80120-36-1Relevant articles and documents
Electrochemical two-electron oxygen reduction reaction (ORR) induced aerobic oxidation of α-diazoesters
Chen, Liang,Gao, Meng,Lu, Cuifen,Ma, Chao,Ruan, Mengyao,Wen, Ziyang,Yang, Fan,Yang, Guichun
, p. 2168 - 2171 (2022/02/17)
Electrochemical oxygen reduction reaction (ORR) is a powerful tool for introducing oxygen functional groups in synthetic chemistry. However, compared with the well-developed one-electron oxygen reduction process, the applications of two-electron oxygen re
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: Synthesis of propargyl alcohols and α-ketoesters
Ni, Ke,Meng, Ling-Guo,Ruan, Hongjie,Wang, Lei
supporting information, p. 8438 - 8441 (2019/07/22)
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere (N2 or O2). A N2 atmosphere favours propargyl alcohols via a direct C-C coupling process, whereas an O2 atmosphere results in the generation of α-ketoesters through the oxidative CC/C-O coupling pathway.
Electrochemistry-Enabled Ir-Catalyzed Vinylic C-H Functionalization
Yang, Qi-Liang,Xing, Yi-Kang,Wang, Xiang-Yang,Ma, Hong-Xing,Weng, Xin-Jun,Yang, Xiang,Guo, Hai-Ming,Mei, Tian-Sheng
supporting information, p. 18970 - 18976 (2019/12/04)
Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.
Three-Component Activation/Alkynylation/Cyclocondensation (AACC) Synthesis of Enhanced Emission Solvatochromic 3-Ethynylquinoxalines
Merkt, Franziska K.,H?wedes, Simon P.,Gers-Panther, Charlotte F.,Gruber, Irina,Janiak, Christoph,Müller, Thomas J. J.
, p. 8114 - 8125 (2018/04/02)
2-Substituted 3-ethynylquinoxaline chromophores can be readily synthesized by a consecutive activation–alkynylation–cyclocondensation (AACC) one-pot sequence in a three-component manner. In comparison with the previously published four-component glyoxylation starting from electron-rich π-nucleophiles, the direct activation of (hetero)aryl glyoxylic acids allows the introduction of substituents that cannot be directly accessed by glyoxylation. By introducing N,N-dimethylaniline as a strong donor in the 2-position, the emission solvatochromicity of 3-ethynylquinoxalines can be considerably enhanced to cover the spectral range from blue–green to deep red–orange with a single chromophore in a relatively narrow polarity window. The diversity-oriented nature of the synthetic multicomponent reaction concept enables comprehensive investigations of structure–property relationships by Hammett correlations and Lippert–Mataga analysis, as well as the elucidation of the electronic structure of the emission solvatochromic π-conjugated donor–acceptor systems by DFT and time-dependent DFT calculations with the PBEh1PBE functional for a better reproduction of the dominant charge-transfer character of the longest wavelength absorption band.
Switchable C-H Functionalization of N-Tosyl Acrylamides with Acryloylsilanes
Song, Shengjin,Lu, Ping,Liu, Huan,Cai, Sai-Hu,Feng, Chao,Loh, Teck-Peng
supporting information, p. 2869 - 2872 (2017/06/13)
A controllable Rh-catalyzed protocol to access alkylation and alkenylation-annulation of N-tosyl acrylamide with acryloyl silane is reported. In contrast to the directing group or catalyst-dependent divergent sp2 C-H alkylation/alkenylation, the intrinsic property of acryloylsilane allows the switchable reaction manifold, thereby affording either alkylation or annulation products with slight modification of the reaction conditions.
Novel Synthesis of α-Keto Esters and Amides by an sp3 C-H Oxidation of Nitromethyl Aryl Ketones Promoted by Ion-Supported (Diacetoxyiodo)benzene
Jiang, Xiaoying,Gan, Bing,Liu, Jiwei,Xie, Yuanyuan
supporting information, p. 2737 - 2741 (2016/11/25)
A simple and efficient method is described for the preparation of α-keto esters or amides from nitromethyl aryl ketones. In the presence of nucleophiles (alcohols or amines), the ion-supported (di-acetoxyiodo)benzene-promoted sp3 C-H oxidation of nitromethyl aryl ketones proceeded efficiently under mild conditions to give the corresponding α-keto esters and amides in moderate to good yields. This is the first reported use of (diacetoxyiodo)benzene in the synthesis of α-keto esters and amides. The reaction is ecofriendly and has the -advantages of mild conditions, short reaction times, and a recyclable reagent.
Rhodium-Catalyzed Hydrocarboxylation of Olefins with Carbon Dioxide
Kawashima, Shingo,Aikawa, Kohsuke,Mikami, Koichi
supporting information, p. 3166 - 3170 (2016/07/19)
The catalytic hydrocarboxylation of styrenes derivatives and α,β-unsaturated carbonyl compounds with CO2(101.3 kPa) in the presence of an air-stable rhodium catalyst was explored. The combination of [RhCl(cod)]2(cod = cyclooctadiene) as a catalyst and diethylzinc as a hydride source allowed for effective hydrocarboxylation and provided the corresponding α-aryl carboxylic acids in moderate to excellent yields. In this catalytic process with carbon dioxide, intervention of the RhI–H species, which could be generated from the RhIcatalyst and diethylzinc, was clarified. Significantly, the catalytic asymmetric hydrocarboxylation of α,β-unsaturated esters with carbon dioxide was also performed by employing a cationic rhodium complex possessing (S)-(–)-4,4′-bi-1,3-benzodioxole-5,5′-diylbis(diphenylphosphine) [(S)-SEGPHOS] as a chiral diphosphine ligand. A plausible model for asymmetric induction was proposed by determination of the absolute configuration of the product.
Rhodium(iii)-catalyzed C-H allylation of electron-deficient alkenes with allyl acetates
Feng, Chao,Feng, Daming,Loh, Teck-Peng
supporting information, p. 342 - 345 (2015/01/09)
Rhodium-catalyzed C-H allylation of acrylamides with allyl acetates is reported. The use of weakly coordinating directing group resulted in high reaction efficiency, broad functionality tolerance and excellent γ-selectivity, which opens a new synthetic pathway for the access of 1,4-diene skeletons.
Rhodium(III)-catalyzed olefinic C-H alkynylation of acrylamides using tosyl-imide as directing group
Feng, Chao,Feng, Daming,Luo, Yang,Loh, Teck-Peng
supporting information, p. 5956 - 5959 (2015/01/08)
The Rh(III)-catalyzed C-H alkynylation of acrylamide derivative is realized using a hypervalent alkynyl iodine reagent. The use of a weakly coordinating directing group proved to be of critical importance. This reaction displays broad functional group tolerance and high efficiency, which opens a new synthetic pathway to access functionalized 1,3-enyne skeletons.
Directing-group-assisted copper-catalyzed olefinic trifluoromethylation of electron-deficient alkenes
Feng, Chao,Loh, Teck-Peng
supporting information, p. 122414 - 122417 (2013/12/04)
Assistance provided: The directing group in the title reaction not only activates the substrates but also allows the stereospecific formation of cis-trifluoromethylated products. The reaction is operationally simple and tolerates a wide variety of functional groups, thus providing an efficient method for the stereoselective synthesis of β-CF3-functionalized acrylamide derivatives. Copyright
