I2-Mediated Oxidative C-O Bond Formation for the Synthesis of 1,3,4-Oxadiazoles from Aldehydes and Hydrazides
Wenquan Yu*, Gang Huang, Yueteng Zhang, Hongxu Liu, Lihong Dong, Xuejun Yu, Yujiang Li and Junbiao Chang*
*College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan Province 450001, China, Email: wenquan_yuzzu.edu.cn, changjunbiaozzu.edu.cn
W. Yu, G. Huang, Y. Zhang, H. Liu, L. Dong, X. Yu, Y. Li, J. Chang, J. Org. Chem., 2013, 78, 10337-10343.
DOI: 10.1021/jo401751h (free Supporting Information)
Stoichiometric molecular iodine mediates a practical and transition-metal-free oxidative cyclization of acylhydrazones into 1,3,4-oxadiazoles in the presence of potassium carbonate. Even crude acylhydrazone substrates obtained from the condensation of aldehydes and hydrazides can be converted. A series of symmetrical and asymmetrical 2,5-disubstituted 1,3,4-oxadiazoles can be conveniently generated in an efficient and scalable fashion.
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P. Niu, J. Kang, X. Tian, L. Song, H. Liu, J. Wu, W. Yu, J. Chang, J. Org. Chem., 2015, 80, 1018-1024.