- Palladium-catalyzed reactions of aryl iodides with trimethylsilylacetylenes and disubstituted alkynes: The synthesis of diarylacetylenes and triarylethylenes
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Treatment of 2.5 equiv. of aryl iodide with trimethylsilylacetylene in the presence of 3 equiv. of sodium methoxide and 5 mol% of Pd(PPh3)4 under refluxing methanol for 6 h gave diarylacetylene in good chemical yields. When the catalyst was replaced by Pd(dba)2 and 5 equiv. of aryl iodide were added under the same reaction conditions, triarylethylenes were obtained in 70-85% yields. Only the sterically hindered o-methoxyiodobenzene and 2-iodothiophene gave the diarylacetylene, but also in good chemical yield. Reaction of aryl iodides with disubstituted alkynes in the presence of Pd(OAc)2 and sodium methoxide in methanol produced trisubstituted ethylenes in modest to good yields. The hydrogenolysis of the organopalladium is proposed through β-hydride elimination of the palladium methanolate intermediates.
- Wu, Ming-Jung,Wei, Li-Mei,Lin, Chi-Fong,Leou, Shiow-Piaw,Wei, Li-Lan
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Read Online
- Stereochemistry of the Vinylic SRN1 Reaction of Triarylvinyl Halides. the Structure of the Intermediate α-Arylvinyl Radical
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Evidence for the intermediacy of a vinyl radical in the vinylic SRN1 reaction (SRN1(V)) of 2-anisyl-1,2-diphenylvinyl bromide 2 is obtained. The photostimulated SRN!(V) reaction of pinacolone enolate ion with (E)-2 and (Z)-2, which are used as stereoindicators, gives complete loss of the original stereochemistry of the two precursors in the substituted and hydrodehalogenated products; i.e., stereoconvergence is found. It is concluded that in the reaction of 2 a -substituted a-phenylvinyl radical is a reactive intermediate and that it has either a linear structure or an average linear structure due to a rapidly interconverting E,Z mixture of bent radicals. This conclusion is supported by comparing the stereochemical course of the SRN1(V) reaction with those of other reactions of the same precursor, which unambiguously give rise to the same α-phenylvinyl radical intermediate by alternative mechanisms. Among the reactions investigated, the hydrodehalogenation of precursor 2 by LAH appears to take place by an ET mechanism.
- Galli, Carlo,Gentili, Patrizia,Guarnieri, Alessandra,Rappoport, Zvi
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Read Online
- The [(E,E,E)-1,6,11-tris(p-toluenesulfonyl)-1,6,11-triazacyclopentadeca-3,8, 13-triene]Pd(0) complex in the hydroarylation of alkynes in ionic liquids. An approach to quinolines
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The hydroarylation of alkynes can be successfully conducted in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) in the presence of the [(E,E,E)-1,6,11-tris(p-toluenesulfonyl)-1,6,11-triazacyclopentadeca-3,8, 13-triene]Pd(0) complex. Th
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Moreno-Ma?as, Marcial,Vallribera, Adelina
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Read Online
- Pd-Catalyzed Coupling of N-Tosylhydrazones with Benzylic Phosphates: Toward the Synthesis of Di- or Tri-Substituted Alkenes
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This study shows that various di- and tri-substituted alkenes with high chemoselectivity were obtained in good to high yields by coupling N-tosylhydrazones (NTHs) with benzylic phosphates as electrophilic partners. The obtained new catalytic system consis
- Zhang, Kena,Provot, Olivier,Alami, Mouad,Tran, Christine,Hamze, Abdallah
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p. 1249 - 1261
(2022/02/07)
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- One-pot Sonogashira–Hydroarylation reaction catalyzed by anionic palladium complexes in an aqueous medium
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It was found that anionic Pd(II) complexes of type [CA]2[PdCl4] and [CA]2[Pd2Cl6] (CA = imidazolium or pyridinium cation) are effective catalysts for copper-free Sonogashira coupling in an aqueous med
- Dziadas, M.,Trzeciak, A. M.,Wójcik, E.
