834-89-9Relevant academic research and scientific papers
Cu(I)/Chiral Bisoxazoline-Catalyzed Enantioselective Doyle-Kirmse Reaction of Allenyl Sulfides with α-Diazoesters
Li, Shu-Sen,Wang, Jianbo,Wang, Kang
supporting information, (2022/03/17)
Herein, a Cu(I)-catalyzed enantioselective Doyle-Kirmse reaction of allenyl sulfides and α-diazoesters is reported, which provides an efficient synthetic route to enantio-enriched chiral tertiary homopropargylic sulfides. This reaction features high enantioselectivities (up to 96 % ee) and good functional group tolerance. The alkyl substituted α-diazoester has also been demonstrated as the efficient substrates in the asymmetric Doyle-Kirmse reaction. Mechanistic studies, including kinetic experiments, were conducted to gain insights into the details of the reaction pathway. The potential synthetic utility of this protocol has also been demonstrated.
Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers
Pang, Yue,Leutzsch, Markus,N?thling, Nils,Katzenburg, Felix,Cornella, Josep
supporting information, p. 12487 - 12493 (2021/08/30)
Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support a Bi(I)/Bi(III) redox cycle that comprises C(sp2)-F oxidative addition, F/H ligand metathesis, and C(sp2)-H reductive elimination. Isolation and characterization of a cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests the feasible oxidative addition of Phebox-Bi(I) into the C(sp2)-F bond. Spectroscopic evidence was provided for the formation of a transient Phebox-Bi(III)(4-tetrafluoropyridyl) hydride during catalysis, which decomposes at low temperature to afford the corresponding C(sp2)-H bond while regenerating the propagating Phebox-Bi(I). This protocol represents a distinct catalytic example where a main-group center performs three elementary organometallic steps in a low-valent redox manifold.
Copper-Catalyzed Direct C-H Alkylation of Polyfluoroarenes by Using Hydrocarbons as an Alkylating Source
Xie, Weilong,Heo, Joon,Kim, Dongwook,Chang, Sukbok
supporting information, p. 7487 - 7496 (2020/08/06)
Construction of carbon-carbon bonds is one of the most important tools in chemical synthesis. In the previously established cross-coupling reactions, prefunctionalized starting materials were usually employed in the form of aryl or alkyl (pseudo)halides or their metalated derivatives. However, the direct use of arenes and alkanes via a 2-fold oxidative C-H bond activation strategy to access chemoselective C(sp2)-C(sp3) cross-couplings is highly challenging due to the low reactivity of carbon-hydrogen (C-H) bonds and the difficulty in suppressing side reactions such as homocouplings. Herein, we present the new development of a copper-catalyzed cross-dehydrogenative coupling of polyfluoroarenes with alkanes under mild conditions. Relatively weak sp3 C-H bonds at the benzylic or allylic positions, and nonactivated hydrocarbons could be alkylated by the newly developed catalyst system. A moderate-to-high site selectivity was observed among various C-H bonds present in hydrocarbon reactants, including gaseous feedstocks and complex molecules. Mechanistic information was obtained by performing combined experimental and computational studies to reveal that the copper catalyst plays a dual role in activating both alkane sp3 C-H bonds and sp2 polyfluoroarene C-H bonds. It was also suggested that the noncovalent π-πinteraction and weak hydrogen bonds formed in situ between the optimal ligand and arene substrates are key to facilitating the current coupling reactions.
Copper-Catalysed Suzuki-Miyaura Cross-Coupling of Highly Fluorinated Aryl Boronate Esters with Aryl Iodides and Bromides and Fluoroarene?Arene π-Stacking Interactions in the Products
Budiman, Yudha P.,Friedrich, Alexandra,Radius, Udo,Marder, Todd B.
, p. 5387 - 5396 (2019/08/16)
A combination of copper iodide and phenanthroline as the ligand is an efficient catalyst for Suzuki-Miyaura cross-coupling of highly fluorinated boronate esters (aryl?Bpin) with aryl iodides and bromides to generate fluorinated biaryls in good to excellent yields. This method represents a nice alternative to traditional cross-coupling methods which require palladium catalysts and stoichiometric amounts of silver oxide. We note that π???π stacking interactions dominate the molecular packing in the partly fluorinated biaryl crystals investigated herein. They are present either between the arene and perfluoroarene, or solely between arenes or perfluoroarenes, respectively.
Highly Selective Pd-Catalyzed Direct C-F Bond Arylation of Polyfluoroarenes
Luo, Zhi-Ji,Zhao, Hai-Yang,Zhang, Xingang
supporting information, p. 2543 - 2546 (2018/05/17)
A directing-group-free palladium-catalyzed direct arylation of simple polyfluoroarenes with arylboronic acids through selective C-F bond activation is described. The combination of Pd(OAc)2 with BrettPhos was identified as an efficient catalytic system to promote the reaction with high regioselectivity and broad substrate scope. Preliminary mechanistic studies reveal that the oxidative addition of Pd to the C-F bond is involved in the catalytic cycle.
