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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Novel intramolecular photocyclization of α-arylthiophene derivatives
Noriyoshi Arai1, Koichiro Tanaka, Takeshi Ohkuma
1Division of Chemical Process Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan. n-arai@eng.hokudai.ac.jp
Abstract:
Photoirradiation of α-arylthiophene derivatives linked with an alkene moiety through a three-atom spacer gave unprecedented cyclobutene-fused perhydrothiapentalene-type compounds in high yields, but neither [2 + 2] nor [4 + 2] cycloaddition products. The reaction afforded a single diastereomer in many cases. The chemical structure and relative configuration of a typical product were unambiguously determined by X-ray crystallographic analysis.
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