Synlett 2014; 25(5): 615-630
DOI: 10.1055/s-0033-1340487
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© Georg Thieme Verlag Stuttgart · New York

The Design and Synthesis of Planar Chiral Ligands and Their Application to Asymmetric Catalysis

Nicholas A. Butta, Delong Liub, Wanbin Zhang*a, b
  • aSchool of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. of China
  • bSchool of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. of China   Email: wanbin@sjtu.edu.cn
Further Information

Publication History

Received: 30 September 2013

Accepted after revision: 26 November 2013

Publication Date:
31 January 2014 (eFirst)

Abstract

Ferrocene- and ruthenocene-based planar chiral ligands have been developed and used in transition-metal-catalyzed asymmetric allylic substitutions, asymmetric hydrogenations, and asymmetric conjugate addition reactions. The most common ferrocene ligands, which have bis(oxazoline) substituents on the cyclopentadiene rings, have been modified to create new planar chiral C 2-symmetric ligands, some of which have shown excellent potential in the aforementioned reactions. A series of planar chiral ruthenocene ligands have also been developed and their activities differ from those of their ferrocene counterparts.

1 Introduction

2 The Design and Synthesis of Planar Chiral Ligands

2.1 Ferrocene-Based Ligands

2.2 Ruthenocene-Based Ligands

3 Applications of Planar Chiral Ligands in Asymmetric Reactions

3.1 Asymmetric Allylic Alkylation

3.2 Asymmetric Allylic Amination

3.3 Asymmetric Allylic Alkylation with Enamines as Nucleophiles

3.4 Asymmetric Alkylation of Aryl Aldehydes

3.5 Asymmetric Hydrogenation

3.6 1,4-Asymmetric Conjugation Reactions

4 Summary