Aminoferrocene lithiation by boron trifluoride activation
Costa Metallinos1, Josh Zaifman, Laura Dodge
1Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2S 3A1, Canada. cmetallinos@brocku.ca
Organic Letters
|July 18, 2008
Summary
Researchers developed a new method for direct C2-lithiation of aminoferrocenes. This approach provides efficient access to diverse organometallic compounds, potentially enabling asymmetric synthesis.
Area of Science:
- Organometallic Chemistry
- Synthetic Organic Chemistry
Background:
- Aminoferrocenes are valuable building blocks in organic synthesis.
- Existing methods for functionalizing aminoferrocenes often rely on carbon- or sulfur-based directing groups, which can be less efficient or versatile.
Purpose of the Study:
- To develop a novel and direct method for the C2-lithiation of monosubstituted aminoferrocenes.
- To explore the utility of BF3-complexation in directing regioselective functionalization of ferrocene derivatives.
Main Methods:
- Lithiation of BF3-complexed dimethylaminoferrocene using an organolithium reagent.
- Electrophilic quench of the lithiated intermediate to introduce various functional groups.
- Characterization of the resulting structurally diverse products.
Main Results:
- Exclusive C2-lithiation ortho to the dimethylamino group was achieved.
- Structurally diverse products were obtained in high yields (76-94%) after electrophile quench.
- This represents the first direct C2-lithiation of a monosubstituted aminoferrocene.
Conclusions:
- The developed method offers a rapid and complementary route to functionalized aminoferrocenes.
- This direct C2-lithiation strategy bypasses the need for traditional directing groups.
- The methodology holds promise as a precursor for developing asymmetric synthetic processes involving aminoferrocenes.
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