Macrocycles multicomponent assembly

Christinat, N. ScopeUiti, R. Severin, K. Multicomponent assembly of boronic acid based macrocycles and cages. Angew. Chem. Int. Ed. 2008, 47, 1848-1852. 

In comparison with the fabrication of alkynyl- or alkenyl-linked multicomponent assemblies, there are few examples dedicated to aryl-Pcs. Such attempts are mainly based on Suzuki or Stille couplings. Hence, Odobel et al. [80] reported the construction of a Pc macrocycle carrying a trimethyltin function, thus allowing... 

The amine function in Pcs was also found to be versatile as it allows for the facile incorporation of other photoactive or electroactive species. In particular such amino-functionalized Pcs can be easily reacted with perylene dianhydride to undergo formation of the corresponding diimides such as 18 (Fig. 13) [90-92], The Pc building blocks, carrying either a spacered amino or an anilino group, respectively, were thus implemented into the perylene structure by melting of the two components in imidazole to result in the construction of the corresponding multicomponent assemblies. The pathway toward such structures can also be performed by first introduction of the phthalonitrile to the perylene followed by the formation of the macrocycle [93],... 

Rotaxanes and catenanes are supramolecular (multicomponent) species [2b, 8, 9, 13, 14] strictly related to, but also very different from, pseudorotaxanes (Fig. 1). Whereas pseudorotaxanes can undergo dissociation into their wire-like and macrocyclic components, rotaxanes and catenanes are interlocked species, whose dissociation requires breaking of a covalent bond. The general strategy to prepare rotaxanes and catenanes with high yields is based on the template effect [15], which relies on the presence of molecular recognition sites in the components to be assembled. 

It was found that the presence of an amino or aldehyde groups in the meta-position of the arylboronic acid did not interfere in the macrocyclization reaction. This allowed the effective assembly of functionalized boronic acids, dihydroxypyridine ligands, and amines or aldehydes, respectively, in a multicomponent procedure affording pen-tameric boronic acid macrocycles (Scheme 4.7) and tetramer derivatives (Scheme 4.8). 

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