Synthesis and chiral recognition properties of poly (N-propargylamide) gels derived from ornithine and lysine

Copolymerization of ornithine- and lysine-derived N-propargylamides, N-alpha-tert-butoxycarbonyl-N-delta-fluorenylmethoxycarbonyl-L-ornithine N'-propargylamide (1), N-alpha-tert-butoxycarbonyl-N-epsilon-fluorenylmethoxycarbonyl-L-lysine N'-propargylamide (2), N-alpha-fluorenylmethoxycarbonyl-N-delta-tert-butoxycarbonyl-L-ornithine N'-propargylamide (3), and N-alpha-fluorenylmethoxycarbonyl-N-epsilon-tert-butoxycarbonyl-L-lysine N'-propargylamide (4) with dipropargyl adipate was carried out using (nbd)Rh+[eta(6)-C6H5B-(C6H5)(3)] as a catalyst in THF to obtain polymer gels in 80-93% yields. The gels adsorbed N-benzyloxycarbonyl L-alanine, N-benzyloxycarbonyl L-alanine methyl ester, and (S)-(+)-1-phenyl-1,2-ethanediol preferably than the corresponding optical isomers. The order of chiral discrimination was poly(l) > poly(4) > poly(2), poly(3) gels. The fluorenylmethoxycarbonyl groups of the gels could be partly removed by piperidine treatment, leading to increase of adsorptivity but decrease of chiral recognition ability. (C) 2008 Wiley Periodicals, Inc.