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supporting information
(2022/01/26)
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- Oxime ligands for Pd catalysis of the Mizoroki–Heck reaction, Suzuki–Miyaura coupling & annulation reactions
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Monodentate and bidentate chelating oximes are readily available ligands for the Pd catalysis of the Mizoroki–Heck reaction and the Suzuki coupling. High yields were obtained in the Suzuki coupling in aqueous dioxane with TBABr as additive. The oximes can be easily synthesized from the corresponding ketones or aldehydes and thus provide a very large number of nitrogen-based ligands. They have the advantage of not undergoing oxidative degradation, common for phosphine ligands. Chelating oximes with Pd(OAc)2, activate aryl iodides to give high yields of the substitution products in the Mizoroki–Heck reactions as well as the Suzuki coupling. Acetophenone oxime ligand with Pd(OAc)2, catalyzed the reaction of aryl iodides with 1,2-disubstituted alkenes in moderate to high yields. As a test example, the LaRock indole annulation and synthesis of isocoumarin were achieved with acetophenone oxime ligand and Pd(OAc)2 in high yields.
- Bangar, Pronnoy G.,Nahide, Pradip D.,Meroliya, Heena K.,Waghmode, Shobha A.,Iyer, Suresh
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p. 308 - 316
(2020/10/06)
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- Polysubstituted ethylene compound as well as preparation method and application thereof
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The invention discloses a polysubstituted ethylene compound as well as a preparation method and application thereof. The invention particularly discloses a preparation method of a polysubstituted ethylene compound as shown in a formula III, which comprises the following step: in an organic solvent, carrying out reaction as shown in the specification on a compound as shown in a formula I and a compound as shown in a formula II in the presence of a palladium catalyst, a phosphine ligand and alkali to obtain the polysubstituted ethylene compound as shown in the formula III. The preparation methodcan be suitable for various types of substrates, and the configuration of double bonds is controllable.
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Paragraph 0125-0129; 0145-0149; 0200-0204
(2020/12/30)
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- Mizoroki–Heck reaction of 1,2-disubstituted aryl alkenes: Variables of synthesis, solvent and ligand modulation of reactivity
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Reaction of aryl iodides with 1,2-disubstituted aryl alkenes in the presence of TBABr/TBACl gave high yields of the Mizoroki–Heck product. Phosphine ligands were used for the modulation of reactivity and stereoselectivity, for the reaction of 4-iodoanisole with cinnamaldehyde. tert-Bu3P.HBF4 gave the highest E:Z ratio of 1:0.08. The use of PEG-200 and PEG-400 as solvent could activate the reaction of aryl iodides with various 1,2-disubstituetd aryl alkenes.
- Bangar, Pronnoy G.,Jawalkar, Priyanka R.,Dumbre, Swapnil R.,Raut, Pallavi K.,Patil, Dharmaraj J.,Tv, Neethu,Sudhakaran, Shana,Iyer, Suresh
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supporting information
p. 3796 - 3803
(2020/09/01)
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- Nickel-Catalyzed Hydroarylation of Alkynes under Reductive Conditions with Aryl Bromides and Water
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An operationally simple nickel-catalyzed hydroarylation reaction for alkynes is described. This three-component coupling reaction utilizes commercially available alkynes and aryl bromides, along with water and Zn. An air-stable and easily synthesized Ni(II) precatalyst is the only entity used in the reaction that is not commercially available. This reductive cross-coupling reaction displays a fairly unusual anti selectivity when aryl bromides with ortho substituents are used. In addition to optimization data and a preliminary substrate scope, complementary experiments including deuterium labeling studies are used to provide a tentative catalytic mechanism. We believe this report should inspire and inform other Ni-catalyzed carbofunctionalization reactions.
- Barber, E. Ryan,Hynds, Hannah M.,Stephens, Claudia P.,Lemons, Holli E.,Fredrickson, Emily T.,Wilger, Dale J.
