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Updated: Jul 26, 2025

Light-driven Enzymatic Decarboxylation
Published on: May 22, 2016
Visible-Light-Promoted 6π Photocyclization of ortho-Biaryl-Appended β-Ketoesters
Shen-Zhen Zhang1, Shan-Shan Zhang1, Jun-Li Li1
1Key Laboratory of Analytical Science and Technology of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education, Key Laboratory of Chemical Biology of Hebei Province and College of Chemistry and Materials Science, Hebei University, Baoding 071002, P. R. China.
Abstract:
A photocatalyst- and additive-free visible-light-induced 6π-photocyclization of ortho-biaryl-appended β-ketoesters has been developed. Upon irradiation with visible light, substrates undergo 6-endo-trig cyclization/1,5-H shift to 9,10-dihydrophenanthren-9-ols with high efficiency and selectivity. The reaction proceeds via conrotatory ring closure followed by a suprafacial 1,5-hydrogen shift leading to the observed single trans-fused products. Preliminary mechanistic studies reveal the feasibility of both 1,5-H shift and intersystem crossing of the diradical intermediate.
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