Journal of the American Chemical Society, Vol.136, No.41, 14401-14404, 2014
Pd-Catalyzed alpha-Arylation of Trimethylsilyl Enolates of alpha,alpha-Difluoroacetamides
We report the arylation and heteroarylation of alpha,alpha-difluoro-alpha-(trimethylsilyl)acetamides with aryl and heteroaryl bromides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)(2)Cy as ligand. A broad range of electronically varied aryl and heteroaryl bromides underwent this transformation to afford alpha-aryl-alpha,alpha-difluoroacetamides in high yields. Due to the electrophilicity of the fluorinated amide, this palladium-catalyzed cross-coupling reaction provides a versatile platform to generate a range of ?,?-difluoro carbonyl compounds, such as alpha-aryl-alpha,alpha-difluoroketones, -acetaldehydes, -acetates, and acetic acids, and difluoroalkyl derivatives, such as 2-aryl-2,2-difluoroethanols and -ethylamines, under mild conditions.