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p. 11612 - 11622
(2019/10/02)
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- An Interrupted Pummerer/Nickel-Catalysed Cross-Coupling Sequence
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An interrupted Pummerer/nickel-catalysed cross-coupling strategy has been developed and used in the elaboration of styrenes. The operationally simple method can be carried out as a one-pot process, involves the direct formation of stable alkenyl sulfonium salt intermediates, utilises a commercially available sulfoxide, catalyst, and ligand, operates at ambient temperature, accommodates sp-, sp2-, and sp3-hybridised organozinc coupling partners, and delivers functionalised styrene products in high yields over two steps. An interrupted Pummerer/cyclisation approach has also been used to access carbo- and heterocyclic alkenyl sulfonium salts for cross-coupling.
- Aukland, Miles H.,Talbot, Fabien J. T.,Fernández-Salas, José A.,Ball, Matthew,Pulis, Alexander P.,Procter, David J.
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p. 9785 - 9789
(2018/07/31)
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- Geometry-Constrained Iminopyridyl Palladium-Catalyzed Hydroarylation of Alkynes to Prepare Tri-substituted Alkenes Using Alcohol as Reductant
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We developed an efficient and straightforward method to prepare tri-substituted alkenes through palladium-catalyzed hydroarylation of alkynes with aryl bromides. Diarylacetylenes and alkyl(aryl)acetylenes could be well hydroarylated with various aryl bromides in moderate to excellent yields. Mechanistic studies suggested that alcohol was the reductant to provide hydride through β-H elimination. Gram scale reaction further demonstrated the practicality and efficiency of the newly developed strategy. (Figure presented.).
- Wu, Ke,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Jin, Liqun,Hu, Xinquan
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supporting information
p. 3038 - 3043
(2018/08/01)
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- Silver sequestration of halides for the activation of Pd(OAc)2 catalyzed Mizoroki-Heck reaction of 1,1 and 1,2 - Disubstituted alkenes
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A ligand free catalytic system consisting of Pd(OAc)2 (cat) and stoichiometric quantities of silver salts, AgOAc or AgBF4, exhibit high efficiency in the Mizoroki-Heck arylation, transforming aryl iodides and 1,1 as well as 1,2 disubstituted alkenes into 1,1,2 – trisubstituted aryl alkenes in excellent yields in very short reaction times.
- Bangar, Pronnoy G.,Jawalkar, Priyanka R.,Dumbre, Swapnil R.,Patil, Dharmaraj J.,Iyer, Suresh
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- Employing Water as the Hydride Source in Synthesis: A Case Study of Diboron Mediated Alkyne Hydroarylation
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We present an approach to utilize water as the hydride source via Pd(II)/Pd(0) catalysis. As a case study, we have achieved a diboron mediated Pd(II)-catalyzed hydroarylation of alkynes using arylboronic acids. This approach not only complements conventional reactivity of Pd via Pd(0)/Pd(II) cycle for the hydroarylation but also utilizes water as the hydride source. We believe this would particularly be beneficial in utilizing water as a reagent.
- Rao, Santhosh,Joy, M. Nibin,Prabhu, Kandikere Ramaiah
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p. 13707 - 13715
(2018/11/30)
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- Copper-Catalyzed Hydroarylation of Internal Alkynes: Highly Regio- and Diastereoselective Synthesis of 1,1-Diaryl, Trisubstituted Olefins
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The copper-catalyzed hydroarylation of internal, unsymmeric alkynes is presented. Trisubstituted alkenes are obtained as single diastereomers in good to excellent yields and excellent regioselectivities. The scope of the reaction is presented with respect to alkyne and aryl iodide coupling partners. Initial mechanistic experiments indicate a hydrocupration event followed by a two-electron oxidative addition/reductive elimination pathway.
- Kortman, Gregory D.,Hull, Kami L.
