2979-05-7Relevant articles and documents
Cobalt-catalyzed homocoupling of terminal alkynes: Synthesis of 1,3-diynes
Krafft,Hirosawa,Dalal,Ramsey,Stiegman
, p. 7733 - 7736 (2001)
Homocoupling of terminal alkynes proceeds using Co2(CO)8 pretreated with phenanthroline to give good yields of 1,3-diynes under mild conditions.
Efficient and recyclable reaction system for the homocoupling of terminal acetylenes
Lu, Xiaoling,Zhang, Yuhong,Luo, Chengcai,Wang, Yanguang
, p. 2503 - 2511 (2006)
Diynes were synthesized in high yields by homocoupling of terminal arylacetylenes and terminal alkylacetylenes in Cu(OAc)2-PEG (polyethyleneglycol) with NaOAc as a base. Cu(OAc)2-PEG was readily recycled via solvent precipitation with efficient recyclability. Copyright Taylor & Francis Group, LLC.
Trithiocarbonate Anion as a Sulfur Source for the Synthesis of 2,5-Disubstituted Thiophenes and 2-Substituted Benzo[ b]thiophenes
Paix?o, Douglas B.,Rampon, Daniel S.,Salles, Helena D.,Soares, Eduardo G. O.,Bilheri, Filipe N.,Schneider, Paulo H.
supporting information, p. 12922 - 12934 (2020/11/26)
The trithiocarbonate anion (CS32-) was generated in situ from CS2 and KOH in dimethyl sulfoxide by a simple method and used as a novel synthetic equivalent of the S2- synthon for the synthesis of 2,5-disubstituted thiophenes from 1,3-butadiynes. Additionally, this system was employed for the metal-free synthesis of 2-substituted benzo[b]thiophenes from 2-haloalkynyl (hetero)arenes. These compounds were obtained from a cheap and readily available sulfur source in moderate to good yields, with good functional group tolerance.
Synthesis of 8-carbo substituted 2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-ones and their thienoangelicin derivatives
Olomola, Temitope O.,Mphahlele, Malose J.
, (2019/12/03)
Tandem Sonogashira cross-coupling and heteroannulation of 7-hydroxy-8-iodo-2-(trifluoromethyl)chromen-4-one with terminal acetylenes afforded the 8-carbo–substituted 2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-ones 2a–i. The latter were reacted with methyl mercaptoacetate in the presence of triethylamine to afford the corresponding 7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one derivatives 3a–i. The structures of the prepared compounds were characterized using a combination of NMR (1H-, 13C & 19F-), IR and mass spectroscopic techniques, and confirmed by single X-ray crystal structures of 8-(3-fluorophenyl)-2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-one (2b) and 2-phenyl-7-(trifluoromethyl)-7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one (3a). The highlight of this investigation is the conversion of 2-(trifluoromethyl)–substituted 4H-furo[2,3-h]chromen-4-ones into trifluoromethyl–substituted thienoangelicin analogues.
Copper-Mediated Deacylative Coupling of Ynones via C-C Bond Activation under Mild Conditions
Feng, Lili,Hu, Tingjun,Zhang, Saisai,Xiong, Heng-Ying,Zhang, Guangwu
, p. 9487 - 9492 (2019/12/02)
The intermolecular deacylative coupling of unstrained ynones via C-C bond activation was accomplished by a CuCl-bpy system under mild reaction conditions. This protocol features facile cleavage of the C-C bond at room temperature, broad substrate scope, and efficient construction of important symmetric and unsymmetrical 1,3-diyne adducts through homo or cross coupling of ynones, respectively. The preliminary mechanistic investigations indicated that an acyl copper(III) complex is likely involved in this process.
Palladium-Catalyzed Aerobic Homocoupling of Alkynes: Full Mechanistic Characterization of a More Complex Oxidase-Type Behavior
Toledo, Alberto,Funes-Ardoiz, Ignacio,Maseras, Feliu,Albéniz, Ana C.
