Noncovalent Immobilization of Cationic Ruthenium Complex in a Metal-Organic Framework by Ion Exchange Leading to a Heterogeneous Olefin Metathesis Catalyst for Use in Green Solvents

A simple strategy for noncovalent immobilization of an olefin metathesis catalyst inside a (Cr)MIL-101-SO3Na metal-organic framework (MOF) was presented. The olefin metathesis active core - an alkylidene complex bearing an ammonium-tagged NHC ligand (Apeiron's FixCat) - was immobilized by ion exchange facilitated by the use of crown ether. The hybrid material thus obtained was shown with a number of model substrates to exhibit high activity and selectivity in a wide range of solvents. Next, selected polyfunctional pharmaceutically related substrates were transformed using 0.8-0.5 mol % of the Ru@MOF in polar solvents such as acetone and dimethyl carbonate, making this technology interesting in the context of green solvent utilization.