A Ligand-Enabled Palladium-Catalyzed Highly para-Selective Difluoromethylation of Aromatic Ketones
Guangliang Tu, Chunchen Yuan, Yuting Li, Jingyu Zhang, and Yingsheng Zhao*（赵应声）
Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry Chemical Engineering and Materials Science, Soochow University Suzhou 215123 (P. R. China)
Angew. Chem. Int. Ed. 2018, 57, 15597 --15601
A practical and highly para‐selective C−H difluoromethylation of aromatic ketones has been developed by employing tetrakis(triphenylphosphine)palladium(0) as the catalyst and triphenylphosphine as the ligand. In addition to general aromatic ketones, this transformation was compatible with bioactive compounds and well‐known drugs, such as oxybenzone, ketoprofen, zaltoprofen, and propafenone. Moreover, a mechanistic study revealed that a palladium intermediate coordinated by a carbonyl group promotes highly para‐selective difluoromethylation.