title: Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity.
abstract: Two ruthenium olefin metathesis initiators featuring electronically modified quinoline-based chelating carbene ligands are introduced. Their reactivity in RCM and ROMP reactions was tested and the results were compared to those obtained with the parent unsubstituted compound. The studied complexes are very stable at high temperatures up to 140 °C. The placement of an electron-withdrawing functionality translates into an enhanced activity in RCM. While electronically modified precatalysts, which exist predominantly in the trans-dichloro configuration, gave mostly the RCM and a minor amount of the cycloisomerization product, the unmodified congener, which preferentially exists as its cis-dichloro isomer, shows a switched reactivity. The position of the equilibrium between the cis- and the trans-dichloro species was found to be the crucial factor governing the reactivity of the complexes.
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Żukowska
authors.affiliation: Institute of Chemistry and Technology of Materials, Graz University of Technology, NAWI Graz, Stremayrgasse 9, 8010 Graz, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Pump
authors.affiliation: Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089; Warszawa, Poland.
authors.forename: Aleksandra E
authors.initials: AE
authors.lastname: Pazio
authors.affiliation: Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089; Warszawa, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Woźniak
authors.affiliation: Kaust Catalysis Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Luigi
authors.initials: L
authors.lastname: Cavallo
authors.affiliation: Institute of Chemistry and Technology of Materials, Graz University of Technology, NAWI Graz, Stremayrgasse 9, 8010 Graz, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Slugovc
keywords: DFT calculations; olefin metathesis; ring closing metathesis; ring-opening metathesis polymerisation; ruthenium