Alma,García, Juventino J.
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- A rhodium(i)-oxygen adduct as a selective catalyst for one-pot sequential alkyne dimerization-hydrothiolation tandem reactions
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An air-stable rhodium(i)-oxygen adduct featuring a CNC-pincer ligand, based on 1,2,3-triazol-5-ylidenes, catalyzes the homo-dimerization and hydrothiolation of alkynes, affording the gem-enyne and α-vinyl sulfide isomers, respectively, with excellent selectivity. A one-pot stepwise strategy allows the selective catalytic preparation of non-symmetric bis-vinyl sulfides, as well as the alkyne dimerization-hydrothiolation tandem reactions.
- Kleinhans, George,Guisado-Barrios, Gregorio,Liles, David C.,Bertrand, Guy,Bezuidenhout, Daniela I.
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supporting information
p. 3504 - 3507
(2016/03/04)
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