582-77-4Relevant academic research and scientific papers
In Situ Formation of Cationic π-Allylpalladium Precatalysts in Alcoholic Solvents: Application to C-N Bond Formation
Steinsoultz, Philippe,Bailly, Aurélien,Wagner, Patrick,Oliva, Estefania,Schmitt, Martine,Grimaud, Laurence,Bihel, Frédéric
, p. 560 - 567 (2022/01/03)
We report an efficient Buchwald-Hartwig cross-coupling reaction in alcoholic solvent, in which a low catalyst loading showed excellent performance for coupling aryl halides (I, Br, and Cl) with a broad set of amines, amides, ureas, and carbamates under mild conditions. Mechanistically speaking, in a protic and polar medium, extremely bulky biarylphosphine ligands interact with the dimeric precatalyst [Pd(π-(R)-allyl)Cl]2 to form the corresponding cationic complexes [Pd(π-(R)-allyl)(L)]Cl in situ and spontaneously. The resulting precatalyst further evolves under basic conditions into the corresponding L-Pd(0) catalyst, which is commonly employed for cross-coupling reactions. This mechanistic study highlights the prominent role of alcoholic solvents for the formation of the active catalyst.
Visible-Light-Promoted Iron-Catalyzed N-Arylation of Dioxazolones with Arylboronic Acids
Tang, Jing-Jing,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
, p. 13955 - 13961 (2021/11/20)
A visible-light-promoted and simple iron salt-catalyzed N-arylation was achieved efficiently under external photosensitizer-free conditions. Arylboronic acids and bench-stable dioxazolones were used for this cross-coupling reaction. This reaction features high reactivity, wide substrate scope, good functional group tolerance, simple operation procedure, and mild reaction conditions. Preliminary mechanistic investigations were conducted to support a radical pathway. This method may contribute to shift the paradigm of iron-catalyzed C-N bond construction and nitrene transfer chemistry.
Dihydroquinazolines enhance 20S proteasome activity and induce degradation of α-synuclein, an intrinsically disordered protein associated with neurodegeneration
Campbell, Molly V.,Davies, Steven B.,Fiolek, Taylor J.,Magyar, Christina L.,Mosey, R. Adam,Savich, Christopher J.,Tepe, Jetze J.,Wall, Tyler J.
supporting information, (2021/02/06)
Aggregates or oligomeric forms of many intrinsically disordered proteins (IDPs), including α-synuclein, are hallmarks of neurodegenerative diseases, like Parkinson's and Alzheimer's disease, and key contributors to their pathogenesis. Due to their disordered nature and therefore lack of defined drug-binding pockets, IDPs are difficult targets for traditional small molecule drug design and are often referred to as “undruggable”. The 20S proteasome is the main protease that targets IDPs for degradation and therefore small molecule 20S proteasome enhancement presents a novel therapeutic strategy by which these undruggable IDPs could be targeted. The concept of 20S activation is still relatively new, with few potent activators having been identified thus far. Herein, we synthesized and evaluated a library of dihydroquinazoline analogues and discovered several promising new 20S proteasome activators. Further testing of top hits revealed that they can enhance 20S mediated degradation of α-synuclein, the IDP associated with Parkinson's disease.
A practical and sustainable protocol for direct amidation of unactivated esters under transition-metal-free and solvent-free conditions
Chen, Cheng,Cheng, Hua,Du, Min-Chen,Qian, Liang,Qin, Xin,Sang, Wei,Yao, Wei-Zhong,Yuan, Ye,Zhang, Rui
supporting information, p. 3972 - 3982 (2021/06/17)
In this paper, a NaOtBu-mediated synthesis approach was developed for direct amidation of unactivated esters with amines under transition-metal-free and solvent-free conditions, affording a series of amides in good to excellent yields at room temperature. In particular, an environmentally friendly and practical workup procedure, which circumvents the use of organic solvents and chromatography in most cases, was disclosed. Moreover, the gram-scale production of representative products3a,3wand3auwas efficiently realized by applying operationally simple, sustainable and practical procedures. Furthermore, this approach was also applicable to the synthesis of valuable molecules such as moclobemide (a powerful antidepressant), benodanil and fenfuram (two commercial agricultural fungicides). These results demonstrate that this protocol has the potential to streamline amide synthesis in industry. Meanwhile, quantitative green metrics of all the target products were evaluated, implying that the present protocol is advantageous over the reported ones in terms of environmental friendliness and sustainability. Finally, additional experiments and computational calculations were carried out to elucidate the mechanistic insight of this transformation, and one plausible mechanism was provided on the basis of these results and the related literature reports.