Method for preparing fluorinated aromatic hydrocarbons by photo/nickle concerted catalysis
-
Paragraph 0021; 0022; 0024; 0029-0032, (2018/09/11)
The invention discloses a method for preparing fluorinated aromatic hydrocarbons by photo/nickle concerted catalysis. According to the method, cheap metal nickel salt is used as a catalyst, adding ofa ligand is not needed, and the catalyst cooperates with trace photosensitizer in visible light radiation to catalyze a fluoro aryl zinc reagent and an aryl halide to generate Negishi cross-coupling,so as to prepare a fluorinated aromatic hydrocarbons compound. The coupling reaction functional group is good in tolerance, a substrate is wide in applicability, and multiple fluorinated aromatic hydrocarbons compounds (80-96%) can be obtained at high yield in a near room temperature. Compared with a palladium catalysis system reported in the literature, the photo-nickle concerted catalysis systemadopted by the method disclosed by the invention has the advantages that the use amount of the photosensitizer is low, a nickel catalyst is low in price, expensive ligand does not need to be added, and environment-friendly, economical and practical effects are achieved; by combining with a flowing synthesis technology, the method can easily realize automatic synthesis of important fluorinated aromatic hydrocarbons compounds.
With metal nickel catalyzed C - X of the key is formed organic photosensitizer and its synthetic method (by machine translation)
-
Paragraph 0080-0083, (2018/09/11)
The invention discloses a formed metal nickel catalyzed C - X key organic photosensitizer and its synthetic method, wherein X represents C, O or N, the organic photosensitizer to common beryllium two pyrrole (BODIPY) as the skeleton, in the boron atom or skeleton is introduced on the aromatic group, derived from one kind has superior light oxidation-reduction properties of the organic photosensitizer. Compared with the literature reports of expensive metal ruthenium or iridium photosensitizer, these novel organic photosensitizer has the advantages of simple synthesis, the price is cheap, consumption is low, and the obvious advantages of heavy metal. It is particularly important, under the condition of no external ligand, [...] of the photosensitizer can be formed with the metal nickel catalyzed C - C, C - O and C - N and other important chemical bond, has important application value. (by machine translation)
Dissecting Porosity in Molecular Crystals: Influence of Geometry, Hydrogen Bonding, and [π···π] Stacking on the Solid-State Packing of Fluorinated Aromatics
Hashim, Mohamed I.,Le, Ha T. M.,Chen, Teng-Hao,Chen, Yu-Sheng,Daugulis, Olafs,Hsu, Chia-Wei,Jacobson, Allan J.,Kaveevivitchai, Watchareeya,Liang, Xiao,Makarenko, Tatyana,Miljani?, Ognjen ?.,Popovs, Ilja,Tran, Hung Vu,Wang, Xiqu,Wu, Chia-Hua,Wu, Judy I.
supporting information, p. 6014 - 6026 (2018/05/05)
Porous molecular crystals are an emerging class of porous materials that is unique in being built from discrete molecules rather than being polymeric in nature. In this study, we examined the effects of molecular structure of the precursors on the formation of porous solid-state structures with a series of 16 rigid aromatics. The majority of these precursors possess pyrazole groups capable of hydrogen bonding, as well as electron-rich aromatics and electron-poor tetrafluorobenzene rings. These precursors were prepared using a combination of Pd- and Cu-catalyzed cross-couplings, careful manipulations of protecting groups on the nitrogen atoms, and solvothermal syntheses. Our study varied the geometry and dimensions of precursors, as well as the presence of groups capable of hydrogen bonding and [π···π] stacking. Thirteen derivatives were crystallographically characterized, and four of them were found to be porous with surface areas between 283 and 1821 m2 g-1. Common to these four porous structures were (a) rigid trigonal geometry, (b) [π···π] stacking of electron-poor tetrafluorobenzenes with electron-rich pyrazoles or tetrazoles, and (c) hydrogen bonding between the terminal heteroaromatic rings.
Ligand-induced reactivity of β-diketiminate magnesium complexes for regioselective functionalization of fluoroarenes: Via C-H or C-F bond activations
Davin, Laia,McLellan, Ross,Kennedy, Alan R.,Hevia, Eva
supporting information, p. 11650 - 11653 (2017/11/03)
Using β-diketiminate Mg(ii) complexes containing either alkyl, aryl or amide groups, the regioselective functionalization of a wide range of fluoroarenes is accomplished but in uniquely different ways. Overcoming common limitations of traditional s-block bases, kinetically activated [(DippNacnac)Mg(TMP)] (1) deprotonates these molecules at room temperature, trapping sensitive fluoroaryl anions that can then engage in Negishi cross-coupling; whereas [(DippNacnac)Mg(R)THF] (R = nBu, Ph, benzofuryl) have proved to be effective reagents for C-F bond alkylation/arylation via pyridine directed C-F bond cleavage.
Mild and Efficient Ni-Catalyzed Biaryl Synthesis with Polyfluoroaryl Magnesium Species: Verification of the Arrest State, Uncovering the Hidden Competitive Second Transmetalation and Ligand-Accelerated Highly Selective Monoarylation
Wang, Junya,Meng, Ge,Xie, Kun,Li, Liting,Sun, Huaming,Huang, Zhiyan
, p. 7421 - 7430 (2017/11/10)
Employing a nickel catalyst and electron-deficient polyfluoroaryl magnesium species, a highly selective monoarylation of polyfluoroarenes containing multiple identical coupling sites has been achieved for the first time, which represents a long-standing p
