2933-77-9Relevant academic research and scientific papers
Nucleophilic aromatic substitution of unactivated fluoroarenes enabled by organic photoredox catalysis
Nicewicz, David A.,Pistritto, Vincent A.,Schutzbach-Horton, Megan E.
supporting information, p. 17187 - 17194 (2020/11/02)
Nucleophilic aromatic substitution (SNAr) is a classical reaction with well-known reactivity toward electron-poor fluoroarenes. However, electron-neutral and electron-rich fluoro(hetero)arenes are considerably underrepresented. Herein, we present a method for the nucleophilic defluorination of unactivated fluoroarenes enabled by cation radical-accelerated nucleophilic aromatic substitution. The use of organic photoredox catalysis renders this method operationally simple under mild conditions and is amenable to various nucleophile classes, including azoles, amines, and carboxylic acids. Select fluorinated heterocycles can be functionalized using this method. In addition, the late-stage functionalization of pharmaceuticals is also presented. Computational studies demonstrate that the site selectivity of the reaction is dictated by arene electronics.
Green synthesis of N-(2-hydroxyethyl)anilines by the selective alkylation reaction in H2O
Guo, Hui,Hao, Jia,Sun, Tingting,Wang, Zuoyao,Cao, Jian,Zhang, Guobao
, p. 1 - 6 (2020/07/21)
Based on our previous work, a safer and more sustainable protocol for the synthesis of N-(2-Hydroxyethyl)anilines has been developed. The synthesis included the selective alkylation reaction of aniline with 2-chloroethanol in H2O, eliminating the need for any catalysts and solvents during synthesis. Comparing with our previous work, the salient features of this methodology are eco-friendliness, economic benefit, and the ease of obtaining target compounds. The selective alkylation reaction in H2O is amenable to scale-up for the synthesis of N-(2-Hydroxyethyl)anilines.
N-arylation method in aqueous phase system with substituted quinoline or isoquinoyl hydrazide pyridine-N-oxide as ligand
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Paragraph 0065; 0066; 0067; 0068, (2019/03/28)
The invention relates to an N-arylation method in an aqueous phase system with substituted quinoline or isoquinoyl hydrazide pyridine-N-oxide as a ligand. The N-arylation method in the aqueous phase system with the substituted quinoline or isoquinoyl hydrazide pyridine-N-oxide as the ligand comprises the following steps of: adding a catalyst, the ligand, a raw material, alkali, a phase transferring catalyst and a solvent into a reactor, heating and stirring, after the reaction is ended, separating and purifying a reaction solution to obtain an N-arylation product, wherein the raw material is aryl halide and a nitrogen-containing nucleophilic reagent, the solvent is a mixed solution of water and ethanol, and the catalyst is metal copper, or a copper oxide, or monovalent copper salt, or bivalent copper salt. The N-arylation method in the aqueous phase system with substituted quinoline or isoquinoyl hydrazide pyridine-N-oxide as the ligand has the characteristics of simplicity in operation, wide substrate application range, simplicity and easiness in separating products, high yield, economical process, environmental protection and the like.
An Effective Heterogeneous Copper Catalyst System for C-N Coupling and Its Application in the Preparation of 2-Methyl-4-methoxydiphenylamine (MMDPA)
Yi, Zhou,Huang, Manna,Wan, Yiqian,Zhu, Xinhai
, p. 3911 - 3920 (2018/09/29)
A ligand-recyclable, environmentally benign heterogeneous catalyst system composed of CuI and polystyrene-supported N (-(4-(aminomethyl)naphthalen-1-yl)- N (-phenyl-1 H -pyrrole-2-carbohydrazide (PSAP) has been established for Ullmann type C-N coupling based on the homogeneous catalyst system N ′, N ′-diphenyl-1 H -pyrrole-2-carbohydrazide/CuI. This heterogeneous catalyst system maintained the catalytic effectiveness of the homogeneous catalyst. A variety of functionalized aryl bromides can be efficiently aminated with aryl amines and aliphatic amines with high selectivity for amines over alcohols. Moreover, a practical application of this catalyst system to promote the reaction of commercially available 4-methoxy-2-methylaniline and bromobenzene in 10 mmol scale, provided 2-methyl-4-methoxydiphenylamine (MMDPA) with 93% yield with the merit of the approach being simple operation for work-up and purification.
Room-Temperature CuI-Catalyzed Amination of Aryl Iodides and Aryl Bromides
Ding, Xiaomei,Huang, Manna,Yi, Zhou,Du, Dongchen,Zhu, Xinhai,Wan, Yiqian
, p. 5416 - 5423 (2017/05/25)
A general and effective CuI/N′,N′-diaryl-1H-pyrrole-2-carbohydrazide catalyst system was developed for the amination of aryl iodides and bromides at room temperature with good chemoselectivity between -OH and -NH2 groups. Only 5 mol % of CuI and ligands was needed in this protocol to effect the amination of various aryl bromides and aryl iodides with a wide range of aliphatic and aryl amines (1.3 equiv).
