title: Catalytic asymmetric hydrogenation of pyrimidines.
abstract: The asymmetric hydrogenation of pyrimidines proceeded with high enantioselectivity (up to 99% ee) using an iridium catalyst composed of [IrCl(cod)]2, a ferrocene-containing chiral diphosphine ligand (Josiphos), iodine, and Yb(OTf)3 (cod = 1,5-cyclooctadiene). The chiral catalyst converted various 4-substituted pyrimidines into chiral 1,4,5,6-tetrahydropyrimidines in high yield. The lanthanide triflate is crucial for achieving the high enantioselectivity as well as for activating the heteroarene substrate.
authors.affiliation: Department of Chemistry, Graduate School of Sciences, and International Research Center for Molecular Systems (IRCMS), Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); JST ACT-C, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan). rkuwano@chem.kyushu-univ.jp.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kuwano
authors.forename: Yuta
authors.initials: Y
authors.lastname: Hashiguchi
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Ikeda
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ishizuka
keywords: asymmetric catalysis; heterocycles; hydrogenation; iridium; lanthanides