Quinine versus carbamoylated quinine-based chiral anion exchangers. A comparison regarding enantioselectivity for N-protected amino acids and other chiral acids.

摘要: First, a chiral stationary phase was prepared by immobilization of the naturally occurring alkaloid quinine onto 3-mercaptopropyl-modified silica gel via radical addition reaction and it evaluated for direct HPLC enantioseparation acidic compounds under buffered hydro-organic mobile conditions. Second, its enantioselectivity retention characteristics representative set N-derivatized α-amino acids other were compared with those similar weak anion exchanger based on tert.-butyl carbamoylated derivative as selector. The results clearly indicate that introduction carbamoyl functionality at secondary hydroxyl group C9 provides new additional sites intermolecular interactions analytes this can profoundly change improve recognition ability, especially amide, carbamate sulfonamide derivatives amino including DNB, Bz, Ac, For, Z, Fmoc, Boc DNS-protected acids. impact rigid hydrogen donor–acceptor – directing stereoselective selector–selectand complexation bonding in comparison to plain selector is further alkylation nitrogen atom either and/or function leucine (N-methyl leucine) derivatized DNB or DNP groups.