14805-91-5

Usage

Synthesis Reference(s)

Tetrahedron Letters, 23, p. 3255, 1982 DOI: 10.1016/S0040-4039(00)87584-X

Upstream product

• 68-12-2 N,N-dimethyl-formamide 
• 694-59-7 pyridine N-oxide 
• 109-04-6 2-bromo-pyridine 
• 67-56-1 methanol 

Downstream Products

• 154822-30-7 3-hydroxy-4-methoxy-2-phenyl-3-(2-pyridyl)-2,3-dihydro-1H-isoindolin-1-one 
• 154822-27-2 3-hydroxy-7-methoxy-2-phenyl-3-(2-pyridyl)-2,3-dihydro-1H-isoindolin-1-one 
• 154822-28-3 3-hydroxy-3-(pyridin-2-yl)-5-methoxy-2-phenyl-2,3-dihydro-1H-isoindol-1-one 
• 1137-68-4 2-(2'-pyridyl)benzimidazole 
• 1006876-27-2 N,N-dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine-2-carboxamide 

Relevant academic research and scientific papers

Site-Selective Functionalization of Pyridinium Derivatives via Visible-Light-Driven Photocatalysis with Quinolinone

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.

Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium

Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.