Synthesis of 2,3-Diperfluoroalkylated Quinoxalines via Selenium-Catalyzed Reductive C-C Coupling of Vicinal Perfluoroalkyl Formimidoyl Chlorides.

A direct and efficient approach to access structurally interesting 2,3-diperfluoroalkylated quinoxalines via selenium-catalyzed reductive C-C construction of vicinal bis(perfluoroalkyl formimidoyl chloride)s has been disclosed. This protocol features the use of easily accessible starting materials, scalability, and a diverse functional group tolerance. Mechanism studies suggested that this reaction may involve an interesting selenium-containing seven-membered-ring intermediate and proceed through an electrocyclization/selenium reductive elimination pathway, which is significantly different from the traditional transition-metal-catalyzed reductive coupling strategies of alkyl halides.

Copper-catalyzed cross-coupling and sequential allene-mediated cyclization for the synthesis of 1,2,3-triazolo[1,5-a]quinolines.

In this paper, a tandem reaction involving copper-catalyzed cross-coupling and allene-mediated cyclization of 1-(2-ethynylaryl)-1,4-disubstituted-1,2,3-triazole with N-tosylhydrazone has been developed. This method features operational simplicity, excellent functional group compatibility, broad substrate scope, and easily available feedstock, providing an efficient and practical strategy for the synthesis of highly functionalized 1,2,3-triazolo[1,5-a]quinolines.