Wang Haoyang, Xu Chu, Zhang Li, Tang Qinghong, Guo Yinlong, Lu Long
Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, PR China.
Eur J Mass Spectrom (Chichester). 2011;17(2):145-57. doi: 10.1255/ejms.1122.
The CH(3)OH solutions of pyrimidinyloxy-N-arylbenzylamines (1-5) in the presence of Mg(II)X(2) salts (X = Cl or ClO(4)) were investigated by electrospray ionization mass spectrometry and tandem mass spectrometry (MS/MS) subsequently, showing that the cationic Mg(II) complexes 1-5·MgX(+) were important active complexes or intermediates for initiating interesting Smiles rearrangement reactions in both the gas and solution phases. By using different MgX(2) salts and selecting a set of reactants with different substitutes, the role of the counter-ion (X(-)) and the structure effect of the reactants on the Mg(II) catalyzed Smiles rearrangement reactions were studied. Moreover, the solvent effect on Mg(II) catalyzed Smiles rearrangement reactions was revealed by studying the CH(3)OH adduct complexes of 1-5·MgCl(+), which showed that the coordination of CH(3)OH to the Mg(II) center in the complexes decreased the reaction tendency. The mechanisms involved in the gas-phase Mg(II) catalyzed Smiles rearrangement reactions were proposed on the basis of MS/MS experiments and theoretical computations, showing some unique chemistries initiated by introducing Mg(II) into the template molecules.
随后，通过电喷雾电离质谱和串联质谱（MS/MS）对嘧啶氧基-N-芳基苄胺（1-5）在Mg(II)X₂盐（X = Cl或ClO₄）存在下的CH₃OH溶液进行了研究，结果表明阳离子Mg(II)配合物1-5·MgX⁺是在气相和溶液相中引发有趣的斯迈尔斯重排反应的重要活性配合物或中间体。通过使用不同的MgX₂盐并选择一组具有不同取代基的反应物，研究了抗衡离子（X⁻）的作用以及反应物的结构对Mg(II)催化的斯迈尔斯重排反应的影响。此外，通过研究1-5·MgCl⁺的CH₃OH加合物配合物揭示了溶剂对Mg(II)催化的斯迈尔斯重排反应的影响，结果表明CH₃OH与配合物中Mg(II)中心的配位降低了反应倾向。基于MS/MS实验和理论计算提出了气相Mg(II)催化的斯迈尔斯重排反应的机理，显示了通过将Mg(II)引入模板分子引发的一些独特化学性质。
