Insights into the Decomposition of Olefin Metathesis Precatalysts

• Published in: Angewandte Chemie International Edition Vol. 53; no. 34; pp. 8995 - 8999
• Main Authors: Manzini, Simone, Poater, Albert, Nelson, David J., Cavallo, Luigi, Slawin, Alexandra M. Z., Nolan, Steven P.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 18-08-2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Decomposition; Decomposition reactions; density functional calculations; Density functional theory; Formations; hydride ligands; Isopropyl alcohol; Ligands; Mathematical analysis; Metathesis; Olefins; reaction mechanisms; ruthenium; reaction mechanisms; density functional calculations; ruthenium; hydride ligands; metathesis
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201403770

The decomposition of a series of benzylidene, methylidene, and 3‐phenylindenylidene complexes has been probed in alcohol solution in the presence of base. Tricyclohexylphosphane‐containing precatalysts are shown to yield [RuCl(H)(H2)(PCy3)2] in isopropyl alcohol solutions, while 3‐phenylindenylidene complexes lead to η5‐(3‐phenyl)indenyl products. The potential‐energy surfaces for the formation of the latter species have been probed using density functional theory studies.
Ligands make a difference: The decomposition of olefin metathesis precatalysts in isopropyl alcohol leads to a series of differing complexes. Bis(tricyclohexylphosphane)‐bearing complexes decompose to yield [RuCl(H)(H2)(PCy3)2], while bis(triphenylphosphane) and bis(iBu‐Phoban)‐bearing indenylidene complexes yield η5‐(3‐phenyl)indenyl complexes. The (3‐phenyl)indenylidene to η5‐indenyl rearrangement for three complexes has been probed using DFT calculations.