title: Asymmetric catalysis with an inert chiral-at-metal iridium complex.
abstract: The development of a chiral-at-metal iridium(III) complex for the highly efficient catalytic asymmetric transfer hydrogenation of β,β'-disubstituted nitroalkenes is reported. Catalysis by this inert, rigid metal complex does not involve any direct metal coordination but operates exclusively through weak interactions with functional groups properly arranged in the ligand sphere of the iridium complex. Although the iridium complex relies only on the formation of three hydrogen bonds, it exceeds the performance of most organocatalysts with respect to enantiomeric excess (up to 99% ee) and catalyst loading (down to 0.1 mol %). This work hints at an advantage of structurally complicated rigid scaffolds for non-covalent catalysis, which especially relies on conformationally constrained cooperative interactions between the catalyst and substrates.
authors.affiliation: Fujian Provincial Key Laboratory of Chemical Biology, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China.
authors.forename: Liang-An
authors.initials: LA
authors.lastname: Chen
authors.forename: Weici
authors.initials: W
authors.lastname: Xu
authors.forename: Biao
authors.initials: B
authors.lastname: Huang
authors.forename: Jiajia
authors.initials: J
authors.lastname: Ma
authors.forename: Lun
authors.initials: L
authors.lastname: Wang
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xi
authors.forename: Klaus
authors.initials: K
authors.lastname: Harms
authors.forename: Lei
authors.initials: L
authors.lastname: Gong
authors.forename: Eric
authors.initials: E
authors.lastname: Meggers
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D006865:Hydrogenation; D007495:Iridium / Q000737:chemistry*; D009574:Nitro Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D056831:Coordination Complexes; D009574:Nitro Compounds; D007495:Iridium