Synthetic Approach to Benzocyclobutenones Using Visible Light and a Phosphonate Auxiliary
Takaaki Yano, Tairin Kawasaki, Tatsuya Yuhki, Naoki Ishida and Masahiro Murakami*
*Department of Synthetic Chemistry and Biological Chemistry, Kyoto University, Katsura, Kyoto 615-8510, Japan, Email: murakamisbchem.kyoto-u.ac.jp
T. Yano, T. Kawasaki, T. Yuhki, N. Ishida, M. Murakami, Org. Lett., 2018, 20, 1224-1227.
DOI: 10.1021/acs.orglett.8b00160 (free Supporting Information)
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In a two-step procedure to synthesize benzocyclobutenones from (o-alkylbenzoyl)phosphonates, a visible-light-driven cyclization reaction forming phosphonate-substituted benzocyclobutenols is followed by an elimination reaction of the H-phosphonate as the recyclable auxiliary. The method provides access to a wide variety of functionalized benzocyclobutenones, including those difficult to synthesize by conventional methods.
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