title: Chiral cyclopentadienyl iridium(III) complexes promote enantioselective cycloisomerizations giving fused cyclopropanes.
abstract: The cyclopentadienyl (Cp) group is a very important ligand for many transition-metal complexes which have been applied in catalysis. The availability of chiral cyclopentadienyl ligands (Cp(x) ) lags behind other ligand classes, thus hampering the investigation of enantioselective processes. We report a library of chiral Cp(x) Ir(III) complexes equipped with an atropchiral Cp scaffold. A robust complexation procedure reliably provides Cp(x) Ir(III) complexes with tunable counterions. In a proof-of-concept application, the iodide-bearing members are shown to be highly selective for enyne cycloisomerization reactions. The dehydropiperidine-fused cyclopropane products are formed in good yields and enantioselectivities.
authors: Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015 Lausanne (Switzerland) http://isic.epfl.ch/lcsa.
authors: Michael
authors: M
authors: Dieckmann
authors: Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015 Lausanne (Switzerland) http://isic.epfl.ch/lcsa.
authors: Yun-Suk
authors: YS
authors: Jang
authors: Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015 Lausanne (Switzerland) http://isic.epfl.ch/lcsa. nicolai.cramer@epfl.ch.
authors: Nicolai
authors: N
authors: Cramer
keywords: asymmetric catalysis; cycloisomerization; cyclopentadienyl ligands; enantioselectivity; iridium