Synthesis of Benzoxazoles from 2-Aminophenols and β-Diketones Using a Combined Catalyst of Brønsted Acid and Copper Iodide
Muhammad Shareef Mayo, Xiaoqiang Yu*, Xiaoyu Zhou, Xiujuan Feng, Yoshinori Yamamoto and Ming Bao*
*State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116023, China, Email: yuxiaoqiangdlut.edu.cn, mingbaodlut.edu.cn
M. S. Mayo, X. Yu, X. Zhou, X. Feng, Y. Yamamoto, M. Bao, J. Org. Chem., 2014, 79, 6310-6314.
DOI: 10.1021/jo501089k (free Supporting Information)
see article for more reactions
Cyclization reactions of 2-aminophenols with β-diketones catalyzed by a combination of Brønsted acid and CuI give various 2-substituted benzoxazoles. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.
see article for more examples