A Pyridine-Acetylene-Aniline Oligomer: Saccharide Recognition and Influence of this Recognition Array on the Activity as Acylation Catalyst

In order to create new functions of foldamer-type hosts, various kinds of recognition arrays are expected to be developed. Here, a pyridine-acetylene-aniline unit is presented as a new class of a saccharide recognition array. The conformational stabilities of this array were analyzed by DFT calculation, and suggested that a pyridine-acetylene-aniline oligomer tends to form a helical structure. An oligomer of this array was synthesized, and its association for octyl β-D-glucopyranoside was confirmed by ¹H NMR measurements. UV/Vis, circular dichroism, and fluorescence titration experiments revealed its high affinity for octyl glycosides in apolar solvents (K_a=10⁴ to 10⁵ M⁻¹). This oligomer was relatively stable under basic conditions, and therefore this array was expected to be applied to the derivatization of saccharides. A 4-(dialkylamino)pyridine attached pyridine-acetylene-aniline oligomer proved to catalyze the acylation of the octyl glucoside.