Incorporation of Functional Guest Molecules into an Internally Functionalizable Dendrimer through Olefin Metathesis

A poly(aryl ether) dendrimer bearing 22 allyl groups throughout the interior of the molecule has been prepared using a convergent synthetic approach. The internal functionalities of this dendrimer can be used to attach small molecule guests to the interior of the dendrimer using olefin metathesis. A ruthenium-based Grubbs catalyst was used to covalently attach an allylated pyrene and imidazolidinone via cross-metathesis. The extent of coupling was estimated by UV, NMR, and elemental analysis data. The high tolerance of cross-metathesis to a range of functional groups enables the incorporation of a wide range of molecules and provides access to different inner environments in one step from a single source of dendrimer.