Highly efficient Heck reactions of aryl bromides with n-butyl acrylate mediated by a palladium/phosphine-imidazolium salt system.
[reaction: see text] A new phosphine-imidazolium salt, L.HBr (1, L = (1-ethylenediphenylphosphino-3-(mesityl))imidazol-2-ylidene), has been prepared. A combination of 0.5 mol % of Pd(dba)(2) and 0.5 mol % of L.HBr in the presence of 2 equiv of Cs(2)CO(3) as base has proven to be highly efficient in the Heck coupling reactions of aryl bromides (from electron-deficient to electron-rich aryl bromides) with n-butyl acrylate.
Yang
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Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA.
Lee
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HM
Nolan
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