title: Mechanism of rhodium-catalyzed cyclopropanation/cyclization of allenynes.
abstract: The rhodium-catalyzed cyclopropanation/cyclization of allenynes was investigated by means of DFT calculations. The results show that the cyclopropanation via the proposed stepwise C(sp(3))-H activation (σ-bond metathesis/C-H reductive elimination) was kinetically unfavorable. Instead, a concerted C(sp(3))-H activation pathway, namely the metal-assisted σ-bond metathesis, in which the hydrogen was directly transferred to the rhodacyclopentane assisted by the Rh center followed by a C-C reductive elimination, was found to explain the experimental results.
authors: Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P. R. China.
authors: Genping
authors: G
authors: Huang