title: Brønsted acid activation strategy in transition-metal catalyzed asymmetric hydrogenation of N-unprotected imines, enamines, and N-heteroaromatic compounds.
abstract: Asymmetric hydrogenation plays an important role in organic synthesis, but that of the challenging substrates such as N-unprotected imines, enamines, and N-heteroaromatic compounds (1H-indoles, 1H-pyrroles, pyridines, quinolines, and quinoxalines) has only received increased attention in the past three years. Considering the interaction modes of a Brønsted acid with a Lewis base, Brønsted acids may be used as the ideal activators of C=N bonds. This Minireview summarizes the recent advances in transition-metal-catalyzed, Brønsted acid activated asymmetric hydrogenation of these challenging substrates, thus offering a promising substrate activation strategy for transformations involving C=N bonds.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023, China. zkyu@dicp.ac.cn
authors.forename: Zhengkun
authors.initials: Z
authors.lastname: Yu
authors.forename: Weiwei
authors.initials: W
authors.lastname: Jin
authors.forename: Quanbin
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006865:Hydrogenation; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D028561:Transition Elements / Q000737:chemistry*
chemical_list: D006571:Heterocyclic Compounds; D007097:Imines; D028561:Transition Elements