- Highly stereoselective addition of stannylcuprates to alkynones
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The addition of stannylcuprate reagents such as (Bu3Sn)(PhS)CuLi to alkynones has been found to proceed in high yield and with excellent stereoselectivity for the Z isomer of the product (>95%). The behavior of the stannylcuprates is thus very different from that of their "carbocuprate" counterparts such as Me2CuLi or Me2Cu(CN)Li2 which are nonstereoselective. Furthermore, in contrast to the reactions of (R3Sn)(PhS)CuLi with the corresponding alkynoates, the presence of a proton source in the reaction medium has no effect on the stereoselectivity of the reaction of alkynones.
- Nielsen, Thomas E.,Cubillo de Dios, Maria A.,Tanner, David
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Read Online
- Flexible Construction of Functionalized-Pyrroles under Palladium or Copper Catalysis in the Presence of BF3 ? Et2O
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We have developed a flexible approach enabling the access to highly functionalized pyrroles under palladium or copper catalysis in the presence of BF3 ? Et2O. This catalytic methodology utilizes commercially available amines as react
- Guo, Wusheng,Liu, Teng,Liu, Yin,Wei, Kun,Yan, Biwei
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supporting information
(2022/01/26)
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- Highly Chemo- And Enantioselective Rh-Catalyzed Hydrogenation of β-Sulfonyl-α,β-unsaturated Ketones: Access to Chiral γ-Ketosulfones
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Rh-catalyzed highly chemo- and enantioselective hydrogenation of β-sulfonyl-α,β-unsaturated ketones was first successfully developed. Remarkably, a variety of enantioenriched γ-ketosulfones were generated in good to high yields with excellent chemo/enantioselectivities (82-99% yields, >99:1 chemoselectivity, 88 to >99% ee). Moreover, the gram-scale asymmetric hydrogenation was carried out smoothly in 97% yield and 97% ee. Preliminary DFT computations furnished a reasonable explanation for the high chemoselectivity and enantioselectivity.
- Liu, Gang,Yin, Congcong,Yang, Xuanliang,Li, Anqi,Wang, Minyan,Zhang, Xumu,Dong, Xiu-Qin
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supporting information
p. 19 - 24
(2021/01/13)
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- Synthesis of 2-isoxazolyl-2,3-dihydrobenzofuransviapalladium-catalyzed cascade cyclization of alkenyl ethers
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A novel palladium-catalyzed cascade cyclization reaction of alkenyl ethers with alkynyl oxime ethers for the construction of poly-heterocyclic scaffolds has been developed, in which the electron-rich alkene moiety functions as a three-atom unit, simultaneously dealing well with the coordination and regioselectivity of electron-rich olefins under metal catalysis. The strategy features excellent regio- and chemoselectivities as well as good functional group tolerance. Moreover, the newly formed 2-isoxazolyl-2,3-dihydrobenzofuran products can be further transformed to diverse complex heterocycles, demonstrating their potential applications in organic synthesis and medicinal chemistry.
- Zhou, Fei,Li, Can,Li, Meng,Jin, Yangbin,Jiang, Huanfeng,Zhang, Yingjun,Wu, Wanqing
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supporting information
p. 4799 - 4802
(2021/05/25)
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- Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through in Situ Generated Cycloheptenol Derivatives
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An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I2 was the key to the reaction.
- Wang, Mengdan,Yin, Liqiang,Cheng, Lu,Yang, Yajie,Li, Yanzhong
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p. 12956 - 12963
(2021/09/13)
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- One-Pot Palladium-Catalyzed Carbonylative Sonogashira Coupling using Carbon Dioxide as Carbonyl Source
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Carbonylation coupling reaction has emerged as a powerful and versatile strategy for the construction of carbonyl-containing compounds in modern synthetic chemistry over the past years. Carbon dioxide, a renewable one carbon molecule, has become one of the most attractive and promising alternative carbonyl sources due to its highly abundance, nontoxicity and stability in comparison with CO in recent years. However, in most cases, a two-chamber technique was generally necessary to allow the CO-producing and CO-consuming processes to perform successfully because of the complexities and incompatibility of reaction conditions, when carbon dioxide was utilized as carbonyl source. Herein, a practical one-pot protocol using carbon dioxide as the carbonyl source for the palladium-catalyzed carbonylative Sonogashira coupling has been established, providing an expedient and practical route to a wide range of functionalized alkynones and indoxyls under mild reaction conditions. By finding a suitable catalytic system, the method allowed the CO-generating and CO-consuming processes to proceed in one pot, wherein carbon monoxide was generated in situ from the reduction of carbon dioxide in the absence of any fluoride reagents. Simple and safe operation, readily available substrates, good functional group tolerance and mild reaction conditions are the features of the method.
