Alkyne gem-Hydrogenation: Formation of Pianostool Ruthenium Carbene Complexes and Analysis of Their Chemical Character

Tobias Biberger; Christopher P Gordon; Markus Leutzsch; Sebastian Peil; Alexandre Guthertz; Christophe Copéret; Alois Fürstner

doi:10.1002/anie.201904255

Alkyne gem-Hydrogenation: Formation of Pianostool Ruthenium Carbene Complexes and Analysis of Their Chemical Character

Angew Chem Int Ed Engl. 2019 Jun 24;58(26):8845-8850. doi: 10.1002/anie.201904255. Epub 2019 May 17.

Authors

Tobias Biberger¹, Christopher P Gordon², Markus Leutzsch¹, Sebastian Peil¹, Alexandre Guthertz¹, Christophe Copéret², Alois Fürstner¹

Affiliations

¹ Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany.
² Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland.

PMID: 31025788
DOI: 10.1002/anie.201904255

Abstract

Parahydrogen (p-H₂ ) induced polarization (PHIP) NMR spectroscopy showed that [Cp^X Ru] complexes with greatly different electronic properties invariably engage propargyl alcohol derivatives into gem-hydrogenation with formation of pianostool ruthenium carbenes; in so doing, less electron rich Cp^X rings lower the barriers, stabilize the resulting complexes and hence provide opportunities for harnessing genuine carbene reactivity. The chemical character of the resulting ruthenium complexes was studied by DFT-assisted analysis of the chemical shift tensors determined by solid-state ¹³ C NMR spectroscopy. The combined experimental and computational data draw the portrait of a family of ruthenium carbenes that amalgamate purely electrophilic behavior with characteristics more befitting metathesis-active Grubbs-type catalysts.

Keywords: NMR spectroscopy; carbene complexes; chemical shift tensors; parahydrogen; ruthenium.

Abstract

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