A number of metathesis reactions were successfully conducted in 4-methyltetrahydropyran, including both standard model dienes, as well as more complex substrates, such as analogues of biologically active compounds and active pharmaceutical ingredients. To place this solvent in a context of pharmaceutical R + D, larger-scale syntheses of SUAM 1221, a prolyl endopeptidase inhibitor with potential application in Alzheimer disease treatment, and a derivative of sildenafil, an analogue of the popular Viagra drug, were executed. In the latter case, despite all the setup being made in air, the metathesis reaction at a 33 g scale proceeded very well with relatively low catalyst loading and without need of aqueous workup or column chromatography.

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.

Promoted by homogeneous Ru-benzylidene complexes, the olefin metathesis reaction is a powerful methodology for C-C double bonds formation that can find a number of applications in green chemical production. A set of heterogeneous olefin metathesis pre-catalysts composed of ammonium-tagged Ru-benzylidene complexes 4 (commercial FixCat™ catalyst) and 6 (in-house made) immobilized on solid supports such as 13X zeolite, metal-organic framework (MOF), and SBA-15 silica were obtained and tested in catalysis. These hybrid materials were doped with various amounts of ammonium-tagged styrene derivative 5—a precursor of a spare benzylidene ligand—in order to enhance pre-catalyst regeneration via the so-called release-return “boomerang effect”. Although this effect was for the first time observed inside the solid support, we discovered that non-doped systems gave better results in terms of the resulting turnover number (TON) values, and the most productive were hybrid catalysts composed of 4@MOF, 4@SBA-15, and 6@SBA-15.