350-98-1Relevant articles and documents
Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
Brittain, William D. G.,Cobb, Steven L.
, p. 5793 - 5798 (2021/08/01)
This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
supporting information, p. 4843 - 4848 (2021/06/28)
A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
Iron-catalyzed cross-coupling of N?methoxy amides and arylboronic acids for the synthesis of N-aryl amides
Li, Jinhui,Liu, Jin-Biao,Luo, Nianhua,Qiu, Guanyinsheng,Ren, Shangfeng,Wang, Ying,Xie, Huilin
, (2021/11/11)
An efficient iron-catalyzed synthesis of N-aryl amides from N?methoxy amides and arylboronic acids is developed. FeCl3 is used as the sole catalyst for the cross-coupling reaction between N?methoxy amides and arylboronic acids without any other
Acetonitrile and benzonitrile as versatile amino sources in copper-catalyzed mild electrochemical C-H amidation reactions
Budnikova, Yulia,Kononov, Alexander,Rizvanov, Ildar,Strekalova, Sofia
, p. 37540 - 37543 (2021/12/07)
A mild, efficient electrochemical approach to the site-selective direct C-H amidation of benzene and its derivatives with acetonitrile and benzonitrile has been developed. It has been shown that joint electrochemical oxidation of various arenes in the presence of a copper salt as a catalyst and nitriles leads to the formation of N-phenylacetamide from benzene and N-benzylacetamides from benzyl derivatives (up to 78% yield). A favorable feature of the process is mild conditions (room temperature, ambient pressure, no strong oxidants) that meet the criteria of green chemistry.
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.
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.
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.
Nickel/briphos-catalyzed transamidation of unactivated tertiary amides
Kim, Hyunwoo,Lee, Sunwoo,Shin, Taeil,Yang, Dahyeon
supporting information, p. 6053 - 6057 (2020/10/27)
The transamidation of tertiary amides was achieved via nickel catalysis in combination with briphos ligands. N-Methyl-N-phenylbenzamide derivatives reacted with primary amines in the presence of NiCl2/briphos L4 to provide the transamidated products in moderate to good yields. Primary aromatic amines delivered higher product yields than aliphatic amines.
A Unified and Practical Method for Carbon–Heteroatom Cross-Coupling using Nickel/Photo Dual Catalysis
Escobar, Randolph A.,Johannes, Jeffrey W.
supporting information, (2020/04/17)
While carbon–heteroatom cross-coupling reactions have been extensively studied, many methods are specific and limited to a particular set of substrates or functional groups. Reported here is a general method that allows for C?O, C?N and C?S cross-coupling reactions under one general set of conditions. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel(II) complex, is responsible for the key reductive elimination step that couples aryl bromides, iodides, and chlorides to 1° and 2° alcohols, amines, thiols, carbamates, and sulfonamides, and is amenable to scale up via a flow apparatus.
Switching from biaryl formation to amidation with convoluted polymeric nickel catalysis
Sen, Abhijit,Dhital, Raghu N.,Sato, Takuma,Ohno, Aya,Yamada, Yoichi M.A.
, p. 14410 - 14418 (2020/12/21)
A stable, reusable, and insoluble poly(4-vinyl-pyridine) nickel catalyst (P4VP-NiCl2) was prepared through the molecular convolution of poly(4-vinylpyridine) (P4VP) and nickel chloride. We proposed a coordination structure of the Ni center in the precatalyst based on elemental analysis and Ni K-edge XANES, and we confirmed that it is consistent with Ni K-edge EXAFS. The Suzuki?Miyaura-type coupling of aryl halides and arylboronic esters proceeded using P4VP-NiCl2 (0.1 mol % Ni) to give the corresponding biaryl compounds in up to 94% yield. Surprisingly, when the same reaction of aryl halides and arylboronic acid/ester was carried out in the presence of amides, the amidation proceeded predominantly to give the corresponding arylamides in up to 99% yield. In contrast, the reaction of aryl halides and amides in the absence of arylboronic acid/ester did not proceed. P4VP-NiCl2 successfully catalyzed the lactamization for preparing phenanthridinone. P4VP-NiCl2 was reused five times without significant loss of catalytic activity. Pharmaceuticals, natural products, and biologically active compounds were synthesized efficiently using P4VPNiCl2 catalysis. Nickel contamination in the prepared pharmaceutical compounds was not detected by ICP-MS analysis. The reaction was scaled to multigrams without any loss of chemical yield. Mechanistic studies for both Suzuki?Miyaura and amidation were performed.
