Abstract
Platinum and palladium chiral bisphosphine complexes and their counterion effects in asymmetric Diels−Alder reactions have been investigated. The reaction of cyclopentadiene and various bidentate dienophiles in the presence of a catalytic amount of Pt(II)− or Pd(II)−BINAP complex proceeds with excellent endo/exo selectivity as well as endo enantioselectivity (up to 99% ee).