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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Structural Transformation of Azonia[5]helicene Photoproduct via Reaction Field Function of Layered Inorganic Material
Kyosuke Arakawa1, Tetsuya Shimada2, Tamao Ishida2,3
1Department of Applied and Pure Chemistry, Tokyo University of Science, 2641 Yamasaki, Noda-city, Chiba 278-8510, Japan.
Abstract:
In an attempt to generalize "on surface synthesis", which has unique potential in the area of organic synthesis, the focus was placed on layered silicates having a highly flat surface. The photoreaction of (±)-13-bromo-6a-azonia[5]helicene (AHHBr) and (±)-2-bromo-13-methyl-6a-azonia[5]helicene (AHBrMe) in solution and within the layers was examined. In the case of AHBrMe, the photoproduct was different from that in solution. 1H nuclear magnetic resonance (NMR), Fourier transform-infrared spectroscopy (FT-IR), and electrospray ionization-mass spectrometry (ESI-MS) measurements revealed that the photoproduct obtained within the layers was a benzo-perylene molecule with a completely flat lactone structure (AL). This study is the first example of the successful conversion of a chemical reaction path due to the steric effect of the flat surface of layered silicate.
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