Stereoselective transformations with configurationally labile alpha-phenylselenoalkyllithium compounds

被引:37
作者
Hoffmann, RW
Klute, W
机构
关键词
asymmetric alkylations; chiral auxiliaries; kinetics; organolithium compounds; stereoselective syntheses;
D O I
10.1002/chem.19960020614
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Complexation of the configurationally labile alpha-phenylselenoalkyllithium compound 8 with 1,2-bisdimethylaminocyclohexane 15 led to two diastereomeric complexes 13 and 14 in a 7:3 ratio. Owing to ligand acceleration the complexes 13 and 14 added more rapidly to benzaldehyde than the uncomplexed organolithium compound 8. Trapping of complexes 13 and 14 by benzaldehyde was shown to occur more rapidly than their equilibration. This corresponds to non-Curtin-Hammett kinetics, in which enantiomeric enrichment in the products reflects the equilibrium ratio of the complexes 13 and 14.
引用
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页码:694 / 700
页数:7
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