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[摘要]：The hemilabile ligand 1-((2R,5R)-2,5-dimethyl-1-oxophospholan-1-yl)-2-((2R,5R)-2,5-dimethyl phospholan-1-yl)benzene has proven to be a successful ligand for the Cu-catalyzed addn. of diethylzinc to N-phosphinoylimines. The and enantiomeric ratios (19.0:1 to 99.0:1 er). This paper describes a general structure/selectivity study in which the three ligand subunits (chiral phospholane-linker-labile coordinating group) are systematically modified and tested in the Cu-catalyzed addn. of diethylzinc to the N-phosphinoylimine derived from benzaldehyde. This study led to the discovery of a new class of effective chiral ligands that combine a chiral phospholane unit and an achiral phosphine oxide, e.g. (2R,5R)-1-[2-[bis(4-methoxyphenyl)phosphoryl]phenyl]-2,5-dimethylpho spholane. The crystal and mol. structures of 2-((2R,5R)-2,5-dimethyl-1-oxophospholan-1-yl)-3-((2R,5R)-2,5-dimethyl phospholan-1-yl)benzothiophene and (5R)-1-[2-((2R,5R)-2,5-dimethylphospholan-1-yl)phenyl]-2,2,5-trimethylp hospholane 1-oxide were detd. by x-ray crystallog. |
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