Entry point into new trimeric and tetrameric imide‐based macrocyclic esters derived from isophthaloyl dichloride and methyl 6‐aminonicotinate. (1st January 2013)

• Record Type: Journal Article
• Authors: Mocilac, Pavle; Gallagher, John F.
• Is Part Of: Acta crystallographica. Volume 69:Part 1(2013:Feb.)
• Page Start: 62
• Page End: 69
• Publication Date: 2013-01-01
• Subjects: Crystallography -- Periodicals; Crystallization -- Periodicals; Chemical structure -- Periodicals; Solid state physics -- Periodicals; 530.41105
• DOI: 10.1107/S0108768112047416
• Languages: English
• ISSNs: 0108-7681

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The one‐step reaction of isophthaloyl dichloride with the 2‐aminopyridine derivative (methyl 6‐aminonicotinate) yields (i) a trimer‐based macrocycle (EsIO)₃ and (ii) a tetramer‐based macrocycle (EsIO)₄ in modest isolated synthetic yields (total of 25%), together with (iii) longer open‐chain oligomers. The macrocyclization relies on the semi‐flexible imide <italic>hinge</italic> formed by reaction of the 2‐amino(pyridine) functional group with two acyl chloride functional groups. The determining factors in macrocycle synthesis are: (<italic>a</italic>) imide formation using the heteroaromatic <italic>ortho</italic>‐N functionality; (<italic>b</italic>) the inherent ability of the imide to twist by 85–115° from planarity (as measured by the CO...CO imide torsion angles), thereby providing a <italic>hinge</italic> for macrocyclic ring closure or potentially (non)helical assembly in oligomer/polymer formation; (<italic>c</italic>) the conformational flexibility of the isophthaloyl group with <italic>meta</italic>‐related carbonyl groups to twist and adopt either <italic>syn</italic> or <italic>anti</italic> conformations, although the <italic>syn</italic> conformation is observed structurally for all isophthaloyl groups in both (EsIO)₃ (trezimide) and (EsIO)₄ (tennimide) macrocycles.</p> </abstract>