23967-95-5Relevant academic research and scientific papers
Aromatic oligoamides with a rare ortho-connectivity: Synthesis and study of ortho-arylopeptoids
Hjelmgaard, Thomas,Nielsen, John
, p. 3574 - 3589 (2013)
Even though aromatic oligoamides composed of aromatic amino acids in a one-way sequence attract ever increasing research interest, backbones connected through ortho-linked aromatics remain rare. Herein, we present the first synthesis and study of N-alkylated ortho-aminomethyl- benzamides termed ortho-arylopeptoids . The ortho-arylopeptoids may, with a few exceptions, be synthesized either in solution or on solid-phase using unique and highly efficient submonomer methods with similar levels of high generality and efficiency to those previously demonstrated for meta- and para-arylopeptoids. NMR studies indicated a more restricted rotation about the amide bonds in ortho-arylopeptoids, presumably due to a more congested backbone structure resulting from the ortho-connectivity pattern. Intriguingly, tert-butyl and phenyl side chains offer complete control over the amide conformations; whereas arylopeptoid residues with tert-butyl side chains adopt a 100 % cis amide conformation, the opposite 100 % trans amide conformation was observed in arylopeptoids with phenyl side chains. The tert-butyl moiety can furthermore serve as a protecting group during synthesis, which can later be removed to allow the amide to adopt a 100 % trans conformation instead.