- Xiong, Wenfang,Wu, Bowen,Zhu, Baiyao,Tan, Xiaobin,Wang, Lu,Wu, Wanqing,Qi, Chaorong,Jiang, Huanfeng
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p. 2843 - 2851
(2021/05/10)
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- Synthesis and Characterization of Ag@g?C3N4 and Its Photocatalytic Evolution in Visible Light Driven Synthesis Of Ynone
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The primary aim of this work is to synthesize photocatalyst to promote the synthesis of ynones. In this context, we synthesized AgNPs@g?C3N4 nanocomposite. The nanocomposite was characterized by using SEM, HR-TEM, XRD, EDS, ICP-AES,
- Patel, Sunil B.,Vasava, Dilip V.
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p. 631 - 641
(2019/12/03)
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- Visible-light-mediated photocatalytic cross-coupling of acetenyl ketones with benzyl trifluoroborate
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In this report, we describe a simple visible light-triggered Barbier-type reaction by employing acetenyl ketones with benzyl trifluoroborates. Through a radical-radical cross-coupling process, this photocatalytic protocol furnished a wide range of tertiary propargyl alcohols. Mechanistic investigation indicated that proton-coupled electron transfer (PCET) might be involved in the photochemical transformations.
- Zhang, Lingchun,Chu, Yanle,Ma, Peizhi,Zhao, Shujuan,Li, Qiaoyan,Chen, Boya,Hong, Xuejiao,Sun, Jun
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supporting information
p. 1073 - 1077
(2020/02/22)
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- Iron(III) chloride-promoted cyclization of α,-alkynic tosylhydrazones with diselenides: Synthesis of 4-(arylselanyl)-1: H-pyrazoles
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A highly efficient iron(iii) chloride-promoted cyclization between α,-alkynic tosylhydrazones and diselenides to form a 4-(arylselanyl)-1H-pyrazole skeleton is studied. This reaction forms C-N and C-Se bonds in one step by utilizing inexpensive iron(iii) chloride instead of expensive transition metal additives. This strategy features easily synthesized substrates, mild reaction conditions and high tolerance to functional groups.
- Ji, Shun-Jun,Li, Fang-Hui,Li, Jian,Wang, Shun-Yi,Yao, Hai-Feng
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supporting information
p. 1987 - 1993
(2020/03/23)
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- Bifunctional phosphine ligand-enabled gold-catalyzed direct cycloisomerization of alkynyl ketones to 2,5-disubstituted furans
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An efficient synthesis of 2,5-disubstituted furans directly from alkynyl ketones has been developed via tandem gold(i)-catalyzed isomerization of alkynyl ketones to allenyl ketones and cycloisomerization. The key to the success of this chemistry is the use of a biphenyl-2-ylphosphine ligand featuring a critical remote tertiary amino group.
- Hu, Xiaojun,Zhou, Bingwei,Jin, Hongwei,Liu, Yunkui,Zhang, Liming
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supporting information
p. 7297 - 7300
(2020/07/14)
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- Copper-catalyzed method for preparing aldehyde or ketone compound by oxidizing alcohol with oxygen as oxidizing agent and application
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The invention discloses a copper-catalyzed method for preparing an aldehyde or ketone compound by oxidizing alcohol with oxygen as an oxidizing agent. Reaction is performed in an organic solvent for 4-48 hours at room temperature by using copper salt and nitroxide free radicals as catalysts and oxygen or air as an oxidizing agent to efficiently oxidize an alcohol compound into the corresponding aldehyde or ketone compound. The method is simple to operate, free of chlorides corrosive to equipment, available in raw materials and reagents, mild in reaction conditions, wide in substrate universality, good in functional group compatibility, convenient in separation and purification, environmentally friendly in the whole process and free of pollution, and is a method suitable for industrial production.
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Paragraph 0028-0030; 0049-0054; 0169-0174; 0196-0243
(2020/08/18)
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- Ionic liquid-mediated benzoyl transfer-coupling in the Suzuki and Sonogashira reactions and aryl transfer-coupling by decarbonylative Heck reaction, using N-Benzoyl-saccharin (NBSac) as reagent
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The efficacy of N-benzoyl-saccharin (NBSac) as reagent for selective benzoyl transfer-coupling in the Suzuki reaction in BMIM-IL/[PAIM][NTf2] as solvent/base, and in the Sonogashira reaction employing guanidinium-IL (GIL) as solvent, are demonstrated. Decarbonylative aryl transfer-coupling occurs in the Heck reaction employing GIL as solvent. The reactions are catalyzed by Pd(OAc)2 or NiCl2(dppp), are performed under mild conditions in good yields, and have the potential for recycling/reuse of the IL solvent. Collectively, these methods provide facile access to diverse libraries of diarylketones, keto-ethynes and diaryl-ethenes.
