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。