Complementing Pyridine‐2,6‐bis(oxazoline) with Cyclometalated N‐Heterocyclic Carbene for Asymmetric Ruthenium Catalysis
Long Li, Feng Han, Xin Nie, Yubiao Hong, Sergei I. Ivlev, Eric Meggers
Abstract
Abstract A strategy for expanding the utility of chiral pyridine‐2,6‐bis(oxazoline) (pybox) ligands for asymmetric transition metal catalysis is introduced by adding a bidentate ligand to modulate the electronic properties and asymmetric induction. Specifically, a ruthenium(II) pybox fragment is combined with a cyclometalated N‐heterocyclic carbene (NHC) ligand to generate catalysts for enantioselective transition metal nitrenoid chemistry, including ring contraction to chiral 2H‐azirines (up to 97 % ee with 2000 TON) and enantioselective C(sp 3 )−H aminations (up to 97 % ee with 50 TON).
Topics & Concepts
OxazolineEnantioselective synthesisCarbeneRutheniumChemistryPyridineDenticityCatalysisLigand (biochemistry)Combinatorial chemistryStereochemistryMedicinal chemistryMetalOrganic chemistryReceptorBiochemistrySynthesis and Catalytic ReactionsCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and Catalysis