- Malunavar, Shruti S.,Sutar, Suraj M.,Prabhala, Pavankumar,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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- Synthesis of (: Z)-β-halo α,β-unsaturated carbonyl systems via the combination of halotrimethylsilane and tetrafluoroboric acid
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A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Br?nsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-β-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.
- Da Silva, Vitor A. F.,Da Silva, Gustavo P.,Matsuo, Bianca T.,Ali, Akbar,Davis, Rebecca L.,Zukerman-Schpector, Julio,Corrêa, Arlene G.,Paix?o, Márcio W.
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supporting information
p. 519 - 526
(2019/01/24)
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- Copper-Catalyzed Aminoboration from Hydrazones to Generate Borylated Pyrazoles
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Herein we report an aminoboration reaction that employs inexpensive, Earth-abundant, and commercially available Cu(OTf)2 as an effective catalyst in the direct addition of B-N σ bonds to C-C π bonds, generating borylated pyrazoles, which are us
- Tu, Kim N.,Kim, Scott,Blum, Suzanne A.
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supporting information
p. 1283 - 1286
(2019/02/26)
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- Synthesis of 1-Cyano-3-acylnaphthalenes via Formal [4+2] Benzannulation of 2-(2-Alkynylphenyl)acetonitriles and Alkynones
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Effective transition-metal-free formal [4+2] benzannulation for the preparation of 1-cyano-3-acylnaphthalenes from 2-(2-alkynylphenyl)acetonitriles and alkynones through sequential C-C bond coupling has been developed. This protocol is characterized by mi
- Chen, Lu-Lu,Zhang, Jing-Wen,Yang, Wan-Wan,Fu, Ji-Ya,Zhu, Jun-Yan,Wang, Yan-Bo
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p. 8090 - 8099
(2019/06/27)
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- Fast and Efficient Continuous Flow Method for the Synthesis of Ynones and Pyrazoles
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In this study, we developed a convenient and efficient two-step method for the synthesis of ynones in a flow reactor, through the generation of lithium acetylide and its subsequent reactions with acid chlorides. Using this approach, we obtained the ynones in moderate to good yields at room temperature. Moreover, we transformed the ynones into pyrazole derivatives through coupling with hydrazines. This transition metal-free process, mild reaction conditions, and broad functional group tolerance are all attractive features in comparison with conventional bench-top methods.
- Kandasamy, Mohanraj,Ganesan, Balaji,Hung, Min-Yuan,Lin, Wei-Yu
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supporting information
p. 3183 - 3189
(2019/05/28)
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- Palladium-Catalyzed Cascade Annulation/Allylation of Alkynyl Oxime Ethers with Allyl Halides: Rapid Access to Fully Substituted Isoxazoles
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A novel and efficient approach for the synthesis of functionalized isoxazoles via palladium-catalyzed cascade annulation/allylation of alkynyl oxime ethers with allyl halides has been established. The present protocol exhibits mild reaction conditions, good functional group compatibility, and convenient operation. Moreover, scalability was performed and further decoration of the isoxazole product was achieved.
- Li, Can,Li, Jianxiao,Zhou, Fei,Li, Chaosheng,Wu, Wanqing
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p. 11958 - 11970
(2019/10/11)
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- One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling-intramolecular cyclization
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Catalyst efficacy of in situ generated Pd-nanoparticles (PdNPs) in the regioselective one-pot synthesis of 3,5-di & 3,4,5-trisubstituted pyrazoles and 3,5-disubstituted isoxazoles in environmentally benign PEG-400/H2O medium, which involves the sequential (i) Cu-free acyl-Sonogashira coupling (ASC) and (ii) intramolecular ynone-amine cyclization under PTC conditions was described. The results of controlled experiments support the operation of two sequential catalytic cycles (ASC/cyclization) and achievement of complementary/opposite regioselectivity via ynone-bound palladium in a one-pot approach. Moreover, the in situ PdNPs recovered after the first catalytic cycle of the one-pot reaction sequence have been reused again five times successively. Besides, prior to the above studies, the efficacy of some common Pd-N-heterocyclic carbene (Pd-NHC) complexes in catalyzing the same one-pot two-step reaction sequence (Cu-free ASC/cyclization) both in water and organic solvents was also optimized. In situ generation of PdNPs from above Pd-NHCs in water was also identified, but they are not reusable due to their large size distribution.
