Ring-closing metathesis in biphasic BMI·PF₆ionic liquid/toluene medium: a powerful recyclable and environmentally friendly process

Abstract

Biphasic BMI[middle dot]PF(6)/toluene solvent is a remarkably suitable and clean medium for performing olefin metathesis with a new 2nd generation ionic liquid supported-ruthenium catalyst: high levels of recyclability and reusability combined with a high reactivity were obtained with a variety of di- or tri-substituted and/or oxygen-containing dienes, and very low residual ruthenium levels were detected (1 to 22 ppm) in the products.

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

“…In order to develop a more environmentally friendly olefin metathesis process in RTILs [11], we have recently immobilized the ruthenium catalysts 8 [12] and 9 [13] in the 1-butyl-3-methylimidazolium hexafluorophosphate (BMI AE PF 6 ) 1. In a pioneering work, Buisjmann and co-workers [11a] had observed that the GrubbsÕ catalyst 2 dissolved in BMI AE PF 6 promoted the RCM of several dienes for at least three cycles.…”

Synthesis of Polypentenamer and Poly(Vinyl Alcohol) with a Phase‐Separable Polyisobutylene‐Supported Second‐Generation Hoveyda–Grubbs Catalyst

“…Some of the most commonly employed strategies to obtain supported metathesis catalysts consist of immobilizing the ruthenium alkylidene complex on to insoluble polymers, [19][20][21][22] soluble polymers, [23][24][25][26] inorganic supports, 27-29 perfluorinated 30,31 and ionic-liquid tags. [32][33][34][35] ( Figure 1). Herein we will focus on the use of soluble polymer supported Nheterocyclic carbene (NHC) Ru metathesis catalysts.…”

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].…”