Resorcinarene-based cavitands with chiral amino acid substituents for chiral amine recognition
作者:Na Li、Fan Yang、Hillary A. Stock、David V. Dearden、John D. Lamb、Roger G. Harrison
DOI:10.1039/c2ob25613d
日期:——
Resorcinarene-based deep cavitands alanine methyl resorcinarene acid (AMA), alanine undecyl resorcinarene acid (AUA) and glycine undecyl resorcinarene acid (GUA), which contain chiral amino acids, have been synthesized. The upper rim of the resorcinarene host is elongated with four identical substituents topped with alanine and glycine groups. The structures of the new resorcinarenes were elucidated by nuclear magnetic resonance (NMR), mass spectrometry (MS) and the sustained off-resonance irradiation collision induced dissociation (SORI-CID) technique in FTICR-MS. These studies revealed that eight water molecules associate to the cavitand, two for each alanine group. The alanine substituent groups are proposed to form a kite-like structure around the resorcinarene scaffold. The binding of AMA, AUA, and GUA with chiral R- and S-methyl benzyl amines was studied by 1H NMR titration, and compared to that of a binary L-tartaric acid and the monoacid phthalyl alanine (PA). The results show that these compounds interact with amine guests; however, with four carboxylic acid groups, they bind several amine molecules strongly while the binary L-tartaric acid only binds one amine guest strongly. The simple compound PA, which contains one carboxylic group, shows weak binding to the amines. The 1H NMR titration of AUA with primary, secondary, and tertiary chiral amines showed that it can discriminate between these three types of amines and showed chiral discrimination for chiral secondary amines.
我们合成了含有手性氨基酸的间苯二酚基深空穴剂丙氨酸甲基间苯二酚酸(AMA)、丙氨酸十一烷基间苯二酚酸(AUA)和甘氨酸十一烷基间苯二酚酸(GUA)。间苯二酚主基的上缘被拉长,顶端有四个相同的取代基,分别是丙氨酸和甘氨酸基团。新型间苯二酚的结构是通过核磁共振(NMR)、质谱(MS)和 FTICR-MS 中的持续非共振辐照碰撞诱导解离(SORI-CID)技术阐明的。这些研究表明,空位体上有八个水分子,每个丙氨酸基团上有两个水分子。据推测,丙氨酸取代基团在间苯二酚支架周围形成了一个类似风筝的结构。通过 1H NMR 滴定法研究了 AMA、AUA 和 GUA 与手性 R-和 S-甲基苄胺的结合,并与二元 L-酒石酸和单酸邻苯二甲酸丙氨酸(PA)的结合进行了比较。结果表明,这些化合物都能与胺客体相互作用;但是,它们含有四个羧酸基团,能与多个胺分子紧密结合,而二元 L-酒石酸只能与一个胺客体紧密结合。含有一个羧基的简单化合物 PA 与胺的结合力较弱。AUA 与伯胺、仲胺和叔胺的 1H NMR 滴定结果表明,它可以区分这三种类型的胺,并对手性仲胺显示出手性区分。