Highly efficient synthesis of beta-amino acid derivatives via asymmetric hydrogenation of unprotected enamines.
A direct asymmetric hydrogenation of unprotected enamino esters and amides is described. Catalyzed by Rh complexes with Josiphos-type chiral ligands, this method gives beta-amino esters and amides in high yield and high ee (93-97% ee). No acyl protection/deprotection is required.
Department of Process Research, Merck Research Laboratories, Merck and Co., Inc., Rahway, New Jersey 07065, USA. yi_xiao@merck.com
Yi
Y
Hsiao
Nelo R
NR
Rivera
Thorsten
T
Rosner
Shane W
SW
Krska
Eugenia
E
Njolito
Fang
F
Wang
Yongkui
Y
Sun
Joseph D
JD
Armstrong
Edward J J
EJ
Grabowski
Richard D
RD
Tillyer
Felix
F
Spindler
Christophe
C
Malan
D000475:Alkenes / Q000737:chemistry; D000577:Amides / Q000138:chemical synthesis*; D000588:Amines / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis*; D006865:Hydrogenation; D013237:Stereoisomerism
D000475:Alkenes; D000577:Amides; D000588:Amines; D000596:Amino Acids; D004952:Esters