401-75-2Relevant academic research and scientific papers
Mild and Selective Rhodium-Catalyzed Transfer Hydrogenation of Functionalized Arenes
Wang, Yuhan,Chang, Zhiqian,Hu, Yan,Lin, Xiao,Dou, Xiaowei
supporting information, p. 1910 - 1914 (2021/03/08)
Diboron-mediated rhodium-catalyzed transfer hydrogenation of functionalized arenes is reported. In addition to good functional group tolerance, the reaction features operational simplicity and controllable chemoselectivity. The general applicability of this procedure is demonstrated by the selective hydrogenation of a range of arenes, including functionalized benzenes, biphenyls, and polyaromatics.
PRODUCTION METHOD OF CYCLIC COMPOUND
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Paragraph 0057-0058; 0062-0063, (2021/05/05)
PROBLEM TO BE SOLVED: To provide an industrially simple production method of a cyclic compound. SOLUTION: A production method of a cyclic compound includes a step to obtain a reduced form (B) by reducing an unsaturated bond in a ring structure of an aromatic compound (A) by means of catalytic hydrogenation of the aromatic compound (A) or its salt using palladium carbon as a catalyst under a normal pressure, in which the aromatic compound (A) has one or more ring structures selected from a group consisting of a five membered-ring, a six membered-ring, and a condensed ring of the five membered-ring or the six membered-ring with another six membered-ring, a hetero atom can be included in the ring structure, and the aromatic compound (A) can have one or two side chains bonded to the ring structure and does not have any carbon-carbon triple bond in the side chain. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
Trifluoromethyl Thianthrenium Triflate: A Readily Available Trifluoromethylating Reagent with Formal CF3+, CF3?, and CF3-Reactivity
Jia, Hao,H?ring, Andreas P.,Berger, Florian,Zhang, Li,Ritter, Tobias
supporting information, p. 7623 - 7628 (2021/05/26)
Here we report the synthesis and application of trifluoromethyl thianthrenium triflate (TT-CF3+OTf-) as a novel trifluoromethylating reagent, which is conveniently accessible in a single step from thianthrene and triflic anhydride. We demonstrate the use of TT-CF3+OTf- in electrophilic, radical, and nucleophilic trifluoromethylation reactions.
Direct C(sp3)?H Trifluoromethylation of Unactivated Alkanes Enabled by Multifunctional Trifluoromethyl Copper Complexes
Choi, Geunho,Lee, Geun Seok,Park, Beomsoon,Kim, Dongwook,Hong, Soon Hyeok
supporting information, p. 5467 - 5474 (2021/01/20)
A mild and operationally simple C(sp3)?H trifluoromethylation method was developed for unactivated alkanes by utilizing a bench-stable CuIII complex, bpyCu(CF3)3, as the initiator of the visible-light photoinduced reaction, the source of a trifluoromethyl radical as a hydrogen atom transfer reagent, and the source of a trifluoromethyl anion for functionalization. The reaction was initiated by the generation of reactive electrophilic carbon-centered CF3 radical through photoinduced homolytic cleavage of bpyCu(CF3)3, followed by hydrogen abstraction from an unactivated C(sp3)?H bond. Comprehensive mechanistic investigations based on a combination of experimental and computational methods suggested that C?CF3 bond formation was enabled by radical–polar crossover and ionic coupling between the resulting carbocation intermediate and the anionic CF3 source. The methylene-selective reaction can be applied to the direct, late-stage trifluoromethylation of natural products and bioactive molecules.
Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions?
Tanaka, Nao,Usuki, Toyonobu
, p. 5514 - 5522 (2020/07/24)
Hydrogenation of over a dozen aromatic compounds, including both heteroarenes and arenes, over palladium on carbon (Pd/C, 1–100 molpercent) with H2-balloon pressure at room temperature is reported. Analyses using pyridine as a model substrate revealed that acetic acid was the best solvent, as using only 1 molpercent Pd/C provided piperidine quantitatively. Substrate scope analysis and density functional theory calculations indicated that reaction rates are highly dependent on frontier molecular orbital characteristics and the steric bulkiness of substituents. Moreover, the established method was used for the concise synthesis of the anti-Alzheimer drug donepezil (Aricept?).
Iterative Preparation of Platinum Nanoparticles in an Amphiphilic Polymer Matrix: Regulation of Catalytic Activity in Hydrogenation
Hamasaka, Go,Osako, Takao,Srisa, Jakkrit,Torii, Kaoru,Uozumi, Yasuhiro
supporting information, p. 147 - 152 (2020/01/23)
We demonstrate that iteration of the seeded preparation of platinum nanoparticles dispersed in an amphiphilic polystyrene-poly(ethylene glycol) resin (ARP-Pt) regulates their catalytic activity in the hydrogenation of aromatic compounds in water. The catalytic activity of the fifth generation of ARP-Pt [G5] prepared through four iterations of the seeded preparation was far superior to that of the initial ARP-Pt [G1] in the hydrogenation of aromatic compounds in water.
