Metal‐ and Reagent‐Free Highly Selective Anodic Cross‐Coupling Reaction of Phenols
作者:Bernd Elsler、Dieter Schollmeyer、Katrin Marie Dyballa、Robert Franke、Siegfried R. Waldvogel
DOI:10.1002/anie.201400627
日期:2014.5.12
The direct oxidative cross‐coupling of phenols is a very challenging transformation, as homo‐coupling is usually strongly preferred. Electrochemical methods circumvent the use of oxidizing reagents or metal catalysts and are therefore highly attractive. Employing electrolytes with a high capacity for hydrogen bonding, such as methanol with formic acid or 1,1,1,3,3,3‐hexafluoro‐2‐propanol, a direct
苯酚的直接氧化交叉偶联是非常具有挑战性的转化,因为通常强烈优选均相偶联。电化学方法避免了氧化剂或金属催化剂的使用,因此极具吸引力。使用具有高氢键结合能力的电解质,例如甲醇与甲酸或1,1,1,1,3,3,3-六氟-2-丙醇,在不分隔的电池中直接电解可提供混合的2,2'-双酚具有高选择性。这种温和的方法可耐受各种部分,例如叔丁基,叔丁基与其他强亲电介质不相容,但对于随后催化成型产物的应用至关重要。