- Thirukovela, Narasimha Swamy,Balaboina, Ramesh,Botla, Vinayak,Vadde, Ravinder,Jonnalagadda, Sreekantha Babu,Vasam, Chandra Sekhar
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p. 6471 - 6481
(2019/11/20)
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- Acyl Radicals from Benzothiazolines: Synthons for Alkylation, Alkenylation, and Alkynylation Reactions
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We describe herein a fundamentally new visible light-driven homolytic C-C bond breaking mode for the generation of acyl radicals from C2-acyl-substituted benzothiazolines. The reactive species can be used as versatile synthons for formal radical alkylatio
- Li, Lei,Guo, Shan,Wang, Qi,Zhu, Jin
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p. 5462 - 5466
(2019/08/01)
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- Synthesis of novel 3-[(1-glycosyl-1H-1,2,3-triazol-4-yl)- methylamino]ket-2-en-1-ones
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[Figure not available: see fulltext.] Nine 3-[(1-β-D-ribofuranosyl- and 3-[(1-β-D-glucopyranosyl-1H-1,2,3-triazol-4-yl)methylamino]ket-2-en-1-ones have been synthesized by copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction between propargylamine
- Kumar, Banty,Maity, Jyotirmoy,Kumar, Amit,Khatri, Vinod,Shankar, Bhawani,Prasad, Ashok K.
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p. 362 - 368
(2018/06/04)
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- Diversity-oriented four-component synthesis of solid state luminescent difluoro oxazaborinines
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(Hetero)aroyl chlorides, alkynes, anilines, and BF3 diethyl etherate are reacted in an alkynylation-amination-cyclization one-pot process to give trisubstituted difluoro oxazaborinines in moderate to very good yield in the sense of a consecutiv
- Dohe, Janis,Ko?mann, Janina,Müller, Thomas J.J.
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p. 198 - 217
(2018/05/22)
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- Merging " Anti-Baldwin" 3- Exo-Dig Cyclization with 1,2-Alkynyl Migration for Radical Alkylalkynylation of Unactivated Olefins
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A new combination of "anti-Baldwin" 3-exo-dig cyclization with 1,2-alkynyl migration of 1,4-enynes with simple cycloalkanes was established, enabling C-C breaking and reconstruction to access a wide range of α-alkynyl ketones with generally good yields by
- Zhao, Qi,Ji, Xiao-Shuang,Gao, Yi-Yun,Hao, Wen-Juan,Zhang, Ke-Ying,Tu, Shu-Jiang,Jiang, Bo
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supporting information
p. 3596 - 3600
(2018/06/26)
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- Copper-catalyzed stereo- and chemoselective synthesis of enaminones via Michael type addition
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Abstract: An efficient strategy for the synthesis of α ,β -unsaturated enaminones by the nucleophilic addition of N-heterocycles such as indole and imidazoles onto electronically bias alkynones under mild reaction conditions is described. Key feature of this reaction is the chemoselective addition of N-heterocycles onto ynones without affecting the 1 o amino groups (aromatic and aliphatic) of 5-aminoindole and tryptamine. The stereochemistry of the products was controlled by the tuning of reaction time. The mechanism of the reaction involves the Michael type addition of N-heterocycles on ynones via allene formation. Graphical Abstract: [Figure not available: see fulltext.].
- Patel, Monika,Sushmita,Verma, Akhilesh Kumar
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- Rhodium-Catalyzed Intermolecular trans-Disilylation of Alkynones with Unactivated Disilanes
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Disilylation of alkynes could provide rapid entry to synthetically useful 1,2-bissilyl-alkenes, but is currently limited to activated disilanes reacting in an intramolecular fashion. Reported herein is an efficient rhodium(I)-catalyzed intermolecular disi
- He, Tao,Liu, Li-Chuan,Guo, Le,Li, Bin,Zhang, Qing-Wei,He, Wei
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supporting information
p. 10868 - 10872
(2018/07/31)
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- An effective preparation of both 1,3-diketones and nitriles from alkynones with oximes as hydroxide sources
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An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
- Chen, Pei,Zhang, Qian-Qian,Guo, Jia,Chen, Lu-Lu,Wang, Yan-Bo,Zhang, Xiao
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p. 6958 - 6966
(2018/10/02)
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- Regio- and Stereoselective Hydrosulfonylation of Electron-Deficient Alkynes: Access to Both E- and Z-β-Sulfonyl-α,β-Unsaturated Carbonyl Compounds
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A metal-free hydrosulfonylation of electron-deficient alkynes with sodium sulfinates or sulfinic acids to access both E- and Z-β-sulfonyl-α,β-unsaturated carbonyl compounds has been developed. We propose that this reaction via a hydroxylallene intermediate delivers the thermodynamically stable E isomer, or via a concerted termolecular AdE3 mechanism affords Z isomer. The stereoselectivity of addition (syn or anti) can be controlled by varying the sulfonyl sources and acidic buffer solutions. This protocol exhibits broad substrate scope for internal or terminal alkynes including various substituted ynones and alkynyl esters. This approach is mild, efficient, operationally simple and easy to be scaled-up. (Figure presented.).
