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Asymmetric Aldol Reaction Using Bis-ProPhenol Ligands

By: William Sommer, Aldrich ChemFiles 2008, 8.6, 10.

Aldrich ChemFiles 2008, 8.6, 10.

The aldol reaction is an important tool for the synthesis of complex molecules. However, the chemo- and regioselectivity of this reaction is usually poor. In view of these challenges, Trost and co-workers developed a new ligand capable of performing aldol reactions enantioselectively.1 The approach taken by the researchers was to look at the different requirements for a good catalyst for asymmetric transformations. The final structure of the catalyst is a semi-crown complex which allows good chiral recognition as well as a path for easy exchange of product. The ligand structure is based on a p-cresol backbone. To probe the activity of the ligand, various aldehydes were reacted with various aryl ketones with overall good yields and excellent selectivity (Scheme 1).


Scheme 1.

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Materials

     

References

  1. Trost, B. M. et al. J. Am. Chem. Soc. 2000, 122, 12003.

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