70028-19-2Relevant academic research and scientific papers
Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions
Breitenfeld, Jan,Ruiz, Jesus,Wodrich, Matthew D.,Hu, Xile
, p. 12004 - 12012 (2013)
Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N 2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the oxidative addition of alkyl halide. The catalysis is second-order in Grignard reagent, first-order in catalyst, and zero-order in alkyl halide. A transient species, [(N2N)Ni-alkyl 2](alkyl2-MgCl), is identified as the key intermediate responsible for the activation of alkyl halide, the formation of which is the turnover-determining step of the catalysis.
