fulltext.study @t Gmail

Imines derived from (1S,2R)-norephedrine as catalysts in the enantioselective addition of diethylzinc to aldehydes

Paper ID Volume ID Publish Year Pages File Format Full-Text
42784 45941 2009 9 PDF Available
Title
Imines derived from (1S,2R)-norephedrine as catalysts in the enantioselective addition of diethylzinc to aldehydes
Abstract

Purpose of the research was to determine the activity of chiral imine ligands prepared from (1S,2R)-norephedrine for the enantioselective addition of diethylzinc to aldehydes. Imine ligands reveal medium enantioselectivity, with the ee exceeding 30%. The highest ee (97%) was obtained for imine with 9-anthryl substituent, when p-methoxybenzaldehyde was used as substrate. The yields of the reaction obtained after 24–72 h reached 76–96%. The absolute configuration of the addition product depends on the geometry of presented transition states and π–π stacking interactions between the investigated ligands and the benzaldehyde substrate. Imine ligands derived 2-hydroxyacetophenone and with 9-anthryl substituent reveal strong absorbance in UV–vis spectra. Intermediates for the imines – diethylzinc – based catalysis and probable mechanisms were proposed.

Graphical abstractA series of chiral imine ligands was prepared from (1S,2R)-norephedrine and applied for the enantioselective addition of diethylzinc to aldehydes. The absolute configuration of the addition product depends on the imine's nitrogen substituent. The highest ee (97%) was observed for imine with 9-anthryl substituent, when applied for p-methoxybenzaldehyde as substrate. Imine ligands derived 2-hydroxyacetophenone and with 9-anthryl substituent reveal strong absorbance in UV–vis spectra. Intermediates for the imines – diethylzinc – based catalysis and probable mechanisms were proposed.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Imine; Diethylzinc addition; Norephedrine derivatives; Activity
First Page Preview
Imines derived from (1S,2R)-norephedrine as catalysts in the enantioselective addition of diethylzinc to aldehydes
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 357, Issue 2, 15 April 2009, Pages 150–158
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us