Title | Dinuclear pincer-palladium(II) complexes and their use as homogeneous or heterogeneous catalyst for the aldol reaction of methyl isocyanoacetate. |
Publication Type | Journal Article |
Year of Publication | 2001 |
Authors | Gimenez, R, Swager, TM |
Journal | Journal of Molecular Catalysis A: Chemical |
Volume | 166 |
Pagination | 265–273 |
ISSN | 1381-1169 |
Keywords | dinuclear pincer palladium homogeneous heterogeneous catalyst prepn aldol isocyanoacetate |
Abstract | 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)] |
DOI | 10.1016/S1381-1169(00)00420-9 |