Selective Functionalization of Chiral Ferrocenyl Acetals. Easy Access to Various Tri- and Tetrasubstituted Ferrocenes with Controlled Geometry

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• 作者：Jé ; rô ; me Chiffre ; Yannick Coppel ; Gilbert G. A. Balavoine ; Jean-Claude Daran ; and Eric Manoury
• 刊名：Organometallics
• 出版年：2002
• 出版时间：October 14, 2002
• 年：2002
• 卷：21
• 期：21
• 页码：4552 - 4555
• 全文大小：112K
• 年卷期：v.21,no.21(October 14, 2002)
• ISSN：1520-6041

文摘

The lithiation of 2-substituted chiral dioxane2, followed by electrophilic trapping of the lithiatedintermediate, yields various 1,5-disubstitued acetals withgood yields and excellent control of the geometry. Theseacetals can be easily hydrolyzed into various 1,5-disubstitued ferrocenecarboxaldehydes (in an enantiomericallypure form if the two substituents are different), whichcan be furthermore substituted on the other Cp ring toyield unprecedented 2,5,1'-ferrocenecarboxaldehydes (inan enantiomerically pure form if they are chiral). Thethree substituents on ferrocenecarboxaldehyde can bedifferent: this is, to the best of our knowledge, the firstexample of enantiomerically pure 1,2,3,1'-tetrasubstituted ferrocene with planar chirality only.