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

Abstract

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 (Ka=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.

Chiral Assemblies of Planar and Achiral meta-Arylene Ethynylene Macrocycles Induced by Saccharide Recognition

“…Scheme shows the synthetic procedure of the macrocycle 2 . The pyridine monomer 3 , the aniline monomer 4 , and the trimer building block 6 were prepared according to literature methods. , Sonogashira reaction using 3 and an excess of 4 yielded the trimer building block 5 . The trimers 5 and 6 were subjected to react together without CuI under a dilute condition to furnish 2 .…”

“…Tetrahydrofuran (THF) was freshly distilled from sodium benzophenone ketyl before use. Macrocycles 1a and 1b , pyridine monomer 3 , aniline monomer 4 , trimer building block 6 , oct-β- d -Man , and oct-β- d -Fru were prepared according to literature methods.…”

“…In addition, we newly developed a pyridine–acetylene–aniline macrocycle 2 , possessing another push–pull-type hydrogen-bonding motif (Figure ). We had revealed that a chain-type oligomer consisting of the pyridine–acetylene–aniline units binds to saccharides by multiple hydrogen bonds . Therefore, 2 was also expected to bind to saccharides and form chiral assemblies.…”

Synthesis of Rigid Macrocyclic Phenols and Their Catalytic Applications in Diels‐Alder Reactions

“…Scheme 1 shows the synthetic procedure of the macrocyclic catalyst 4 a . The starting material, 2,6‐diiodo‐4‐butylaniline ( 7 ), was prepared by our previous literature method [10] . The Sandmeyer reaction of 7 with ethanol‐reduction process gave 1‐butyl‐3,5‐diiodobenzene ( 8 ).…”

“…The starting material, 2,6-diiodo-4-butylaniline (7), was prepared by our previous literature method. [10] The Sandmeyer reaction of 7 with ethanol-reduction process gave 1-butyl-3,5-diiodobenzene (8). Monoethynyl and diethynyl derivatives 9 and 10 were obtained by the Sonogashira reactions between 8 and trimethylsilylacetylene (TMSC�CH) followed by desilylation.…”