title: Chiral Phosphate in Rhodium-Catalyzed Asymmetric [2+2+2] Cycloaddition: Ligand, Counterion, or Both?
abstract: Investigations based on NMR spectroscopy, mass spectrometry, and DFT calculations shed light on the metallic species generated in the rhodium-catalyzed asymmetric [2+2+2] cycloaddition reaction between diynes and isocyanates with the chiral phosphate TRIP. The catalytic mixture comprising [{Rh(cod)Cl}2 ], 1,4-diphenylphosphinobutane (dppb), and Ag(S)-TRIP actually gives rise to two species, both having an effect on the stereoselectivity. One is a rhodium(I) complex in which TRIP is a weakly coordinating counterion, whereas the other is a bimetallic Rh/Ag complex in which TRIP is a strongly coordinating X-type ligand.
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 8232), Case Courrier 229, 4 place Jussieu, 75252, Paris Cedex 05, France. marion.barbazanges@upmc.fr.
authors.forename: Marion
authors.initials: M
authors.lastname: Barbazanges
authors.affiliation: Institut des Sciences Chimiques de Rennes, Université de Rennes 1, Campus de Beaulieu, 35042, Rennes Cedex, France.
authors.forename: Elsa
authors.initials: E
authors.lastname: Caytan
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 8232), Case Courrier 229, 4 place Jussieu, 75252, Paris Cedex 05, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Lesage
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 8232), Case Courrier 229, 4 place Jussieu, 75252, Paris Cedex 05, France. corinne.aubert@upmc.fr.
authors.forename: Corinne
authors.initials: C
authors.lastname: Aubert
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 8232), Case Courrier 229, 4 place Jussieu, 75252, Paris Cedex 05, France. louis.fensterbank@upmc.fr.
authors.forename: Louis
authors.initials: L
authors.lastname: Fensterbank
authors.affiliation: ICMMO, Univ. Paris-Sud, CNRS UMR 8182, Université Paris-Saclay, 91405, Orsay cedex, France.|ICSN, CNRS UPR 2301, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gandon
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 8232), Case Courrier 229, 4 place Jussieu, 75252, Paris Cedex 05, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Ollivier
keywords: chirality; cycloaddition; homogeneous catalysis; ligand effects; rhodium