Beilstein J. Org. Chem.2018,14, 1660–1667, doi:10.3762/bjoc.14.142
]arene di(oxybutoxy)benzoic acid with monoamido-functionalized pillar[5]arenes resulted in the diamido-bridged tris-pillar[5]arenes, which successfully form the unique bis-[1]rotaxanes bearing longer than diaminopropylene diamido bridges.
Keywords: bis-[1]rotaxane; mechanically interlocked molecule
, −1.62 ppm and −2.08 ppm in tris-pillar[5]arene 9d. Therefore, 1H NMR spectra of 9b–d indicated that the diaminoalkylene chain ambiguously inserted in the cavity of the pillar[5]arene. In other words, the fascinating bis-[1]rotaxane structures were formed in the tris-pillar[5]arenes 9b–d. Here, the
NOE correlations clearly indicated the two bridged diaminohexylene chain threading into the cavity of the two pillar[5]arenes to form the bis-[1]rotaxane. The similar correlations were also observed in the NOESY spectra of the tris-pillar[5]arene 9b and 9c (see Supporting Information File 1, Figures
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Graphical Abstract
Scheme 1:
Synthesis of pillar[5]arene mono(oxyalkoxy)benzoic acids 3a–c.