Base-Promoted Formal [4 + 3] Annulation between 2-Fluorophenylacetylenes and Ketones: A Route to Benzoxepines
Lu Ouyang, Chaorong Qi*, Haitao He, Youbin Peng, Wenfang Xiong, Yanwei Ren and Huanfeng Jiang*
*School of Chemistry and Chemical Engineering, State Key Lab of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China, Email: crqiscut.edu.cn, jianghfscut.edu.cn
L. Ouyang, C. Qi, H. He, Y. Peng, W. Xiong, Y. Ren, H. Jiang, J. Org. Chem., 2016, 81, 912-919.
DOI: 10.1021/acs.joc.5b02487 (free Supporting Information)
A base-promoted formal [4 + 3] annulation between 2-fluorophenylacetylenes and ketones provides a straightforward access to a wide range of functionalized benzoxepines in good yields. This transition-metal-free reaction proceeds through a tandem α-vinylation of the carbonyl compound followed by an intramolecular nucleophilic aromatic substitution (SNAr) reaction of the in situ generated β,γ-unsaturated ketone intermediates.
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