Effect of acid catalysis on the direct electrophilic fluorination of ketones, ketals, and enamides using Selectfluor™
作者:Jack Liu、Johann Chan、Craig M. Bryant、Petar A. Duspara、Ernest E. Lee、David Powell、Hua Yang、Ziping Liu、Chris Walpole、Edward Roberts、Robert A. Batey
DOI:10.1016/j.tetlet.2012.03.074
日期:2012.6
The fluorination of ketones, ketals, and enamides has been achieved using the electrophilic fluorinating reagent Selectfluor™ (F-TEDA-BF4). For the reactions of ketones and ketals the use of sulfuric acid (0.1 equiv) as an additive was found to facilitate the reaction leading to more rapid product formation. This behavior is analogous to the known effects of acid catalysis on the bromination of ketones
使用亲电子氟化试剂Selectfluor™(F-TEDA-BF 4)。对于酮和缩酮的反应,发现使用硫酸(0.1当量)作为添加剂有助于反应,从而导致更快的产物形成。该行为类似于酸催化作用对酮的溴化的已知作用。反应通常具有很高的选择性,导致形成单氟化产物,并且可以使用基于N-保护的哌啶酮的底物以高达85 mmol的反应规模完成反应。在MeOH存在下的反应取决于底物导致相应的氟代酮或氟代缩酮的形成。以这种方式形成氟代缩酮以及环状酰胺的氟化是多组分偶联反应的实例。