new and simple one-pot procedure for the palladium-catalyzedintermolecular α-arylation of esters is described. A number of esters can be functionalized with a wide range of aryl bromides using Pd(OAc)2 or Pd2(dba)3 and bulky electron-rich o-biphenyl phosphines 1−3. Under the reaction conditions, using LiHMDS as base, α-arylation proceeds at roomtemperature or at 80 °C with very good yields and high
Palladium-Catalyzed α-Arylation of Esters with Chloroarenes
作者:Takuo Hama、John F. Hartwig
DOI:10.1021/ol800258u
日期:2008.4.1
Palladium-catalyzed alpha-arylations of esters with chloroarenes are reported. The reactions of chloroarenes with the sodium enolates of tert-butyl propionate and methyl isobutyrate occur in high yields with 0.2-1 mol % of [P(t-Bu)3]PdBr}2 or the combination of Pd(dba)2 and P(t-Bu)3 as catalyst. The reactions of chloroarenes with the Reformatsky reagent of tert-butylacetate were most challenging but occurred