Connection of Metallamacrocycles via Dynamic Covalent Chemistry: A Versatile Method for the Synthesis of Molecular Cages

Abstract

A modular approach for the synthesis of cage structures is described. Reactions of [(arene)RuCl(2)](2) [arene = p-cymene, 1,3,5-C(6)H(3)Me(3), 1,3,5-C(6)H(3)(i-Pr)(3)] with formyl-substituted 3-hydroxy-2-pyridone ligands provide trinuclear metallamacrocycles with pendant aldehyde groups. Subsequent condensation reactions with di- and triamines give molecular cages with 3, 6, or 12 Ru centers in a diastereoselective and chemoselective (self-sorting) fashion. Some of the cages can also be prepared in one-pot reactions by mixing [(arene)RuCl(2)](2) with the pyridone ligand and the amine in the presence of base. The cages were comprehensively analyzed by X-ray crystallography. The diameter of the largest dodecanuclear complex is ∼3 nm; the cavity sizes range from 290 to 740 Å(3). An amine exchange process with ethylenediamine allows the clean conversion of a dodecanuclear cage into a hexanuclear cage without disruption of the metallamacrocyclic structures.

Highly Regioselective Copper‐Catalyzed Benzylic CH Amination by N‐Fluorobenzenesulfonimide

“…The successful diamination of xylene provides the simplest access to benzylic diamines, which are the important units in polyamides and molecular cages. [29,30] The above results clearly show the efficiency and generality of this amination method (Schemes 2 and 3). Next, the selectivity of the reaction was studied (Scheme 4).…”

Neutral discrete metal–organic cyclic architectures: Opportunities for structural features and properties in confined spaces

“…Severin and co-workers [198] reported that substituents at position 4 of the 3-hydroxy-2-pyridone ligand did not interfere with the self-assembly of (arene)Ru(II) complexes to produce trinuclear metallacycles. The com- .…”

“…One-pot reactions were feasible for preparing simple Scheme 32. Synthesis of the metallamacrocycles 91a-c and 92a,b [198]. a Scheme 33.…”

“…a Scheme 33. Synthesis of cages 93 by [1 + 1] condensation of extended trialdehydes 92 with triamine and one-pot synthesis [198]. a Scheme 34.…”

Coordination-Driven Supramolecular Macromolecules via the Directional Bonding Approach

“…Such transformations can be triggered by external means, such as light, solvent, or chemical signals [84][85][86][87][88][89]. For Pt-based SCCs, this process exploits the same preference for heteroligation as is used in multicomponent assembly.…”