title: Highly active chiral phosphoramide-Zn(II) complexes as conjugate acid-base catalysts for enantioselective organozinc addition to ketones.
abstract: A highly efficient enantioselective organozinc (R2Zn) addition to ketones catalyzed by chiral phosphoramide-Zn(II) complexes (1-10 mol %) has been developed. These complexes serve as conjugate Lewis acid-Lewis base catalysts. Chiral phosphoramides are derived from an inexpensive natural amino acid (i.e., L-valine). From a variety of nonactivated aromatic and aliphatic ketones, the corresponding optically active tertiary alcohols were obtained in high yields with high enantioselectivities (up to 98% ee) under the mild reaction conditions.
authors: Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
authors: Manabu
authors: M
authors: Hatano
authors: Takashi
authors: T
authors: Miyamoto
authors: Kazuaki
authors: K
authors: Ishihara