“Second Generation” Ruthenium Carbene Complexes with a cis-Dichloro Arrangement

Abstract

The synthesis, characterization, and catalytic activity of a series of unprecedented ruthenium-based metathesis catalysts bearing a cis-dichloro arrangement, an N-heterocyclic carbene, and a chelating carbene ligand derived from 2-vinylbenzaldehyde or 2-vinylbenzoic acid ester are presented.

New Indenylidene‐Schiff Base‐Ruthenium Complexes for Cross‐Metathesis and Ring‐Closing Metathesis

“…This would be a good choice when commercial polymerization technology requires a latent catalyst. [42][43][44] Most metathesis catalysts are operative at room temperature and are therefore not well suited for applications where catalyst latency is beneficial.…”

A latent s‐chelated ruthenium benzylidene initiator for ring‐opening metathesis polymerization

“…A few examples of thermally latent ROMP initiators can be found in the literature. For instance, a Ru complex featuring a chelating carbene ligand derived from 2-vinylbenzaldehyde developed by Slugovc et al 9 efficiently polymerized norbornene derivatives 10 at elevated temperatures, although total inactivity at room temperature could not be achieved. The first examples of thermally triggered ROMP initiators, that showed no activity in solution at room temperature for prolonged periods, were achieved by quinoline-and quinoxaline-chelated Ru complexes, 11 although in this case relatively high polydispersities ([2) were obtained together with very high molecular weights.…”

Cationic versus Neutral RuIIN‐Heterocyclic Carbene Complexes as Latent Precatalysts for the UV‐Induced Ring‐Opening Metathesis Polymerization

“…In contrast to most of the other ruthenium complexes, the two chloro ligands in compound 4 b are in a cis arrangement. Bond lengths and angles ( Figure 1) are in the usual range, [13,15] with the exception of Ru À Cl(2) that is positioned trans to the NHC ligand, which is longer than in comparable complexes reported in literature (253.44 (9) vs. 236.62 pm). [15] Reaction of complex […”