Stereocontrol of planar-chiral paracyclophanes by using adsorption-induced asymmetric transformation

ORGN 663

Nobuhiro Kanomata, Hajime Machida, and Jun Oikawa. Department of Industrial Chemistry, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki, 214-8571, Japan

Adsorption-induced asymmetric transformation (AIAT) of [11]paracyclophane derivatives, (Rp, S)-1 and (Sp, S)-2, was accomplished on alumina to shift their equilibrium to the better adsorbate, (Sp, S)-2 with up to 69% de via rope-skipping isomerization between 1 and 2. Preferential accumulation of (S)-planar chirality was observed in any cases for AIAT of various [11]paracyclophane derivatives having hydroxyethylamine chiral auxiliaries. We also found that AIAT works well for stereocontrol of structurally similar [10]parapyridinophane derivatives.