title: Cobalt-mediated [2+2+2] cycloaddition versus C-H and N-H activation of 2-pyridones and pyrazinones with alkynes: a theoretical study.
abstract: DFT computations have been executed aimed at illuminating the variety of pathways by which pyridones react with alkynes in the presence of [CpCoL(2)]: NH-2-pyridones furnish N-dienylated ligands (N-H activation pathway), N-methyl-2-pyridones are converted into ligated cyclohexadienes ([2+2+2] cocycloaddition pathway), and N-alkynyl-2-pyridones may undergo either [2+2+2] cocycloaddition or C-dienylation (C-H activation), depending on the length of the tether. The calculations predict the formation of the experimentally observed products, including their regio- and stereochemical make up. In addition, the unusual regiochemical outcome of the all-intramolecular [2+2+2] cycloaddition of N,N'-dipentynylpyrazinedione was rationalized by computation, which led to the discovery of a new mechanism.
authors.affiliation: Université Pierre et Marie Curie-Paris 6, Laboratoire de Chimie Organique (UMR CNRS 7611), Institut de Chimie Moléculaire (FR 2769), case. 229 place Jussieu, 75252 Paris cedex 05, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Aubert
authors.forename: Vincent
authors.initials: V
authors.lastname: Gandon
authors.forename: Anaïs
authors.initials: A
authors.lastname: Geny
authors.forename: Thilo J
authors.initials: TJ
authors.lastname: Heckrodt
authors.forename: Max
authors.initials: M
authors.lastname: Malacria
authors.forename: Elisa
authors.initials: E
authors.lastname: Paredes
authors.forename: K Peter C
authors.initials: KP
authors.lastname: Vollhardt