2687-91-4Relevant articles and documents
Ultra-fast Cycling for Multiplexed Cellular Fluorescence Imaging
Ahmed, Maaz S.,Carlson, Jonathan C. T.,Ko, Jina,Oh, Juhyun,Weissleder, Ralph
, (2020)
Rapid analysis of single and scant cell populations is essential in modern diagnostics, yet existing methods are often limited and slow. Herein, we describe an ultra-fast, highly efficient cycling method for the analysis of single cells based on unique li
Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst
Klarner, Mara,Bieger, Sandra,Drechsler, Markus,Kempe, Rhett
supporting information, p. 2157 - 2161 (2021/05/21)
The selective hydrogenation of functionalized olefins is of great importance in the chemical and pharmaceutical industry. Here, we report on a nanostructured nickel catalyst that enables the selective hydrogenation of purely aliphatic and functionalized olefins under mild conditions. The earth-abundant metal catalyst allows the selective hydrogenation of sterically protected olefins and further tolerates functional groups such as carbonyls, esters, ethers and nitriles. The characterization of our catalyst revealed the formation of surface oxidized metallic nickel nanoparticles stabilized by a N-doped carbon layer on the active carbon support.
Photoredox-Catalyzed Simultaneous Olefin Hydrogenation and Alcohol Oxidation over Crystalline Porous Polymeric Carbon Nitride
Qiu, Chuntian,Sun, Yangyang,Xu, Yangsen,Zhang, Bing,Zhang, Xu,Yu, Lei,Su, Chenliang
, p. 3344 - 3350 (2021/07/26)
Booming of photocatalytic water splitting technology (PWST) opens a new avenue for the sustainable synthesis of high-value-added hydrogenated and oxidized fine chemicals, in which the design of efficient semiconductors for the in-situ and synergistic utilization of photogenerated redox centers are key roles. Herein, a porous polymeric carbon nitride (PPCN) with a crystalline backbone was constructed for visible light-induced photocatalytic hydrogen generation by photoexcited electrons, followed by in-situ utilization for olefin hydrogenation. Simultaneously, various alcohols were selectively transformed to valuable aldehydes or ketones by photoexcited holes. The porosity of PPCN provided it with a large surface area and a short transfer path for photogenerated carriers from the bulk to the surface, and the crystalline structure facilitated photogenerated charge transfer and separation, thus enhancing the overall photocatalytic performance. High reactivity and selectivity, good functionality tolerance, and broad reaction scope were achieved by this concerted photocatalysis system. The results contribute to the development of highly efficient semiconductor photocatalysts and synergistic redox reaction systems based on PWST for high-value-added fine chemical production.
Bidentate NHC-Cobalt Catalysts for the Hydrogenation of Hindered Alkenes
Wei, Zeyuan,Wang, Yujie,Li, Yibiao,Ferraccioli, Raffaella,Liu, Qiang
, p. 3082 - 3087 (2020/10/02)
Herein, we report a series of easily accessible bidentate N-heterocyclic carbene (NHC) cobalt catalysts, which enable the hydrogenation of hindered alkenes under mild conditions. The four-coordinated bidentate NHC-Co(II) complexes were characterized by X-ray diffraction, elemental analysis, ESI-HRMS, and magnetic moment measurements, revealing a distorted-tetrahedral geometry and a high-spin configuration of the metal center. The activity of the in situ formed catalytic system, which was obtained from easily available NHC precursors, CoCl2, and NaHBEt3, was identical with those of well-defined NHC-cobalt catalysts. This highlights the potential utility of this reaction system.
N-Alkylation of N-trimethylsilyl derivatives of lactams, amides, and imides with alkyl sulfonates
Baukov, Yu. I.,Kramarova, E. P.,Negrebetsky, Vad. V.,Shagina, A. D.,Shipov, A. G.,Tarasenko, D. V.
, p. 398 - 400 (2020/04/15)
The reaction of N-trimethylsilyl derivatives of amides and imides with alkyl sulfonates on heating affords the corresponding N-alkyl derivatives and trimethylsilyl sulfonates.
Extending the chemical product tree: A novel value chain for the production of: N -vinyl-2-pyrrolidones from biogenic acids
Haus, Moritz Otto,Louven, Yannik,Palkovits, Regina
, p. 6268 - 6276 (2019/12/03)
The sustainable production of polymers from biogenic platform chemicals shows great promise to reduce the chemical industry's dependence on fossil resources. In this context, we propose a new two-step process leading from dicarboxylic acids, such as succinic and itaconic acid, to N-vinyl-2-pyrrolidone monomers. Firstly, the biogenic acid is reacted with ethanolamine and hydrogen using small amounts of water as solvent together with solid catalysts. For effective conversion, the optimal catalyst (carbon supported ruthenium) has to hold the ability of activating H2 as well as (imide) CO bonds. The obtained products, N-(2-hydroxyethyl)-2-pyrrolidones, are subsequently converted in a continuous gas phase dehydration over simple sodium-doped silica, with excellent selectivity of above 96 mol% and water as the sole by-product. With a final product yield of ≥72 mol% over two process steps and very little waste due to the use of heterogeneous catalysis, the proposed route appears promising-commercially as well as in terms of Green Chemistry.
