Enantioselective ring-opening reactions of racemic ethynyl epoxides via copper-allenylidene intermediates: efficient approach to chiral beta-amino alcohols.
Enantioselective copper-catalyzed ring-opening reactions of racemic ethynyl epoxides with amines using (R)-DTBM-MeO-BIPHEP as a chiral ligand have been found to give the corresponding amino alcohols in high yields with up to 94% ee. The reaction is considered to proceed via copper-allenylidene complexes as key intermediates. This methodology may provide a novel synthetic approach to optically active amino alcohols, the structures of which are widely found in many natural products, biologically active compounds, and chiral ligands.
Hattori
Gaku
G
Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.
Yoshida
Akiko
A
Miyake
Yoshihiro
Y
Nishibayashi
Yoshiaki
Y