21354-40-5Relevant academic research and scientific papers
Efficient copper catalysts for C[sbnd]H bond arylation under microwave heating: Direct access to multi-substituted pivanilides
Yang, Hyun Ji,Mathew, Bijoy P.,Oh, Dong Gun,Myung, Kyungjae,Kwak, Ja Hun,Hong, Sung You
, p. 83 - 86 (2017)
We herein describe a parallel comparison between homogeneous and heterogeneous copper catalysts for microwave-assisted direct C[sbnd]H bond arylation. These catalytic systems feature enhanced catalytic activities, unique bulky ligand/base effects, mild co
Ligand-free copper-catalyzed direct amidation of diaryliodonium salts using nitriles as amidation reagents
Cheng, Hui-cheng,Guo, Penghu,Ji, Hong-bing,Ma, Jiao-li,Zhang, Yang,Zhou, Lichao,Zhou, Xuming
supporting information, (2021/04/19)
An efficient and practical methodology for the synthesis of N-arylamides has been developed via copper-catalyzed amidation of diaryliodonium salts with nitriles. Various substituted aryl nitriles and aliphatic nitriles could be applied in the reaction, providing a series of N-arylated amides in moderate to good yields. This procedure provides an alternative route for the synthesis of various N-arylamides. A proposed mechanism based on control experiments is also presented.
Benzylidene succinimides as 3C synthons for the asymmetric tandem Mannich reaction/transamidation of cyclic trifluoromethyl ketimines to obtain F3C-containing polycyclic dihydroquinazolinones
Zhang, Xia-Yan,Dou, Pei-Hao,Lu, Wen-Ya,You, Yong,Zhao, Jian-Qiang,Wang, Zhen-Hua,Yuan, Wei-Cheng
supporting information, p. 2927 - 2930 (2021/03/23)
By taking advantage of benzylidene succinimides as a new class of 3C synthons, a highly diastereo- and enantioselective tandem Mannich reaction/transamidation has been established by reacting them with cyclic trifluoromethylN-acyl ketimines. Using aCinchonaalkaloid-derived squaramide as the catalyst, the tandem reaction proceeded smoothly under mild conditions and afforded a range of F3C-containing chiral polycyclic dihydroquinazolinones with excellent results (up to 99% yield, all cases >20?:?1 dr, up to 99% ee).
Metal-free transamidation of benzoylpyrrolidin-2-one and amines under aqueous conditions
Joseph, Devaneyan,Lee, Sunwoo,Park, Myeong Seong
supporting information, p. 6227 - 6232 (2021/07/28)
N-Acyl lactam amides, such as benzoylpyrrolidin-2-one, benzoylpiperidin-2-one, and benzoylazepan-2-one reacted with amines in the presence of DTBP and TBAI to afford the transamidated products in good yields. The reactions were conducted under aqueous conditions and good functional group tolerance was achieved. Both aliphatic and aromatic primary amines displayed good activity under metal-free conditions. A radical reaction pathway is proposed.
Preparation method of N-aryl amide compound
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Paragraph 0040-0045, (2020/07/13)
The invention discloses a preparation method of an N-aryl amide compound, which comprises the following steps: (1) putting diaryliodonium salt and Cu(OAc)2 into a Schlenk tube provided with a magneticstirring rod; (2) sequentially adding DCE, H2O and nitrile by using an injector, sealing the Schlenk tube, and stirring for reaction at 80 DEG C; (3) cooling the obtained solution to room temperature, and performing extraction with EtOAc; and combining organic layers, performing washing with saline water, and performing drying with anhydrous Na2SO4; and (4) removing volatile matters in vacuum, and purifying residues through column chromatography to obtain the N-aryl amide compound. Through a large number of experiments, a substrate with a simple structure is screened, the reaction conditionsare mild, the yield is high, the pollution is small, and the application prospect is wide.
