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

Journal article

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.

Authors: Boulho, C; Oulié, P; Vendier, L; Etienne, M; Pimienta, V

• Publication status: Published
• Journal: Journal of the American Chemical Society
• Volume: 132
• Issue: 40
• Pages: 14239-14250
• Publication date: 2010-10-01
• DOI: 10.1021/ja1061505
• EISSN: 1520-5126
• ISSN: 0002-7863
• Language: English