2-Unsubstituted Imidazole N-Oxides as Novel Precursors of Chiral 3-Alkoxyimidazol-2-ylidenes Derived from trans-1,2-Diaminocyclohexane and Other Chiral Amino Compounds.
- Mlostoń G Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL-91-403 Łódź, Poland.
- Celeda M Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL-91-403 Łódź, Poland.
- Jasiński M Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL-91-403 Łódź, Poland.
- Urbaniak K Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL-91-403 Łódź, Poland.
- Boratyński PJ Department of Organic Chemistry, Wrocław University of Technology, Wyspiańskiego 27, PL-50-370 Wrocław, Poland.
- Schreiner PR Justus Liebig University, Institute of Organic Chemistry, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany.
- Heimgartner H Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
- 2019-12-08
Published in:
- Molecules (Basel, Switzerland). - 2019
N-alkoxyimidazolium salts
carbene sulfurization
chiral compounds
chiral nucleophilic carbenes
imidazole N-oxides
imidazole-2-thiones
Cyclohexylamines
Imidazoles
Oxides
English
'Desymmetrization' of trans-1,2-diaminocyclohexane by treatment with α,ω-dihalogenated alkylation reagents leads to mono-NH2 derivatives ('primary-tertiary diamines'). Upon reaction with formaldehyde, these products formed monomeric formaldimines. Subsequently, reactions of the formaldimines with α-hydroxyiminoketones led to the corresponding 2-unsubstituted imidazole N-oxide derivatives, which were used here as new substrates for the in situ generation of chiral imidazol-2-ylidenes. Upon O-selective benzylation, new chiral imidazolium salts were obtained, which were deprotonated by treatment with triethylamine in the presence of elemental sulfur. Under these conditions, the intermediate imidazol-2-ylidenes were trapped by elemental sulfur, yielding the corresponding chiral non-enolizable imidazole-2-thiones in good yields. Analogous reaction sequences, starting with imidazole N-oxides derived from enantiopure primary amines, amino alcohols, and amino acids, leading to the corresponding 3-alkoxyimidazole-2-thiones were also studied.
- Language
-
- English
- Open access status
- gold
- Identifiers
-
- DOI 10.3390/molecules24234398
- PMID 31810181
- Persistent URL
- https://sonar.ch/global/documents/47695
Statistics
Document views: 56
File downloads:
- Full-text: 0