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p. 6220 - 6224
(2017/09/15)
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- Stereoselective synthesis of trisubstituted alkenes via cobalt-catalyzed double dehydrogenative borylations of 1-alkenes
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A highly selective cobalt-catalyzed single and double dehydrogenative borylations (DHBs) of terminal alkenes have been developed for the synthesis of trans-monoborylalkenes and diborylalkenes, respectively. While the cobalt-catalyzed double DHBs of aryl 1
- Wen, Huanan,Zhang, Lei,Zhu, Suzhen,Liu, Guixia,Huang, Zheng
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p. 6419 - 6425
(2017/11/09)
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- Borylation of Olefin C-H Bond via Aryl to Vinyl Palladium 1,4-Migration
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The aryl to vinyl palladium 1,4-migration was realized for the first time. The generated alkenyl palladium species was trapped by diboron reagents under Miyaura borylation conditions, providing a new method to synthesize β,β-disubstituted vinylboronates. The excellent regioselectivity and broad substrate scope were observed for this novel transformation.
- Hu, Tian-Jiao,Zhang, Ge,Chen, Ya-Heng,Feng, Chen-Guo,Lin, Guo-Qiang
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p. 2897 - 2900
(2016/03/19)
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- A decarboxylative approach for regioselective hydroarylation of alkynes
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Regioselective activation of aromatic C-H bonds is a long-standing challenge for arene functionalization reactions such as the hydroarylation of alkynes. One possible solution is to employ a removable directing group that activates one of several aromatic C-H bonds. Here we report a new catalytic method for regioselective alkyne hydroarylation with benzoic acid derivatives during which the carboxylate functionality directs the alkyne to the ortho-C-H bond with elimination in situ to form a vinylarene product. The decarboxylation stage of this tandem sequence is envisioned to proceed with the assistance of an ortho-alkenyl moiety, which is formed by the initial alkyne coupling. This ruthenium-catalysed decarboxylative alkyne hydroarylation eliminates the common need for pre-existing ortho-substitution on benzoic acids for substrate activation, proceeds under redox-neutral and relatively mild conditions, and tolerates a broad range of synthetically useful aromatic functionality. Thus, it significantly increases the synthetic utility of benzoic acids as easily accessible aromatic building blocks.
- Zhang, Jing,Shrestha, Ruja,Hartwig, John F.,Zhao, Pinjing
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p. 1144 - 1151
(2016/11/28)
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- Unexpected and powerful effect of chlorobenzene in direct palladium-catalyzed cascade Sonogashira-hydroarylation reaction
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A ubiquitous accelerating effect of chlorobenzene (PhCl) was observed unexpectedly in the Pd-catalyzed cascade Sonogashira-hydroarylation reaction. This new type of carbon-carbon bond forming cross-coupling reaction was efficiently catalysed by Pd2(dba)3 in the presence of a catalytic amount of PhCl, which provides a facile and direct approach to the synthesis of trisubstituted olefins.
- Yu, Bo,Xu, Wei,Sun, Huaming,Yu, Binxun,Zhang, Guofang,Xu, Li-Wen,Zhang, Weiqiang,Gao, Ziwei
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p. 8351 - 8354
(2015/02/19)
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- Stereoselective synthesis of triarylethylenes via copper-palladium catalyzed decarboxylative cross-coupling: Synthesis of (Z)-tamoxifen
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The first Cu/Pd-catalyzed decarboxylative cross-coupling of 3,3-diarylacrylic acids with aryl bromides is described. Triarylethylenes were obtained in high yields with excellent stereoselectivities. This methodology was successfully applied to the stereos
- Cahiez, Gérard,Moyeux, Alban,Poizat, Ma?l
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p. 8982 - 8984
(2014/08/05)
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- Synthesis of trisubstituted alkenes via direct oxidative arene-alkene coupling
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The use of an inorganic oxidant with an acetic acid/acetonitrile solvent combination has been identified as optimal for direct arene/1,2-disubstituted alkene oxidative couplings, providing an efficient route to trisubstituted alkenes. The acetonitrile cosolvent dramatically accelerates the rate of reaction, and an insoluble inorganic oxidant limits unwanted oxidation of substrates. The scope of this procedure is illustrated with arenes and alkenes containing electron-donating and -withdrawing substituents resulting in a general synthetic strategy to trisubstituted alkenes. In situ ESI-MS analysis of the reaction components has identified the key Pd intermediates in the Fujiwara-Moritani catalytic cycle.
