Extended Study of Visible-Light-Induced Photocatalytic [4 + 2] Benzannulation: Synthesis of Polycyclic (Hetero)Aromatics.
Herein we report an extended study of [4 + 2] benzannulation reactions of 2-(hetero)aryl-substituted anilines with alkynes by visible light photocatalysis. The method requires the use oftBuONO as a diazotizing agent and 0.3 mol % of fac-Ir(ppy)3as a photocatalyst at room temperature. The reaction proceeded in a chemo- and regioselective manner with high functional group tolerance under mild conditions allowing the preparation of a wide variety of polycyclic (hetero)aromatic compounds, including phenanthrenes, in moderate to high yields. This procedure is amenable to gram-scale synthesis of 9-phenylphenanthrene.
Department of Chemistry, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
Tanmay
T
Chatterjee
Department of Chemistry, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
Da Seul
DS
Lee
Department of Chemistry, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea.
Eun Jin
0000-0002-6607-1851
EJ
Cho