259268-91-2Relevant articles and documents
New indenylidene-type metathesis catalysts bearing unsymmetrical N-heterocyclic ligands with mesityl and nitrobenzyl substituents
Malinowska, Marta,Kozlowska, Mariana,Hryniewicka, Agnieszka,Witkowski, Stanis?aw,Morzycki, Jacek W.
, p. 1091 - 1100 (2016)
New indenylidene-type second generation catalysts bearing modified unsymmetrically substituted N- heterocyclic carbene ligands were synthesized. The com- plexes contain an N-mesityl and N?-nitrobenzyl substituted NHC ligand. The precursors of free carbenes—imidazolinium salts—were obtained in an easy and environment- friendly way (under aqueous or neat conditions). The new catalysts were prepared by reaction of in situ generated carbenes with a 1st generation indenylidene catalyst, containing pyridine ligands instead of tricyclohexylphosphine. The complexes were tested in RCM, CM, and ene-yne metathesis model reactions in commercial-grade solvents in air. Their activities were compared with that of commercially available indenylidene catalyst. The structures of complexes and their stability were investigated using static DFT calculations with mixed basis set.
Novel olefin metathesis ruthenium catalysts bearing backbone-substituted unsymmetrical NHC ligands
Paradiso, Veronica,Bertolasi, Valerio,Grisi, Fabia
, p. 5932 - 5935 (2014)
Stable Ru-based catalysts containing unsymmetrical N-heterocyclic carbene (NHC) ligands with phenyl substituents on the backbone in syn and anti stereochemical relationships have been easily prepared and fully characterized. Preliminary investigation reve
Synthesis of siloxy-modified second generation Hoveyda-Grubbs catalysts and their catalytic activity
Rogalski, Szymon,Pietraszuk, Cezary,Marciniec, Bogdan
, p. 3918 - 3922 (2009)
Efficient syntheses of the first ruthenium alkylidene complexes bearing siloxide ligands are described. Second generation Hoveyda-Grubbs catalyst is shown to undergo efficient functionalization with a number of potassium silanolates to give disiloxy deriv
Activated Hoveyda-Grubbs Olefin Metathesis Catalysts Derived from a Large Scale Produced Pharmaceutical Intermediate – Sildenafil Aldehyde
Monsigny, Louis,Pi?tkowski, Jakub,Trzybiński, Damian,Wo?niak, Krzysztof,Niena?towski, Tomasz,Kajetanowicz, Anna,Grela, Karol
supporting information, p. 4590 - 4604 (2021/08/13)
Two EWG-activated Hoveyda-Grubbs-type ruthenium complexes (Sil-II and Sil-II’) were obtained, characterized, and screened in a set of olefin metathesis reactions. These catalysts were conveniently synthesized from a commercially available pharmaceutical building block – Sildenafil aldehyde – in two steps only. Stability and catalytic activity tests disclosed that the bulkier NHC-ligand bearing catalyst Sil-II’ is visibly more stable and productive than its smaller NHC-analogue Sil-II. Good application profile of catalyst Sil-II’ was confirmed in a set of diverse metathesis reactions including ring-closing metathesis (RCM) and cross-metathesis (CM) of complex polyfunctional substrates of medicinal chemistry interest, including a challenging macrocyclization of the Pacritinib precursor. Compatibility of the new catalyst with various green solvents was checked and metathesis of Sildenafil and Tadalafil-based substrates was successfully conducted in acetone. The mechanism of Sil-II’ initiation has been investigated through kinetic experiments unveiling that the decrease of the steric hindrance of the chelating alkoxy moiety (from iPrO to EtO) favors the interchange initiation pathway over the typical dissociation pathway for other popular 2nd generation Hoveyda-Grubbs catalysts. (Figure presented.).
Compositions And Methods For Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis
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Paragraph 0172-0173; 0222-0223; 0235; 0238, (2020/04/29)
The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by v
