4489-23-0Relevant academic research and scientific papers
Catalytic, contra-Thermodynamic Positional Alkene Isomerization
Occhialini, Gino,Palani, Vignesh,Wendlandt, Alison E.
supporting information, p. 145 - 152 (2022/01/19)
The positional isomerization of C═C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here, we report
Facile Synthesis of Chiral Arylamines, Alkylamines and Amides by Enantioselective NiH-Catalyzed Hydroamination
Meng, Lingpu,Yang, Jingjie,Duan, Mei,Wang, You,Zhu, Shaolin
supporting information, p. 23584 - 23589 (2021/09/28)
Regio- and enantioselective hydroarylamination, hydroalkylamination and hydroamidation of styrenes have been developed by NiH catalysis with a simple bioxazoline ligand under mild conditions. A wide range of enantioenriched benzylic arylamines, alkylamines and amides can be easily accessed by nitroarenes, hydroxylamines and dioxazolones, respectively as amination reagents. The chiral induction in these reactions is proposed to proceed through an enantiodifferentiating syn-hydronickellation step.
A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
, p. 6684 - 6690 (2021/05/31)
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
Electrochemical Aziridination of Internal Alkenes with Primary Amines
Bartolomeu, Aloisio de A.,Dyga, Marco,Goo?en, Lukas J.,Laudadio, Gabriele,No?l, Timothy,O?eka, Maksim,de Bruin, Bas,de Oliveira, Kleber T.,van Leest, Nicolaas P.
, p. 255 - 266 (2021/01/19)
An electrochemical approach to prepare aziridines via an oxidative coupling between alkenes and primary alkyl amines was realized. The reaction is carried out in an electrochemical flow reactor, leading to short reaction/residence times (5 min), high yields, and broad scope. At the cathode, hydrogen is generated, which can be used in a second reactor to reduce the aziridine yielding the corresponding hydroaminated product.Aziridines are useful synthetic building blocks, widely employed for the preparation of various nitrogen-containing derivatives. As the current methods require the use of prefunctionalized amines, the development of a synthetic strategy toward aziridines that can establish the union of alkenes and amines would be of great synthetic value. Herein, we report an electrochemical approach, which realizes this concept via an oxidative coupling between alkenes and primary alkylamines. The reaction is carried out in an electrochemical flow reactor leading to short reaction/residence times (5 min), high yields, and broad scope. At the cathode, hydrogen is generated, which can be used in a second reactor to reduce the aziridine, yielding the corresponding hydroaminated product. Mechanistic investigations and DFT calculations revealed that the alkene is first anodically oxidized and subsequently reacted with the amine coupling partner.The central tenet in modern synthetic methodology is to develop new methods only using widely available organic building blocks. As a direct consequence, new activation strategies are required to cajole the coupling partners to react and, subsequently, forge new and useful chemical bonds. Using electrochemical activation, our methodology enables for the first time the direct coupling between olefins and amines to yield aziridines. Aziridines display interesting pharmacological activity and serve as valuable synthetic intermediates to prepare diverse nitrogen-containing derivatives. Interestingly, the sole byproduct generated in this process is hydrogen, which can be subsequently used to reduce the aziridine into the corresponding hydroaminated product. Hence, this electrochemical methodology can be regarded as green and sustainable from the vantage point of upgrading simple and widely available commodity chemicals.
Iron(II) and Copper(I) Control the Total Regioselectivity in the Hydrobromination of Alkenes
Cruz, Daniel A.,Sinka, Victoria,De Armas, Pedro,Steingruber, Hugo Sebastian,Fernández, Israel,Martín, Víctor S.,Miranda, Pedro O.,Padrón, Juan I.
supporting information, p. 6105 - 6109 (2021/08/18)
A new method that allows the complete control of the regioselectivity of the hydrobromination reaction of alkenes is described. Herein, we report a radical procedure with TMSBr and oxygen as common reagents, where the formation of the anti-Markovnikov product occurs in the presence of parts per million amounts of the Cu(I) species and the formation of the Markovnikov product occurs in the presence of 30 mol % iron(II) bromide. Density functional theory calculations combined with Fukui's radical susceptibilities support the obtained results.
