1903-64-6Relevant academic research and scientific papers
POCl3 promoted metal-free synthesis of tertiary amides by coupling of carboxylic acids and N,N-disubstituted formamides
Bi, Xiaojing,Li, Junchen,Shi, Enxue,Li, Yu,Liu, Ying,Wang, Hongmei,Xiao, Junhua
supporting information, p. 236 - 240 (2019/04/25)
Herein we report a robust and synthetically useful catalyst-free amination methodology by the coupling of carboxylic acids and N-substituted formamides using POCl3 as a promoter. Versatile amides with a wide array of substituent groups were prepared within only 1 h in good to excellent yields. And even multi-substituted aromatic carboxylic acids could give the desired products with satisfactory results.
Site-Selective Functionalization of Pyridinium Derivatives via Visible-Light-Driven Photocatalysis with Quinolinone
Kim, Inwon,Kang, Gyumin,Lee, Kangjae,Park, Bohyun,Kang, Dahye,Jung, Hoimin,He, Yu-Tao,Baik, Mu-Hyun,Hong, Sungwoo
supporting information, p. 9239 - 9248 (2019/06/24)
The selective installation of phosphinoyl and carbamoyl moieties on the pyridine scaffold is an important transformation in synthetic and medicinal chemistry. By employing quinolinone as an efficient organic photocatalyst, we developed a catalytic system driven by visible light that forms phosphinoyl and carbamoyl radicals, which react with various heteroarenium derivatives under mild, transition-metal-free conditions. This straightforward and environmentally friendly synthetic method represents a new approach to site-divergent pyridine functionalization that offers considerable advantages in both simplicity and efficiency. Ambient temperature is sufficient for the formation of the reactive radicals, and the site-selectivity can be switched from C2 to C4 by changing the radical coupling sources. Under standard reaction conditions, phosphinoyl radicals give access to C4 products, while carbamoyl radicals selectively give C2 products. We found that the carbamoyl radical overcomes the intrinsic preference for forming the ortho-product by allowing the oxo functionality of the carbamoyl radical to electrostatically engage the nitrogen of the pyridinium substrate, which preferentially gives the ortho-product. The phosphinoyl radical cannot engage in the same interaction, because the phosphorus is too large. This novel synthetic route tolerates a broad range of substrates and provides a convenient and powerful synthetic tool for accessing the core structures of numerous privileged scaffolds.
Preparation of Thioanisole Biscarbanion and C-H Lithiation/Annulation Reactions for the Access of Five-Membered Heterocycles
Zhu, Ranran,Liu, Zheyuan,Chen, Jie,Xiong, Xiaoyu,Wang, Yuntao,Huang, Lin,Bai, Jinshan,Dang, Yanfeng,Huang, Jianhui
supporting information, p. 3161 - 3165 (2018/06/11)
The synthesis, isolation, and X-ray structure of a thioanisole-based trilithium complex are reported. On the basis of the double-lithiation strategy, two novel synthetic methodologies have been developed under mild reaction conditions (room temperature): (1) reactions of lithiated thioanisoles with nitriles give benzoisothiazoles via a [3 + 2]-type of approach with two new bond formations and (2) formation of benzothiophenes from thioanisoles and amides through a [4 + 1] pattern forming 4 new chemical bonds.
Ru-catalyzed direct amidation of carboxylic acids with N-substituted formamides
Bi, Xiaojing,Li, Junchen,Shi, Enxue,Wang, Hongmei,Gao, Runli,Xiao, Junhua
, p. 8210 - 8214 (2016/11/23)
The direct amidation of carboxylic acids with N-substituted formamides has been accomplished via ruthenium catalysis. In the presence of ruthenium catalyst, a versatile range of carboxylic acids and N-substituted formamides undergoes amidation reaction to produce synthetically useful amides in good yields. C[dbnd]O in amide product came from benzoic acid but not N-substituted formamides, and which was confirmed by Isotope experiment.