Amidation of Aryl Chlorides Using a Microwave-Assisted, Copper-Catalyzed Concurrent Tandem Catalytic Methodology
Chang, Raymond K.,Clairmont, Brice P.,Lin, Shirley,MacArthur, Amy H. Roy
supporting information, p. 4448 - 4454 (2019/11/13)
A concurrent tandem catalytic (CTC) methodology has been developed for the amidation of aryl chlorides where the aryl chloride is first converted to an aryl iodide via halogen exchange and the aryl iodide is subsequently transformed into the aryl amide. A variety of aryl chlorides were converted to aryl amides in up to 85% isolated yield using 20 mol % CuI, 60 mol % N,N′-cyclohexane-1,2-diamine, 2.2 equiv of K2CO3, and 1.05-1.5 equiv of amide in acetonitrile at 200 °C after 0.75-1 h. The same copper/ligand system served as multifunctional catalyst for both steps of the concurrent catalytic process with iodide present in substoichiometric amounts. Mechanistic studies were consistent with CTC amidation occurring via a nonradical mechanism. Kinetic modeling was conducted to investigate the effect of competitive direct amidation of an aryl chloride or aryl bromide on the formation of product over time during a CTC amidation reaction.
Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
supporting information, p. 237 - 241 (2019/01/10)
Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
General rhodium-catalyzed oxidative cross-coupling reactions between anilines: Synthesis of unsymmetrical 2,2′-diaminobiaryls
Shi, Yang,Liu, Jiahui,Yang, Yudong,You, Jingsong
supporting information, p. 5475 - 5478 (2019/05/16)
Described herein is a dual chelation-assisted RhCl3-catalyzed oxidative C-H/C-H cross-coupling reaction of aniline derivatives. The highlight of this methodology is the chemo- and regioselective cross-coupling between electronically similar substrates, which represents a highly challenging task in oxidative Ar-H/Ar-H cross-coupling reactions. Furthermore, this Cp?-free catalytic reaction tolerates a range of functional groups and requires only a low molar ratio of coupling partners. These features expedite the synthesis of unsymmetrical 2,2′-diaminobiaryls.
Acyl-Directed ortho-Borylation of Anilines and C7 Borylation of Indoles using just BBr3
Iqbal, Saqib A.,Cid, Jessica,Procter, Richard J.,Uzelac, Marina,Yuan, Kang,Ingleson, Michael J.
supporting information, p. 15381 - 15385 (2019/10/22)
Indoles are privileged heterocycles found in many biologically active pharmaceuticals and natural products. However, the selective functionalization of the benzenoid moiety in indoles in preference to the more reactive pyrrolic unit is a significant challenge. Herein we report that N-acyl directing groups enable the C7-selective C?H borylation of indoles using just BBr3. This transformation shows some functional-group tolerance and notably proceeds with C6 substituted indoles. The directing group can be readily removed in situ and the products isolated as the pinacol boronate esters. Acyl-directed electrophilic borylation can be extended to carbazoles and anilines with excellent ortho selectivity. 4-amino-indoles are amenable to this process, with acyl group installation and directed electrophilic C?H borylation enabling selective formation of C5-BPin-indoles.
Highly Chemoselective, Transition-Metal-Free Transamidation of Unactivated Amides and Direct Amidation of Alkyl Esters by N-C/O-C Cleavage
Li, Guangchen,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
supporting information, p. 11161 - 11172 (2019/08/07)
The amide bond is one of the most fundamental functional groups in chemistry and biology and plays a central role in numerous processes harnessed to streamline the synthesis of key pharmaceutical and industrial molecules. Although the synthesis of amides is one of the most frequently performed reactions by academic and industrial scientists, the direct transamidation of tertiary amides is challenging due to unfavorable kinetic and thermodynamic contributions of the process. Herein, we report the first general, mild, and highly chemoselective method for transamidation of unactivated tertiary amides by a direct acyl N-C bond cleavage with non-nucleophilic amines. This operationally simple method is performed in the absence of transition metals and operates under unusually mild reaction conditions. In this context, we further describe the direct amidation of abundant alkyl esters to afford amide bonds with exquisite selectivity by acyl C-O bond cleavage. The utility of this process is showcased by a broad scope of the method, including various sensitive functional groups, late-stage modification, and the synthesis of drug molecules (>80 examples). Remarkable selectivity toward different functional groups and within different amide and ester electrophiles that is not feasible using existing methods was observed. Extensive experimental and computational studies were conducted to provide insight into the mechanism and the origins of high selectivity. We further present a series of guidelines to predict the reactivity of amides and esters in the synthesis of valuable amide bonds by this user-friendly process. In light of the importance of the amide bond in organic synthesis and major practical advantages of this method, the study opens up new opportunities in the synthesis of pivotal amide bonds in a broad range of chemical contexts.
