Covalent Post‐Assembly Modification: A Synthetic Multipurpose Tool in Supramolecular Chemistry

Abstract

The use of covalent post-assembly modification (PAM) in supramolecular chemistry has grown significantly in recent years, to the point where PAM is now a versatile synthesis tool for tuning, modulating and expanding the functionality of self-assembled complexes and materials. PAM underpins supramolecular templatesynthesis strategies, enables modular derivatization of supramolecular assemblies, permits the covalent 'locking' of unstable structures, and can trigger controlled structural transformations between different assembled morphologies. This review discusses key examples of PAM spanning a range of material classes, including discrete supramolecular complexes, selfassembled soft nanostructures and hierarchically ordered polymeric and framework materials. As such, we hope to highlight how PAM has continued to evolve as a creative and functional addition to the synthetic chemist's toolbox for constructing bespoke self-assembled complexes and materials.

Design and Applications of Water-Soluble Coordination Cages

“…To further probe the stability of these tetrahedra, the authors investigated the covalent postassembly modification (PAM) , of cage 65 bearing one NH 2 group on each of its six carboxylate linkers . The Mannich reaction of 65 with formaldehyde in methanol and water at 25 °C was monitored by ESI-TOF-MS (Figure b).…”

Transformation networks of metal–organic cages controlled by chemical stimuli

“…32,34 Others have focused on more specific aspects such as lighttriggered transformations, 35 redox active assemblies, [36][37][38] guestinduced reconfigurations 39 and covalent post-assembly modification (PAM). 40,41 In this review, we focus on chemically-controlled transformations of metal-organic cages and provide a library of recently reported strategies that transform cages and allow the creation of new architectures. Apart from touching on a few key precedents, we highlight work published over the past five years and thus not included in prior reviews.…”

Metal-Stabilized Boronate Ester Cages

“…To demonstrate the feasibility of a postsynthetic functionalization 52 via an imine bond formation, we examined the reaction of 5-Zn with 4-pentylaniline. An imine formation was achieved by heating a solution of the two compounds in acetonitrile for 48 h. The resulting imine-decorated cage 7-Zn was obtained after a precipitation with diethyl ether with an isolated yield of 65% (Scheme 5).…”