Organocatalysts for the asymmetric reduction of aromatic ketimines with trichlorosilane

MacDougall, Kenneth N. (2008) Organocatalysts for the asymmetric reduction of aromatic ketimines with trichlorosilane. PhD thesis, University of Glasgow.

Abstract

Asymmetric reduction of N-aryl ketimines 189a j, 212, and 213 with trichlorosilane can be catalyzed by new N-methyl L-amino acid-derived Lewis-basic organocatalysts, such as bisamide 197c (10 mol%), in toluene at room temperature with high enantioselectivity (≤92% ee). The structure-reactivity investigation shows that the product configuration is controlled by the nature of the side chain of the catalyst scaffold (e.g., i Pr vs Me, as in 197c and 208c), so that catalysts of the same absolute configuration may induce the formation of the opposite enantiomers of the product. Arene-arene interactions between the catalyst and the incoming imine appear to be the prerequisite for asymmetric induction. This metal-free, organocatalytic protocol is competitive with the traditional, metal-catalyzed methodology.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: organocatalysis, reduction, ketimines, trichlorosilane, synthesis
• Subjects: Q Science > QD Chemistry
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Kocovsky, Prof. Pavel
• Date of Award: 2008
• Depositing User: Mr Kenneth N MacDougall
• Unique ID: glathesis:2008-123
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 02 Mar 2009
• Last Modified: 16 Feb 2017 15:06
• URI: https://theses.gla.ac.uk/id/eprint/123