title: Cobalt-Catalyzed Cyclization of N-Methoxy Benzamides with Alkynes using an Internal Oxidant through C-H/N-O Bond Activation.
abstract: The cyclization of substituted N-methoxy benzamides with alkynes in the presence of an easily affordable cobalt complex and NaOAc provides isoquinolone derivatives in good to excellent yields. The cyclization reaction is compatible with a range of functional group-substituted benzamides, as well as ester- and alcohol-substituted alkynes. The cobalt complex [Co(III) Cp*(OR)2 ] (R=Me or Ac) serves as an efficient catalyst for the cyclization reaction. Later, isoquinolone derivatives were converted into 1-chloro and 1-bromo substituted isoquinoline derivatives in excellent yields in the presence of POCl3 or PBr3 .
authors.affiliation: Department of Chemistry, Indian Institute of Science Education and Research, Pune, 411021, India.
authors.forename: Ganesan
authors.initials: G
authors.lastname: Sivakumar
authors.affiliation: Department of Chemistry, Indian Institute of Science Education and Research, Pune, 411021, India.
authors.forename: Arjun
authors.initials: A
authors.lastname: Vijeta
authors.affiliation: Department of Chemistry, Indian Institute of Science Education and Research, Pune, 411021, India. mjeganmohan@iiserpune.ac.in.
authors.forename: Masilamani
authors.initials: M
authors.lastname: Jeganmohan
keywords: C−H activation; annulation; cobalt; heterocycles; homogeneous catalysis