N2H4-H2O Enabled Umpolung Cyclization of o-Nitro Chalcones for the Construction of Quinoline N-Oxides
Guan Zhang, Kai Yang, Shihui Wang, Qiang Feng and Qiuling Song*
*College of Chemical Engineering, College of Material Sciences Engineering at Huaqiao University, 668 Jimei Boulevard, Xiamen, Fujian 361021, P. R. China, Email: qsonghqu.edu.cn
G. Zhang, K. Yang, S. Wang, Q. Feng, Q. Song, Org. Lett., 2021, 23, 595-600.
DOI: 10.1021/acs.orglett.0c04162 (free Supporting Information)
see article for more reactions
The use of hydrazine under basic conditions enables an efficient and general construction of quinoline N-oxides from ortho-nitro chalcones via umpolung of carbonyl groups. This transition-metal free method offers good functional group tolerance, environmental friendliness, and mild reaction conditions with nitrogen gas as byproduct.
see article for more examples