ChemInform Abstract: Design, Synthesis, and Application of a C2 Symmetric Chiral Ligand for Enantioselective Conjugate Addition of Organolithium to α,β-Unsaturated Aldimine.

✍ Scribed by Mitsuru Shindo; Kenji Koga; Kiyoshi Tomioka

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 39 KB
• Volume: 30
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199923028

✦ Synopsis

Design, Synthesis, and Application of a C 2 Symmetric Chiral Ligand for Enantioselective Conjugate Addition of Organolithium to α,β-Unsaturated Aldimine. -Acyclic aldimines (I), cyclic aldimines (IV), and naphthaldehyde imines like (VI) undergo enantioselective conjugate additions to organolithiums in the presence of (R,R)-1,2-dimethoxy-1,2-diphenylethane (DDE), to give after hydrolysis and reduction with NaBH 4 the corresponding alcohols. It is found that DDE and its (S,S)-1,2-dimethoxy-1,2-dimethyl analogue give the best enantioselectivities compared with other chiral (R,R)-or (S,S)-1,2dimethyl-1,2-dialkoxy derivatives. This suggests that the methyl groups on the ether oxygen control the stereoselectivity of the reaction. -(SHINDO, MIT-