Unsymmetric bidentate ligands in metal-catalyzed carbonylation of alkenes.
Characteristic features of unsymmetric bidentate ligands, in which the two coordination atoms are not equivalent, are reviewed with a focus on their use in metal-catalyzed olefin carbonylations. High enantioselectivity for a variety of substrates was achieved using ligand 9 in Rh-catalyzed hydroformylation. Unsymmetric ligand 21e shows high productivity accompanied by high regio- and enantioselectivities in the Pd-catalyzed alternating copolymerization of 1-alkene with CO. The advantages of electronic unsymmetry are demonstrated especially in the spectroscopic observation of single steps involved in catalytic cycles.
Nozaki
Kyoko
K
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. nozaki@chembio.t.u-tokyo.ac.jp