Journal article

Publication year: 2019

Pages: 4398-

Journal: Molecules

Volume number: 24

Issue number: 23

Open access status: Gold

DOI Link: https://doi.org/10.3390/molecules24234398

Publisher: MDPI

Abstract: 
'Desymmetrization' of trans-1,2-diaminocyclohexane by treatment with alpha,omega-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 alpha-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.

Harvard Citation style: Mloston, G., Celeda, M., Jasinski, M., Urbaniak, K., Boratynski, P., Schreiner, P., et al. (2019) 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, Molecules, 24(23), p. 4398. https://doi.org/10.3390/molecules24234398

APA Citation style: Mloston, G., Celeda, M., Jasinski, M., Urbaniak, K., Boratynski, P., Schreiner, P., & Heimgartner, H. (2019). 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. Molecules. 24(23), 4398. https://doi.org/10.3390/molecules24234398