Intra- and intermolecular complexation in C(6) monoazacoronand substituted cyclodextrinsElectronic supplementary information (ESI) available: 1H 600 MHz 2D ROESY NMR spectra. See http://www.rsc.org/suppdata/ob/b3/b316450k/
作者:Julia S. Lock、Bruce L. May、Philip Clements、Stephen F. Lincoln、Christopher J. Easton
DOI:10.1039/b316450k
日期:——
The preparation of 6A-deoxy-6A-(6-(2-(1,4,7,10-tetraoxa-13-azacyclopentadecan-13-yl)acetamido)hexylamino)-α-cyclodextrin, 3, 6A-deoxy-6A-(6-(2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)acetamido)hexylamino)-α-cyclodextrin, 4, and their β-cyclodextrin analogues, 5 and 6, are described. 1H (600 MHz) ROESY NMR spectra of the C(6) substituted β-cyclodextrins, 5 and 6, are consistent with the intramolecular complexation of their azacyclopentadecanyl- and azacyclooctadecanyl(acetamido)hexylamino substituents in the β-cyclodextrin annulus in D2O at pD = 8.5 whereas those of their α-cyclodextrin analogues, 3 and 4 are not complexed in the α-cyclodextrin annulus. This is attributed to the monoazacoronand components of the substituents being able to pass through the β-cyclodextrin annulus whereas they are too large to pass through the α-cyclodextrin annulus. However, the substituents of 3 and 4 are intermolecularly complexed by β-cyclodextrin to form pseudo [2]-rotaxanes. Metallocyclodextrins are formed by 5 through complexation by the monoazacoronand substituent component for which log (K/dm3 mol−1)
= <2, 6.34 and 5.38 for Ca2+, Zn2+ and La3+, respectively, in aqueous solution at 298.2 K and I
= 0.10 mol dm−3
(NEt4ClO4).
描述了6A-去氧-6A-(6-(2-(1,4,7,10-四氧-13-氮杂环戊十五烷-13-基)乙酰氨基)六氨基)-α-环糊精(3)、6A-去氧-6A-(6-(2-(1,4,7,10,13-五氧-16-氮杂环十八烷-16-基)乙酰氨基)六氨基)-α-环糊精(4)及其β-环糊精类似物(5和6)的制备。C(6)取代的β-环糊精(5和6)的1H(600 MHz)ROESY NMR光谱表明,在pD = 8.5的D2O中,它们的氮杂环戊十五烷和氮杂环十八烷(乙酰氨基)六氨基取代基在β-环糊精环形结构内发生了分子内复合,而它们的α-环糊精类似物(3和4)则未在α-环糊精环形结构中复合。这归因于取代基的单氮杂冠烷组分能够穿过β-环糊精环形结构,而对α-环糊精环形结构来说则过大。然而,3和4的取代基通过β-环糊精发生了分子间的复合,形成伪[2]-旋转烷。通过5的单氮杂冠烷取代组分的复合形成金属环糊精,其中对于Ca²⁺、Zn²⁺和La³⁺在298.2 K和I = 0.10 mol dm⁻³(NEt4ClO4)的水溶液中的log (K/dm³ mol⁻¹)分别为 <2、6.34和5.38。