Direct β-Acyloxylation of Enamines via PhIO-Mediated Intermolecular Oxidative C-O Bond Formation and Its Application to the Synthesis of Oxazoles
Xin Liu, Ran Cheng, Feifei Zhao, Daisy Zhang-Negrerie, Yunfei Du* and Kang Zhao*
*Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China, Email: duyunfeiertju.edu.cn, kangzhaotju.edu.cn
X. Liu, R. Cheng, F. Zhao, D. Zhang-Negrerie, Y. Du, K. Zhao, Org. Lett., 2012, 14, 5480-5483.
DOI: 10.1021/ol3025583 (free Supporting Information)
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The use of iodosobenzene (PhIO) as an oxidant realizes an intermolecular oxidative C(sp2)-O bond formation between enamines and various carboxylic acids, including N-protected amino acids. This direct β-acyloxylation of enamine compounds tolerates a wide range of functional groups and furnishes various β-acyloxy enamines that can be conveniently converted to oxazoles via cyclodehydration.
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