Synthesis of Enantiopure 1‐Aryl‐1‐butylamines and 1‐Aryl‐3‐butenylamines by Diastereoselective Addition of Allylzinc Bromide to Imines Derived from (R)‐Phenylglycine Amide

The synthesis of enantiopure 1‐aryl‐1‐butylamines via a highly diastereoselective addition of allylzinc bromide to imines derived from ( R )‐phenylglycine amide is reported. These are synthesised by a three‐step procedure, which involves: (a) formation of the chiral imines; (b) asymmetric addition of the allylzinc reagent; (c) removal of the chiral auxiliary by means of a reductive or non‐reductive method. The reductive method provides 1‐aryl‐1‐butylamines whereas the non‐reductive method preserves the double bond to afford 1‐aryl‐3‐butenylamines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)