- Jones, Roderick C.,Galezowski, Michal,O'Shea, Donal F.
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p. 8044 - 8053
(2013/09/12)
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- Controlled mono- and double-Heck reaction catalyzed by a dicarbene dipalladium complex
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The phosphine-free mono- and double-Heck reaction of terminal olefins with electron-deficient and electron-rich aryl halides (iodides and bromides) is described. These reactions are catalyzed by the dicarbene dipalladium complex 1 by controlling the stoichiometry of the aryl halide and the olefine, the loading of the palladium catalyst, as well as using different base, and with or without additive. The procedure of double-Heck reaction allows β,β- diarylation and β,β′-diarylation of terminal olefins and affords trisubstituted olefins in good to excellent yields.
- Li, Yunfei,Liu, Gang,Cao, Changsheng,Wang, Shuzhan,Li, Yuling,Pang, Guangsheng,Shi, Yanhui
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p. 6241 - 6250
(2013/07/27)
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- Ambient arylmagnesiation of alkynes catalysed by ligandless nickel(ii)
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A simple and efficient catalytic arylmagnesiation of diarylacetylenes and aryl(alkyl)acetylenes is accomplished by NiCl2·6H2O at r.t. in the absence of stabilising ligands. The corresponding tetra-substituted alkenes can be obtained in good yields by subsequent treatment with different electrophiles. The Royal Society of Chemistry 2013.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy
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p. 10121 - 10123
(2013/10/22)
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- Straightforward iron-catalyzed synthesis of vinylboronates by the hydroboration of alkynes
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An iron-catalyzed hydroboration of alkynes to produce vinylboronates has been examined. With a straightforward system composed of iron carbonyls and pinacolborane, good to excellent yields and chemoselectivities were achieved for a variety of alkynes. Cop
- Haberberger, Michael,Enthaler, Stephan
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supporting information
p. 50 - 54
(2013/02/23)
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- Palladium-catalyzed desulfitative hydroarylation of alkynes with sodium sulfinates
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A palladium-catalyzed desulfitative hydroarylation of alkynes with aryl sulfinic acid sodium salts is described. The reaction showed good regio- and stereoselectivity, and afforded the hydroarylation products in good yields. Various functional groups were well tolerated under the optimized reaction conditions.
- Liu, Saiwen,Bai, Yang,Cao, Xiangxiang,Xiao, Fuhong,Deng, Guo-Jun
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supporting information
p. 7501 - 7503
(2013/08/23)
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- Cobalt-catalyzed addition of arylzinc reagents to alkynes to form ortho-alkenylarylzinc species through 1,4-cobalt migration
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Migratory carbometalation: A cobalt-Xantphos complex catalyzes the addition of an arylzinc reagent to an unactivated internal alkyne; the reaction most likely involves insertion of the alkyne into an arylcobalt species and vinyl-to-aryl 1,4-cobalt migration, followed by transmetalation with the arylzinc reagent. Interception of the resulting ortho-alkenylarylzinc species with electrophiles allows access to 1-alkenyl arenes functionalized in the 2-position. Copyright
- Tan, Boon-Hong,Dong, Jinghua,Yoshikai, Naohiko
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p. 9610 - 9614
(2012/11/07)
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- Oxidative heck arylation for the stereoselective synthesis of tetrasubstituted olefins using nitroxides as oxidants
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One, two, and three! Nitroxides and dioxygen serve as oxidants in highly stereoselective oxidative Pd-catalyzed Heck arylations in which aryl boronic acids are used to synthesize triarylalkyl-substituted olefins. The reactions occur under very mild conditions at room temperature. As an example, the threefold sequential arylation of methyl acrylate is the crucial step in the stereoselective synthesis of Z-Tamoxifen.
