Collect. Czech. Chem. Commun.
2000, 65, 243-266
https://doi.org/10.1135/cccc20000243
Crystal Structures and Reactivity of 3a,5a,8a,10a-Tetraazaperhydropyrene Derivatives. An Alternative Approach to Selective Nitrogen Alkylation of 1,4,8,11-Tetraazacyclotetradecane (Cyclam)
Jan Kotek, Petr Hermann*, Pavel Vojtíšek, Jan Rohovec and Ivan Lukeš
Department of Inorganic Chemistry, Charles University, Hlavova 2030, 128 40 Prague 2, Czech Republic
Abstract
1-Alkyl and 1,8-dialkyl-1,4,8,11-tetraazacyclotetradecanes (alkyl = benzyl or methyl) were synthesised through cis-aminal of cyclam which was obtained by reaction of glyoxal and cyclam. The corresponding trans-aminal was synthesised from the respective linear tetraamine and glyoxal followed by cyclisation using 1,2-dibromoethane. The trans-aminal derivatives cannot be used for preparation of cyclam or its derivatives due to exceptional stability of the aminal bridge. The different reactivity of both cis- and trans-aminals is discussed on the basis of the X-ray structures determined for a series of the cyclam derivatives and could be explained by steric hindrance in the trans-aminals.
Keywords: Azacrown compounds; N-Ligands; Amines; cis-Tetraazaperhydropyrene; trans-Tetraazaperhydropyrene; Selective protection; Cyclam; Crystal structure; NMR spectroscopy 13C; X-Ray diffraction.
References: 71 live references.
