- Synthesis of trisubstituted alkenes by Ni-catalyzed hydroalkylation of internal alkynes with cycloketone oxime esters
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A method for Ni-catalyzed hydroalkylation of internal alkynes with cycloketone oxime esters was developed. The reaction has a broad substrate scope. This hydroalkylation shows excellent regio-and stereo-selectivity. This method enables readily available starting materials to be used to access a range of cyano-substituted single-configuration trisubstituted alkenes. These are valuable feedstock chemicals and are widely used in synthetic and medicinal chemistry.
- Lu, Xiao-Yu,Liu, Chuang-Chuang,Jiang, Run-Chuang,Yan, Lu-Yu,Liu, Qi-Le,Wang, Qing-Qing,Li, Jia-Mei
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supporting information
p. 14191 - 14194
(2020/11/24)
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- Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
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Since its discovery in 1938, hydroformylation has been thoroughly investigated and broadly applied in industry (>107 metric ton yearly). However, the ability to precisely control its regioselectivity with well-established Rh- or Co-catalysts has thus far proven elusive, thereby limiting access to many synthetically valuable aldehydes. Pd-catalysts represent an appealing alternative, yet their use remains sparse due to undesired side-processes. Here, we report a highly selective and exceptionally active catalyst system that is driven by a novel activation strategy and features a unique Pd(I)-Pd(I) mechanism, involving an iodide-assisted binuclear step to release the product. This method enables β-selective hydroformylation of a large range of alkenes and alkynes, including sensitive starting materials. Its utility is demonstrated in the synthesis of antiobesity drug Rimonabant and anti-HIV agent PNU-32945. In a broader context, the new mechanistic understanding enables the development of other carbonylation reactions of high importance to chemical industry.
- Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
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supporting information
p. 18251 - 18265
(2020/11/02)
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- In Situ Generation of Alkynylzinc and Its Subsequent Negishi Reaction in a Flow Reactor
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A highly efficient and convenient Negishi cross-coupling reaction has been developed for the synthesis of unsymmetrical alkynes and enynes in a continuous-flow process. The reaction proceeds through an in situ generated alkynylzinc reagent by the reaction of lithium acetylide with zinc halide at room temperature followed by a cross-coupling reaction with aryl or vinyl iodides. The notable features of this work compared to the conventional benchtop method are mild reaction conditions, good to excellent yields, broad functional-group compatibility, short residence time (73 sec) and especially desilylation of TMS group with the residence time of only 10.5 sec.
- Kandasamy, Mohanraj,Huang, Yu- Hsuan,Ganesan, Balaji,Senadi, Gopal Chandru,Lin, Wei-Yu
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p. 4349 - 4356
(2019/07/03)
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- Nickel Phosphite/Phosphine-Catalyzed C-S Cross-Coupling of Aryl Chlorides and Thiols
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A method for the coupling of aryl chlorides and thiophenols using an air-stable nickel(0) catalyst is described. This thioetherification procedure can be effectively applied to a range of electronically diverse aryl/heteroaryl chlorides without more expensive metal catalysts such as palladium, iridium, or ruthenium. This investigation also illustrates both, a variety of thiol coupling partners and, in certain cases, the use of Cs2CO3.
- Jones, Kieran D.,Power, Dennis J.,Bierer, Donald,Gericke, Kersten M.,Stewart, Scott G.
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supporting information
p. 208 - 211
(2018/01/17)
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- Palladium-free and phosphine-free Sonogashira coupling reaction of aryl halides with terminal alkynes catalyzed by boehmite nanoparticle-anchored Cu(I) diethylenetriamine complex
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In this work, a novel diethylenetriamine-functionalized-boehmite nanoparticle-supported Cu(I) catalyst is synthesized. The catalyst prepared is then characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray
- Bakherad, Mohammad,Doosti, Rahele,Mirzaee, Mahdi,Jadidi, Khosrow,Amin, Amir H.,Amiri, Omid
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p. 7347 - 7363
(2017/10/06)
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- Microwave-enhanced cross-coupling reactions involving alkynyltrifluoroborates with aryl bromides
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Palladium-catalyzed alkynylation has emerged as one of the most reliable methods for the synthesis of alkynes which are often used in natural product syntheses and material science. An efficient method for coupling alkynyltrifluoroborates with various aryl bromides in the presence of a palladium catalyst has been developed using microwave irradiation. The microwave reactions are rapid and efficient.
- Coltuclu, Vitali,Dadush, Eric,Naravane, Abhijit,Kabalka, George W.
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p. 1755 - 1761
(2013/04/10)
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- Efficient copper-catalyzed sonogashira couplings of aryl halides with terminal alkynes in water
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An efficient copper-catalyzed method has been developed for Sonogashira couplings of aryl halides with terminal alkynes in water. The protocol uses inexpensive CuBr as the catalyst, 1,10-phenanthroline as the ligand, tetrabutylammonium bromide (TBAB) as the phase-transfer catalyst, environmentally friendly water as the solvent, and various internal alkynes were synthesized in good to excellent yields. Georg Thieme Verlag Stuttgart - New York.
- Yang, Daoshan,Li, Bing,Yang, Haijun,Fu, Hua,Hu, Liming
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scheme or table
p. 702 - 706
(2011/04/26)
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- Cp*Li as a base: application to palladium-catalyzed cross-coupling reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminal acetylenes
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The reaction of aryl-X or alkenyl-X (X=I, Br, OTf, ONf) with terminal acetylenes in the presence of a catalytic amount of Pd(OAc)2 provided the alkynylated products in good yields by using Cp*Li (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) as a base.