Bifunctional Metal-Organic Layers for Tandem Catalytic Transformations Using Molecular Oxygen and Carbon Dioxide
Jiang, Xiaomin,Lan, Guangxu,Lin, Wenbin,Ni, Kaiyuan,Quan, Yangjian,Shi, Wenjie,Song, Yang,Wang, Cheng
supporting information, p. 16718 - 16724 (2021/10/21)
Tandem catalytic reactions improve atom- and step-economy over traditional synthesis but are limited by the incompatibility of the required catalysts. Herein, we report the design of bifunctional metal-organic layers (MOLs), HfOTf-Fe and HfOTf-Mn, consisting of triflate (OTf)-capped Hf6 secondary building units (SBUs) as strong Lewis acidic centers and metalated TPY ligands as metal active sites for tandem catalytic transformations using O2 and CO2 as coreactants. HfOTf-Fe effectively transforms hydrocarbons into cyanohydrins via tandem oxidation with O2 and silylcyanation whereas HfOTf-Mn converts styrenes into styrene carbonates via tandem epoxidation and CO2 insertion. Density functional theory calculations revealed the involvement of a high-spin FeIV (S = 2) center in the challenging oxidation of the sp3 C-H bond. This work highlights the potential of MOLs as a tunable platform to incorporate multiple catalysts for tandem transformations.
Electro-mediated PhotoRedox Catalysis for Selective C(sp3)–O Cleavages of Phosphinated Alcohols to Carbanions
Barham, Joshua P.,K?nig, Burkhard,Karl, Tobias A.,Reiter, Sebastian,Tian, Xianhai,Yakubov, Shahboz,de Vivie-Riedle, Regina
supporting information, p. 20817 - 20825 (2021/08/18)
We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)?O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)?O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
Method for synthesizing alkyl olefin through coupling of double-bond carbon-hydrogen bond and saturated carbon-hydrogen bond
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Paragraph 0060-0064; 0084, (2021/02/10)
The invention discloses a method for synthesizing alkyl olefin through coupling of a double-bond carbon-hydrogen bond and a saturated carbon-hydrogen bond. According to to the method, one-pot reactionis implemented on olefin and sulfoxide in the presence of ferric salt and hydrogen peroxide to generate alkyl olefin; in the method, sulfoxide is simultaneously used as a hydrocarbylation reagent anda solvent of olefin, and a reaction product is alkyl olefin from sulfoxide alkyl coupled with olefin carbon atoms, so that an olefin carbon chain is increased; the reaction conditions are mild, the selectivity is good, the yield is high, and industrial production is facilitated.
Method for synthesizing 1, 2-disubstituted olefin through reaction of terminal group olefin and sulfoxide
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Paragraph 0053-0054; 0057-0062; 0071, (2021/02/10)
The invention discloses a method for synthesizing 1, 2-disubstituted olefin by reaction of terminal olefin and sulfoxide. According to the method, terminal olefin with sulfoxide make reaction in one pot in the presence of ferric salt and hydrogen peroxide to generate the 1, 2-disubstituted olefin. sulfoxide is simultaneously used as a hydrocarbylation reagent and a solvent of olefin, and a reaction product is 1, 2-disubstituted olefin of which a terminal carbon atom in terminal olefin is coupled with a sulfoxide alkyl group, so that an olefin carbon chain is increased; the reaction conditionsare mild, the selectivity is high, the yield is high, and industrial production is facilitated.
Ruthenium-Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
Huang, Lin,Bismuto, Alessandro,Rath, Simon A.,Trapp, Nils,Morandi, Bill
supporting information, p. 7290 - 7296 (2021/03/01)
The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination of a redox-active ligand and a sterically hindered aryl radical intermediate has unleashed this novel strategy. Importantly, mechanistic investigations have been performed to provide a conceptual framework for the further development of this new catalytic dehydrogenation system.
