Multi-Layer Macromonocyclic Polyamines. I. Molecular Design and Synthesis of Component Monocyclic Precursors

We designed ``multi-layer macromonocyclic polyamines'' which might be appropriate polymorphismic molecular scaffolds as host-molecules in ionic or molecular interaction with small or large guest ions or molecules. In polymorphismic molecules, several macromonocyclic polyamines with the same and/or different ring sizes and nitrogen contents are connected to each other by alkylene spacers with various length of the chain. Actual target molecules are characterized by possessing methylene chain arrays of natural polyamines, and we have synthesized from simple starting materials fourteen component macromonocycles with various sizes, 12- to 34-membered rings containing three to eight nitrogen atoms, as essential building blocks required for construction of multi-layer molecules. Our method of synthesis was shown to be very efficient. In a final step, the N-protecting benzyl group was successfully removed by hydrogenation on 10%-Pd/C under 4 kg cm-2 H2 to give the cyclic amine precursors, which could be internal...