438583-58-5Relevant academic research and scientific papers
Oxidative Addition of Alkenyl and Alkynyl Iodides to a AuI Complex
Bower, John F.,Cadge, Jamie A.,Russell, Christopher A.,Sparkes, Hazel A.
, p. 6617 - 6621 (2020/03/13)
The first isolated examples of intermolecular oxidative addition of alkenyl and alkynyl iodides to AuI are reported. Using a 5,5′-difluoro-2,2′-bipyridyl ligated complex, oxidative addition of geometrically defined alkenyl iodides occurs readily, reversibly and stereospecifically to give alkenyl-AuIII complexes. Conversely, reversible alkynyl iodide oxidative addition generates bimetallic complexes containing both AuIII and AuI centers. Stoichiometric studies show that both new initiation modes can form the basis for the development of C?C bond forming cross-couplings.
Strategy to isolate ionic gold sites on silica surface: Increasing their efficiency as catalyst for the formation of 1,3-diynes
Didó, Cezar A.,Coelho, Felipe L.,Closs, Maurício B.,Deon, Monique,Horowitz, Flavio,Bernardi, Fabiano,Schneider, Paulo H.,Benvenutti, Edilson V.
, (2020/02/11)
A new strategy is presented to obtain an efficient heterogeneous gold catalyst constituted by isolated ionic gold sites, which is known to be effective in alkyne coupling reaction. The procedure is based on a significant difference between offered gold amount and available adsorbent sites on the support, ensuring the formation of very active isolated gold ion sites. In order to achieve this purpose, mesoporous silica xerogel was grafted with an ionic silsesquioxane containing charged ammonium quaternary group. The modified silica showed 0.25 mmol of cationic sites per gram of material and presented thermal stability up to 200 °C. This material was applied as support for immobilization of Au(III) ions as square planar AuCl4? complex. The gold amount offered was just 12 % of the exchangeable capacity. The catalyst was efficiently applied in the cross coupling reactions, in which only 0.22 mol% was applied to obtain symmetric and non-symmetric 1,3-diynes.
Transition metal-free coupling of terminal alkynes and hypervalent iodine-based alkyne-transfer reagents to access unsymmetrical 1,3-diynes
Sch?rgenhumer,Waser
supporting information, p. 7561 - 7563 (2018/11/02)
A variety of unsymmetrical 1,3-diynes can easily be accessed in good yields under catalyst- and transition metal-free conditions by reacting terminal alkynes with hypervalent iodine-based electrophilic alkyne-transfer reagents.
Copper(II)/Palladium(II) catalysed highly selective cross-coupling of terminal alkynes in supercritical carbon dioxide
Wang, Yunlong,Suo, Quanling,Han, Limin,Guo, Linlin,Wang, Yaqi,Li, Fawang
, p. 1918 - 1925 (2018/03/12)
An efficient protocol for the synthesis of unsymmetrical 1,3-diynes was developed using supercritical carbon dioxide (ScCO2) as the solvent. The direct coupling of two different terminal alkynes is catalysed by a bimetallic catalyst, CuCl2·2H2O/Pd(NH3)4Cl2·H2O, in the presence of the base tetramethylethylenediamine (TMEDA) and O2. In pure ScCO2, our bimetallic catalytic system maintains high activity over a wide substrate scope to provide unsymmetrical 1,3-diynes in good to excellent yields. In the proposed reaction mechanism, the synergistic cooperation between copper(II) and palladium(II) centres is responsible for the superior selectivity of the cross-coupling.
Highly efficient synthesis of unsymmetrical 1,3-diynes from organoalane reagents and alkynyl bromides mediated by a nickel catalyst
Mo, Song,Shao, Xue-Bei,Zhang, Gang,Li, Qing-Han
, p. 27243 - 27247 (2017/07/11)
Highly efficient and simple cross-coupling reactions of alkynylbromides with organoalane reagents for the synthesis of unsymmetrical 1,3-diynes derivatives using Ni(OAc)2 (2-5 mol%)/(o-furyl)3P (4-10 mol%) as a catalyst are reported. Excellent yields (up to 94%) were obtained for a wide range of substrates at rt or 60 °C for 2-3 h in Et2O or toluene.
Synthesis method of asymmetric conjugated diyne
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Paragraph 0084-0089, (2017/08/29)
The invention provides a synthesis method of asymmetric conjugated diyne. The synthesis method comprises the following steps of A, mixing a catalyst with phenanthroline and a strong base, then adding cis-alkenyl bromide, terminal alkyne and a solvent in an argon atmosphere, and agitating, refluxing and making an obtained mixture react for 20h to 24h under a condition of 140 to 150 DEG C; B, extracting, drying and concentrating a product, and then separating and purifying the product through column chromatography, so that the asymmetric conjugated diyne is obtained. Compared with the prior art, the synthesis method provided by the invention is low in cost, easy in the obtaining of raw materials, relatively convenient to operate, high in efficiency, wide in serviceable range and suitable for the reaction of multiple substrates; further, the catalyst can be recycled.
