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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Regio- and stereo-selective [4+4] photodimerization of angular-shaped dialkyltetracenedithiophene
Tze-Gang Hsu1, Hsiao-Chieh Chou, Ming-Ju Liang
1Department of Applied Chemistry, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan 300, Republic of China. yjcheng@mail.nctu.edu.tw.
Abstract:
Angular-shaped dialkyltetracenedithiophenes (aTDTs) undergo [4+4] photodimerization in solution to form a butterfly-shaped skeleton. This reaction proceeds in a regio- and stereo-selective manner, forming only a single planosymmetric syn-[2,2]-daTDT out of six possible products. The photocycloaddition of aTDTs can take place topochemically in the thin-film state while maintaining regio- and stereo-selectivity. Stronger aliphatic dispersion forces and π-π interactions play important roles in forming the eclipsed dimeric complex that leads to the syn-[2,2]-daTDT isomer.
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