- He, Zhiheng,Kirchberg, Sylvia,Froehlich, Roland,Studer, Armido
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supporting information; experimental part
p. 3699 - 3702
(2012/05/20)
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- Pd-catalyzed heck reactions of aryl bromides with 1,2-diarylethenes
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A catalytic system composed of Pd(OAc)2 and P(o-tol)3 was found to be effective for the Heck reaction of aryl bromides with diarylethylenes. Using K2CO3 as a base and DMF as a solvent, trisubstituted olefins were obtained in good to excellent yields. Aryl bromides containing an electron-withdrawing group in para position were less reactive for the Heck coupling reaction and gave substantial amount of homocoupling by-product suggesting that oxidative addition is not the rate-determining step. Electron withdrawing group substituent in the para position of stilbene affects the regioselectivity of the reaction. In this case, the phenyl group from the Ph-Pd complex migrates preferentially to the same carbon of the double bond to which the phenyl is bonded. Finally, a one pot sequential double Heck arylation of styrene was performed, giving trisubstituted olefin with an overall yield of 73percent.
- Limberger, Jones,Poersch, Silvia,Monteiro, Adriano L.
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p. 1389 - 1394
(2012/04/23)
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- A homogeneous, recyclable polymer support for rh(I)-catalyzed c-c bond formation
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A robust and practical polymer-supported, homogeneous, recyclable biphephos rhodium(I) catalyst has been developed for C-C bond formation reactions. Control of polymer molecular weight allowed tuning of the polymer solubility such that the polymer-supported catalyst is soluble in nonpolar solvents and insoluble in polar solvents. Using the supported rhodium catalysts, addition of aryl and vinylboronic acids to the electrophiles such as enones, aldehydes, N-sulfonyl aldimines, and alkynes occurs smoothly to provide products in high yields. Additions of terminal alkynes to enones and industrially relevant hydroformylation reactions have also been successfully carried out. Studies show that the leaching of Rh from the polymer support is low and catalyst recycle can be achieved by simple precipitation and filtration.
- Jana, Ranjan,Tunge, Jon A.
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experimental part
p. 8376 - 8385
(2011/12/04)
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- Synthesis of polysubstituted olefins by Pd-catalyzed cross-coupling reaction of tosylhydrazones and aryl nonaflates
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Aryl nonaflates are employed as electrophiles in the Pd-catalyzed cross-coupling with tosylhydrazones affording di-, tri-, and tetrasubstituted olefins. Fine tunning of the reaction conditions are required to accomplish the coupling successfully, includin
- Barluenga, Jose,Florentino, Lucia,Aznar, Fernando,Valdes, Carlos
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p. 510 - 513
(2011/03/22)
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- Construction of polysubstituted olefins through Ni-Catalyzed direct activation of Alkenyl C-O of substituted alkenyl acetates
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(Figure Presented) Reliable companion: For the first time cross-coupling between alkenyl acetates and arylboroxines/PhZnCl has been developed via Ni catalysis. Alkenyl acetates could be well-differ-entiated from aryl acetates (see scheme). This reliable method provides a convenient pathway to construct polysubstituted styrene derivatives.
- Sun, Chang-Liang,Yang, Wang,Xiao, Zhou,Wu, Zhen-Hua,Li, Bi-Jie,Guan, Bing-Tao,Shi, Zhang-Jie
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supporting information; experimental part
p. 5844 - 5847
(2010/09/03)
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- Trans-stilbene as a starting material for the synthesis of tamoxifen based on palladium-catalyzed cross-coupling reactions
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(Z)-Tamoxifen was synthesized from a simple olefin (trans-stilbene) in 5 steps and 40% overall yield (Z/E = 74:26). The phenyl substituted group (4-Me2NCH2CH2OC6H4) was attached by a bromination-dehydrobromination-Suzuki reaction sequence. Subsequently, the ethyl group was attached to the triarylated olefin by a bromination-Negishi reaction sequence. Both the Suzuki and Negishi cross-coupling processes are stereospecific, and the stereo-selectivity depends only on the bromination-dehydrobromination reactions. (Z)-Tamoxifen was also obtained from trans-stilbene in only 3 steps by using Heck reaction-bromination- Negishi reaction sequence in 57% overall yield (Z/E = 65:35). Georg Thieme Verlag Stuttgart.