β-Amino alcohols from anilines and ethylene glycol through heterogeneous Borrowing Hydrogen reaction
Llabres-Campaner, Pedro J.,Ballesteros-Garrido, Rafael,Ballesteros, Rafael,Abarca, Belén
supporting information, p. 5552 - 5561 (2017/08/22)
Borrowing Hydrogen (BH), also called Hydrogen Autotransfer (HA), reaction with neat ethylene glycol represents a key step in the preparation of β-amino alcohols. However, due to the stability of ethylene glycol, mono-activation has rarely been achieved. Herein, a combination of Pd/C and ZnO is reported as heterogeneous catalyst for this BH/HA reaction. This system results in an extremely air and moisture stable, and economic catalyst able to mono-functionalize ethylene glycol in water, without further activation of the diol. In this work, different diols and aromatic amines have been explored affording a new approach towards amino alcohols. This study reveals how the combination of two solid species can afford interesting catalytic properties in heterogeneous phase. ZnO activates ethylene glycol while Pd/C is the responsible of the BH/HA cycle. This catalytic system has also been found useful to dehydrogenate indoles affording indolines that undergo in situ BH/HA cycle prior to re-aromatization, representing a tandem heterogeneous process.
N-Arylazetidines: Preparation through Anionic Ring Closure
Quinodoz, Pierre,Drouillat, Bruno,Wright, Karen,Marrot, Jéro?me,Couty, Fran?ois
, p. 2899 - 2910 (2016/04/26)
We report herein an efficient synthesis of diversely substituted N-aryl-2-cyanoazetidines based on an anionic ring-closure reaction. These compounds can be prepared from β-amino alcohols in enantiomerically pure form through a three-step sequence involving (i) copper-catalyzed N-arylation, (ii) N-cyanomethylation of the secondary aniline, and (iii) one-pot mesylation followed by ring closure induced by a base. This high-yielding sequence gives access to azetidines with a predictable and adjustable substitution pattern and also with predictable diastereoselectivity. These compounds are susceptible to multiple further derivatizations through Suzuki coupling or nitrile transformation, thus appearing as valuable new scaffolds for medicinal chemistry. Their rigid shape, featuring an almost planar N-arylamine and a planar four-membered ring, was revealed by both AM1 calculations and X-ray crystallography.
Room-Temperature Practical Copper-Catalyzed Amination of Aryl Iodides
Deldaele, Christopher,Evano, Gwilherm
, p. 1319 - 1328 (2016/04/20)
An efficient and highly practical procedure is reported for the Ullmann-Goldberg-type copper-catalyzed amination of aryl iodides. By using a combination of copper iodide and proline in the presence of an excess of an amine, a wide range of aryl iodides can be readily aminated at room temperature. The reaction proceeds well regardless of the electronic properties of the starting aryl iodide and the amination products can be obtained without the need for purification by column chromatography in most cases. Owing to its efficiency and the mildness of the reaction conditions, this amination could also be extended to the amination of complex aryl iodides at room temperature.
Palladium-catalyzed intramolecular carbene insertion into C(sp3)-H bonds
Solé, Daniel,Mariani, Francesco,Bennasar, M.-Llu?sa,Fernández, Israel
supporting information, p. 6467 - 6470 (2016/06/01)
A palladium-catalyzed carbene insertion into C(sp3)-H bonds leading to pyrrolidines was developed. The coupling reaction can be catalyzed by both Pd0 and PdII, is regioselective, and shows a broad functional group tolerance. This reaction is the first example of palladium-catalyzed C(sp3)-C(sp3) bond assembly starting from diazocarbonyl compounds. DFT calculations revealed that this direct C(sp3)-H bond functionalization reaction involves an unprecedented concerted metalation-deprotonation step. Pd in action: Palladium has been used to catalyze the C(sp3)-H insertion of metal carbenoids derived from α-diazoesters to form pyrrolidines through intramolecular assembly of C(sp3)-C(sp3) bonds. A reaction mechanism involving a metalation-deprotonation step instead of the usual concerted but asynchronous process is proposed.
Highly Efficient Mechanochemical N-Arylation of Amino Alcohols and Diamines with Cu0 Powder
Martina, Katia,Rinaldi, Laura,Baricco, Francesca,Boffa, Luisa,Cravotto, Giancarlo
, p. 2789 - 2794 (2015/12/18)
Cu0-catalysed arylations have rightly acquired great importance over the last decade. This paper reports the N-arylation of amino alcohols and diamines with iodobenzene derivatives in a planetary ball mill and an investigation into the procedure. This newly developed solvent-free protocol is fast, efficient and occurs under the mechanochemical activation of metallic copper powder. It does not require additional ligands and gives excellent yields. This paper aims to broaden the scope of mechanochemical Cu0-activation and so a new one-pot, two-step synthesis that combines CuAAC and N-arylation has been successfully performed and reported herein.
