Olefin metathesis in room temperature ionic liquids using imidazolium-tagged ruthenium complexes

Metathesis of 1‐Octene in Ionic Liquids and Other Solvents: Effects of Substrate Solubility, Solvent Polarity and Impurities

“…However, attachment of an "ionic liquid tag" to catalyst ligands hugely improves the recyclability of the system. [12][13][14][15] Interestingly, neither of these nor most other studies involving transition metal catalysts attach any importance to the purity of the ionic liquid used as solvent, although it is known that impurities such as water, amines or halides, stemming from the preparation of the ionic liquid, affect the reaction outcome, especially if transition metal catalysts are used. [4,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] In this sense, the conclusions drawn from this present study are certainly transferable to other catalytic reactions.…”

The activity of covalently immobilized Grubbs–Hoveyda type catalyst is highly dependent on the nature of the support material

“…In the case of 8a, 285 ppm of Ru were found in the product; with 8b, the value was 684 ppm of Ru [43]. These results were not as low as the best systems reported so far [31][32][33][34][35] but were in the range observed for other supported Ru-complexes [36][37][38][39][40][41][42].…”

“…Several time-consuming or cost-intensive methods were developed to reduce the metal contamination after reaction [12][13][14][15][16]. Immobilization of the Ru-complexes is a strategy to avoid the contamination from the very start as can be seen in the literature [31][32][33][34][35][36][37][38][39][40][41][42].…”

RTILs in Catalytic Olefin Metathesis Reactions

“…These goals were only partially reached since complex C8 proved ineffective for the challenging RCM of 18 even under optimized solvent mixture of [bmim] [PF 6 ]/toluene (25/75) whereas it could be reused in the RCM of 16 and 17 (Scheme 12) [68]. Interestingly, when C8 was used under biphasic conditions, the organic products extracted contained a very low residual amount of ruthenium typically below 22 ppm even though a rather high initial catalyst loading of 5 mol% was used.…”