4755-33-3Relevant academic research and scientific papers
Mild Hydrogenation of α-Pinene Catalyzed by Ru Nanoparticles Loaded on Boron-doped Amphiphilic Core-Shell Mesoporous Molecular Sieves
Yu, Fengli,Xie, Lihua,Wu, Fangzhu,Yuan, Bing,Xie, Congxia,Yu, Shitao,Liu, Xien,Wang, Lei,Wang, Dan
, p. 1518 - 1525 (2019)
Highly dispersed and stable catalysts comprising Ru nanoparticles supported on boron-doped amphiphilic core-shell mesoporous molecular sieves (MMS?C@MMS?NH2/B/Ru) with alkyl-modified hydrophobic silica core and NH2-functionalized hydrophilic silica shell are successfully prepared for use in hydrogenation of α-pinene for the first time. Dodecyl-modified MMS?C12@MMS?NH2/B/Ru exhibits the best catalytic activity under mild hydrogenation conditions. The abundant ?NH2 functional groups on the molecular sieve surface and their amphipathy allow the sieves to facilitate attachment of more Ru nanoparticles, and to simplify their dispersion in the water-organic reaction medium. Moreover, B-doped molecular sieves may adjust their acidity to meet the needs of α-pinene hydrogenation. Under mild reaction conditions (25 °C, 1 MPa H2, and 1 h), α-pinene can be completely converted with 99 % selectivity to cis-pinane, because every nanocomposite is equivalent to a microreactor. The catalytic activity does not change much over 5 cycles, indicating that Ru nanoparticles are stably loaded on the molecular sieves.
The Exploration of Sensitive Factors for the Selective Hydrogenation of α-Pinene Over Recyclable Ni-B/KIT-6 Catalyst
Deng, Qiao,Hu, Tianding,Huang, Jinyan,Huang, Pengpeng,Jiang, Lihong,Shan, Shaoyun,Su, Hongying,Wang, Yaming,Yang, Wenjuan,Zheng, Yane,Zhi, Yunfei
, (2021/10/08)
The supported Ni-B/KIT-6 amorphous alloy catalyst was prepared by chemical reduction method for the hydrogenation reaction of α-pinene. The catalyst was characterized by XRD, BET, SEM–EDS, TEM, XPS, ICP and DLS, the influences of single factor of catalyst on its structure, morphology and performance were investigated and analyzed. It was found that the amount of Ni loading, preparation pH and B/Ni molar ratio had great effects on the reduction amount, dispersion and specific surface area of the catalyst, resulted in affecting the catalytic performance of the catalyst. The optimum synthesis conditions were at m(Ni2+)/m(KIT-6) = 1:3, pH 13 and n(B)/n(Ni) = 1.5, obtaining a 90.62% conversion of α-pinene and 97.67% selectivity of cis-pinane. In addition, the catalysts also exhibited better repeatability and stability. Graphic Abstract: [Figure not available: see fulltext.]
Highly Selective Hydrogenation of C═C Bonds Catalyzed by a Rhodium Hydride
Gu, Yiting,Lisnyak, Vladislav G.,Norton, Jack R.,Salahi, Farbod,Snyder, Scott A.,Zhou, Zhiyao
supporting information, p. 9657 - 9663 (2021/07/19)
Under mild conditions (room temperature, 80 psi of H2) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selective hydrogenation of the C═C bond in α,β-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the β position and substrates possessing an array of additional functional groups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic studies reveal that no radical intermediates are involved, and the catalyst appears to be homogeneous, thereby affording important complementarity to existing protocols for similar hydrogenation processes.
