| 摘要 |
The present invention is concerned with a novel process for the racemization of atropisomeric bis(phosphine oxide) compounds of formula I SEE FORMULA 1 in their (S) or (R) or non-racemic form, for the preparation of optical acti ve bisphosphine ligands, which form optical active complexes with transition metals. These complexes are used as catalysts in a number of asymmetric reactions. The racemization is thermal and carried out in high or low boiling solvent, under normal or elevated pressure at 10 5 to 3.5x10 7 Pa. The heating is performed in a system which allows heating up to 400.degree.C (reactor, autoclave, aluminum block, round - bottom flask with heating/stirring mantle and the like) or by microwave irradiation or in the melt at a temperature from 260 to 400.degree.C, preferably from 280 to 380.degree.C, batchwise or in a continuous manner.
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