American Chemical Society
ja202992p_si_002.cif (18.25 kB)

Iron-Catalyzed Intermolecular [2π + 2π] Cycloaddition

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posted on 2011-06-15, 00:00 authored by Sarah K. Russell, Emil Lobkovsky, Paul J. Chirik
The bis(imino)pyridine iron dinitrogen compounds, (iPrPDI)Fe(N2)2 and [(MePDI)Fe(N2)]22-N2) (RPDI = 2,6-(2,6-R2-C6H3NCMe)2C5H3N; R = iPr, Me), promote the catalytic intermolecular [2π + 2π] cycloaddition of ethylene and butadiene to form vinylcyclobutane. Stoichiometric experiments resulted in isolation of a catalytically competent iron metallocycle intermediate, which was shown to undergo diene-induced C–C reductive elimination. Deuterium labeling experiments establish competitive cyclometalation of the bis(imino)pyridine aryl substituents during catalytic turnover.