Catalytic Asymmetric Phase‐Transfer Michael Reaction and Mannich‐Type Reaction of Glycine Schiff Bases with Tartrate‐Derived Diammonium Salts |
| |
Authors: | Tomoyuki Shibuguchi Hisashi Mihara Akiyoshi Kuramochi Takashi Ohshima Dr. Masakatsu Shibasaki Prof. Dr. |
| |
Affiliation: | Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033, Japan, Fax: (+81)?3‐5684‐5206 |
| |
Abstract: | Catalytic asymmetric Michael and Mannich‐type reactions of glycine Schiff bases with chiral two‐center organocatalysts, tartrate‐derived diammonium salts (TaDiASs), are described. On the basis of conformational studies, optimized TaDiASs with a 2,6‐disubstituted cyclohexane spiroacetal were newly designed. These TaDiASs catalyzed the asymmetric Michael and Mannich‐type reactions of glycine Schiff bases with higher enantioselectivity than previous catalysts. In the Mannich‐type reaction, aromatic N‐Boc‐protected imines (Boc=tert‐butoxycarbonyl) as well as enolizable alkyl imines were applicable. As a synthetic application of the catalytic asymmetric Mannich‐type reaction with the optimized TaDiASs, we developed a catalytic asymmetric total synthesis of (+)‐nemonapride, which is an antipsychotic agent. |
| |
Keywords: | amino acids asymmetric catalysis conformation analysis phase‐transfer catalysis Schiff bases |
|
|