title: Unusual NHC-Iridium(I) Complexes and Their Use in the Intramolecular Hydroamination of Unactivated Aminoalkenes.
abstract: N-heterocyclic carbene (NHC) ligands with naphthyl side chains were employed for the synthesis of unsaturated, yet isolable [(NHC)Ir(cod)](+) (cod=1,5-cyclooctadiene) complexes. These compounds are stabilised by an interaction of the aromatic wingtip that leads to a sideways tilt of the NHC-Ir bond. Detailed studies show how the tilting of such N-heterocyclic carbenes affects the electronic shielding properties of the carbene carbon atom and how this is reflected by significant upfield shifts in the (13) C NMR signals. When employed in the intramolecular hydroamination, these [(NHC)Ir(cod)](+) species show very high catalytic activity under mild reaction conditions. An enantiopure version of the catalyst system produces pyrrolidines with excellent enantioselectivities.
authors.affiliation: School of Chemistry and Biochemistry, University of Western Australia, 35 Stirling Highway, 6009, Crawley, WA, Australia.
authors.forename: Gellért
authors.initials: G
authors.lastname: Sipos
authors.affiliation: School of Chemistry and Biochemistry, University of Western Australia, 35 Stirling Highway, 6009, Crawley, WA, Australia.
authors.forename: Arnold
authors.initials: A
authors.lastname: Ou
authors.affiliation: Centre for Microscopy, Characterisation and Analysis, University of Western Australia, 35 Stirling Highway, 6009, Crawley, WA, Australia.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Skelton
authors.affiliation: Kaust Catalysis Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Laura
authors.initials: L
authors.lastname: Falivene
authors.affiliation: Kaust Catalysis Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Luigi
authors.initials: L
authors.lastname: Cavallo
authors.affiliation: School of Chemistry and Biochemistry, University of Western Australia, 35 Stirling Highway, 6009, Crawley, WA, Australia. reto.dorta@uwa.edu.au.
authors.forename: Reto
authors.initials: R
authors.lastname: Dorta
keywords: carbenes; density functional calculations; heterocycles; hydroamination; iridium