Ascorbic Acid, Vitamin C
Aryl radicals generated in situ from arene diazonium fluoroborates promoted by ascorbic acid enable a convenient and general oxidative arylation of vinyl arenes in air at room temperature in the absence of any additive and visible light irradiation. Various 2-aryl acetophenones have been obtained in good yields.
B. Majhi, D. Kundu, B. C. Ranu, J. Org. Chem., 2015, 80, 7739-7745.
In situ nitrosation of anilines followed by reduction with ascorbic acid to form aryl radicals and thiolation with disulfides provided aryl sulfides. This mild, metal-free synthesis of aryl sulfides proceeded smoothly without heating or irradiation. This strategy can be expanded to the synthesis of aryl selenides.
M.-j. Bu, G.-p. Lu, C. Cai, Synlett, 2015, 26, 1841-1846.