title: Copper-Mediated Cross-Dehydrogenative Coupling of 2-Methylpyridine and 8-Methylquinoline with Methyl Ketones and Benzamides.
abstract: A synthetic method to prepare (E)-(pyridin-2-yl)enones and (E)-(quinolin-8-yl)enones that relies on the respective copper(I)-catalyzed formal cross-dehydrogenative coupling (CDC) reaction of 2-methylpyridine and 8-methylquinoline with methyl ketones has been discovered. The mechanism was delineated to follow a pathway involving oxidation of the N-heterocycle to its corresponding aldehyde adduct prior to reaction with the methyl ketone. The versatility and substrate dependent divergence in the reactivity of the copper-mediated CDC strategy was exemplified by its application to the synthesis of N-(quinolin-8-ylmethyl)amide and N-(quinolin-8-ylmethyl)aniline adducts on switching the cross-coupling partner to benzamides or an aniline derivative.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Gadde Sathish
authors.initials: GS
authors.lastname: Kumar
authors.affiliation: School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia.
authors.forename: Joshua William
authors.initials: JW
authors.lastname: Boyle
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Ciputra
authors.initials: C
authors.lastname: Tejo
authors.affiliation: School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia. phil.chan@monash.edu, P.W.H.Chan@warwick.ac.uk.|Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK. phil.chan@monash.edu, P.W.H.Chan@warwick.ac.uk.
authors.forename: Philip Wai Hong
authors.initials: PW
authors.lastname: Chan
keywords: C−H bond activation; copper; cross-dehydrogenative coupling; homogeneous catalysis; synthetic methods