Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands

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Title:Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands
Creators:
Pedersen, Brian
Rein, Tobias
Søtofte, Inger
Norrby, Per-Ola
Tanner, David
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 68, 5, pp. 885-898
Uncontrolled Keywords:Quantum mechanical calculations, Chiral sulfoxides, N ligands, Asymmetric additions, Carbanions, Diastereoselectivity, Organolithium reagents, Imines

Abstract

Some new results on asymmetric synthesis <i>via</i> the addition of α-metalated methyl tolyl sulfoxides to imines are presented. Good diastereoselectivity (up to &gt;98% d.e. for product <strong>3g</strong>) can be obtained under conditions of kinetic control (short reaction time, low temperature). The transition state (a six-membered "flat chair") was probed by quantum mechanical calculations, which underpinned the idea of using external chiral ligands to enhance the diastereoselectivity of otherwise moderately selective reactions. In this way, the diastereomeric ratio of the product <strong>3a</strong> could be raised from (84:16) to (&gt;99:1) by use of a readily available <i>C</i><sub>2</sub>-symmetric bis(sulfonamide) ligand. <p>

Title:Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands
Creators:
Pedersen, Brian
Rein, Tobias
Søtofte, Inger
Norrby, Per-Ola
Tanner, David
Uncontrolled Keywords:Quantum mechanical calculations, Chiral sulfoxides, N ligands, Asymmetric additions, Carbanions, Diastereoselectivity, Organolithium reagents, Imines
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:68
Number:5
Page Range:pp. 885-898
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20030885UNSPECIFIED
ID Code:2091
Item Type:Article
Deposited On:06 Feb 2009 17:15
Last Modified:06 Feb 2009 16:15

Citation

Pedersen, Brian; Rein, Tobias; Søtofte, Inger; Norrby, Per-Ola; Tanner, David (2003) Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands. Collection of Czechoslovak Chemical Communications, 68 (5). pp. 885-898. ISSN 0010-0765

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