Direct catalytic asymmetric aldol reactions of thioamides: toward a stereocontrolled synthesis of 1,3-polyols.
A direct catalytic asymmetric aldol reaction of thioamides with a soft Lewis acid/hard Brønsted base cooperative catalytic system comprising (R,R)-Ph-BPE/[Cu(CH(3)CN)(4)]PF(6)/LiOAr is described. Highly chemoselective deprotonative activation of thioamides allows for a direct aldol reaction of alpha-nonbranched aliphatic aldehydes, which are susceptible to self-condensation. Facile reduction of the thioamide functionality and a catalyst-controlled second aldol reaction provides 1,3-diols in a highly stereoselective manner.
Iwata
Mitsutaka
M
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yazaki
Ryo
R
Suzuki
Yuta
Y
Kumagai
Naoya
N
Shibasaki
Masakatsu
M
D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D011108:Polymers / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013854:Thioamides / Q000737:chemistry*
D000447:Aldehydes; D011108:Polymers; D013854:Thioamides; C024617:polyol; C116609:3-hydroxybutanal