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.
Hsiao
Yi
Y
Department of Process Research, Merck Research Laboratories, Merck and Co., Inc., Rahway, New Jersey 07065, USA. yi_xiao@merck.com
Rivera
Nelo R
NR
Rosner
Thorsten
T
Krska
Shane W
SW
Njolito
Eugenia
E
Wang
Fang
F
Sun
Yongkui
Y
Armstrong
Joseph D
JD
Grabowski
Edward J J
EJ
Tillyer
Richard D
RD
Spindler
Felix
F
Malan
Christophe
C
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