Environmentally responsible, safe, and chemoselective catalytic hydrogenation of olefins: ppm level Pd catalysis in recyclable water at room temperature
Gallou, Fabrice,Gao, Eugene S.,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 6055 - 6061 (2020/10/14)
Textbook catalytic hydrogenations are typically presented as reactions done in organic solvents and oftentimes under varying pressures of hydrogen using specialized equipment. Catalysts new and old are all used under similar conditions that no longer reflect the times. By definition, such reactions are both environmentally irresponsible and dangerous, especially at industrial scales. We now report on a general method for chemoselective and safe hydrogenation of olefins in water using ppm loadings of palladium from commercially available, inexpensive, and recyclable Pd/C, together with hydrogen gas utilized at 1 atmosphere. A variety of alkenes is amenable to reduction, including terminal, highly substituted internal, and variously conjugated arrays. In most cases, only 500 ppm of heterogeneous Pd/C is sufficient, enabled by micellar catalysis used in recyclable water at room temperature. Comparison with several newly introduced catalysts featuring base metals illustrates the superiority of chemistry in water.
Room Temperature Iron-Catalyzed Transfer Hydrogenation and Regioselective Deuteration of Carbon-Carbon Double Bonds
Espinal-Viguri, Maialen,Neale, Samuel E.,Coles, Nathan T.,MacGregor, Stuart A.,Webster, Ruth L.
supporting information, p. 572 - 582 (2019/01/08)
An iron catalyst has been developed for the transfer hydrogenation of carbon-carbon multiple bonds. Using a well-defined β-diketiminate iron(II) precatalyst, a sacrificial amine and a borane, even simple, unactivated alkenes such as 1-hexene undergo hydrogenation within 1 h at room temperature. Tuning the reagent stoichiometry allows for semi- and complete hydrogenation of terminal alkynes. It is also possible to hydrogenate aminoalkenes and aminoalkynes without poisoning the catalyst through competitive amine ligation. Furthermore, by exploiting the separate protic and hydridic nature of the reagents, it is possible to regioselectively prepare monoisotopically labeled products. DFT calculations define a mechanism for the transfer hydrogenation of propene with nBuNH2 and HBpin that involves the initial formation of an iron(II)-hydride active species, 1,2-insertion of propene, and rate-limiting protonolysis of the resultant alkyl by the amine N-H bond. This mechanism is fully consistent with the selective deuteration studies, although the calculations also highlight alkene hydroboration and amine-borane dehydrocoupling as competitive processes. This was resolved by reassessing the nature of the active transfer hydrogenation agent: experimentally, a gel is observed in catalysis, and calculations suggest this can be formulated as an oligomeric species comprising H-bonded amine-borane adducts. Gel formation serves to reduce the effective concentrations of free HBpin and nBuNH2 and so disfavors both hydroboration and dehydrocoupling while allowing alkene migratory insertion (and hence transfer hydrogenation) to dominate.
Hydrogenation of hydrophobic substrates catalyzed by gold nanoparticles embedded in Tetronic/cyclodextrin-based hydrogels
Chevry,Menuel,Léger,No?l,Monflier,Hapiot
, p. 9865 - 9872 (2019/07/04)
Hydrogenation of alkenes, alkynes and aldehydes was investigated under biphasic conditions using Au nanoparticles (AuNP) embedded into combinations of α-cyclodextrin (α-CD) and a poloxamine (Tetronic90R4). Thermo-responsive AuNP-containing α-CD/Tetronic90R4 hydrogels are formed under well-defined conditions of concentration. The AuNP displayed an average size of ca. 7 nm and a narrow distribution, as determined by TEM. The AuNP/α-CD/Tetronic90R4 system proved to be stable over time. Upon heating above the gel-to-sol transition temperature, the studied catalytic system allowed hydrogenation of a wide range of substrates such as alkenes, alkynes and aldehydes under biphasic conditions. Upon repeated heating/cooling cycles, the Au NP/α-CD/Tetronic90R4 catalytic system could be recycled several times without a significant decline in catalytic activity.
