meso-Tetraphenylporphine as a prochiral solvating agent (pro-CSA): A physicochemical study
meso-Tetraphenylporphine as a prochiral solvating agent (pro-CSA): A physicochemical study
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内消旋四苯基卟啉作为前手性溶剂化剂（pro-CSA）：一项物理化学研究
DOI：
10.1142/s1088424619501141
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Jonathan P. Hill
中科院分区：
文献类型：
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作者：
Jan Labuta;Shinsuke Ishihara;Jonathan P. Hill
中四苯基卟啉（TPP）可作为前手性溶剂化剂（procsa）用于手性有机酸对映异构体过量（ee）的核磁共振检测，本研究用的是2-苯氧丙酸（PPA）。亲csa感应机制的独特之处在于它不依赖于非对映体的形成。本文讨论了温度、客体交换率和结合强度等因素对校准曲线构建的影响（观察到诱导化学位移与非等效性之间的线性关系）。我们采用了各种核磁共振技术，包括变温核磁共振，滴定实验和核磁共振谱线形状分析。结果表明，每个TPP/酸性客体对的传感条件都需要优化。对于TPP/PPA主客系统，最佳工作温度为-32℃，可接受范围为-28℃至-50℃。上界是由于PPA对TPP的完全双质子化，下界是由于PPA在TPP结合位点的客交换率的限制。这些发现是典型的卟啉型双质子化前csa，为设计下一代传感分子提供了有价值的见解。
Meso-tetraphenylporphine (TPP) can be used as a prochiral chiral solvating agent (pro-CSA) for NMR detection of enantiomeric excess (ee) of chiral organic acids, in this study 2-phenoxypropionic acid (PPA). The pro-CSA sensing mechanism is unique in that it does not depend on formation of diastereomers. Here we discuss the factors affecting construction of the calibration curves (observed linearity between induced chemical shift non-equivalency andee) including temperature, guest exchange rate and binding strength. We have employed various NMR techniques including variable temperature NMR, titration experiments and analyses of NMR spectral line shapes. It is confirmed that optimization ofeesensing conditions is required for each TPP/acid guest pair. For the TPP/PPA host–guest system, an optimum operating temperature is -32C with an acceptable range from -28C to -50C. The upper bound is due to complete diprotonation of TPP by PPA and the lower bound is due to the limit of PPA guest exchange rate at TPP’s binding sites. These findings, typical for porphyrin-type diprotonated pro-CSAs, yields valuable insight for design of the next generation ofeesensing molecules.