Cationic acetylacetonate palladium complexes/boron trifluoride etherate catalyst systems for hydroamination of vinylarenes using arylamines

A simple and solvent-free protocol using cationic acetylacetonate palladium complexes with mono-/bidentate phosphine ligands activated with BF3·OEt2 as in situ-formed catalyst for hydroamination of vinylarenes with arylamines have been developed. Excellent catalytic activities were obtained using [Pd(acac)(PPh3)2][BF4]/BF3·OEt2/i-PrOH catalyst system with the addition of a small amount of palladium (0.2-0.05 mol%) to the reaction mixture. Furthermore, the novel unexpected diphosphine-bridged palladium complexes have been prepared and characterized: [Pd(acac)(dpppt)]2[BF4]2 and [Pd(acac)(dpph)]2[BF4]2 (dpppt - 1,5-bis(diphenylphosphino)pentane, dpph - 1,6-bis(diphenylphosphino)hexane)