5929-72-6Relevant academic research and scientific papers
Solid-state self-inclusion: The missing link
Lloyd, Gareth O.,Alen, Jo,Bredenkamp, Martin W.,De Vries, Elise J. C.,Esterhuysen, Catharine,Barbour, Leonard J.
, p. 5354 - 5358 (2006)
Molecular cannibalism: The concept of self-inclusion in the solid state can be subjective. A host-guest system is prepared in which the same compound (2,7-dimethyl-octa-3,5-diyne-2,7-diol) unequivocally plays both roles simultaneously. (Figure Presented).
Asymmetric synthesis of C2-symmetric axially chiral biaryls through rhodium-catalyzed and alkyne-controlled diastereoselective double [2+2+2] cycloaddition
Mori, Ayaka,Araki, Tatsuya,Miyauchi, Yuta,Noguchi, Keiichi,Tanaka, Ken
, p. 6774 - 6778 (2013)
The asymmetric synthesis of C2-symmetric axially chiral biaryls was achieved by the cationic rhodium(I)/1,3-bis(diphenylphosphino)propane (dppp) complex catalyzed diastereoselective double [2+2+2] cycloaddition of (R)-3-butyn-2-ol-derived tetraynes with functionalized monoynes. Interestingly, the use of propiolates afforded biaryls possessing large dihedral angles, and in contrast, the use of propargyl alcohol afforded biaryls possessing small dihedral angles. A cationic rhodium(I)/1,3-bis(diphenylphosphino)propane (dppp) complex catalyzed double [2+2+2] cycloaddition of (R)-3-butyn-2-ol-derived tetraynes with functionalized monoynes affords C2-symmetric axially chiral biaryls with complete diastereoselectivity. The use of propiolates affords biaryls possessing large dihedral angles, and in contrast, the use of propargyl alcohol affords biaryls possessing small dihedral angles. nbd = norbornadiene. Copyright
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.
Preparation method of water-soluble vitamin E participated conjugated diyne compound
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Paragraph 0137-0141, (2021/11/14)
The water-soluble vitamin E participates in the green preparation method of the conjugated diyne compound, the water serves as a reaction solvent, the use amount of the organic solvent is reduced, and zero emission of the solvent is realized. The excellent physicochemical properties of water are fully utilized, the reaction conditions are mild and efficient, the surfactant TPGS - 750 - M can be recycled through treatment, and the principle of environmental friendliness is completely met. The reaction substrate is wide in applicability, can catalyze the aryl alkyne, can catalyze the aliphatic hydrocarbon, and provides a simple and environment-friendly preparation method for the synthesis of the conjugated diyne. The copper catalyst which is more suitable for the reaction and reaction medium of the invention is screened out, and the yield is greatly improved.
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.
Tuning of cross-Glaser products mediated by substrate-catalyst polymeric backbone interactions
Ali, Md. Ehesan,Dar, Arif Hassan,Gowri, Vijayendran,Jayamurugan, Govindasamy,Kaur, Sharanjeet,Mukhopadhyaya, Aritra,Neethu, K. M.,Sartaliya, Shaifali,Selim, Abdul
supporting information, p. 2582 - 2585 (2020/03/10)
Tuning of cross-Glaser products using different polymeric backbones supported by copper oxide nano-catalysts has been demonstrated by tweaking the substrate-catalyst interactions under greener conditions. Further, highly reactive magnetically separable and recyclable catalyst with scalability is demonstrated.
SUBSTITUTED IMIDAZOLECARBOXYLATE DERIVATIVES AND THE USE THEREOF
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Paragraph 0912-0914, (2020/12/08)
A compound is shown in formula (I). The derivatives of the compound include a stereoisomer, a pharmaceutically acceptable salt, a solvate, a prodrug, a metabolite, a deuterated derivative. The compound is a structurally novel substituted imidazole formate derivative. Substituted imidazole formate derivatives are used in preparing a drug with sedative, hypnotic and/or anesthetic effects, as well as a drug that can control the state of epilepsy. The compound has a good inhibitory effect on the central nervous system, and provides a new option for clinical screening of and/or preparation of a drug with sedative, hypnotic and/or anesthetic effects and controlling the state of epilepsy.
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.
Metallomicelle catalyzed aerobic tandem desilylation/Glaser reaction in water
Tang, Shanyu,Li, Longjia,Ren, Xuanhe,Li, Jiao,Yang, Guanyu,Li, Heng,Yuan, Bingxin
supporting information, p. 2899 - 2904 (2019/06/17)
PEG-grafted nitrogen ligands were synthesized. The corresponding copper complexes serve as metallomicellar nanoreactors for the aerobic tandem desilylation/Glaser coupling of TMS-protected alkynes in water. The protocol is also suitable for base-free homocoupling of terminal alkynes. The metallomicellar catalyst could be recycled 5 times with minor loss of reactivity.
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.
