Organocuprate Cross-Coupling: The Central Role of the Copper(III) Intermediate and the Importance of the Copper(I) Precursor


  • Rapid Injection NMR in Mechanistic Organocopper Chemistry, part 4. For part 3, see reference [9]. NSF grants 0353061 and 0321056 supported this work. The authors thank D. Deadwyler for the fabrication and maintenance of the rapid-injection equipment, JEOL for their technical assistance, and J.P. Snyder for many helpful discussions.


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CuIIIin focus: The key intermediate in copper-mediated cross-coupling reactions has long been believed to be a “copper(III) intermediate”. Investigation of reactions of a variety of methyl Gilman reagents Me2CuLi⋅LiX with EtI using rapid-injection NMR spectroscopy conditions reveals a number of formally CuIII tetracoordinate square-planar intermediates (see scheme) with a surprising range of stabilities.