56947-80-9Relevant academic research and scientific papers
Tris(trimethylsilyl)silane in the Alkylation of Heteroaromatic Bases with Alkyl Halides
Togo, Hideo,Hayashi, Ken,Yokoyama, Masataka
, p. 641 - 644 (1993)
Protonated heteroaromatic bases were easily alkylated via radical pathways using alkyl halides in the presence of tris(trimethylsilyl)silane under photochemical or thermal conditions.
Radical Alkylation of Heteroaromatic Bases with Polysilane Compounds
Togo, Hideo,Hayashi, Ken,Yokoyama, Masataka
, p. 2522 - 2527 (1994)
Alkyl halides were treated with protonated heteroaromatic bases in the presence of 1,1,1,3,3,3-hexamethyl-2,2-bis(trimethylsilyl)trisilane under photochemical conditions to give the corresponding alkylated heteroaromatic bases easily.The alkylation of pro
Photochemical Magnetic Field Effects of 4-Methyl-2-quinolinecarbonitrile
Hata, Norisuke,Nishida, Naoya
, p. 3423 - 3430 (1985)
The irradiation of 4-methyl-2-quinolinecarbonitrile 1 in ethanol or cyclohexane resulted in the formation of 2-(1-hydroxyethyl)-4-methylquinoline 2 or 2-cyclohexyl-4-methylquinoline 3 in the yield of ca. 48 or 65percent.The effects of an external magnetic field upon the photosubstitution reaction were investigated in either the absence or presence of 1,3-pentadiene (triplet quencher).In the case of the photosubstitution reaction (1->2) in ethanol, the chemical yield of 2 increased quadratically with an increase in the field strength (magnetic field effect due to HFI-J mechanism).The addition of 1,3-pentadiene caused a complete disappearance of the Δg magnetic field effect.Thus, the formation of 2 at a zero field was concluded to occur from the S1-state via the singlet hydrogen-bonded radical pair.In the case of the photosubstitution reaction (1->3) in cyclohexane, the chemical yield of 3 decreased steeply upon the application of a magnetic field of 40mT (magnetic field effect due to HFI mechanism) and a further increase in the field strength resulted in a quadratic increase in the yield (magnetic field effect due to Δg mechanism).Neither an HFI nor a Δg magnetic field effect was observed in the presence of 1,3-pentadiene.The reaction was thus concluded to proceed from the S1 and T1 states via the singlet and triplet radical pairs.Reaction mechanisms deduced from the external magnetic field effects were consistent with the results of Stern-Volmer analyses.
Visible-light-mediated photoredox decarbonylative Minisci-type alkylation with aldehydes under ambient air conditions
Wang, Zhongzhen,Ji, Xiaochen,Zhao, Jinwu,Huang, Huawen
, p. 5512 - 5516 (2019)
Visible-light-induced photoredox decarbonylative C-C bond formation with aldehydes is described for the first time. Minisci-type alkylation reactions of N-heteroarenes proceed smoothly at ambient temperature with air as the sole oxidant. The present sustainable protocol uses readily available organofluorescein as a photocatalyst, cheap and green oxidant and a sustainable power source, thus featuring potential for applications in late-stage modification of valuable molecules.
Substituted 4-methylquinolines as a new class of anti-tuberculosis agents
Jain, Rahul,Vaitilingam, Balasubramanian,Nayyar, Amit,Palde, Prakash B.
, p. 1051 - 1054 (2003)
We report synthesis and anti-tuberculosis activities of a series of novel ring-substituted quinolines. The most effective compound of the series 3d (MIC=6.25 μg/mL, Mycobacterium tuberculosis H37Rv strain) was synthesized in one step; thus is an attractive lead molecule for anti-tuberculosis drug development. The results of this study represent the discovery of ring-substituted 4-methylquinolines as new class of potential anti-tuberculosis agents.
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
supporting information, (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Radical chain monoalkylation of pyridines
Dénès, Fabrice,Jangra, Harish,Meléndez, Camilo,Mulliri, Kleni,Renaud, Philippe,Rieder, Samuel,Zipse, Hendrik
, p. 15362 - 15373 (2021/12/14)
The monoalkylation of N-methoxypyridinium salts with alkyl radicals generated from alkenes (via hydroboration with catecholborane), alkyl iodides (via iodine atom transfer) and xanthates is reported. The reaction proceeds under neutral conditions since no acid is needed to activate the heterocycle and no external oxidant is required. A rate constant for the addition of a primary radical to N-methoxylepidinium >107 M-1 s-1 was experimentally determined. This rate constant is more than one order of magnitude larger than the one measured for the addition of primary alkyl radicals to protonated lepidine demonstrating the remarkable reactivity of methoxypyridinium salts towards radicals. The reaction has been used for the preparation of unique pyridinylated terpenoids and was extended to a three-component carbopyridinylation of electron-rich alkenes including enol esters, enol ethers and enamides.
An ultrastable olefin-linked covalent organic framework for photocatalytic decarboxylative alkylations under highly acidic conditions
Bu, Xiubin,Tian, Miao,Wang, Yichen,Wang, Yichun,Yang, Xiaobo
, p. 4272 - 4279 (2021/06/30)
The application of two-dimensional covalent organic frameworks (2D-COFs) as photoredox catalysts offers sustainable alternatives for visible-light-driven organic transformations. However, under highly complicated organic reaction conditions, maintaining their basic structure and photoactivity is always neglected, which impedes their potential in more organic reaction types and industrial use. Herein, we describe a visible-light-driven decarboxylative alkylation of heterocycles catalysed by an olefin-linked covalent organic framework (2D-COF-2) instead of the commonly used precious metal complexes and organic dyes. A wide range of alkylated heterocycles were selectively and efficiently synthesized under heterogeneous reaction conditions. Relying on the ultrastability of olefin linkage, 2D-COF-2 maintained its basic structure and photoactivity under highly acidic conditions. Moreover, its streamlining industrial potential was demonstrated in recycling experiments, functionalization of bioactive molecules and scale-up reactions.
A General Organocatalytic System for Electron Donor-Acceptor Complex Photoactivation and Its Use in Radical Processes
De Pedro Beato, Eduardo,Melchiorre, Paolo,Spinnato, Davide,Zhou, Wei
supporting information, p. 12304 - 12314 (2021/08/20)
We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with a variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts' stability and the method's high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
Phosphoric Acid Mediated Light-Induced Minisci C?H Alkylation of N-Heteroarenes
Jin, Songyang,Geng, Xinxin,Li, Yujun,Zheng, Ke
supporting information, p. 969 - 972 (2021/02/01)
Herein, we report an environmentally-friendly light-induced Minisci alkylation of N-heteroarenes with a broad substrate scope using diphenyl phosphate as catalyst under metal- and photocatalyst-free conditions. The radical precursor redox-active esters (R