- Zhang, Wei,Johnson, Gabriel M.,Guan, Zhi,He, Yan-Hong
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supporting information
p. 4562 - 4570
(2018/10/24)
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- Novel (N-heterocyclic carbene)Pd(pyridine)Br2 complexes for carbonylative Sonogashira coupling reactions: Catalytic efficiency and scope for arylalkynes, alkylalkynes and dialkynes
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New N,N′-substituted imidazolium salts and their corresponding dibromidopyridine–palladium(II) complexes were successfully synthesized and characterized. Reactions of palladium bromide with the newly synthesized N,N′-substituted imidazolium bromides (2a a
- Ibrahim, Mansur,Malik, Imran,Mansour, Waseem,Sharif, Muhammad,Fettouhi, Mohammed,El Ali, Bassam
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- Integration of co2 reduction with subsequent carbonylation: Towards extending chemical utilization of co2
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Currently, it still remains a challenge to amplify the spectrum of chemical fixation of CO2, although enormous progress has been achieved in this field. In view of the widespread applications of CO in a myriad of industrial carbonylation processes, an alternative strategy is proposed in which CO2 reduction to CO is combined with carbonylation with CO generated ex situ, which affords efficiently pharmaceutically and agrochemically attractive molecules. As such, CO2 in this study was efficiently reduced by triphenysilane using CsF to CO in a sealed two-chamber reactor. Subsequently, palladium-catalyzed aminocar-bonylation, carbonylative Sonogashira coupling of aryl iodides, and rhodium(I)-mediated Pauson–Khand-type reaction proceeded smoothly to yield amides, alkynones, and bicyclic cy-clopentenones, respectively. Furthermore, the formed alkynones can further be successfully converted to a series of heterocycles, for example, pyrazoles, 3a-hydroxyisoxazolo[3,2-a]isoindol-8-(3aH)-one derivatives and pyrimidines in moderate yields. The striking features of this protocol include operational simplicity, high efficiency, and relatively broad application scope, which represents an alternative avenue for CO2 transformation.
- Lang, Xian-Dong,He, Liang-Nian
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- Efficient Synthesis of Polysubstituted Pyrroles Based on [3+2] Cycloaddition Strategy Utilizing [1,2]-Phospha-Brook Rearrangement under Br?nsted Base Catalysis
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An efficient method for the synthesis of polysubstituted pyrroles was established based on the [3+2] cycloaddition strategy utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The less-explored approach of the [3+2] cycloaddition, that is, the reaction of a C3 subunit with imines, was successfully achieved by making use of newly designed C3 subunits containing the requisite umpolung. The two-step formal [3+2] cycloaddition involves the catalytic generation of an α-oxygenated propargyl anion through the [1,2]-phospha-Brook rearrangement followed by γ-addition to the imine under Br?nsted base catalysis and the subsequent intramolecular cyclization mediated by Au catalyst or a halogenation reagent to afford polysubstituted pyrroles having a variety of substituents in a positional selective manner. The pyrroles thus synthesized were amenable to further transformations, such as palladium-catalyzed cross-coupling reactions. The operationally very simple method with readily available substrates provides new access to a diverse array of well-organized polysubstituted pyrroles.
- Kondoh, Azusa,Iino, Akio,Ishikawa, Sho,Aoki, Takuma,Terada, Masahiro
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supporting information
p. 15246 - 15253
(2018/10/15)
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- Visible-light-mediated dehydrogenative cross-coupling between terminal alkynes and aldehydes by employing a supramolecular polymeric ensemble of PBI derivative
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A supramolecular polymer of PBI derivative and ZnO NPs has been developed which exhibits remarkable efficiency in direct dehydrogenative cross-coupling between terminal alkynes and aldehydes for the synthesis of ynones under photocatalytic conditions.
- Kataria, Meenal,Deol, Harnimarta,Singh, Gurpreet,Kumar, Manoj,Bhalla, Vandana
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supporting information
p. 822 - 826
(2018/02/06)
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- Nano CoCuFe2O4 catalyzed coupling reaction of acid chlorides with terminal alkynes: A powerful toolbox for palladium-free ynone synthesis
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The present work describes the application of nano CoCuFe2O4 toward the coupling reaction of acyl chlorides with terminal alkynes. By this catalytic system, ynone derivatives were formed in high yields via a palladium-free strategy.
