2571-54-2Relevant articles and documents
Electrochemical Oxidative C?H Cyanation of Quinoxalin-2(1H)-ones with TMSCN
Li, Yifan,Liu, Ping,Sun, Peipei,Tong, Jinwen,Zhan, Yanling
, p. 2193 - 2197 (2021)
Both quinoxalin-2(1H)-ones and nitriles are valuable organic compounds, and it is an interesting task to introduce cyano into quinoxalin-2(1H)-ones. Herein a regioselective C?H cyanation of quinoxalin-2(1H)-ones was developed with a nucleophilic cyano source TMSCN under electrochemical oxidative conditions. This process allowed the synthesis of C3 cyanated quinoxalin-2(1H)-ones in moderate to excellent yields in the absence of transition-metal catalysts and organic hydroperoxides.
Copper-Catalyzed One-Pot Synthesis of Quinazolinones from 2-Nitrobenzaldehydes with Aldehydes: Application toward the Synthesis of Natural Products
Pal, Shantanu,Sahoo, Subrata
, p. 18067 - 18080 (2021/12/06)
A novel, efficient, and atom-economical approach for the construction of quinazolinones from 2-nitrobenzaldehydes has been unveiled via copper-catalyzed nitrile formation, hydrolysis, and reduction in one pot for the first time. In this reaction, urea is used as a source of nitrogen for nitrile formation, hydrazine hydrate is used for both the reduction of the nitro group and the hydrolysis of nitrile, and atmospheric oxygen is used as the sole oxidant. The method portrays a wide substrate scope with good functional group tolerances. Moreover, this method was applied for the synthesis of schizocommunin, tryptanthrin, phaitanthrin-A, phaitanthrin-B, and 8H-quinazolino[4,3-b]quinazolin-8-one.
Site-Selective Electrochemical C-H Cyanation of Indoles
Li, Laiqiang,Hou, Zhong-Wei,Li, Pinhua,Wang, Lei
supporting information, p. 5983 - 5987 (2021/08/16)
An electrochemical approach for the site-selective C-H cyanation of indoles employing readily available TMSCN as cyano source has been developed. The electrosynthesis relies on the tris(4-bromophenyl)amine as a redox catalyst, which achieves better yield and regioselectivity. A variety of C2- and C3-cyanated indoles were obtained in satisfactory yields. The reactions are conducted in a simple undivided cell at room temperature and obviate the need for transition-metal reagent and chemical oxidant.
DIBENZOTHIOPHENE SALT AS ALKYNYLATING AND CYANATING AGENT
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Paragraph 0098, (2021/08/27)
The present invention describes a new alkynylation and cyanation agent, as well as its preparation and use to introduce nitrile (cyano) or alkyne groups into chemical target molecules by means of an electrophilic reaction. To enable an electrophilic reaction, the chemical backbone of dibenzothiophene was used.
Conversions of aryl carboxylic acids into aryl nitriles using multiple types of Cu-mediated decarboxylative cyanation under aerobic conditions
Cai, Hu,Cao, Xihan,Fu, Zhengjiang,Guo, Shengmei,Wang, Shuiliang
supporting information, p. 8381 - 8385 (2020/11/05)
Here, we used malononitrile or AMBN as a cyanating agent to develop efficient and practical protocols for Cu-mediated decarboxylative cyanations, under aerobic conditions, of aryl carboxylic acids bearing nitro and methoxyl substituents at the ortho position as well as of heteroaromatic carboxylic acids. These protocols involved economical methods to synthesize value-added aryl nitriles from simple and inexpensive raw materials. Further diversification of the 2-nitrobenzonitrile product was performed to highlight the practicality of the protocols. This journal is
Dual Ligand-Enabled Nondirected C-H Cyanation of Arenes
Chen, Hao,Mondal, Arup,Wedi, Philipp,Van Gemmeren, Manuel
, p. 1979 - 1984 (2019/02/19)
Aromatic nitriles are key structural units in organic chemistry and, therefore, highly attractive targets for C-H activation. Herein, the development of an arene-limited, nondirected C-H cyanation based on the use of two cooperatively acting commercially available ligands is reported. The reaction enables the cyanation of arenes by C-H activation in the absence of directing groups and is therefore complementary to established approaches.
Ligand-Promoted Non-Directed C?H Cyanation of Arenes
Liu, Luo-Yan,Yeung, Kap-Sun,Yu, Jin-Quan
supporting information, p. 2199 - 2202 (2019/01/24)
This article reports the first example of a 2-pyridone accelerated non-directed C?H cyanation with an arene as the limiting reagent. This protocol is compatible with a broad scope of arenes, including advanced intermediates, drug molecules, and natural products. A kinetic isotope experiment (kH/kD=4.40) indicates that the C?H bond cleavage is the rate-limiting step. Also, the reaction is readily scalable, further showcasing the synthetic utility of this method.
Organic semiconductor photocatalyst can bifunctionalize arenes and heteroarenes
Ghosh, Indrajit,Khamrai, Jagadish,Savateev, Aleksandr,Shlapakov, Nikita,Antonietti, Markus,K?nig, Burkhard
, p. 360 - 366 (2019/08/15)
Photoexcited electron-hole pairs on a semiconductor surface can engage in redox reactions with two different substrates. Similar to conventional electrosynthesis, the primary redox intermediates afford only separate oxidized and reduced products or, more rarely, combine to one addition product. Here, we report that a stable organic semiconductor material, mesoporous graphitic carbon nitride (mpg-CN), can act as a visible-light photoredox catalyst to orchestrate oxidative and reductive interfacial electron transfers to two different substrates in a two- or three-component system for direct twofold carbon–hydrogen functionalization of arenes and heteroarenes. The mpg-CN catalyst tolerates reactive radicals and strong nucleophiles, is straightforwardly recoverable by simple centrifugation of reaction mixtures, and is reusable for at least four catalytic transformations with conserved activity.
5-(Cyano)dibenzothiophenium Triflate: A Sulfur-Based Reagent for Electrophilic Cyanation and Cyanocyclizations
Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
supporting information, p. 9496 - 9500 (2019/06/27)
The synthesis of 5-(cyano)dibenzothiophenium triflate 9, prepared by activation of dibenzo[b,d]thiophene-5-oxide with Tf2O and subsequent reaction with TMSCN is reported, and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not required for the transfer process. We additionally report herein biomimetic cyanocyclization cascade reactions, which are not promoted by typical electrophilic cyanation reagents, demonstrating the superior ability of 9 to trigger challenging transformations.
GaCl3-Catalyzed C-H Cyanation of Indoles with N-Cyanosuccinimide
Wang, Xue,Makha, Mohamed,Chen, Shu-Wei,Zheng, Huaiji,Li, Yuehui
, p. 6199 - 6206 (2019/05/24)
An efficient GaCl3-catalyzed direct cyanation of indoles and pyrroles using bench-stable electrophilic cyanating agent N-cyanosuccinimide was achieved and afforded 3-cyanoindoles and 2-cyanopyrroles in good yields and excellent regioselectivities. Notably, this protocol exhibited high reactivity for unprotected indoles and was applicable to a broad range of indole and pyrrole substrates.
