Abstract
In this work, we explore the reactivity induced by coordination of a CO molecule trans to the Ru-benzylidene bond of a prototype Ru-olefin metathesis catalyst bearing a N-heterocyclic carbene (NHC) ligand. DFT calculations indicate that CO binding to the Ru center promotes a cascade of reactions with very low-energy barriers that lead to the final crystallographically characterized product, in which the original benzylidene group has attacked the proximal aromatic ring of the ligand leading to a cycloheptatriene ring through a Buchner ring expansion. In conclusion, the overall mechanism is best described as a carbene insertion into a C-C bond of the aromatic N-substituent of the NHC ligand, forming a cyclopropane ring. This cyclopropanation step is followed by a Buchner ring expansion reaction, leading to the experimentally observed product presenting a cycloheptatriene ring.
Original language | English (US) |
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Pages (from-to) | 1-6 |
Number of pages | 6 |
Journal | THEORETICAL CHEMISTRY ACCOUNTS |
Volume | 131 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2012 |
Keywords
- Cyclopropanation
- Deactivation
- Homogeneous catalysis
- N-heterocyclic carbene
- Olefins metathesis
ASJC Scopus subject areas
- Physical and Theoretical Chemistry