Asymmetric hydroformylation using homogeneous and polymer-bound chiral platinum catalysts
Abstract
The PtCl2–SnCl2 complexes of the chiral ligands (4R, 5R)-2,2-dimethyl-4,5-bis (diphenylphosphinomethyl)-1,3-dioxolan [(–)-DIOP] and its bis(dibenzophosphole) analogue (–)-DBP-DIOP were employed as catalysts in homogeneous asymmetric hydroformylations of styrene, and high optical yields (ca. 94%) were obtained, the polymer-bound (–)-DIOP–PtCl2–SnCl2 giving optical yields of 25–30%; the rates, branched:normal isomer ratios, and optical yields were dependent on the gas pressure, H2:CO ratio, and temperature.