Asymmetric synthesis of enantiomerically pure 4-aminoglutamic acids via methylenedimerization of chiral glycine equivalents with dichloromethane under operationally convenient conditions

We found that simple stirring of a biphasic mixture of the Ni(II) complex of glycine Schiff base 2 solution in dichloromethane with 30% aqueous NaOH in the presence of PT catalyst nBu4N+Br− at room temperature for 24 h results in the formation of diastereo- and enantiomerically pure Ni(II) complex 3, containing (2S,4S) 4-aminoglutamic acid, in high chemical yield. The procedure described in this communication represents a synthetically efficient method for the asymmetric synthesis of 4-aminoglutamic acid on large scale.