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C-H bond activation of benzene by unsaturated η2-cyclopropene and η2-benzyne complexes of niobium.

06:00 EDT 23rd September 2010 | BioPortfolio

Summary of "C-H bond activation of benzene by unsaturated η2-cyclopropene and η2-benzyne complexes of niobium."

We report the synthesis of a niobium cyclopropyl complex, Tp(Me2)NbMe(c-C(3)H(5))(MeCCMe), and show that thermal loss of methane from this compound generates an intermediate that is capable of activating both aliphatic and aromatic C-H bonds. Isotopic labeling, trapping studies, a detailed kinetic analysis, and density functional theory all suggest that the active intermediate is an η(2)-cyclopropene complex formed via β-hydrogen abstraction rather than an isomeric cyclopropylidene species. C-H activation chemistry of this type represents a rather unusual reactivity pattern for η(2)-alkene complexes but is favored in this case by the strain in the C(3) ring which prevents the decomposition of the key intermediate via loss of cyclopropene.

Affiliation

CNRS, Laboratoire de Chimie de Coordination, 205 Route de Narbonne, F-31077 Toulouse, France.

Journal Details

This article was published in the following journal.

Name: Journal of the American Chemical Society
ISSN: 1520-5126
Pages: 14239-50

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