title: Construction of contiguous tetrasubstituted chiral carbon stereocenters via direct catalytic asymmetric aldol reaction of alpha-isothiocyanato esters with ketones.
abstract: Construction of contiguous tetrasubstituted chiral carbon stereocenters via direct catalytic asymmetric aldol reaction of alpha-substituted alpha-isothiocyanato esters with unactivated simple ketones is described. A Bu(2)Mg/Schiff base catalyst promoted the aldol addition/cyclization sequence at room temperature, giving protected alpha-amino-beta-hydroxy esters with contiguous tetrasubstituted chiral carbon stereocenters in 99 to 68% yield, 98:2 to 74:26 dr, and 98 to 82% ee.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Yoshino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morimoto
authors.forename: Gang
authors.initials: G
authors.lastname: Lu
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsunaga
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Shibasaki
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D004952:Esters; D007659:Ketones; D002244:Carbon