Asymmetric reduction of imines with trichlorosilane, catalyzed by sigamide, an amino acid-derived formamide: scope and limitations

Malkov, A. V., Vrankova, K., Stoncius, S. and Kocovsky, P. (2009) Asymmetric reduction of imines with trichlorosilane, catalyzed by sigamide, an amino acid-derived formamide: scope and limitations. Journal of Organic Chemistry, 74(16), pp. 5839-5849. (doi: 10.1021/jo900561h)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1021/jo900561h

Abstract

Enantioselective reduction of ketimines 6-10 With trichlorosilane can be catalyzed by the N-methyl valine-derived Lewis-basic formamide (S)-23 (Sigamide) with high enantioselectivity (<= 97% ee) land low catalyst loading, (1 - 5 mol %) at room temperature in toluene. The reaction is efficient with ketimines derived from aromatic amines (aniline and anisidine) and aromatic, heteroaromatic, conjugated, and even nonaromatic ketones 1-5, in which the steric difference between the alkyl groups R-1 and R-2 is sufficient. Simple nitrogen heteroaromatics (8a,b,d) exhibit low enantioselectivities due to the competing coordination of the reagent but increased steric hindrance in the Vicinity of the nitrogen (8c,e) results in a considerable improvement. Cyclic imines 32d-d exhibited low to modest enantioselectivities.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Malkov, Dr Andrei and Stoncius, Mr Sigitas and Vrankova, Miss Kvetoslava and Kocovsky, Professor Pavel
Authors: Malkov, A. V., Vrankova, K., Stoncius, S., and Kocovsky, P.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of Organic Chemistry
Publisher:American Chemical Society
ISSN:0022-3263
ISSN (Online):1520-6904
Published Online:16 June 2009

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
370221New organocatalysts from amino acids exploitation of Chiral Relay and Aromatic Interactions in Asymmetric CatalysisAndrei MalkovEngineering & Physical Sciences Research Council (EPSRC)GR/S87294/01Chemistry