Highly Selective Palladium‐Catalyzed Direct CH α‐Monoarylation of Carbonyl Compounds using Water Containing the Surfactant Polyoxyethylene‐α‐Tocopheryl Sebacate (PTS) as a Solvent

Highly selective direct CH α‐monoarylation reactions of 4‐chromanones, ketones and 2‐phenylacetaldehyde with aryl halides have been performed in satisfactory yields by using a tris(dibenzylideneacetone)dipalladium(0)/tri‐tert‐butylphosphine tetrafluoroborate catalyst system, potassium bicarbonate as the base and a solvent consisting of pure water containing a small amount of polyoxyethylene‐α‐tocopheryl sebacate (PTS). Analogous reaction conditions have been employed in a tandem process leading to phenyl‐substituted isocoumarins from carbonyl compounds and methyl 2‐bromobenzoate.