Synthesis and Application of a Permanently Immobilized Olefin-Metathesis Catalyst

Abstract

Immobilized on Merrifield polystyrene, catalyst 1 shows high activity and stability in different types of olefin metathesis. The products can be isolated in high purity by simple filtration, while the immobilized catalyst 1 can be recycled and used up to four times in the ring‐closing metathesis of 2. Mes=methane sulfonate, Ts=toluene sulfonate, Cy=cyclohexyl.

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

“…[16][17][18] However, even after a single chromatography step the residual ruthenium in the final product in some cases is still too high 2-2400 ppm. 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).…”

Recent Advances in Alkene Metathesis

“…Jafarpour and coworkers [126] later prepared less-polymer-swelling-dependent analogues 79-81 bound to macroporous PS. We have developed the permanently immobilised catalyst 82, which was the first polymer-supported catalyst reported to be active across a range of metathesis reactions such as RCM, enyne CM and RRM [127]. Catalysts which incorporate readily modified Recent Advances in Alkene Metathesis 115 isopropoxybenzylidene ligands are ideal for adaptation to solid-phase catalysis; with variable catalyst physical properties obtainable depending on the particular solid support employed.…”

N-Heterocyclic carbenes as highly efficient ancillary ligands in homogeneous and immobilized metathesis ruthenium catalytic systems

“…Of the former type of ligand, N,N-dialkyls are found to have stronger metal-carbon bonds than the N,N-diaryls of a comparable size. Chiral 26 and immobilized 27 N-heterocyclic carbene ligands have opened new ways for creating modular catalytic systems of a high synthetic utility in organic chemistry. Along these lines, NHC structures 13-19 for NHC ligands reflect ubiquitously applied motifs in asymmetric catalysis: pinene-or camphor-derived chiral auxiliaries, oxazolines from optically active amino acids, atropisomerism in binaphthyl systems and the planar chirality of ferrocene.…”