Facile Preparation of N -Alkyl-2-pyrrolidones in a Continuous-Flow Microreactor
Zhou, Feng,Zhang, Boyu,Liu, Hongchen,Wen, Zhenghui,Wang, Kejun,Chen, Guangwen
, p. 504 - 511 (2018/04/27)
N-Alkyl-2-pyrrolidones have been widely used in the petrochemical industry, the agricultural chemical industry, electronic materials, etc. The distinct advantages of using N-alkyl-2-pyrrolidones as solvents or reaction media make them particularly important. A continuous-flow microreactor was exploited for the preparation of N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP) in a highly controlled and safe manner; thus, its use improved the efficiency of the process. Various conditions (temperature, residence time, molar ratio of amine to γ-butyrolactone (GBL), GBL concentration, water content, and presence of H3BO3 catalyst) were investigated to improve the synthesis of NMP/NEP. A microreactor was employed for the conversion of GBL to NMP and NEP, and the yields reached 94.7% for NMP and 93.9% for NEP under the optimized conditions. Furthermore, a kinetic model based on the reaction mechanism was proposed to guide the design and optimization of the synthesis of NMP/NEP.
Palladium/Phosphorus-Doped Porous Organic Polymer as Recyclable Chemoselective and Efficient Hydrogenation Catalyst under Ambient Conditions
Ding, Zong-Cang,Li, Cun-Yao,Chen, Jun-Jia,Zeng, Jia-Hao,Tang, Hai-Tao,Ding, Yun-Jie,Zhan, Zhuang-Ping
, p. 2280 - 2287 (2017/07/07)
A new type of phosphorus-doped porous organic polymer (POP) has been readily synthesized through a Heck reaction, which could be used not only as a support but also a ligand for palladium nanoparticles. The dual-functional material supported palladium nanocatalyst was used for the efficient and chemoselective hydrogenation of varieties of nitroarenes and α,β-unsaturated compounds, as well as for the synthesis of indoles from 2-nitrophenylacetonitrile under 1 atm hydrogen in green solvents at room temperature. No obvious aggregation and loss of catalytic activity of the new nanocatalyst were observed after 10 runs in the reaction. (Figure presented.).
Matrix-IR spectroscopic investigations of the thermolysis and photolysis of diazoamides
Wentrup, Curt,Bibas, Herve,Kuhn, Arvid,Mitschke, Ullrich,McMills, Mark C.
, p. 10705 - 10717 (2013/11/19)
Matrix photolysis of N,N-dialkyldiazoacetamides 1a-d at 7-10 K results in either the formation of C-H insertion products (in case of N,N-dimethyl and N,N-diethyl diazoamides) or almost exclusive Wolff rearrangement to ketenes (in the case of the cyclic di
N-alkyl functionalised expanded ring N-heterocyclic carbene complexes of rhodium(i) and iridium(i): Structural investigations and preliminary catalytic evaluation
Dunsford, Jay J.,Tromp, Dorette S.,Cavell, Kingsley J.,Elsevier, Cornelis J.,Kariuki, Benson M.
, p. 7318 - 7329 (2013/08/26)
A series of new N-alkyl functionalised 6- and 7-membered expanded ring N-heterocyclic carbene (NHC) pro-ligands 3-6 and their corresponding complexes of rhodium(i) and iridium(i), [M(NHC)(COD)Cl] 7-14 and [M(NHC)(CO) 2Cl] 15-22 are described. The complexes have been characterised by 1H and 13C{1H} NMR, mass spectrometry, IR and X-ray diffraction. It is noted from X-ray diffraction studies that the N-alkyl substituents are found to orientate themselves away from the metal centre due to unfavourable steric interactions resulting in low percent buried volume (%Vbur) values in the solid state. The heterocycle ring size is also found to dictate the spatial orientation of the N-alkyl substituents in the neopentyl functionalised derivatives 10 and 14. The 7-membered derivative 14 allows for a conformational 'twist' of the heterocycle ring with the N-alkyl substituents adopting a mutually trans configuration with respect to each other, while the more rigid 6-membered system 10 does not allow for this conformational 'twist' and consequently the N-alkyl substituents adopt a mutually cis configuration. The σ-donor function of this new class of expanded ring NHC ligand has also been probed by measured IR stretching frequencies of the [M(NHC)(CO)2Cl] complexes 15-22. A preliminary catalytic survey of the hydrogenation of functionalised alkenes with molecular hydrogen under mild conditions has also been undertaken with complex 10, affording an insight into the application of large ring NHC ancillary ligands bearing N-alkyl substituents in hydrogenation transformations.