- Uemura, Minoru,Yorimitsu, Hideki,Oshima, Koichiro
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p. 1829 - 1833
(2008/09/18)
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- Palladium(II) chloride and a (dipyridin-2-ylmethyl)amine-derived palladium(II) chloride complex as highly efficient catalysts for the synthesis of alkynes in water or in NMP and of diynes in the absence of reoxidant
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The (dipyridin-2-ylmethyl)amine-derived palladium chloride complex 1 and PdCl2 are efficient catalysts for cross-coupling reactions between terminal alkynes and aryl iodides or bromides under modified Sonogashira-Cassar-Heck conditions. The alkynylation can be performed under copper-free conditions in water at reflux or at room temperature under air with pyrrolidine as base and tetra-n-butylammonium bromide (TBAB) as additive, with TONs of up to 7 × 104 and TOFs (h-1) of up to 6666. Terminal alkynes can be arylated in NMP as well under copper- and amine-free conditions at 110°C or room temperature, with tetra-n-butylammonium acetate (TBAA) acting as base with TONs up to 2 × 105 and TOFs (h -1) up to 66 666. In general, complex 1 displays a slightly higher efficiency than PdCl2 as catalyst and maintains the same activity after five consecutive runs. Alternatively, these alkynylation processes can be carried out under microwave heating conditions. The homocoupling of terminal alkynes to the corresponding 1,3-diynes proceeds under phosphane-free conditions with the (dipyridin-2-yrmethyl)amine-derived palladium chloride complex 1 or with PdCl2 as catalysts and with CuI as cocatalyst in NMP with use of either TBAA or pyrrolidine as bases. This Glaser-type reaction can be performed at 110°C or at room temp. in the presence of air without the use of a reoxidant. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Gil-Molto, Juan,Najera, Carmen
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p. 4073 - 4081
(2007/10/03)
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- Process for preparing alkynyl-substituted aromatic and heterocyclic compounds
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Mono- and disubstituted aryl or heterocyclic acetylenes are produced by a process comprising reacting an aryl nitrile with an alkynylzinc compound, a bis-alkynylzinc compound, or an alkynylmagnesium compound, in the presence of a nickel/phosphine catalyst.
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Page/Page column 9
(2010/02/12)
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- N-heterocyclic NCN-pincer palladium complexes: A source for general, highly efficient catalysts in Heck, Suzuki, and Sonogashira coupling reactions
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Readily available NCN-pincer palladium complexes comprising two pyrazole units as the source of both N-donor atoms are successfully employed as catalysts in a range of C-C bond-forming reactions. Good to excellent results are obtained in all cases regardless of the electronic nature of the substrates, along with more convenient procedures and comparatively much lower catalysts loadings in Suzuki and Sonogashira couplings. This paper presents the first report of a Sonogashira coupling reaction by means of a NCN catalyst. Georg Thieme Verlag Stuttgart.
- Churruca, Fátima,SanMartin, Raul,Tellitu, Imanol,Domínguez, Esther
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p. 3116 - 3120
(2007/10/03)
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- Aqueous ammonia as a new activator for Sonogashira coupling
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Sonogashira coupling, which is a coupling reaction of terminal alkynes with organic halides, takes place with dilute aqueous ammonia as an activator. The reaction of several terminal alkynes and aryl iodides in the presence of small excess of aqueous ammonia at room temperature furnishes the cross-coupling product in good-to-excellent yields. A water-soluble amine with a high boiling point is alternatively employed for reactions at higher temperatures. A related coupling reaction in the presence of carbon monoxide also proceeded at room temperature and under ambient pressure to afford α,β-alkynyl ketones efficiently.
- Mohamed Ahmed, Mohamed S.,Sekiguchi, Akitoshi,Masui, Kentaro,Mori, Atsunori
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p. 160 - 168
(2007/10/03)
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- C(sp2)-C(sp) and C(sp)-C(sp) Coupling Reactions Catalyzed by Oxime-Derived Palladacycles
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Oxime-derived chloro-bridged palladacycle 8a, derived from 4,4′-dichlorobenzophenone, is an efficient pre-catalyst for the copper- and amine-free Sonogashira coupling between terminal acetylenes and aryl iodides and aryl and vinyl bromides achieving turnover numbers (TON) of up to 72000. Catalyst 8a has also been shown as a effective promoter for the sila-Sonogashira coupling between 1-(trimethylsilyl)alkynes and aryl iodides and bromides in the presence of CuI or Bu4NBr as co-catalysts. This complex also catalyzes efficiently the homocoupling reaction (Glaser-type coupling) between 1-alkynes in NMP at room temperature with TONs of up to 1000. All the reactions can be performed under air and employing reagent-grade chemicals under very low loading conditions, which demonstrates the versatility and high activity of oxime-derived palladacycles.
- Alonso, Diego A.,Na?jera, Carmen,Pacheco, Ma. Carmen
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p. 1146 - 1158
(2007/10/03)
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- A copper- and amine-free Sonogashira-type coupling procedure catalyzed by oxime palladacycles
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Oxime palladacycle derived from 4,4′-dichlorobenzophenone was found to promote the Sonogashira reaction of aryl iodides and aryl bromides with terminal acetylenes using 1 equivalent of tetrabutylammonium acetate in organic solvents generally in 1 h at 110
- Alonso, Diego A,Nájera, Carmen,Pacheco, M Carmen
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p. 9365 - 9368
(2007/10/03)
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- An efficient coupling of aryl iodides with terminal alkynes catalyzed by silica-supported sulfur palladium(0) complex
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A silica-supported sulfur palladium(0) complex was prepared by the direct ligand-exchange reaction of poly-γ-mercaptopropylsiloxane with Pd(PPh3)4. It was an efficient catalyst for the coupling of aryl iodides with terminal alkynes.
- Cai, Ming-Zhong,Song, Cai-Sheng,Huang, Xian
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p. 1935 - 1942
(2007/10/03)
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