Journal of the American Chemical Society, Vol.116, No.4, 1337-1344, 1994
A Novel Anion-Binding Chiral Receptor-Based on a Metalloporphyrin with Molecular Asymmetry - Highly Enantioselective Recognition of Amino-Acid Derivatives
A chiral zinc strapped N-methylated porphyrin (3c) with molecular asymmetry, featuring a metal atom to bind a carboxylate anion and a rigid p-xylylene strap anchored via two amide linkages, was synthesized from mesoporphyrin II with enantiotopic fades, and the optical isomers of 3c were resolved by HPLC. By using 3c as a chiral receptor, the highly enantioselective binding was achieved for the carboxylate anions of N-benzyloxycarbonyl, tert-butoxycarbonyl, 3,5-dinitrobenzoyl, and acetyl amino acids. IR and NMR studies demonstrated the crucial role of the hydrogen bonding interaction between the receptor and substrates in the chiral recognition.
Keywords:TWIN CORONET PORPHYRINS;CYTOCHROME-P-450 ACTIVE-SITE;PROSTHETIC HEME ALKYLATION;STRAPPED PORPHYRINS;IRON PORPHYRIN;CROWN ETHERS;EPOXIDATION;COMPLEXES;TRYPTOPHAN;OXIDATION