Method for synthesizing phosphorus-oxychloride-promoted amide compound
-
Paragraph 0100; 0101; 0102; 0103; 0104, (2017/01/26)
The invention relates to a method for synthesizing a phosphorus-oxychloride-promoted amide compound. The synthesizing method includes the steps that carboxylic acid serves as one reactant, another reactant (N,N-dialkyl methanamide) serves as a solvent, one equivalent of phosphorus oxychloride is added, and the amide compound is prepared. The reaction substrates are low in price and easy to get, the nature is stable, toxicity is small, the reaction speed is high, conditions are moderate, and the reaction substrates can be widely applied to substrates with different functional groups. The efficiently-constructed amide compound is an important molecular skeleton for many medicines, bioactive molecules and natural products, and the synthesizing method is a widely-applicable preparing method for synthesizing the compound.
Easy access to amides through aldehydic C-H bond functionalization catalyzed by heterogeneous Co-based catalysts
Bai, Cuihua,Yao, Xianfang,Li, Yingwei
, p. 884 - 891 (2015/02/19)
A novel synthesis strategy for amides by oxidative amidation of aldehydes is developed using a heterogeneous Co-based catalyst. The Co composite was prepared by simple pyrolysis of a Co-containing MOF, to obtain well-dispersed Co nanoparticles enclosed by carbonized organic ligands. The catalysts were characterized by powder X-ray diffraction (PXRD), N2 physical adsorption, atomic absorption spectroscopy (AAS), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The small Co nanoparticles embedded in the N-doped carbons were highly dispersed with an average size of ca. 7 nm. The Co@C-N materials exhibited significantly enhanced catalytic activity in the oxidative amidation of aldehydes in comparison to those of commercial sources. A series of amides can be easily obtained in good to excellent yields. It was found that the reaction proceeded via radicals under mild conditions, and the carbonyl group in the amide product was from the aldehyde. Moreover, the catalyst could be easily separated by using an external magnetic field and reused several times without significant loss in catalytic efficiency under the investigated conditions. (Chemical Equation Presented).
Cross coupling of acyl and aminyl radicals: Direct synthesis of amides catalyzed by Bu4NI with TBHP as an oxidant
Liu, Zhaojun,Zhang, Jie,Chen, Shulin,Shi, Erbo,Xu, Yuan,Wan, Xiaobing
experimental part, p. 3231 - 3235 (2012/05/05)
A radical solution: A Bu4NI/tert-butyl hydroperoxide (TBHP) catalyzed synthesis of amides through a cross-coupling reaction between acyl and aminyl radicals is described. This method involves the combination of aldehyde C-H bond functionalization and decarbonylation of N,N-disubstituted formamides (see scheme). The cross-coupling is metal-free, has a wide substrate scope, operational simplicity, and gives high yields on scale-up. Copyright
An effective synthesis of N,N-dimethylamides from carboxylic acids and a new route from N,N-dimethylamides to 1,2-diaryl-1,2-diketones
Kumagai, Takashi,Anki, Tomohiro,Ebi, Takahiro,Konishi, Akihito,Matsumoto, Kouzou,Kurata, Hiroyuki,Kubo, Takashi,Katsumoto, Kenta,Kitamura, Chitoshi,Kawase, Takeshi
experimental part, p. 8968 - 8973 (2011/01/04)
Carboxylic acids were heated at 150 °C in DMF in the presence of 1.25 equiv of thionyl chloride to give corresponding N,N-dimethylamides in good yields. Tandem chlorination and amidation reactions occurred in the one-pot procedure. Dicarboxylic acids needed prolonged reaction time to produce bisamides in good yields. Some benzamides were efficiently converted into corresponding 1,2-diaryl-1,2-diketones (benzils) under acyloin condensation conditions in the presence of 4,4′-di-tert-butylbiphenyl (DBB) in THF. Ultrasonic irradiation effectively accelerates the reaction, but it is not critical. However, the presence of DBB is fatal to the reaction. Although a few synthetic methods for benzils from benzoic acids have been reported so far, this method is one of the most convenient and highly reproducible procedures.
