K 2 S 2 O 8 mediated C-3 arylation of quinoxalin-2(1 H )-ones under metal-, photocatalyst- and light-free conditions

• Published in: RSC advances Vol. 10; no. 6; pp. 3615 - 3624
• Main Authors: Dutta, Nibedita Baruah, Bhuyan, Mayurakhi, Baishya, Gakul
• Format: Journal Article
• Language: English
• Published: England 22-01-2020
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/D0RA00013B

Two facile and effective C-3 arylation protocols of quinoxalin-2(1
)-ones with arylhydrazines and aryl boronic acids respectively
free radical cross-coupling reactions under metal-, photocatalyst- and light-free conditions have been unveiled. K
S
O
has been used as an efficient oxidant to generate aryl radicals from arylhydrazines and aryl boronic acids under two different reaction conditions. The generated aryl radicals undergo a free radical coupling reaction at the C-3 position of quinoxalin-2(1
)-ones producing 3-arylquinoxalin-2(1
)-ones in good to excellent yields. The involvement of radicals in the course of the reaction has been demonstrated by radical trapping experiments with 2,2,6,6-tetramethylpiperidine-1-oxyl.