New, chiral 1,3,2-oxazaphospholidine-borane complexes rane complexes 5a-c. This is a further example of the utiliza3a-b and 8a-d were synthesized from the p-amino alcohols tion of the industrial waste material (all-R)-2-azabicyclola-b and 6a-d. The borane complexes 3, 8a, 8c, and 8d [3.3.0]octane-3-carboxylic acid. The catalytic efficiency of were allowed to react with different organolithium com-the chiral 1,3,2-oxazaphospholidine-borane complexes 3a, pounds and afforded the corresponding aminophosphane3b, and 8c was examined in the enantioselective borane reborane complexes 4a-c and 9a-g. Acid methanolysis of duction of some ketones.those complexes led to the formation of the phosphinite-boRhodium complexes of chiral phosphanes are important catalysts in the enantioselective homogeneous hydrogenation of C=C, C=N, and C=O bonds. Thus, rhodium-DI-PAMP catalysts are used for the technical synthesis of the pharmarcon (S)-Dopa [2]. Optically active phosphane ligands such as (o-methoxypheny1)methylphenylphosphane (PAMP) and 1,2-ethandiylbis[(o-methoxyphenyl)phenylphosphane] (DIPAMP) could easily be synthesized from the chiral methoxyphosphane-borane These enantiomerically pure alkoxyphosphane boranes could be prepared by diastereoselective synthesis of the 1,3,2-0xazapho-spholidine-borane complexes and their regio-and stereoselective ring opening with organolithium compounds.The application of an 1,3,2-oxazaphospholidine-borane complex as catalyst in the enantioselective borane reduction of prochiral ketones is known [4].In context with our studies of the utilization of industrial waste materials['], we used the enantiomerically pure P-aminoalcohol (all-R)-l[lal for the synthesis of the chiral methoxyphosphane-borane complexes 5a-b. This alcohol was prepared by the reduction of the nonutilizable enantiomerically pure (aZZ-R)-2-azabicyclo[3.3.0]octane-3-carboxylic acid benzyl ester, a waste material which was obtained in the synthesis of the ACE inhibitor ramiprilrSl by Hoechst AG.The diastereomerically pure 1,3,2-0xazaphospholidine (3S,4aR,6aR,7aR)-2 was prepared by the reaction of bis(diethy1amino)phenylphosphane with the bicyclic, rigid, proline-analogous p-amino alcohol. Treatment of (3S,4aR,6a-R,7aR)-2 with a solution of borane-THF complex afforded the diastereomerically pure 1,3,2-oxazaphospholidine-borane complex (3S,4aR,6aR,7aR)-3 which crystallized from methanol as colourless crystals.
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