A computational study of structures and catalytic activities of Hoveyda-Grubbs analogues bearing coumarin or isopropoxycoumarin moiety

• Published in: Catalysis communications Vol. 91; pp. 43 - 47
• Main Authors: Trzaskowski, B., Ostrowska, K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-03-2017
• Subjects: Coumarins; DFT; Hoveyda-Grubbs catalyst; Olefin metathesis; Ruthenium; Coumarins; DFT; Ruthenium; Olefin metathesis; Hoveyda-Grubbs catalyst
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2016.12.014

The DFT/M06-D3 method was used to investigate structures and activation free energies for a series of Hoveyda-Grubbs-like catalysts with the isopropoxybenzene part replaced by coumarin (2H-chromen-2-one) and ten derivatives of isopropoxycoumarin. Out of ten investigated isopropoxycoumarin derivatives two show free enthalpies of initiation around 3–5kcal/mol lower than the Hoveyda-Grubbs catalyst and free enthalpies of the catalytic cycle around 2–3kcal/mol lower than the Hoveyda-Grubbs suggesting fast initiation. Additionally, correlations between the initiation free enthalpies and ruthenium-oxygen bond strengths as well as natural partial charges on carbene carbon atom have been found, described and rationalized.
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•A series of Hoveyda-Grubbs-like catalysts substituted with coumarin derivatives is studied.•Unsubstituted coumarin chelation of ruthenium is relatively weak.•Selected isopropoxycoumarin derivatives of Ru complexes are good candidates for catalysts.•Correlation between catalysts' initiation rates and RuO bond strengths is found.