Chiral bicyclic NHC/Ir complexes for catalytic asymmetric transfer hydrogenation of ketones.
A diverse series of chiral bicyclic NHC/Ir complexes were prepared via a previously developed divergent synthesis of chiral imidazolium salts. Among the complexes, 8dz was found to be an excellent catalyst precursor for the Ir-catalyzed asymmetric transfer hydrogenation of ketones. The reaction of ketones with 8dz proceeded smoothly to give corresponding alcohols with high enantioselectivities (up to 98%) and productivities (TON up to 4500).
Department of Chemistry, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. kyoshida@faculty.chiba-u.jp ayanagi@faculty.chiba-u.jp.
Kazuhiro
K
Yoshida
Takumi
T
Kamimura
Hiroshi
H
Kuwabara
Akira
A
Yanagisawa