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A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
[2+2] Cycloadditions with an Iron Carbene: A Critical Step in Enyne Metathesis
Melissa R Hoffbauer1, Vlad M Iluc1
1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
Abstract:
Ruthenium carbenes, famously used in olefin metathesis, have impacted numerous research areas, ranging from synthesis to materials and biology. Although in the same group as ruthenium, iron carbenes showing similar reaction patterns have not been reported. Such targets are of high interest because the use of a sustainable metal would lead to a decreased cost, toxicity, and environmental impact of the corresponding compounds. Herein, we report the synthesis of an iron carbene complex, [{PC(sp2)P}Fe(N2)(PMe3)] ([PC(sp2)P] = (bis[2-(di-isopropylphosphino)phenyl]methylene), which is capable of performing [2+2] cycloaddition reactions in the presence of alkynes. Specifically, η3-vinyl carbenes are formed stoichiometrically through a [2+2] cycloaddition between the alkyne and the metal carbene. Additional reactivity of the η3-vinyl carbenes with alkynes yields a second insertion product containing a new iron carbene moiety.
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