Reactivity of Metal Carbenes with Olefins: Theoretical Insights on the Carbene Electronic Structure and Cyclopropanation Reaction Mechanism

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)

Abstract

© 2018 American Chemical Society. Present work addresses the reactivity of several phenyl-substituted metal-carbene complexes with 4-methylstyrene by means of density functional theory OPBE simulations. Different paths that lead to cyclopropanation were explored and compared to the olefin metathesis mechanism. For this purpose, we chose four different catalysts: (i) the Grubbs second-generation olefin metathesis catalyst, (ii) a Grubs second-generation-like complex, in which ruthenium is replaced by iron, and (iii) two iron carbene complexes (a piano stool and a porphyrin iron carbene) that experimentally catalyze alkene cyclopropanation. Results suggest that the nature of the applying mechanism is very sensitive to the coordination around the metal center and the spin state of the metal-carbene complex. Cyclopropanation by open-shell metal-carbene complexes seems to preferentially proceed through a two-step radical mechanism, in which the two C-C bonds are sequentially formed (path C). Singlet-state carbenes proceed either through a direct attack of the olefin to the carbene (path D) when the formation of the metallacycle is not feasible or through a reductive elimination from the metallacyclobutane when this intermediate is accessible both kinetically and thermodynamically (path B).
Original languageEnglish
Pages (from-to)1702-1712
JournalJournal of Physical Chemistry A
Volume122
Issue number6
DOIs
Publication statusPublished - 15 Feb 2018

Fingerprint Dive into the research topics of 'Reactivity of Metal Carbenes with Olefins: Theoretical Insights on the Carbene Electronic Structure and Cyclopropanation Reaction Mechanism'. Together they form a unique fingerprint.

Cite this