- Nunes, Carolina M.,Limberger, Jones,Poersch, Silvia,Seferin, Marcus,Monteiro, Adriano L.
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scheme or table
p. 2761 - 2765
(2010/01/21)
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- Rhodium-copper-TBAF-catalyzed hydroarylation of alkynes with aryl Trimethoxysilanes
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A rhodium-copper-TBAF-catalyzed hydroarylation of alkynes with aryl trimethoxysilanes is described. The procedure utilizes a catalytic amount of copper(II) acetate, rhodium, PPh3 and TBAF·3H2O under air. Some asymmetric alkynes gave
- Lin, Baoda,Liu, Miaochang,Ye, Zhishi,Zhang, Qin,Cheng, Jiang
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experimental part
p. 1714 - 1716
(2009/07/05)
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- Phosphine-free rhodium-catalyzed hydroarylation of diaryl acetylenes with boronic acids
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Rh(CO)2(acac) was found to be an efficient and simple catalyst in hydroarylation of diaryl acetylenes with boronic acids in the absence of phosphine ligand. Thus, triaryl-substituted olefins were prepared in good to excellent yields. No 1,4-rho
- Zhang, Weiwei,Liu, Miaochang,Wu, Huayue,Ding, Jinchang,Cheng, Jiang
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p. 5214 - 5216
(2008/12/20)
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- Palladium-catalysed direct synthesis of benzo[b]thiophenes from thioenols
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The one-pot conversion of thioenols into benzo[b]thiophenes was achieved by using a simple palladium catalyst such as PdCl2 or PdCl 2(cod). The Royal Society of Chemistry.
- Inamoto, Kiyofumi,Arai, Yukari,Hiroya, Kou,Doi, Takayuki
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supporting information; experimental part
p. 5529 - 5531
(2009/04/13)
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- Palladium-catalyzed hydroarylation of alkynes with arenediazonium salts
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The palladium-catalyzed hydroarylation of arenediazonium tetrafluoroborates with alkynes in the presence of triphenylsilane affords stereoselectively hydroarylation products in moderate to high yields. The reaction tolerates a variety of substituents including keto, ester, cyano, and nitro groups and can be performed as a one-pot procedure generating the arenediazonium salt in situ. With ethyl phenylpropynoate as the starting alkyne, the hydroarylation affords ethyl (2)-2-arylcinnamates stereo- and regioselectively.
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Persiani, Daniela
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supporting information; experimental part
p. 1597 - 1600
(2009/04/10)
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- Microwave-assisted one-pot diboration/Suzuki cross-couplings. A rapid route to tetrasubstituted alkenes
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Internal and terminal alkynes undergo rapid platinum(0)-catalyzed diboration with bis(pinacolato)diboron in dioxane to yield cis-1,2-bis(boryl)alkenes under sealed vessel microwave conditions. Subsequent addition of aryl bromides, base and a palladium catalyst to the reaction vial followed by resubjection to microwave conditions provides tetrasubstituted ethylenes in high yields via Suzuki cross-coupling of the boron intermediates.
- Prokopcová, Hana,Ramírez, Jesús,Fernández, Elena,Kappe, C. Oliver
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p. 4831 - 4835
(2008/09/21)
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- Palladium-catalyzed dehydroarylation of triarylmethanols and their coupling with unsaturated compounds accompanied by C-C bond cleavage
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Triarylmethanols are effectively dehydroarylated and reacted with some unsaturated compounds by using an appropriate palladium catalyst system such as Pd(OAc)2-P(1-Nap)3 (1-Nap = 1-naphthyl) to give the corresponding arenes and hydro
- Terao, Yoshito,Nomoto, Michiyo,Satoh, Tetsuya,Miura, Masahiro,Nomura, Masakatsu
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p. 6942 - 6944
(2007/10/03)
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- Sequential reactions of trimethylstannyl anions with vinyl chlorides and dichlorides by the SRN1 mechanism followed by palladium-catalyzed cross-coupling processes
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The reactions of trimethylstannyl ions (Me3Sn-) with vinyl chlorides in liquid ammonia give good yields of vinylstannanes. Some of them react in the dark, and others need light stimulation to react. The fact that these reactions are inhibited by radical and radical anion traps shows that they occur by the SRN1 mechanism. When the reaction takes place with 1,1-dichloro-1-alkenes, monosubstitution reduced products are formed in an E/Z mixture. The efficient synthesis of triarylolefins by Pd(0)-catalyzed cross-coupling reactions of vinylstannanes with several iodoarenes is reported. Similar yields were obtained in one-pot-type reactions.
