23429-36-9Relevant academic research and scientific papers
In Situ Synthesis of CuN4/Mesoporous N-Doped Carbon for Selective Oxidative Crosscoupling of Terminal Alkynes under Mild Conditions
Cao, Yue,Gu, Dong,Lei, Aiwen,Liang, Zhenjin,Su, Yaqiong,Wu, Jinsong,Wu, Yong,Xiao, Wei,Yang, Dali,Yu, Ruohan,Zhang, Dongchao,Zhang, Yuanteng
, (2021/12/23)
The 1,3-conjugated diynes are an important class of chemical intermediates, and the selective crosscoupling of terminal alkynes is an efficient chemical process for manufacturing asymmetrical 1,3-conjugated diynes. However, it often occurs in homogenous conditions and costs a lot for reaction treatment. Herein, a copper catalyzed strategy is used to synthesize highly ordered mesoporous nitrogen-doped carbon material (OMNC), and the copper species is in situ transformed into the copper single-atom site with four nitrogen coordination (CuN4). These features make the CuN4/OMNC catalyst efficient for selective oxidative crosscoupling of terminal alkynes, and a wide range of asymmetrical and symmetrical 1,3-diynes (26 examples) under mild conditions (40?°C) and low substrates ratio (1.3). Density functional theory (DFT) calculations reveal that the aryl–alkyl crosscoupling has the lowest energy barrier on the CuN4 site, which can explain the high selectivity. In addition, the catalyst can be separated and reused by simply centrifugation or filtration. This work can open a facile avenue for constructing single-atom loaded mesoporous materials to bridge homogeneous and heterogeneous catalysis.
Bimetal Cooperatively Catalyzed Arylalkynylation of Alkynylsilanes
Chen, Xing,Li, Mengke,Liu, Zhipeng,Yang, Can,Xie, Haisheng,Hu, Xinwei,Su, Shi-Jian,Jiang, Huanfeng,Zeng, Wei
supporting information, p. 6724 - 6728 (2021/09/08)
An unprecedented Pd/Rh cooperatively catalyzed arylalkynylation of alkynylsilanes was developed to merge an alkynylidene moiety with benzosilacycle. These silaarenes possess a particular aggregation-induced emission behavior. Mechanistic investigations demonstrate that the relay trimetallic transmetalation plays a pivotal role in governing this transformation.
Evidence of a Photoinduced Electron-Transfer Mechanism in the Fluorescence Self-quenching of 2,5-Substituted Selenophenes Prepared through in Situ Reduction of Elemental Selenium in Superbasic Media
De Salles, Helena Domingues,Coelho, Felipe Lange,Paix?o, Douglas Bernardo,Barboza, Cristina Aparecida,Da Silveira Rampon, Daniel,Rodembusch, Fabiano Severo,Schneider, Paulo Henrique
, p. 10140 - 10153 (2021/07/31)
A series of new 2,5-disubstituted selenophene derivatives are described from elemental selenium and 1,3-diynes in superbasic media. The activation of elemental selenium in a KOH/DMSO system allows cyclization with conjugated diynes at room temperature. The cyclization reaction is extended to a broad range of functional groups, for which photophysics were experimentally and theoretically investigated. The selenophene derivatives present absorption maxima in the UV-A region and fluorescence emission in the violet-to-blue region. Fluorescence decay profiles were obtained showing a monoexponential decay with fast fluorescence lifetimes (~0.118 ns), as predicted by the Strickler-Berg relations. In general, in both investigations, no dependence on the solvent polarity on the absorption and emission maxima location was observed. On the other hand, solvents and substituents are shown to play a role in the fluorescence quantum yield values. In addition, a fluorescence self-quenching behavior could be observed, related to a photoinduced electron-transfer mechanism. Theoretical calculations performed at the MP2/ADC(2)/cc-pVDZ level of theory were performed in order to investigate the photophysical features of this series of selenophene derivatives.
Reduced graphene oxide supported copper oxide nanocomposites: An efficient heterogeneous and reusable catalyst for the synthesis of ynones, 1,3-diynes and 1,5-benzodiazepines in one-pot under sustainable reaction conditions
Sarkar, Rajib,Gupta, Ajay,Jamatia, Ramen,Pal, Amarta Kumar
, (2020/03/16)
A greener and efficient method for the synthesis of ynones and 1,3-diynes using copper oxide nanoparticles (CuONPs) doped reduced graphene oxide (CuO@rGO) catalyst under palladium, ligand and solvent free conditions have been developed. The catalyst was s
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.
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.
Copper Nanoparticles on Ordered Mesoporous Carbon Nitride Support: a Superior Catalyst for Homo- and Cross-Coupling of Terminal Alkynes under Base-Free Conditions
Xu, Hang,Wu, Liangying,Tian, Jing,Wang, Jun,Wang, Peng,Niu, Xiyu,Yao, Xiaoquan
, p. 6690 - 6696 (2019/11/02)
A novel ordered mesoporous carbon nitride (OMCN) was synthesized as a functionalized support with 2,4,6-trichloro-1,3,5-triazine and benzidine as starting materials in the presence of SBA-15 as a template. Copper nanoparticles were then loaded on the C–N material to achieve a novel nanocomposite catalyst (Cu NPs-OMCN). The nanocomposite was utilized as a highly efficient catalyst for homo- and cross-coupling of terminal alkynes under base-free conditions in ethanol, and various symmetrical and unsymmetrical 1,3-diynes were obtained with good to excellent yields. Moreover, based on this reaction, a one-pot approach to synthesize 2,5-disubstituted thiophenes and furans from terminal alkynes were developed. Furthermore, the heterogeneous catalyst could be recovered and reused conveniently for several times with satisfactory yields.
Copper (II) catalyzed homocoupling and heterocoupling of terminal alkynes
Holganza, Maria Katrina,Trigoura, Leslie,Elfarra, Suzanne,Seo, Yoona,Oiler, Jeremy,Xing, Yalan
, p. 1179 - 1181 (2019/03/28)
Cu(OTf)2 catalyzed homo– and heterocoupling of aromatic and aliphatic terminal alkynes has been developed. Symmetric and unsymmetric 1,3-diynes have been synthesized in good yields under an aerobic condition in the presence of an organic base D
Self-assembly of catalytically active supramolecular coordination compounds within metal?organic frameworks
Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H.G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E.P.,Domenech-Carbo, Antonio,Leyva-Perez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesus
supporting information, p. 10350 - 10360 (2019/08/20)
Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal?organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs@MOF) and its post-assembly metalation to give a PdII?AuIII supramolecular assembly, crystallography underpinned. These SCCs@MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
Self-Assembly of Catalytically Active Supramolecular Coordination Compounds within Metal-Organic Frameworks
Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H. G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E. P.,Doménech-Carbó, Antonio,Leyva-Pérez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesús
supporting information, p. 10350 - 10360 (2019/08/27)
Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal-organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs?MOF) and its post-assembly metalation to give a PdII-AuIII supramolecular assembly, crystallography underpinned. These SCCs?MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
