title: Hybrids of salicylalkylamides and Mannich bases: control of the amide conformation by hydrogen bonding in solution and in the solid state.
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.
authors.affiliation: Institute of Medical Chemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna, Währingerstrasse 10, Vienna 1090, Austria. christian.dank@univie.ac.at.
authors.forename: Christian
authors.initials: C
authors.lastname: Dank
authors.affiliation: University of Applied Sciences Wiener Neustadt, Konrad-Lorenz-Strasse 10, Tulln a. d. Donau 3430, Austria. barbara.kirchknopf@gmx.at.
authors.forename: Barbara
authors.initials: B
authors.lastname: Kirchknopf
authors.affiliation: Institute of Medical Chemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna, Währingerstrasse 10, Vienna 1090, Austria. matthias.mastalir@gmx.at.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mastalir
authors.affiliation: Institute of Organic Chemistry, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria. hanspeter.kaehlig@univie.ac.at.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Kählig
authors.affiliation: Institute of Organic Chemistry, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria. susanne.felsinger@univie.ac.at.
authors.forename: Susanne
authors.initials: S
authors.lastname: Felsinger
authors.affiliation: Structure Analysis Centre, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria. alexander.roller@univie.ac.at.
authors.forename: Alexander
authors.initials: A
authors.lastname: Roller
authors.affiliation: Structure Analysis Centre, University of Vienna, Währingerstrasse 38, Vienna 1090, Austria. vladimir.arion@univie.ac.at.
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Arion
authors.affiliation: Institute of Medical Chemistry, Center of Pathobiochemistry and Genetics, Medical University of Vienna, Währingerstrasse 10, Vienna 1090, Austria. hubert.gstach@meduniwien.ac.at.
authors.forename: Hubert
authors.initials: H
authors.lastname: Gstach
mesh_terms: D000577:Amides / Q000737:chemistry*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007536:Isomerism; D008352:Mannich Bases / Q000737:chemistry*; D008968:Molecular Conformation; D066244:Proton Magnetic Resonance Spectroscopy; D012457:Salicylamides / Q000138:chemical synthesis / Q000737:chemistry*; D012996:Solutions
chemical_list: D000577:Amides; D008352:Mannich Bases; D012457:Salicylamides; D012996:Solutions