(Bio)Functionalisation of Metal–Organic Polyhedra by Using Click Chemistry

Abstract

The surface chemistry of Metal‐Organic Polyhedra (MOPs) is crucial to their physicochemical properties because it governs how they interact with external substances such as solvents, synthetic organic molecules, metal ions, and even biomolecules. Consequently, the advancement of synthetic methods that facilitate the incorporation of diverse functional groups onto MOP surfaces will significantly broaden the range of properties and potential applications for MOPs. Herein, we describe the use of copper(I)‐catalysed, azide‐alkyne cycloaddition (CuAAC) click reactions to post‐synthetically modify the surface of alkyne‐functionalised cuboctahedral MOPs. To this end, we synthesised a novel Rh(II)‐based MOP with 24 available surface alkyne groups. We have demonstrated that each of the 24 alkyne groups on the surface of our “clickable” Rh‐MOP can be reacted with azide‐containing molecules at room temperature, without compromising the integrity of the MOP. We exploited the wide substrate catalogue and orthogonal nature of CuAAC click chemistry to densely functionalise MOPs with diverse functional groups, including polymers, carboxylic and phosphonic acids, and even biotin moieties, which retained their recognition capabilities once anchored onto the surface of the MOP.

Giant oligomeric porous cage-based molecules

“…Next, we synthesised a dimeric MOP-based molecule (hereafter, MOP-dimer), by coupling (N 3 ) 1 -RhMOP to (alkyne) 1 -RhMOP through a copper( i )-catalysed, azide–alkyne cycloaddition (CuAAC) click reaction. 43 To this end, both MOPs were reacted under homogenous conditions in a mixture of CH 2 Cl 2 /DMF (1 : 1), using copper sulphate and sodium acetate as catalysts, to afford the corresponding crude products as a green solid. To facilitate the purification of the MOP-dimer, all surface TSE protecting groups were cleaved, which yielded a dimeric MOP in which each MOP unit had 23 available carboxylic acid groups.…”

Discovery of 7-Azanorbornane-Based Dual Agonists for the Delta and Kappa Opioid Receptors through an In Situ Screening Protocol

“…A representative example is the copper-catalyzed 1,3-dipolar cycloaddition reaction between azides and alkynes (copper-catalyzed azide-alkyne cycloaddition, CuAAC) [2,3]. This reaction is used in many fields, including material sciences [4], chemical biology [5], and medicinal chemistry [6,7]. In drug discovery projects, the CuAAC reaction is used, by the power of combinatory processes, to prepare a large library of compounds.…”