Chromium-catalyzed ligand-free amidation of esters with anilines
Chen, Changpeng,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 762 - 766 (2021/04/14)
Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.
Fe-mediated synthesis of: N -aryl amides from nitroarenes and acyl chlorides
Wu, Yundong,Guo, Lei,Liu, Yuxuan,Xiang, Jiannan,Jiang, Jun
, p. 15290 - 15295 (2021/05/19)
Amides are prevalent in nature and valuable functional compounds in agrochemical, pharmaceutical, and materials industries. In this work, we developed a selective and mild method for the synthesis of N-aryl amides. Starting from commercially available nitroarenes and acyl halides, N-aryl amides with good yields can be obtained in water. Especially in the process of transformation, Fe dust is the only reductant and additive, and the reaction can be easily performed on a large scale.
Iron-catalyzed oxidative amidation of acylhydrazines with amines
Wang, Yi-Jie,Zhang, Guo-Yu,Shoberu, Adedamola,Zou, Jian-Ping
, (2021/08/18)
A new approach for amide bond formation via a mild and efficient Iron-catalyzed cross-coupling reaction of acylhydrazines and amines using TBHP as oxidant is described. This protocol is compatible with a wide range of amines and acylhydrazines. In addition, the synthetic application of the reaction is presented.
Supported-Pd catalyzed tandem approach for N-arylbenzamides synthesis
Bhattacherjee, Dhananjay,Das, Pralay,Giri, Kousik,Shaifali,Sharma, Ajay Kumar,Sharma, Navneet,Sheetal
, (2021/11/24)
Aryl iodides as dual arylating agent for C-terminal from oxalic acid [(CO2H)2] and N-terminal from sodium azide (NaN3) for N-aryl benzamides (Ar-CO-NH-Ar) synthesis is a rare invention which has been attempted successfully under this study. A single step tandem approach for the synthesis of N-aryl benzamides has been developed through bifunctional transformation of aryl iodides with in-situ CO from (CO2H)2 and NaN3 following two different pathways of carbonylation and azidation. The polystyrene supported palladium (Pd@PS) catalyst was found to be well compatible to perform the domino-reaction in a double layer vial (DLV) system under base, ligand and additive-free conditions. Moreover, the same approach was further extended with aryl azides for unsymmetric N-aryl benzamides (Ar-CO-NH-Ar') synthesis. Furthermore, the DFT studies were also performed to support the proposed mechanism.
Exploration of Cu-catalyzed regioselective hydrodehalogenation of o-haloanilides using EtOH as hydrogen source
Li, Min-Xin,Li, Mei-Ling,Tang, Yan-Ling,Sun, Yun,Qu, Lu,Huang, Feng,Mao, Ze-Wei
supporting information, (2021/05/03)
In present work, we have explored a Cu(acac)2/vasicine-catalyzed regioselective hydrodehalogenation methodology of o-haloanilides using EtOH as hydrogen source and solvent. The catalytic system could selectively dehalogenate 2-Br and 2-I, and features regioselective, efficient and functional group tolerance.
Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant
Yi, Xuewen,Yi, Xuewen,Lei, Siyu,Liu, Wangsheng,Che, Fengrui,Yu, Chunzheng,Liu, Xuesong,Wang, Zonghua,Zhou, Xin,Zhang, Yuexia
supporting information, p. 4583 - 4587 (2020/05/05)
An unprecedented N-demethylation of N-methyl amides has been developed by use of N-fluorobenzenesulfonimide as an oxidant with the aid of a copper catalyst. The conversion of amides to carbinolamines involves successive single-electron transfer, hydrogen-atom transfer, and hydrolysis, and is accompanied by formation of N-(phenylsulfonyl)benzenesulfonamide. Carbinolamines spontaneously decompose to N-demethylated amides and formaldehyde, because of their inherent instability.
