运用Cu(I)催化的1,3-偶极环加成反应(点击化学),以乙酸酐修饰单叠氮环糊精为底层,炔基衍生的天然环糊精为顶层,在硅胶表面通过自下而上的方式构建了一种新型"天然-乙酰基衍生化"三唑桥联杂化复式环糊精手性固定相材料(ANCDCSP),并通过红外光谱、热重和元素分析等测试手段对其结构进行了表征.该固定相材料可提供包合作用、氢键给体、氢键受体、偶极-偶极作用等多重识别位点以及底层和顶层环糊精间的协同效应.在HPLC反相分离模式下,该固定相材料对10种丹磺酰氨基酸类(Dns amino acids)、10种小分子芳香酸(phenyl carboxylic acids)、5种异噁唑啉类(isoxazolines)以及多种其它手性对映体具有良好的手性拆分效果.其中Dns-Phe、DL-3Ph Lac A以及Bendroflumethiazide的分离度分别达到5.3、4.1和4.1,且多数手性对映体的分离度优于课题组先前制备的复式天然环糊精手性固定相(DCDCSP).
A novel tandem-inverted triazole-bridged duplex "native-acetylated" hybrid cyclodextrin(CD) stationary phase material(ANCDCSP) was constructed via a surface-up ‘click' approach. Mono-6-azido-CD was first immobilized onto the pre-dried silica surfaces as the down layer via ether linkage on C2 position, followed by acetylation of the cyclodextrin –OH groups with acetic anhydride. The top layer was fabricated by anchoring the synthesized alkyne functionalized CD onto the down CD layer via organic soluble Cu(I) catalytic 1,3-dipolar cycloaddition reaction(click chemistry) reported by us previously. The obtained crude material was purified by washing with N,N-dimethylformamide(DMF) twice followed by Soxlet extraction with acetone to afford the novel triazole-bridged duplex hybrid CD CSP and its structure was characterized via Fourier Transfer Infrared Spectroscopy(FTIR), thermogravimetric analysis(TG) and elemental analysis(EA). The hybrid bilayer ANCDCSP can provide multiple interaction sites such as H-bonding(OH, C=O, NH), steric effects, dipole-dipole and synergistic effect inclusion complexation, which helps to broaden the CSP's enantioselectivity profile and enhance the enantioselectivity to some specific analytes. The CSP was applied for HPLC enantioseparation of various chiral compounds such as dansyl amino acids, carboxylic aryl acids, isoxazolines and some other racemates under reversed-phase separation mode using methanol/water and methanol/buffer as the mobile phases. Most of the dansyl amino acids and carboxylic aryl acids as well as bendroflumethiazide can be baseline separated. The isoxazolines, phenyl oxirane, atropine, DL-norleucine methyl ester and benfluorex were partially separated. The resolutions of Dns-Phe, DL-3Ph Lac A and Bendroflumethiazide reached 5.3, 4.1 and 4.1, respectively. The separation ability of the current CSP is superior to that of the duplex native cyclodextrins chiral stationary phase(DCDCSP) prepared by our group previously, es