Contribution of Cation-π Interactions in Iminium Catalysis

• Main Authors: Yukie Mori, Shinji Yamada
• Format: Article
• Language: English
• Published: MDPI AG 2012-02-01
• Series: Molecules
• Subjects: cation-π interaction; iminium-π interaction; iminium cation; imidazolidinone organocatalyst; ab initio calculation
• Online Access: http://www.mdpi.com/1420-3049/17/2/2161/

Ab initio calculations were carried out for a benzyl-substituted iminium cation derived from (E)-crotonaldehyde and a chiral imidazolidinone that was developed as an organocatalyst by MacMillan et al. At the MP2 level of theory it is predicted that the phenyl group is close to the iminium moiety in the most stable conformer, suggesting that the cation-π interaction contributes to the stabilization of this conformer. Energy decomposition analyses on model systems indicate that the electrostatic and polarization terms make significant contribution to the attractive interactions between the benzene ring and the iminium cation.