Stepwise Ethene and/or Methyl Acrylate/CO Insertions into the Pd−C Bond of Cationic Palladium(II) Complexes Stabilized by a (P,O) Chelate

Early intermediates along the stepwise multi-insertions of CO, ethene, or methyl acrylate into the palladium–carbon bond of cationic palladium(II) complexes such as 1, which is stabilized by a P,O chelate, have been isolated under ambiant conditions. The crystallographically characterized CO–ethene coupling product 2 reversibly inserts further CO to give the isolated intermediate 3 (not shown), which affords 4 or 5 upon insertion of ethene or methyl acrylate, respectively.