title: Direct asymmetric amination of α-branched cyclic ketones catalyzed by a chiral phosphoric acid.
abstract: Here we report the direct asymmetric amination of α-substituted cyclic ketones catalyzed by a chiral phosphoric acid, yielding products with a N-containing quaternary stereocenter in high yields and excellent enantioselectivities. Kinetic resolution of the starting ketone was also found to occur on some of the substrates under milder conditions, providing enantioenriched α-branched ketones, another important building block in organic synthesis. The utility of this methodology was demonstrated in the short synthesis of (S)-ketamine, the more active enantiomer of this versatile pharmaceutical.
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Yang
authors.forename: F Dean
authors.initials: FD
authors.lastname: Toste
mesh_terms: D000586:Amination; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D007649:Ketamine / Q000138:chemical synthesis*; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007659:Ketones; D010756:Phosphoric Acids; D007649:Ketamine; C030242:phosphoric acid