Adsorption-induced asymmetric transformation of planar-chiral pyridinophanes

✍ Scribed by Nobuhiro Kanomata; Jun Oikawa

• Book ID: 104253488
• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 148 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(03)00699-3

✦ Synopsis

Stereocontrol of cyclophane-type planar chirality was investigated via adsorption-induced asymmetric transformation (AIAT) on a series of inorganic porous adsorbents. The rope-skipping equilibria between bridged nicotinamides (S,3%S)-1 and (R,3%S)-2 shifted preferentially to (R,3%S)-2 to accumulate (R)-configuration of planar chirality with up to 61% de (ca. 4/1 ratio) on alumina. The results are in good contrast to accumulation of the corresponding (S)-configuration via conventional crystallization-induced asymmetric transformation (CIAT) to the solid (S,3%S)-1a-d.