Zhang Shen-Zhen, Zhang Shan-Shan, Li Jun-Li, Shen Shigang, Yang Xiu-Long, Niu Xiaoying
Key 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.
Postdoctoral Research Station of Chemistry Affiliated College of Chemistry and Materials Science, Hebei University, Baoding 071002, P. R. China.
J Org Chem. 2023 Jul 7;88(13):9094-9104. doi: 10.1021/acs.joc.3c00753. Epub 2023 Jun 14.
A photocatalyst- and additive-free visible-light-induced 6π-photocyclization of -biaryl-appended β-ketoesters has been developed. Upon irradiation with visible light, substrates undergo 6--trig cyclization/1,5-H shift to 9,10-dihydrophenanthren-9-ols with high efficiency and selectivity. The reaction proceeds conrotatory ring closure followed by a suprafacial 1,5-hydrogen shift leading to the observed single -fused products. Preliminary mechanistic studies reveal the feasibility of both 1,5-H shift and intersystem crossing of the diradical intermediate.
一种无光催化剂和添加剂的可见光诱导的联芳基取代β-酮酯的6π光环化反应已被开发出来。在可见光照射下，底物高效且选择性地发生6- trig环化/1,5-H迁移反应生成9,10-二氢菲-9-醇。该反应通过对旋环化，随后进行同面1,5-氢迁移，从而得到观察到的单一稠合产物。初步机理研究揭示了双自由基中间体的1,5-H迁移和系间窜越的可行性。