Gold-Catalyzed Cadiot–Chodkiewicz-type Cross-Coupling of Terminal Alkynes with Alkynyl Hypervalent Iodine Reagents: Highly Selective Synthesis of Unsymmetrical 1,3-Diynes
Li, Xiangdong,Xie, Xin,Sun, Ning,Liu, Yuanhong
supporting information, p. 6994 - 6998 (2017/06/08)
A new and efficient method for the synthesis of unsymmetrical 1,3-butadiynes by gold-catalyzed C(sp)–C(sp) cross-coupling of terminal alkynes with alkynyl hypervalent iodine(III) reagents has been developed. The reaction features high selectivity and efficiency, mild reaction conditions, wide substrate scope, and functional-group compatibility, and is a highly attractive complement to existing methods. Mechanistic studies reveal that formation of a phenanthrolinyl-ligated gold(I) complex is crucial for the efficiency and selectivity of the target transformation.
Mesoporous Copper/Manganese Oxide Catalyzed Coupling of Alkynes: Evidence for Synergistic Cooperative Catalysis
Biswas, Sourav,Mullick, Kankana,Chen, Sheng-Yu,Kriz, David A.,Shakil, Md,Kuo, Chung-Hao,Angeles-Boza, Alfredo M.,Rossi, Angelo R.,Suib, Steven L.
, p. 5069 - 5080 (2016/08/18)
Copper oxide supported on mesoporous manganese oxide (meso Cu/MnOx) was synthesized by an inverse micelle templated evaporation induced self-assembly procedure. Controlled aggregation of nanoparticles and a monomodal size distribution of mesopores with tunable structural properties were observed. The material possessed superior catalytic activity in the aerobic oxidative coupling of terminal alkynes. Excellent conversion (>99% in most cases) and selectivity were observed in both homocoupling and cross-coupling of alkynes using the optimized reaction conditions. Use of air as the sole oxidant, avoidance of any kind of additives, ease of product separation, great functional group tolerability, wide synthetic scope, and superior reusability (up to eighth cycle) are the notable features of our catalytic protocol. While the reaction mechanism was elucidated, a synergistic cooperative effect between the copper and manganese has been established, which is responsible for the superior catalytic activity. The labile lattice oxygen of the meso Cu/MnOx played a vital role in deprotonation of the alkyne proton, as supported by TPD and TGA studies. Moreover, for the first time, we designed model complexes for the active sites of the catalyst by DFT calculations and provided a qualitative description of the coupling mechanism, which supports the experimental findings.
Visible-light-activated copper(i) catalyzed oxidative Csp-Csp cross-coupling reaction: Efficient synthesis of unsymmetrical conjugated diynes without ligands and base
Sagadevan, Arunachalam,Lyu, Ping-Chiang,Hwang, Kuo Chu
supporting information, p. 4526 - 4530 (2016/08/18)
A novel visible-light-promoted copper-catalysed process for the Csp-Csp cross-coupling reaction of terminal alkynes at room temperature is described. The current photochemical method is simple, highly functional group compatible, and more viable towards the construction of bio-active 1,3-unsymmetrical conjugated diynes without the need of bases/ligands, additives and expensive palladium/gold catalysts.
{Cu2+-Co3+-Cu2+} and {Cu2+-Fe3+-Cu2+} heterobimetallic complexes and their catalytic properties
Srivastava, Sumit,Ali, Afsar,Tyagi, Adish,Gupta, Rajeev
, p. 2113 - 2123 (2015/04/27)
We report on the heterobimetallic complexes {Cu+-Co3+-Cu+} (3), {Cu+-Fe3+-Cu+} (4), {Cu2+-Co3+-Cu2+} (5), and {Cu2+-Fe3+-Cu2+} (6) and show their catalytic applications in the oxidation of hindered phenols and the oxidative coupling of terminal alkynes. The former reaction produces C-C-coupled and dealkylated products, whereas the latter leads to the homo- and heterocoupling of terminal alkynes. The facile redox interconversion between Cu+ and Cu2+ for the secondary metal ions in these heterobimetallic complexes appears to be essential for the observed catalysis, and an important design aspect is better substrate accessibility and the use of molecular oxygen as the sole oxidant. Heterobimetallic complexes {Cu+-Co3+-Cu+} (3), {Cu+-Fe3+-Cu+} (4), {Cu2+-Co3+-Cu2+} (5), and {Cu2+-Fe3+-Cu2+} (6) have been used as catalysts for the oxidation of substituted phenols and the oxidative homo- and heterocoupling of terminal alkynes.
