22884-95-3Relevant articles and documents
Biomass chitosan-derived nitrogen-doped carbon modified with iron oxide for the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles
Wang, Wei David,Wang, Fushan,Chang, Youcai,Dong, Zhengping
, (2020/11/24)
Nitrogen-doped carbon catalysts have attracted increasing research attention due to several advantages for catalytic application. Herein, cost-effective, renewable biomass chitosan was used to prepare a N-doped carbon modified with iron oxide catalyst (Fe2O3@NC) for nitrile synthesis. The iron oxide nanoparticles were uniformly wrapped in the N-doped carbon matrix to prevent their aggregation and leaching. Fe2O3@NC-800, which was subjected to carbonization at 800 °C, exhibited excellent activity, selectivity, and stability in the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles. This study may provide a new method for the fabrication of an efficient and cost-effective catalyst system for synthesizing nitriles.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Zn-catalyzed cyanation of aryl iodides
Zhao, Lulu,Dong, Yanan,Xia, Qiangqiang,Bai, Jianfei,Li, Yuehui
, p. 6471 - 6477 (2020/06/08)
We report the first example of zinc-catalyzed cyanation of aryl iodides with formamide as the cyanogen source. The transformation was promoted by the bisphosphine Nixantphos ligand. Under optimized conditions, a variety of electron-donating and electron-withdrawing aryl iodides were converted into nitrile products in good to excellent yields. This approach is an exceedingly simple and benign method for the synthesis of aryl nitriles and is likely to proceed via a dinuclear Zn-concerted catalysis.
Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species
Dong, Yanan,Li, Yuehui,Yang, Peiju,Zhao, Shizhen
, (2020/08/19)
Cyano-containing compounds constitute important pharmaceuticals, agrochemicals and organic materials. Traditional cyanation methods often rely on the use of toxic metal cyanides which have serious disposal, storage and transportation issues. Therefore, there is an increasing need to develop general and efficient catalytic methods for cyanide-free production of nitriles. Here we report the reductive cyanation of organic chlorides using CO2/NH3 as the electrophilic CN source. The use of tridentate phosphine ligand Triphos allows for the nickel-catalyzed cyanation of a broad array of aryl and aliphatic chlorides to produce the desired nitrile products in good yields, and with excellent functional group tolerance. Cheap and bench-stable urea was also shown as suitable CN source, suggesting promising application potential. Mechanistic studies imply that Triphos-Ni(I) species are responsible for the reductive C-C coupling approach involving isocyanate intermediates. This method expands the application potential of reductive cyanation in the synthesis of functionalized nitrile compounds under cyanide-free conditions, which is valuable for safe synthesis of (isotope-labeled) drugs.
Dehydrogenation of Primary Alkyl Azides to Nitriles Catalyzed by Pincer Iridium/Ruthenium Complexes
Gan, Lan,Jia, Xiangqing,Fang, Huaquan,Liu, Guixia,Huang, Zheng
, p. 3661 - 3665 (2020/06/02)
Pincer metal complexes exhibit superior catalytic activity in the dehydrogenation of plain alkanes, but find limited application in the dehydrogenation of functionalized organic molecules. Starting from easily accessible primary alkyl azides, here we report an efficient dehydrogenation of azides to nitriles using pincer iridium or ruthenium complexes as the catalysts. This method offers a route to cyanide-free preparation of nitriles without carbon chain elongation and without the use of strong oxidants. Both benzyl and linear aliphatic azides can be dehydrogenated with tert-butylethylene as the hydrogen acceptor to afford nitriles in moderate to high yields. Various functional groups can be tolerated, and the H?C?C?H bond dehydrogenation does not occur for linear alkyl azide substrates. Furthermore, the pincer Ir catalytic system was found to catalyze the direct azide dehydrogenation without the use of a sacrificial hydrogen acceptor.
NHC-catalyzed silylative dehydration of primary amides to nitriles at room temperature
Ahmed, Jasimuddin,Hota, Pradip Kumar,Maji, Subir,Mandal, Swadhin K.,Rajendran, N. M.
supporting information, p. 575 - 578 (2020/01/29)
Herein we report an abnormal N-heterocyclic carbene catalyzed dehydration of primary amides in the presence of a silane. This process bypasses the energy demanding 1,2-siloxane elimination step usually required for metal/silane catalyzed reactions. A detailed mechanistic cycle of this process has been proposed based on experimental evidence along with computational study.
Palladium-Catalyzed Late-Stage Direct Arene Cyanation
Zhao, Da,Xu, Peng,Ritter, Tobias
supporting information, p. 97 - 107 (2019/01/21)
Methods for direct benzonitrile synthesis are sparse, despite the versatility of cyano groups in organic synthesis and the importance of benzonitriles for the dye, agrochemical, and pharmaceutical industries. We report the first general late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance. The reaction is enabled by a dual-ligand combination of quinoxaline and an amino acid-derived ligand. The method is applicable to direct cyanation of several marketed small-molecule drugs, common pharmacophores, and organic dyes. Benzonitriles are some of the most versatile building blocks for organic synthesis, in particular in the pharmaceutical industry, but general methods to make them by direct C–H functionalization are unknown. In this issue of Chem, Ritter and coworkers describe a late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance, enabled by a palladium-dual-ligand catalyst system. The reaction may serve for the late-stage modification of drug candidates. Aryl nitriles constitute an important class of organic compounds that are widely found in natural products, pharmaceuticals, agricultural chemicals, dyes, and materials. Moreover, nitriles are versatile building blocks to access numerous other important molecular structure groups. However, no general method for direct aromatic C–H cyanation is known. All approaches to date require either an appropriate directing group or reactive electron-rich substrates, such as indoles, which limit their synthetic applications. Here we describe an undirected, palladium-catalyzed late-stage aryl C–H cyanation reaction for the synthesis of complex aryl nitriles that would otherwise be more challenging to produce. The wide substrate scope and good functional-group tolerance of this reaction provide direct and quick access to structural diversity for pharmaceutical and agrochemical development.
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.
Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
supporting information, p. 19257 - 19262 (2019/12/02)
Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
Vilsmeier-Haack reagent mediated synthetic transformations with an immobilized iridium complex photoredox catalyst
Zhi, Peng,Xi, Zi-Wei,Wang, Dan-Yan,Wang, Wei,Liang, Xue-Zheng,Tao, Fei-Fei,Shen, Run-Pu,Shen, Yong-Miao
, p. 709 - 717 (2019/01/10)
An immobilized iridium complex photocatalyst Ir(ppy)2(PDVB-py) was synthesized by immobilization of the iridium complex onto the nanoporous vinylpyridine-divinylbenzene copolymer (PDVB-py). Its application for the synthesis of amides, nitriles, and anhydrides was reported via reactions under the action of the visible-light-driven in situ generated Vilsmeier-Haack reagent from CBr4 in DMF. The results showed that this heterogeneous photocatalyst has extremely high activity and excellent stability to be recycled five times.
