Construction of contiguous tetrasubstituted chiral carbon stereocenters via direct catalytic asymmetric aldol reaction of alpha-isothiocyanato esters with ketones.
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.
Yoshino
Tatsuhiko
T
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Morimoto
Hiroyuki
H
Lu
Gang
G
Matsunaga
Shigeki
S
Shibasaki
Masakatsu
M
D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D013237:Stereoisomerism
D004952:Esters; D007659:Ketones; D002244:Carbon