| 摘要 |
The chiral catalyst of general structure 1, or its enantiomer <IMAGE> 1 is prepared by treating the corresponding N-carboxy anhydride of structure 2 <IMAGE> 2 with an aryl metal, especially a phenyl metal such as an aryl magnesium halide, aryl lithium, aryl zinc or aryl cesium, to form a 1,1-diaryl- methanol of structure 3 <IMAGE> 3 followed by treatment with a compound of structure, 4 <IMAGE> 4 The catalyst, wherein R is aromatic, is novel and in some cases superior to the catalyst wherein R is alkyl or aralkyl in directing the chirality of diborane, borane-dimethyl sulfide or borane-tetrahydrofuran reductions of ketones to secondary alcohols.
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