Synthesis 2012; 44(14): 2162-2172
DOI: 10.1055/s-0031-1291009
special topic
© Georg Thieme Verlag Stuttgart · New York

'Click'-BINOLs: A New Class of Tunable Ligands for Asymmetric Catalysis

Stephan Beckendorf
Institute of Organic Chemistry, Münster University, Corrensstr. 40, 48149 Münster, Germany , Fax: +49(251)8333202   Email: olga.garcia@uni-muenster.de
,
Olga García Mancheño*
Institute of Organic Chemistry, Münster University, Corrensstr. 40, 48149 Münster, Germany , Fax: +49(251)8333202   Email: olga.garcia@uni-muenster.de
› Author Affiliations
Further Information

Publication History

Received: 26 March 2012

Accepted: 30 March 2012

Publication Date:
25 May 2012 (online)

Abstract

A new class of easily tunable 1,2,3-triazole-BINOL ligands, 'click'-BINOLs, have been synthesized from readily available alkynes and several azido-BINOL derivatives using the powerful Huisgen [3+2] cycloaddition 'click' approach. The activity of these ligands in asymmetric Lewis acid catalysis has been explored for the first time in the diethylzinc addition to aldehydes. The C 2-symmetric ligand 1d showed an interesting catalytic behavior, which suggests the non-innocent participation of the triazole units. Thus, good enantioselectivities (up to 86% ee) were obtained by both the right selection of the substitution pattern at the triazole ring and the fine tuning of the reaction conditions.

Supporting Information

 
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