Rotaxane amide-containing

The templated syntheses of amide-based rotaxanes discussed until now have made use of the threading-followed-by-capping method. However there are also examples in which the clipping approach has been employed. Leigh, for example, has used a five-component clipping method to prepare [2]rotaxanes. Isophthalamide and peptide-based threads were shown to template the formation of benzylic amide macrocycles about them in non-polar solvents [69, 70]. When the peptide-based threads (49) contain bulky stoppers at their ends, the [2]rotaxanes (50) can be prepared in high yields (see Scheme 24) [71]. 

Altieri A, Aucagne V, Carrillo R, Clarkson GJ, D Souza DM, Dunnett JA, Leigh DA, Mullen KM (2011) Sulfur-containing amide-based [2]rotaxanes and molecular shuttles. Chem Sci 2 1922-1928... 

A bistable porphyrin-containing [2]rotaxane R3 is synthesized with a shuttling benzylic-amide macrocycle mechanically locked onto the thread subunit via hydrogen bonding with two potential stations, as shown in Figure 5. This macrocycle consists of two pyridine groups, which would be easily coordinated with zinc porphyrin. The Zn(n) coordination of porphyrin moiety on the thread... 

Replacement of one or both amide groups of the classical glycylglycine template for rotaxane formation with H-bond acceptors based on various P-containing functional groups resulted in effective motifs for the H-bond -directed synthesis of [2]rotaxanes. ... 

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