| Abstract
| - N-Benzyl substituted aza[1n]metacyclophanes (n = 4, 6, 8, and 10) were prepared in overall 40% isolatedyields via Pd-catalyzed aminations. Analyses of the reaction mixtures showed that aza[14]metacyclophaneand the related polymer were the primary products (∼60% overall yield); aza[1n]metacyclophanes up ton = 14 and linear oligomers with up to 20 nitrogen atoms (with at least three types of end groups) weredetected. Macrocyclic structures for n = 4, 6, and 10 were confirmed by X-ray crystallography. 1,3-Alternate (D2d) and 1,3,5-alternate (S6) conformations in solution on NMR time scale at low temperatureswere found for macrocycles with n = 4 and n = 6, respectively; the barrier for ring inversion wasconsiderably lower for the larger macrocycle.
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