Heterogeneous Cu-MnO Catalyzed Monoselective ortho-Halogenation of Aromatic C−H Bonds under Visible Light

• Published in: Asian journal of organic chemistry 2015-09, Vol.4 (9), p.879-883
• Main Authors: Pal, Provas, Singh, Harshvardhan, Panda, Asit Baran, Ghosh, Subhash Chandra
• Format: Article
• Language: English
• Subjects: 2-phenylpyridine; C−H functionalization; halogenation; heterogeneous catalysis; N-halosuccinimides; Organic chemistry
• ISSN: 2193-5807; 2193-5815
• DOI: 10.1002/ajoc.201500245

Heterogeneous Cu‐MnO‐catalyzed selective monohalogenation of aromatic compounds with cheap N‐halosuccinimide (NXS) as a halogenating agent in the presence of molecular oxygen as an oxidant, under irradiation with visible light is reported. Monochlorination, bromination, and iodinations were achieved in a highly selective fashion. Our developed heterogeneous Cu‐MnO catalyst without any additive and ligands works well for halogenation with electron‐rich substrates and also works selectively with electron poor substrates. Moreover, chlorination occurs efficiently with the more challenging substrates benzoic esters. The heterogeneous nature of the reaction was proven by hot filtration test. I‐NXS: Heterogeneous Cu‐MnO‐catalyzed selective monohalogenation of aromatic compounds with cheap N‐halosuccinimide (NXS) as a halogenating agent in the presence of molecular oxygen as an oxidant under irradiation with visible light is reported. Our catalyst works well without any additive and ligands for halogenation, selective chlorination, bromination, and iodinations were achieved. Moreover, chlorination occurs efficiently with the more challenging substrates benzoic esters.