Polyurea Bearing L-Lysinyl Residue as a Chiral Building Block and Its Application to Optical Resolution

Chial polyureas were prepared from L-Lys-OEt and 2,4-TDI. The optimum polyaddition conditions were determined as follows: [L-Lys-OEt] = 2.08 x 10-1 mol dm-3 and [2,4-TDI] = 2.50 x 10-1 mol dm-3 ([L-Lys-OEt]/[2,4-TDI] = 0.83). The polyuera thus obtained gave a durable self-standing membrane and it was directly converted into molecular recognition membranes by applying an alternative molecular imprinting. The D-isomer molecularly imprinted membrane adsorbed the D-isomer in preference to the L-isomer and vice versa. In the present study, two types of print molecule, such as Z-D-Glu and Z-L-Glu, worked as print molecules though the polyurea consisted of L-lysinyl residue. Those two types of molecularly imprinted membrane showed chiral separation ability. The membrane, which was molecularly imprinted by the D-isomer and preferentially incorporated the D-isomer into the membrane, selectively transported the D-isomer and vice versa.