C O M M U N I C A T I O N S
THF ligands of 7 by the incoming indenyl ligands,11 more detailed
studies will be required to understand the origin of stereocontrol
in these reactions.
The methodology described here should be useful for the
enantioselective synthesis of other bis-indenyl metallocenes and has
the advantage that both enantiomers are available by using either
R,R- or S,S-7. Tuning the steric interactions between the chiral bis-
amide directing ligand and the metallocene framework by variation
of the C1, C3, and N-substituents should enable broad application
of this strategy.6b
Acknowledgment. This work was supported by the National
Science Foundation (CHE-0212210). We thank Dr. Ian Steele for
X-ray structure determinations.
Supporting Information Available: Experimental procedures and
characterization data for new compounds (PDF); X-ray crystallographic
data for R,R-7, S,S,R,R-9a, S,S-10b, and R,R-12 (CIF). This material
References
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Figure 1. Molecular structure and space-filling view of S,S,R,R-9a. H atoms
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Figure 2. Molecular structures of R,R-7 (top) and R,R-12 (bottom). H atoms
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indicates that the chelate rings are flexible. Given the potential
complexity of the mechanism of substitution of the chloride and
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