(S)-BINOL-based boronic ester fluorescence sensors for enantioselective recognition of α-phenylethylamine and phenylglycinol
作者:Jiemin Jiao、Guo Wei、Fei Li、Xuerong Mao、Yixiang Cheng、Chengjian Zhu
DOI:10.1039/c3ra45682j
日期:——
Four chiral fluorescence sensors (S)-L1â4 incorporating boronic ester and (S)-1,1â²-bi-2-naphthol (BINOL) moieties were synthesized and developed for the enantioselective recognition of α-phenylethylamine and phenylglycinol enantiomers. The sensor (S)-L1 shows an obvious fluorescence quenching âturn-offâ response towards enantiomers of both α-phenylethylamine and phenylglycinol. Interestingly, the sensor (S)-L2 can exhibit remarkable fluorescent enhancement âturn-onâ response behavior towards (S)-α-phenylethylamine, but shows no response towards phenylglycinol enantiomers. The SternâVolmer constant (Ksv) values of (S)-L1 are 0.63 à 103 L molâ1 and 4.48 à 103 L molâ1 for (L)- and (D)-phenylglycinol, respectively, and the value of the enantiomeric fluorescence difference ratio (ef) of (S)-L2 is 4.6 for α-phenylethylamine, demonstrating that (S)-L2 could be used as a fluorescence sensor for simple and direct visual discrimination of organic molecule enantiomers. On the contrary, no fluorescence enantioselective recognition response could be observed when using the (S)-BINOL-based boronic ester sensors (S)-L3 and (S)-L4 incorporating bigger naphthyl or 8-methoxyquinolinyl substituent groups.
合成并开发了四种包含硼酸酯和(S)-1,1â²-双-2-萘酚(BINOL)分子的手性荧光传感器(S)-L1â4,用于对δ-苯乙胺和苯基甘氨醇对映体的对映选择性识别。传感器(S)-L1 对δ-苯乙胺和苯基甘氨醇的对映体都有明显的荧光淬灭反应。有趣的是,传感器(S)-L2 对(S)-δ-苯乙胺表现出显著的荧光增强 "urn-on "反应行为,但对苯甘氨醇对映体没有反应。对于(L)-和(D)-苯甘氨醇,(S)-L1的斯特恩-沃尔默常数(Ksv)值分别为0.63 Ã 103 L molâ1 和4.48 Ã 103 L molâ1,而(S)-L2的对映体荧光差异比(ef)值为4。(S)-L2可用作荧光传感器,对有机分子对映体进行简单而直接的视觉判别。相反,使用含有较大萘基或 8-甲氧基喹啉基取代基的 (S)-BINOL 基硼酯传感器 (S)-L3 和 (S)-L4 时,则无法观察到荧光对映体选择性识别反应。