The phenol countdown: Novel imidazole‐based phosphineligands are synthesized on scales up to 100 g by a convenient lithiation–phosphorylation method. The phosphines are stable towards air and moisture and are successfully applied as ligands in the palladium‐catalyzed selectivehydroxylation of arylhalides (see scheme, dba=dibenzylideneacetone).
Palladium-Catalyzed Hydroxylation of Aryl Halides under Ambient Conditions
作者:Alexey G. Sergeev、Thomas Schulz、Christian Torborg、Anke Spannenberg、Helfried Neumann、Matthias Beller
DOI:10.1002/anie.200902148
日期:2009.9.28
temperature Pd‐catalyzed synthesis of phenols from aryl bromides and chlorides is presented. Stoichiometric studies of Pd‐mediated hydroxylation of arylhalides employing a bulky imidazolyl‐phosphine ligand and the novel palladium precursor [Pd(cod)(CH2SiMe3)2] led to development of efficient catalytic synthesis of phenols underambientconditions (see scheme; Ad=adamantyl, cod=1,5‐cyclooctadiene)
降低热量:介绍了第一种室温下Pd催化的由芳基溴化物和氯化物合成苯酚的方法。使用笨重的咪唑基膦配体和新型钯前体[Pd(cod)(CH 2 SiMe 3)2 ]进行的钯介导的芳基卤化物羟基化反应的化学计量研究导致了在环境条件下高效催化合成苯酚的过程(参见方案) ; Ad =金刚烷基,cod = 1,5-环辛二烯)。