Enantioselective 1,4-addition of unmodified ketone catalyzed by a bimetallic Zn-Zn-linked-BINOL complex.
1,4-Addition (Michael addition) of 2-hydroxy-2'-methoxyacetophenone (2) to various alpha,beta-unsaturated ketones was efficiently promoted by a bimetallic Zn-Zn-linked-BINOL complex 3 with good yield (up to 90%) and excellent enantiomeric excess (up to 99% ee). The resulting 2-hydroxy-1,5-diketones were successfully converted to synthetically more versatile esters and amides. [reaction: see text]
Kumagai
N
N
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Matsunaga
S
S
Shibasaki
M
M