Arylation of Phenols. Convenient, Regiospecific Methods for Mono- or Bis-<i>p</i>-fluorophenylations, Suitable for Large Scale Syntheses
作者:Heiner Jendralla、Li-Jian Chen
DOI:10.1055/s-1990-27028
日期:——
Phenols have been arylated by a palladium(0)-catalyzed coupling reaction. Two methods were used: a Grignard reagent of a protected phenol component 2 was coupled with a haloarene, or an umpolung (reversed reactivity) where unprotected phenolic halides 6 were coupled with aryl Grignard reagents. Bis-arylation and regiospecific ortho-, meta- and para-arylations were achieved. Aryl-aryl couplings were insensitive to steric hindrance in the Grignard component, but were inhibited by sulfur-containing substituents in the phenolic component. A thiocyanate substituted biaryl was used to synthesize arylated phenols with various sulfur functionalities.
苯酚通过钯(0)催化的偶联反应实现了芳基化。使用了两种方法:一种是将受保护的苯酚成分 2 的格氏试剂与卤代烃偶联,另一种是将未受保护的酚卤化物 6 与芳基格氏试剂偶联的umpolung(反向反应)。在此过程中,实现了双芳基化和特定区域的正芳基化、偏芳基化和对位芳基化。 芳基-芳基偶联对格氏试剂中的立体阻碍不敏感,但会受到酚类试剂中含硫取代基的抑制。硫氰酸盐取代的双芳基被用来合成具有各种硫官能团的芳基化苯酚。