Palladium‐Catalyzed Asymmetric Markovnikov Hydroxycarbonylation and Hydroalkoxycarbonylation of Vinyl Arenes: Synthesis of 2‐Arylpropanoic Acids

Abstract Asymmetric hydroxycarbonylation is one of the most fundamental yet challenging methods for the synthesis of carboxylic acids. Herein, we reported the development of a palladium‐catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom‐economical approach to an array of 2‐arylpropanoic acids including several commonly used non‐steroidal anti‐inflammatory drugs. The catalytic system has also enabled an asymmetric Markovnikov hydroalkoxycarbonylation of vinyl arenes with alcohols to afford 2‐arylpropanates. Mechanistic investigations suggested that the hydropalladation is irreversible and is the regio‐ and enantiodetermining step, while hydrolysis/alcoholysis is probably the rate‐limiting step.