title: Stereodynamics of bond rotation in tertiary aromatic amides.
abstract: The degree to which the rotations about the C-N and Ar-CO bonds of aromatic amides occur in a concerted manner was investigated by a variety of NMR and kinetic techniques. Otherwise complex kinetic analyses were simplified by exploiting symmetry and asymmetry in the N-substituents of amides. In 2-unsubstituted 1-naphthamides bearing branched N-substituents, most conformational changes about the amide group were by correlated rotation, though uncorrelated Ar-CO rotation also occurred to some extent. In 2-substituted 1-naphthamides, correlated rotation accounted for all of the Ar-CO rotations, though a significant amount of uncorrelated C-N rotation also occurred. Naphthamides bearing branched N-substituents thus turn out to be efficient molecular gears: Compound 12 showed almost no gear slippage.
authors.affiliation: Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Bragg
authors.forename: Jonathan
authors.initials: J
authors.lastname: Clayden
authors.forename: Gareth A
authors.initials: GA
authors.lastname: Morris
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Pink