Abstract

3-Aminomethylation of salicylalkylamides afforded hybrids with a Mannich base. In addition, it triggered the rotation of the amide bond. The observed conformational switch is driven by strong intramolecular hydrogen bonding between the Mannich base and phenolic group. Crystal structure analysis reveals the stabilization of the hybrid molecules by double hydrogen bonding of the phenolic OH, which acts as an acceptor and donor simultaneously. The molecules contain an amide site and a Mannich base site in an orthogonal spatial arrangement. The intramolecular hydrogen bonds are persistent in a nonpolar solvent (e.g., chloroform). The conformational change can be reversed upon protection or protonation of the Mannich base nitrogen.

Details

Title
Hybrids of Salicylalkylamides and Mannich Bases: Control of the Amide Conformation by Hydrogen Bonding in Solution and in the Solid State
Author
Dank, Christian; Kirchknopf, Barbara; Mastalir, Matthias; Kählig, Hanspeter; Felsinger, Susanne; Roller, Alexander; Arion, Vladimir B; Gstach, Hubert
Pages
1686-1711
Publication year
2015
Publication date
2015
Publisher
MDPI AG
e-ISSN
14203049
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1651199873
Copyright
Copyright MDPI AG 2015