The conversion of α-pinene to: Cis-pinane using a nickel catalyst supported on a discarded fluid catalytic cracking catalyst with an ionic liquid layer
Hu, Shunyou,Wang, Linlin,Chen, Xiaopeng,Wei, Xiaojie,Tong, Zhangfa,Yin, Lijiang
, p. 5978 - 5986 (2019/03/12)
The concept of a solid catalyst coated with a thin ionic liquid layer (SCILL) was applied to the stereoselective hydrogenation of α-pinene. Nickel, a non-noble metal, was supported on a discarded fluid catalytic cracking catalyst (DF3C) and then modified with different loadings of the ionic liquid 1-ethanol-3-methylimidazolium tetrafluoroborate ([C2OHmim][BF4]). The resulting catalysts showed a range of conversions and selectivities for the hydrogenation of α-pinene. The SCILL catalysts afforded cis-pinane with high selectivity and their activity depended on the ionic liquid loading. For an ionic liquid loading of 10 wt%, although the catalytic activity was suppressed, the selectivity and conversion could reach above 98% and 99%, respectively. In addition, the catalyst remained stable after 13 runs and the activity was almost unchanged with the conversion maintained at approximately 99%. Thus, the ionic liquid layer not only improved the selectivity for cis-pinane but also protected the active site of the catalyst and prolonged the service lifetime of the catalyst. The SCILL catalytic system provides an example of an ionic liquid catalytic system which eliminates organic solvents from the catalytic process.
Colloid and Nanosized Catalysts in Organic Synthesis: XXII. Hydrogenation of Cycloolefins Catalyzed by Immobilized Transition Metals Nanoparticles in a Three-Phase System
Nebykov,Popov, Yu. V.,Mokhov,Latyshova,Shcherbakova,Nemtseva,Shishkin
, p. 1985 - 1989 (2019/11/29)
The processes of unsaturated cyclic hydrocarbons hydrogenation in a three-phase gas-liquid-solid catalyst system in the presence of nanostructured nickel, cobalt, or iron catalysts in a flow reactor at 130°C and atmospheric pressure have studied. RX3Extra activated carbon, γ-Al2O3, NaX zeolite, and Purolite CT-175 cation-exchange resin have been used as supports; NaBH4 and NH2NH2·H2O were used as reducing agents. The catalytic activity of supported nanoparticles and their selectivity with respect to the product of exhaustive hydrogenation have been investigated.
Amine-Borane Dehydrogenation and Transfer Hydrogenation Catalyzed by α-Diimine Cobaltates
Maier, Thomas M.,Sandl, Sebastian,Shenderovich, Ilya G.,Jacobi von Wangelin, Axel,Weigand, Jan J.,Wolf, Robert
supporting information, p. 238 - 245 (2019/01/04)
Anionic α-diimine cobalt complexes, such as [K(thf)1.5{(DippBIAN)Co(η4-cod)}] (1; Dipp=2,6-diisopropylphenyl, cod=1,5-cyclooctadiene), catalyze the dehydrogenation of several amine-boranes. Based on the excellent catalytic properties, an especially effective transfer hydrogenation protocol for challenging olefins, imines, and N-heteroarenes was developed. NH3BH3 was used as a dihydrogen surrogate, which transferred up to two equivalents of H2 per NH3BH3. Detailed spectroscopic and mechanistic studies are presented, which document the rate determination by acidic protons in the amine-borane.
Highly selective and recyclable hydrogenation of α-pinene catalyzed by ruthenium nanoparticles loaded on amphiphilic core–shell magnetic nanomaterials
Wu, Fang-Zhu,Yu, Feng-Li,Yuan, Bing,Xie, Cong-Xia,Yu, Shi-Tao
, (2019/08/21)
A multifunctional nanomaterial (Fe3O4@SiO2@CX@NH2) comprising a magnetic core, a silicon protective interlayer, and an amphiphilic silica shell is successfully prepared. Ru nanoparticles catalyst loaded on Fe3O4@SiO2@CX@NH2 is used in hydrogenation of α-pinene for the first time. The novel nanomaterial with amphipathy can be used as a solid foaming agent to increase gas–liquid–solid three-phase contact and accelerate the reaction. Under the mild conditions (40?°C, 1?MPa H2, 3?h), 99.9% α-pinene conversion and 98.9% cis-pinane selectivity are obtained, which is by far the best results reported. Furthermore, the magnetic nanocomposite catalyst can be easily separated by an external magnet and reused nine times with high selectivity maintaining.
