Chiral macrocyclic aliphatic oligoimines derived from trans-1,2-diaminocyclohexane.
Aliphatic dialdehydes of rigid structures having a cyclohexane, a bicyclo[2.2.2]octane or a [7]triangulane skeleton, have been condensed with enantiomerically pure trans-1,2-diaminocyclohexane to give [3+3] or [2+2] macrocyclization products. Unlike acyclic aliphatic imines, these macrocyclic oligoimines show enhanced stabilities and their structures in the crystals could be determined by X-ray diffraction analyses. The enantiomerically pure [7]triangulane dialdehyde showed remarkable diastereoselectivity in the condensation with the two enantiomers of trans-1,2-diaminocyclohexane: only one of the enantiomers gave a [2+2] macrocyclization product. Circular dichroism measurements combined with computational analysis show that the lowest energy electronic transition in these cyclic oligoimines is of n-pi* type.
Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan, Poland.
Marcin
M
Kwit
Agnieszka
A
Plutecka
Urszula
U
Rychlewska
Jacek
J
Gawroński
Alexander F
AF
Khlebnikov
Sergei I
SI
Kozhushkov
Karsten
K
Rauch
Armin
A
de Meijere
D018360:Crystallography, X-Ray; D003514:Cyclohexylamines / Q000737:chemistry*; D007097:Imines / Q000138:chemical synthesis* / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism
D003514:Cyclohexylamines; D007097:Imines; D047028:Macrocyclic Compounds; C030435:1,2-cyclohexanediamine