A class of zinc (II) chelates with chiral tertiary amino phenolic alcohols serve as effective catalysts for the enantioselective addition of diethylzinc to aromatic aldehydes with predictable absolute stereochemistry.
Chiral catalysts for the enantioselective addition of organometallic reagents to aldehydes
β Scribed by E.J Corey; Francis J Hannon
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- French
- Weight
- 284 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
A mechanistic model for the enantioselective addition of diethylzinc to benzaldehyde with chiral tridentate lithium complexes as catalysts correctly predicts the observed direction of enantioselectivity which occurs at levels of 8595% ee.
A recent paper from these laboratories described two rationally designed and effective chiral catalysts for the enantioselective conjugate addition of organocopper reagents to a$-en0nes.l Thus, the lithium salt derived 7. This research was assisted financially by a grant from the National Science Foundation.
π SIMILAR VOLUMES
Optically active amino thioacetate derivatives of (+l-norephedrine were found to act as effective catalysts for enantioselective addition of diethylzinc to aldehydes. This reaction provided optically active secondary alcohols with e.e. of up to >99%.
High levels of enantioselectivity have been achieved in the diethylzinc addition to both aromatic and aliphatic aldehydes, employing readily available N-substituted-azetidinyl(diphenylmethyl)methanols as chiral catalysts.