- Matloubi Moghaddam, Firouz,Pourkaveh, Raheleh,Ahangarpour, Marzieh
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- Development of Gold-catalyzed [4+1] and [2+2+1]/[4+2] Annulations between Propiolate Derivatives and Isoxazoles
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Two new gold-catalyzed annulations of isoxazoles with propiolates have been developed. Most isoxazoles follow an initial O attack on the alkyne to afford a [4+1] annulation product. This process results in a remarkable alkyne cleavage of initial propiolates. Unsubstituted isoxazoles proceed through an N attack step to yield formal [2+2+1]/[4+2] annulation products. These two annulation products arise initially from two seven-membered heterocyclic intermediates, which then lead to products.
- Sahani, Rajkumar Lalji,Liu, Rai-Shung
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supporting information
p. 1026 - 1030
(2017/01/18)
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- Copper-Mediated Domino Cyclization/Trifluoromethylation/Deprotection with TMSCF3: Synthesis of 4-(Trifluoromethyl)pyrazoles
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A copper-mediated synthesis of 4-(trifluoromethyl)pyrazoles is described. In one step from readily accessible α,β-alkynic tosylhydrazones, a remarkable domino sequence of cyclization, trifluoromethylation, and detosylation takes place to furnish the 4-CF3 N-H pyrazole cores with good functional group compatibility. The reaction conditions are mild and convenient, at room temperature in air, using the commercially available trifluoromethyltrimethylsilane (TMSCF3) as the CF3 source. The method can be applied to the synthesis of a 4-CF3 analogue of the anti-inflammatory drug celecoxib.
- Wang, Quande,He, Lisi,Li, Kin Keung,Tsui, Gavin Chit
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supporting information
p. 658 - 661
(2017/02/10)
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- A phosphine-free, heterogeneous palladium-catalyzed atom-efficient carbonylative cross-coupling of triorganoindiums with aryl halides leading to unsymmetrical ketones
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The first phosphine-free heterogeneous palladium-catalyzed carbonylative cross-coupling of aryl halides with triorganoindiums has been developed that proceeds smoothly under 1 or 2.5 atm of carbon monoxide in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable unsymmetrical ketones with high atom-economy, good yield, and recyclability of the catalyst. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
- You, Shengyong,Xiao, Ruian,Liu, Haiyi,Cai, Mingzhong
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p. 13862 - 13870
(2017/11/27)
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- A phosphine-free, atom-efficient cross-coupling reaction of triorganoindiums with acyl chlorides catalyzed by immobilization of palladium(0) in MCM-41
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The first phosphine-free heterogeneous palladium(0)-catalyzed cross-coupling of triorganoindiums with acyl chlorides has been developed that proceeds smoothly in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable aryl ketones and α,β-acetylenic ketones with high atom-economy and high yield. This phosphine-free heterogeneous palladium(0) catalyst can be easily prepared from commercially available reagents and recovered by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
- Miao, Jiankang,Huang, Bin,Liu, Haiyi,Cai, Mingzhong
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p. 42570 - 42578
(2017/09/11)
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- Oxyboration with and without a Catalyst: Borylated Isoxazoles via B-O-Bond Addition
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Herein we report an oxyboration reaction with activated substrates that employs B-O σ bond additions to C-C π bonds to form borylated isoxazoles, which are potential building blocks for drug discovery. Although this reaction can be effectively catalyzed by gold, it is the first example of uncatalyzed oxyboration of C-C π bonds by B-O σ bonds-and only the second example that is catalyzed. This oxyboration reaction is tolerant of groups incompatible with alternative lithiation/borylation and palladium-catalyzed C-H activation/borylation technologies for the synthesis of borylated isoxazoles.
- Tu, Kim N.,Hirner, Joshua J.,Blum, Suzanne A.