, p. 7495 - 7506 (2018/07/21)
A combined experimental and computational approach has been used to shed light on the mechanism of the Pd-catalyzed oxidative homocoupling of alkynes using oxygen as the oxidant. Mechanistic understanding is important because of the synthetically relevant direct involvement of oxygen in the oxidative coupling and because of the presence of related processes as undesired side reactions in cross-coupling reactions involving terminal alkynes. A low-ligated [Pd(PPh3)(alkyne)] complex is key in the process, and it can be conveniently generated from allylic palladium(II) complexes in the presence of a base or from Pd(I) allylic dimers as precatalysts. The catalytic coupling occurs by alkyne metalation to give an anionic [Pd(PPh3)(alkynyl)]- complex that is then oxidized by oxygen. The interaction with oxygen occurs only on this electron-rich Pd(0) anionic species and leads to a (κO,κO-peroxo)palladium(II) singlet intermediate that undergoes subsequent protonolysis to give a (κO-hydroperoxo)palladium(II) complex and then hydrogen peroxide. The second alkyne metalation occurs on a Pd(II) derivative to give a bis(alkynyl)palladium(II) complex that evolves to the product by reductive elimination as the product-forming step. This reaction is an oxidase-type process that, in contrast to most Pd-catalyzed oxidative processes, occurs without separation of the substrate transformation and the catalyst oxidation, with these two processes being intertwined and dependent on one another.
Polymer-Supported Cu–Nanoparticle as an Efficient and Recyclable Catalyst for Oxidative Homocoupling of Terminal Alkynes
Aziz, Sk Tarik,Islam, Rafique Ul
, p. 205 - 213 (2017/11/16)
Abstract: Copper nanoparticle on polyaniline support was synthesised by using in situ polymerisation and composite formation technique. This metal polymer nanocomposites material is found to be efficient for homocoupling of terminal alkynes which afford s
The symmetry of the 1, 4 - disubstituted - 1, 3 - butadiyne preparation method
-
Paragraph 0041; 0042; 0043; 0044, (2017/04/07)
The invention discloses a preparation method of symmetric 1,4-disubstituted-1,3-diacetylene. Homocoupling of alkyne is carried out in a solvent in the presence of an alkali with silver as a catalyst to obtain the symmetric 1,4-disubstituted-1,3-diacetylen
Copper catalyzed oxidative homocoupling of terminal alkynes to 1,3-diynes: A Cu3(BTC)2 MOF as an efficient and ligand free catalyst for Glaser-Hay coupling
Devarajan, Nainamalai,Karthik, Murugan,Suresh, Palaniswamy
, p. 9191 - 9199 (2017/11/14)
A straightforward and efficient method has been demonstrated for the oxidative coupling of terminal alkynes using a simple Cu3(BTC)2-metal organic framework as a sustainable heterogeneous copper catalyst. A series of symmetrical 1,3-diynes bearing diverse functional groups have been synthesized in moderate to excellent yields via a Cu3(BTC)2 catalyzed Glaser-Hay reaction. The presence of the coordinatively unsaturated open CuII sites in Cu3(BTC)2 catalyzes the homocoupling in the presence of air, as an environment friendly oxidant without the use of external oxidants, ligands or any additives. The present methodology avoids stoichiometric reagents and harsher or special reaction conditions, and shows good functional group tolerance. The as-prepared catalyst could be separated easily by simple filtration and reused several times without any notable loss in activity. The hot filtration test has investigated the true heterogeneity of the catalyst. Additionally, the powder X-ray diffraction pattern of the reused catalyst revealed the high stability of the catalyst.
Application of the polyacrylonitrile fiber as a novel support for polymer-supported copper catalysts in terminal alkyne homocoupling reactions
Shi, Xian-Lei,Hu, Qianqian,Wang, Fang,Zhang, Wenqin,Duan, Peigao
, p. 233 - 239 (2016/03/08)
A commercially available synthetic polyacrylonitrile fiber, capable of acting as a novel support for polymer-supported copper catalyst in terminal alkyne homocoupling reactions, is presented. Detailed characterization by inductively coupled plasma (ICP) analysis, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) confirmed the changes and stability of the fiber catalyst during the modification and utilization processes. Moreover, the catalytic reactions proceeded at room temperature using air as a green oxidant to afford nearly quantitative yields (95-99%); the fiber catalyst has shown excellent activity and superior recyclability (over 16 cycles); and the procedure is operationally simple and amenable to the gram scale in continuous-flow processing. Furthermore, the prominent features (high strength, good flexibility, etc.) of the polyacrylonitrile fiber make the fiber-supported catalyst very attractive for fixed-bed reactors in the chemical industry.
