Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands
نویسندگان
چکیده
A straightforward synthesis utilizing the ring-opening metathesis polymerization (ROMP) reaction is described for acid-triggered N,O-chelating ruthenium-based pre-catalysts bearing one or two 8-quinolinolate ligands. The innovative pre-catalysts were tested regarding their behavior in ROMP and especially for their use in the synthesis of poly(dicyclopentadiene) (pDCPD). Bearing either the common phosphine leaving ligand in the first and second Grubbs olefin metathesis catalysts, or the Ru-O bond cleavage for the next Hoveyda-type catalysts, this work is a step forward towards the control of polymer functionalization and living or switchable polymerizations.
منابع مشابه
The catalytic performance of Ru–NHC alkylidene complexes: PCy3 versus pyridine as the dissociating ligand
The catalytic performance of NHC-ligated Ru-indenylidene or benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM), cross metathesis, and ring closing enyne metathesis (RCEYM) reactions is compared. While the PCy₃ complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all catalysts show similar activity ...
متن کاملStable ruthenium indenylidene complexes with a sterically reduced NHC ligand.
Stable and active Ru olefin metathesis catalyst 7 bearing a sterically reduced NHC ligand was synthesized. Upon action of pyridine, 7 forms complex 24, the first example of an Ru–indenylidene catalyst bearing a labile pyridine ligand and a sterically less demanding NHC ligand.
متن کاملChelated ruthenium catalysts for Z-selective olefin metathesis.
We report the development of ruthenium-based metathesis catalysts with chelating N-heterocyclic carbene (NHC) ligands that catalyze highly Z-selective olefin metathesis. A very simple and convenient procedure for the synthesis of such catalysts has been developed. Intramolecular C-H bond activation of the NHC ligand, promoted by anion ligand substitution, forms the appropriate chelate for stere...
متن کاملSynthesis of functionalised N-heterocyclic carbene ligands bearing a long spacer and their use in olefin metathesis.
A synthetic route to backbone functionalised imidazolinium salts-NHC ligand precursors has been developed. These tagged NHC ligands can be used to obtain a homogeneous Hoveyda-type catalyst (19) containing a quaternary ammonium group on a C-8 long spacer. Products of olefin metathesis reactions promoted by complex 19 can be readily purified from Ru-residues by filtration of the reaction mixture...
متن کاملRu-Based Z-Selective Metathesis Catalysts with Modified Cyclometalated Carbene Ligands.
A series of cyclometalated Z-selective ruthenium olefin metathesis catalysts with alterations to the N-heterocyclic carbene (NHC) ligand were prepared. X-Ray crystal structures of several new catalysts were obtained, elucidating the structural features of this class of cyclometalated complexes. The metathesis activity of each stable complex was evaluated, and one catalyst, bearing geminal dimet...
متن کامل