Hybrids of Salicylalkylamides and Mannich Bases: Control of the Amide Conformation by Hydrogen Bonding in Solution and in the Solid State

Molecules

Christian Dank³  Barbara Kirchknopf¹  Matthias Mastalir³  Hanspeter Kählig⁴  Susanne Felsinger⁴  Alexander Roller²  Vladimir B. Arion²  Hubert Gstach³ 

[1] University of Applied Sciences Wiener Neustadt, Konrad-Lorenz-Strasse 10, Tulln a. d. Donau 3430, Austria; E-Mail:;X-ray Structure Analysis Centre, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria; E-Mails:;Institute of Medical Chemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna, Währingerstrasse 10, Vienna 1090, Austria; E-Mails:;Institute of Organic Chemistry, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria; E-Mails:

关键词: salicylamide;    Mannich base;    hybrid;    conformation;    intramolecular hydrogen bonding;    conformational switch;   

DOI  :  10.3390/molecules20011686

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.