Visible Light-Induced Catalyst-Free Synthesis of Dibenzo[a,g]carbazoles
Shuangqi Qin, Mingrui Li, Fang-Lin Zhang, Haixing Xuaims:
to develop a mild and efficient synthetic method for the synthesis of dibenzo[a,g]carbazoles
background:
the conventional methods usually include the extending of the conjugate structure of carbazole-based molecules. Recently, photoredox catalysis has been applied into the synthesis of these dibenzocarbazole compounds, however, the existing methods still suffer the vulnerabilities, such as the addition of noble metal catalysts, highly functionalized starting materials, and metal salts, which could not give satisfaction from the practical perspective.
objective:
a photochemical catalyst-free and metal-free route to these important dibenzocarbazole compounds holds significant superiority and great potential to be developed.
method:
The visible light-induced synthesis of dibenzocarbazole is designed as a two-step one-pot reaction via 6π electrocyclization and consequent dehydrogenation, which would be realized by screening of reaction conditions.
result:
a series of dibenzo[a,g]carbazoles were successfully afforded via this method under purple LE at room temperature
conclusion:
the visible light-induced catalyst-free and metal-free synthetic method to dibenzo[a,g]carbazoles has been successfully developed.
other:
this method offers a promising alternative for the construction of benzocarbazole compounds