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supporting information
p. 480 - 483
(2016/02/18)
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- PHOSPHINE COMPOUND HAVING PERFLUORO GROUP, AND COMPLEX BETWEEN METAL AND PHOSPHINE HAVING PERFLUORO GROUP
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PROBLEM TO BE SOLVED: To provide a perfluoroalkylphosphine compound, and a complex between a metal and the perfluoroalkylphosphine. SOLUTION: A perfluoroalkylphosphine compound is a phosphine compound represented by the general formula Rf-PR1R2. In the formula, R1 and R2 are each independently a substituted or unsubstituted hydrocarbon group; Rf is a perfluorinated hydrocarbon group. Also provided is a complex between the perfluoroalkylphosphine and a phosphine coordination metal. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0271; 0275; 0277
(2018/10/16)
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- METHODS OF PRODUCING PHOSPHINE COMPOUND HAVING PERFLUORO GROUP AND COMPLEX BETWEEN METAL AND PHOSPHINE HAVING PERFLUORO GROUP
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PROBLEM TO BE SOLVED: To provide methods of producing a perfluoroalkylphosphine compound improved in a phosphorus element yield and a chemical yield. SOLUTION: A method of producing a perfluoroalkylphosphine compound comprises either reacting a perfluoroalkyl iodide with, e.g., 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TMDPO) or a triarylphosphine such as triphenylphosphine, which are easily available, in the presence of a radical generator such as azobis(isobutyronitrile) or light irradiation, or reacting TMDPO or the like with perfluoroalkyl iodide in the presence of diphenylphosphine, diethylphosphine, dicyclohexylphosphine or the like. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0233; 0235
(2018/10/19)
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- A highly efficient heterogeneous palladium-catalyzed cascade three-component reaction of acid chlorides, terminal alkynes and hydrazines leading to pyrazoles
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In the presence of 0.5 mol% of 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-Pd(OAc)2] and 1.0 mol% of CuI, acid chlorides were coupled with terminal alkynes in Et3N at 50 °C to give α,β-unsaturated ynones, which were converted in situ into pyrazoles by the cycloaddition of hydrazines at room temperature with acetonitrile as cosolvent. The cascade reactions generated a variety of pyrazole derivatives in moderate to good yields, and this heterogeneous palladium catalyst exhibited higher catalytic activity than PdCl2(PPh3)2 and could be recovered and reused for at least 10 consecutive trials without any decreases in activity.
- Chen, Qiurong,Yao, Fang,Yin, Lin,Cai, Mingzhong
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p. 108 - 113
(2016/01/15)
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- A propargyl alcohol oxidation system acetylenic ketone method
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The invention provides a method for preparing acetylenic ketone through oxidizing propargyl alcohol. The method comprises the following steps: in a liquid phase, taking 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) as the catalyst, nitric acid as the co-catalyst, and oxygen gas as the oxidant, and oxidizing propargyl alcohol in an organic solvent so as to produce acetylenic ketone. The method has the advantages of mild conditions, convenient operation, no metal, and little pollution, and is a green and environment-friendly novel method for preparing ketone through oxidizing alcohol with a non-metal catalyst.
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Paragraph 0036; 0037; 0038
(2016/10/10)
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- Palladium-catalyzed Sonogashira coupling of amides: Access to ynones: Via C-N bond cleavage
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The first palladium-catalyzed Sonogashira coupling of amides has been developed, which proceeds via a selective cleavage of the N-acylsaccharin C-N bond. Notably, the new approach employs N-acylsaccharins as coupling partners to give ynones in good to excellent yield. This protocol can be efficiently utilized in the synthesis of a broad array of ynones under low catalyst loading and Cu-free conditions.
- Cui, Ming,Wu, Hongxiang,Jian, Junsheng,Wang, Hui,Liu, Chao,Daniel, Stelck,Zeng, Zhuo
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p. 12076 - 12079
(2016/10/13)
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- Ligand-Controlled Divergent Cross-Coupling Involving Organosilicon Compounds for Thioether and Thioester Synthesis
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A divergent cross-coupling for both thioether and thioester construction from organosilicon compounds has been developed. Predominant selectivity for Hiyama-type coupling and C1 insertion reaction was achieved under the guidance of ligands. Thioether was obtained under ligand-free conditions in which disulfide generated from homocoupling could be prevented. Meanwhile, application of bidentate phosphine ligands under carbon monoxide atmosphere (CO balloon) afforded the thioester with little decomposition, which was revealed through interval NMR tracking.
- Qiao, Zongjun,Jiang, Xuefeng
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p. 1550 - 1553
(2016/05/02)
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- Facile synthesis of iodopyridines from N-propargylic β-enaminones via iodine-mediated electrophilic cyclization Dedicated to the memory of Professor Dr Tu?ma? Sayra?
