1903-64-6Relevant articles and documents
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.
Method for synthesizing phosphorus-oxychloride-promoted amide compound
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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.