Two new bimetallic Pd complexes I (R = t-Bu, Ph) have been synthesized and characterized and their catalytic activity checked for the aldol reaction of aldehydes with Me isocyanoacetate. Each palladium atom is coordinated to an SCS-type ligand and the two pincer units are linked by a chiral spacer. The catalytic aldol reaction of Me isocyanoacetate with aldehydes proceeds quickly but no significant diastereoselectivity and enantioselectivity is found. The comparison with a homologous mononuclear Pd complex shows no differences with the bimetallic compds., concluding that there is no cooperativity between the metal centers. Two silica-supported catalysts prepd. with a bimetallic compd. show catalytic activity with very minor enantioselectivity. [on SciFinder(R)]