Accessing Difluoromethylated and Trifluoromethylated cis-Cycloalkanes and Saturated Heterocycles: Preferential Hydrogen Addition to the Substitution Sites for Dearomatization
Zhang, Xue,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 16785 - 16789 (2019/11/11)
Reported here is a straightforward process in which a cyclic (alkyl)(amino)carbene/Rh catalyst system facilitates the preferential addition of hydrogen to the substitution sites of difluoromethylated and trifluoromethylated arenes and heteroarenes, leading to dearomative reduction. This strategy enables the diastereoselective synthesis of cis-difluoromethylated and cis-trifluoromethylated cycloalkanes and saturated heterocycles, and even allows formation of all-cis multi-trifluoromethylated cyclic products with a defined equatorial orientation of the di- and trifluoromethyl groups. Deuterium-labeling studies indicate that hydrogen preferentially attacks the substitution sites of planar arenes, resulting in dearomatization, possibly with heterogeneous Rh as the reactive species, followed by either reversible or irreversible hydrogen addition to the nonsubstitution sites.
Csp3-Csp3 Bond-Forming Reductive Elimination from Well-Defined Copper(III) Complexes
Paeth, Matthew,Tyndall, Sam B.,Chen, Liang-Yu,Hong, Jia-Cheng,Carson, William P.,Liu, Xingwu,Sun, Xiaodong,Liu, Jinjia,Yang, Kundi,Hale, Elizabeth M.,Tierney, David L.,Liu, Bin,Cao, Zhi,Cheng, Mu-Jeng,Goddard, William A.,Liu, Wei
supporting information, p. 3153 - 3159 (2019/03/06)
Carbon-carbon bond-forming reductive elimination from elusive organocopper(III) complexes has been considered the key step in many copper-catalyzed and organocuprate reactions. However, organocopper(III) complexes with well-defined structures that can undergo reductive elimination are extremely rare, especially for the formation of Csp3-Csp3 bonds. We report herein a general method for the synthesis of a series of [alkyl-CuIII-(CF3)3]- complexes, the structures of which have been unequivocally characterized by NMR spectroscopy, mass spectrometry, and X-ray crystal diffraction. At elevated temperature, these complexes undergo reductive elimination following first-order kinetics, forming alkyl-CF3 products with good yields (up to 91%). Both kinetic studies and DFT calculations indicate that the reductive elimination to form Csp3-CF3 bonds proceeds through a concerted transition state, with a ΔH? = 20 kcal/mol barrier.
Polysilane-Immobilized Rh-Pt Bimetallic Nanoparticles as Powerful Arene Hydrogenation Catalysts: Synthesis, Reactions under Batch and Flow Conditions and Reaction Mechanism
Miyamura, Hiroyuki,Suzuki, Aya,Yasukawa, Tomohiro,Kobayashi, Shu
supporting information, p. 11325 - 11334 (2018/09/06)
Hydrogenation of arenes is an important reaction not only for hydrogen storage and transport but also for the synthesis of functional molecules such as pharmaceuticals and biologically active compounds. Here, we describe the development of heterogeneous Rh-Pt bimetallic nanoparticle catalysts for the hydrogenation of arenes with inexpensive polysilane as support. The catalysts could be used in both batch and continuous-flow systems with high performance under mild conditions and showed wide substrate generality. In the continuous-flow system, the product could be obtained by simply passing the substrate and 1 atm H2 through a column packed with the catalyst. Remarkably, much higher catalytic performance was observed in the flow system than in the batch system, and extremely strong durability under continuous-flow conditions was demonstrated (>50 days continuous run; turnover number >3.4 × 105). Furthermore, details of the reaction mechanisms and the origin of different kinetics in batch and flow were studied, and the obtained knowledge was applied to develop completely selective arene hydrogenation of compounds containing two aromatic rings toward the synthesis of an active pharmaceutical ingredient.
Hydrogenation of arenes, nitroarenes, and alkenes catalyzed by rhodium nanoparticles supported on natural nanozeolite clinoptilolite
Baghbanian, Seyed Meysam,Farhang, Maryam,Vahdat, Seyed Mohammad,Tajbakhsh, Mahmood
, p. 128 - 136 (2015/07/15)
Abstract Nanozeolite clinoptilolite supported rhodium nanoparticles (Rh/NZ-CP) has been prepared and characterized by a variety of techniques, including XRD, BET, TEM, EDX, ICP-OES and XPS analysis. This nanomaterial contains 2 wt% Rh in the range of 5-20 nm metallic nanoparticles distributed on nanozeolite. The catalytic performance of Rh/NZ-CP was evaluated by the hydrogenation of arenes, nitroarenes, and alkenes under moderate reaction conditions. The prepared nanocatalyst can be facilely recovered and reused many times without significant decrease in activity and selectivity. The high catalytic activity, thermal stability and reusability, simple recovery and eco-friendly nature make present catalyst as a unique catalytic system, which is particularly attractive in green chemistry.
