A pair of artificial enantiotopic receptors la and lb composed of (S,S) or (R,R) chiral bicyclic guanidinium, azacrown ether and (t-butyldiphenylsilyloxy) methyl group for amino acid zwitterions have been synthesized....A pair of artificial enantiotopic receptors la and lb composed of (S,S) or (R,R) chiral bicyclic guanidinium, azacrown ether and (t-butyldiphenylsilyloxy) methyl group for amino acid zwitterions have been synthesized. The liquid-liquid competition experiments and 1 H NMR studies indicate that the receptor 1a with (S, S) configuration and 1b with (R,R) configuration selectively recognize L- and D-aromatic amino acids & respectively.展开更多
文摘A pair of artificial enantiotopic receptors la and lb composed of (S,S) or (R,R) chiral bicyclic guanidinium, azacrown ether and (t-butyldiphenylsilyloxy) methyl group for amino acid zwitterions have been synthesized. The liquid-liquid competition experiments and 1 H NMR studies indicate that the receptor 1a with (S, S) configuration and 1b with (R,R) configuration selectively recognize L- and D-aromatic amino acids & respectively.
