Abstract:
Enantiomerically enriched indolines and tetrahydroisoquinolines were synthesized within 5 min to 2 h in high yields from easily accessible (S)-amino acids derived chiral carbocations. The diastereoselective Friedel-Crafts reaction is promoted by Lewis acid (AlCl3) offering trans-diastereoselectivity. The rate of the reaction and diastereoselectivity of the product are significantly influenced by steric hindrance of substituents of amino acids and aryl groups. The methodology can be applied for the synthesis of enantiomercally enriched bioactive scaffold (3S, 4R)-demethoxy-3-isopropyl diclofensine.
