1982-62-3Relevant academic research and scientific papers
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.
Preparation method of N-aryl amide compound
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Paragraph 0082-0086, (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.
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.
Manganese-Mediated Reductive Transamidation of Tertiary Amides with Nitroarenes
Cheung, Chi Wai,Ma, Jun-An,Hu, Xile
supporting information, p. 6789 - 6792 (2018/05/29)
Amides are an important class of organic compounds, which have widespread industrial applications. Transamidation of amides is a convenient method to generate new amides from existing ones. Tertiary amides, however, are challenging substrates for transamidation. Here we describe an unconventional approach to the transamidation of tertiary amides using nitroarenes as the nitrogen source under reductive conditions. Manganese metal alone mediates the reactions and no additional catalyst is required. The method exhibits broad scope and high functional group tolerance.
Synthesis of Quinazolines from N,N′-Disubstituted Amidines via I2/KI-Mediated Oxidative C-C Bond Formation
Lv, Zhigang,Wang, Bingnan,Hu, Zhiyuan,Zhou, Yiming,Yu, Wenquan,Chang, Junbiao
supporting information, p. 9924 - 9930 (2016/11/02)
An I2/KI-promoted oxidative C-C bond formation reaction from C(sp3)-H and C(sp2)-H bonds has been used to construct quinazoline skeletons from N,N′-disubstituted amidines. The required substrates are readily prepared from the corresponding acyl chlorides, anilines, and alkyl/benzylamines by sequential amidation, chlorination, and amination reactions. Under the optimal oxidative cyclization conditions, all these amidines were conveniently transformed into the expected products in moderate to good yields. This practical and environmentally benign approach works well with crude amidine intermediates and can also be carried out on a gram scale.
Imidazolium-supported benzotriazole: an efficient and recoverable activating reagent for amide, ester and thioester bond formation in water
Shakoor, S.M. Abdul,Choudhary, Sunita,Bajaj, Kiran,Muthyala, Manoj Kumar,Kumar, Anil,Sakhuja, Rajeev
, p. 82199 - 82207 (2015/10/12)
An efficient and recyclable imidazolium-supported benzotriazole reagent (Im-CH2-BtH) as a novel synthetic auxiliary has been synthesized and its utility as a carboxyl group activating reagent via the formation of stable imidazolium-supported acyl benzotriazoles was explored for the synthesis of amides, esters and thioesters in water under microwave conditions. The reagent was reused five times without any noticeable loss in activity. It is moisture insensitive and highly stable under thermal and aerobic conditions. The application of imidazolium-supported N-acetyl benzotriazole leads to synthesis of paracetamol on the gram scale under greener conditions in 93% yield.
Copper-catalyzed oxidative amidation between aldehydes and arylamines under mild conditions
Ding, Yongzheng,Zhang, Xian,Zhang, Dongyang,Chen, Yuting,Wu, Zhibing,Wang, Peiyi,Xue, Wei,Song, Baoan,Yang, Song
supporting information, p. 831 - 833 (2015/02/19)
A facile strategy to prepare amide bonds has been developed. A series of amide compounds, including heterocyclic amide compounds, were obtained with moderate to good yields ranging from 31-88% by using copper iodide (CuI) to catalyze the oxidative amidation between aldehydes and amines under solvent-free conditions at room temperature in air.
Efficient microwave access to polysubstituted amidines from imidoylbenzotriazoles
Katritzky, Alan R.,Cai, Chunming,Singh, Sandeep K.
, p. 3375 - 3380 (2007/10/03)
Microwave reactions of primary and secondary amines with imidoylbenzotriazoles 6a-w gave diversely substituted amidines 7a-Aa in 76-94% yields. Convenient preparations of a variety of amides 5a-Ab (87-96%) and imidoylbenzotriazoles 6a-w (56-95%) have also been developed using microwave irradiation under mild conditions and short reaction times. These results demonstrate further the advantages of microwave synthesis and introduce a new application of imidoylbenzotriazoles in the preparation of polysubstituted amidines.
Determination of aromaticity indices of thiophene and furan by nuclear magnetic resonance spectroscopic analysis of their anilides
Lee, Chang Kiu,Yu, Ji Sook,Ji, Young Ran
, p. 1219 - 1227 (2007/10/03)
A series of m- and p-substituted anilides of benzoic acid, 2-thienoic acid, and 2-furoic acid were prepared and their 1H and 13C nmr spectroscopic characteristics were examined. In general, good correlations were observed between the chemical shifts of proton and carbon signals of the acyl aromatic rings and the Hammett σ. Plots of the chemical shift values of the carbonyl carbons of the benzanilides against those of the 2-thienamides and 2-furamides gave an excellent correlation and the values of the slopes are 0.79 and 0.52, respectively, in dimethyl sulfoxide-d6. The slopes could be considered as a set of aromaticity index.