- Corsico, Eduardo F.,Rossi, Roberto A.
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p. 6427 - 6432
(2007/10/03)
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- Synthesis of polysubstituted alkenes by Heck vinylation or Suzuki cross-coupling reactions in the presence of a tetraphosphane-palladium catalyst
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Through the use of [PdCl(C3H5)]2/cis,cis,cis-1,2,3, 4-tetrakis[(diphenylphosphanyl)methyl]cyclopentane as a catalyst, a range of vinyl bromides undergo Suzuki cross-couplings with arylboronic acids in good yields. Furthermore, the catalyst can be used at low loadings, even for reactions of sterically hindered substrates. Mediated by this catalyst, stilbene and 1,1-diphenylethylene undergo Heck reactions with aryl halides to give triarylethylene derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Berthiol, Florian,Doucet, Henri,Santelli, Maurice
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p. 1091 - 1096
(2007/10/03)
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- Synthesis and chiral separation of some antitumor agents
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Four Z-isomers of 1,1-dichloro-2,2,3-triarylcyclopropane (DTACs), designed as potent antitumor agents, were synthesized from their appropriately substituted ethenes, which were prepared from the Grignard reaction followed by the dehydration of their inter
- Singh, Satendra,Meyer, Karen L.,Magarian, Robert A.
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- Triarylcyclopropanes as antiestrogens and antitumor agents
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Triarylcyclopropane derivatives in which one or more of the aryl groups includes a hydroxy as a substituted or unsubstituted or alkoxy or side chain substituent. The compounds are useful as antiestrogens and anti-tumor agents.
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- Conversion of Stilbene to trisubstituted Olefins
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Determination of stereochemistry of bromination-dehydrobromination of both cis and trans-stilbene has been achieved.Coupling of the resulting vinyl bromides with alkyl or aryl groups have been done.The coupling products could serve as intermediates for the synthesis of biologically active tetrasubstituted olefins.
- Al-Hassan, Mohammed I.
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p. 463 - 472
(2007/10/02)
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- Palladium-Catalyzed cross-coupling og Vinylalanes with aryl halides
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Synthesis of tri-and tetrasubstituted olefins was achieved via palladium-catalyzed cross-coupling of vinylalanes with arylhalides.
- Al-Hassan, Mohammed I.
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p. 1413 - 1420
(2007/10/02)
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- Synthesis of Clomid Using Palladium-Catalysed Cross-Coupling
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Two methods of choice for the synthesis of clomid, a tetrasubstituted olefin with antiestrogenic activity, are described.The key reaction is hydroalumination of diphenylacetylene followed by C-C cross-coupling using catalytic amount of Pd0.
- Al-Hassan, Mohammed I.
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p. 1787 - 1796
(2007/10/02)
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- THE PALLADIUM-CATALYZED REACTION OF ARYL IODIDES WITH MONO AND DISUBSTITUTED ACETYLENES: A NEW SYNTHESIS OF TRISUBSTITUTED ALKENES.
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Mono and disubstituted acetylenes react with aryl iodides containing a variety of functional groups in the presence of palladium catalyst, formic acid and a tertiary amine to give trisubstituted alkenes.
- Cacchi, Sandro,Felici, Marcello,Pietroni, Biancarosa
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p. 3137 - 3140
(2007/10/02)
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