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A facile, efficient and general synthetic method for iodopyridines is described. When treated with molecular iodine in the presence of sodium bicarbonate, N-propargylic β-enaminones have underwent electrophilic cyclization to afford iodo-substituted pyrid
- Karabiyikoglu, Sedef,Kelgokmen, Yilmaz,Zora, Metin
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supporting information
p. 4324 - 4333
(2015/06/08)
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- Indium-Catalyzed [2 + 2] Cycloaddition of Allylsilanes to Internal Alkynones
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We have developed an indium-catalyzed [2 + 2] cycloaddition of allylsilanes to alkynones leading to selective cyclobutenone formation. The resulting cyclobutenones were readily converted to the oxidized products by Tamao-Fleming oxidation or the ring-open
- Okamoto, Kazuhiro,Shimbayashi, Takuya,Tamura, Eisuke,Ohe, Kouichi
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supporting information
p. 5843 - 5845
(2015/12/11)
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- Sequential palladium catalyzed coupling-cyclocondensation-coupling (C3) four-component synthesis of intensively blue luminescent biarylsubstituted pyrazoles
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1-, 3-, and 5-Biarylsubstituted pyrazoles can be efficiently prepared by a microwave-assisted consecutive four-component synthesis based upon a sequential Pd-catalyzed coupling-condensation-coupling (C3), a one-pot sequence which concatenates S
- Deni?en, Melanie,Nordmann, Jan,Dziambor, Julian,Mayer, Bernhard,Frank, Walter,Müller, Thomas J. J.
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p. 33838 - 33854
(2015/04/27)
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- Synthesis of 3,5-disubstituted-1H-pyrazoles from acid chlorides, alkynes, and hydrazine in the presence of silica-supported-zinc bromide
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An efficient one-pot palladium- And copper-free procedure has been developed for a convenient synthesis of 3,5-disubstituted-1H-pyrazoles from various acid chlorides, terminal alkynes and hydrazine by a coupling reaction and cyclocondensation sequence. Acid chlorides react with terminal alkynes in the presence of silica-supported-zinc bromide to give α,β-unsaturated ynones, and in situ conversion into pyrazoles by the hydrazine cyclocondensation.
- Keivanloo, Ali,Bakherad, Mohammad,Samangooei, Shahrzad
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p. 484 - 486
(2015/11/03)
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- The thermoregulated ligand-palladium-catalyzed carbonylative Sonogashira coupling of aryl iodides with terminal alkynes in water
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An efficient and recyclable protocol via thermoregulated phase-transfer catalysis to separate the catalyst in pure water for the carbonylative Sonogashira coupling of aryl iodides with terminal alkynes has been successfully developed using the thermoregulated ligand Ph2P(CH2CH2O)nCH3 (n ≈ 22). This method allows the synthesis of a variety of alkynones in moderate to good yields (70-91%) and the catalytic system can be recycled four times without significant loss of activity.
- Hao, Yuanping,Jiang, Jingyang,Wang, Yanhua,Jin, Zilin
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p. 608 - 611
(2015/09/01)
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- Decarboxylative Alkynylation of α-Keto Acids and Oxamic Acids in Aqueous Media
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A mild K2S2O8 promoted decarboxylative alkynylation of α-keto acids and oxamic acids has been developed. This process features mild reaction conditions, a broad substrate scope, and good functional-group tolerance, therefo
- Wang, Hua,Guo, Li-Na,Wang, Shun,Duan, Xin-Hua
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supporting information
p. 3054 - 3057
(2015/06/30)
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- Palladium- and solvent-free synthesis of ynones by copper(I)-catalyzed acylation of terminal alkynes with acyl chlorides under aerobic conditions
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Air-stable CuI/cryptand-22 complex was found to be a highly active catalyst for the solvent-free cross-coupling reaction of terminal alkynes with different acyl chlorides in the presence of Et3N as base to give the corresponding ynon
- Mohammadi, Elmira,Movassagh, Barahman,Navidi, Mozhgan
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- Recyclable and reusable PdCl2(PPh3) 2/PEG-2000/H2O system for the carbonylative Sonogashira coupling reaction of aryl iodides with alkynes
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PdCl2(PPh3)2 in a mixture of water and poly(ethylene glycol) (PEG-2000) is shown to be an extremely active catalyst for the carbonylative Sonogashira coupling reaction of aryl iodides with terminal alkynes. The reaction can be conducted under an atmospheric pressure of carbon monoxide at 25 °C with Et3N as a base, yielding a variety of alkynyl ketones in good to excellent yields. Application of this synthetic method to prepare flavones from o-iodophenol and terminal alkynes was also achieved. The isolation of the products is readily achieved by extraction with diethyl ether, and the PdCl2(PPh3)2/PEG-2000/ H2O system can be easily recycled and reused six times without any loss of catalytic activity. the Partner Organisations 2014.
- Zhao, Hong,Cheng, Mingzhu,Zhang, Jiatao,Cai, Mingzhong
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supporting information
p. 2515 - 2522
(2014/05/06)
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