Iron-catalyzed intermolecular [2π+2π] cycloaddition

Sarah K Russell; Emil Lobkovsky; Paul J Chirik

doi:10.1021/ja202992p

Iron-catalyzed intermolecular [2π+2π] cycloaddition

J Am Chem Soc. 2011 Jun 15;133(23):8858-61. doi: 10.1021/ja202992p. Epub 2011 May 20.

Authors

Sarah K Russell¹, Emil Lobkovsky, Paul J Chirik

Affiliation

¹ Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.

PMID: 21598972
DOI: 10.1021/ja202992p

Abstract

The bis(imino)pyridine iron dinitrogen compounds, ((iPr)PDI)Fe(N(2))(2) and [((Me)PDI)Fe(N(2))](2)(μ(2)-N(2)) ((R)PDI = 2,6-(2,6-R(2)-C(6)H(3)N═CMe)(2)C(5)H(3)N; R = (i)Pr, 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.