title: Expanded ring N-heterocyclic carbenes: a comparative study of ring size in palladium (0) catalysed Mizoroki-Heck coupling.
abstract: The synthesis and characterisation of a range of new 6- and 7-membered expanded ring N-heterocyclic carbene (NHC) complexes of zero valent palladium dvtms (divinyltetramethyldisiloxane) 8-14 is reported, with the first comparative catalytic study probing the effects of large ring N-heterocyclic carbene ligands (6-Mes and 7-Mes) with their analogous 5-membered derivative (IMes) on catalytic performance. The catalytic performances of the [Pd(NHC)(dvtms)] complexes are evaluated in the Mizoroki-Heck coupling of 4-bromoacetophenone and n-butyl acrylate, providing a ready and effective comparison into the influence of ring size and steric congestion on catalytic activity in carbon-carbon cross coupling reactions.
authors.affiliation: School of Chemistry, Main Building, Cardiff University, Cardiff, UK CF10 3AT.
authors.forename: Jay J
authors.initials: JJ
authors.lastname: Dunsford
authors.forename: Kingsley J
authors.initials: KJ
authors.lastname: Cavell