Design and Synthesis of a Chiral N-Tethered Bis(imidazoline) Ligand

Takayoshi Arai; Tomoe Mizukami; Naota Yokoyama; Daisuke Nakazato; Akira Yanagisawa

doi:10.1055/s-2005-917101

LETTER

Design and Synthesis of a Chiral N-Tethered Bis(imidazoline) Ligand

Takayoshi Arai*^a, Tomoe Mizukami^a, Naota Yokoyama^b, Daisuke Nakazato^b, Akira Yanagisawa^a
^a Department of Chemistry, Faculty of Science, Chiba University, Inage 263-8522, Japan
Fax: +81(43)2902889; e-Mail: tarai@faculty.chiba-u.jp;
^b Graduate School of Science and Technology, Chiba University, Inage 263-8522, Japan

Abstract

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Abstract

A chiral nitrogen-tethered bis (imidazoline) ligand (Nb-imidazoline) was newly designed and synthesized in a divergent strategy. Thus, a single coupling reaction of primary amine with two molecules of chloromethylated imidazoline provided the Nb-imidazoline. The copper(II) triflate complex of Nb-imidazoline catalyzed a trans-selective cyclopropanation of styrene with ethyl diazoacetate to give the adduct in high chemical yield with good enantiomeric excess up to 83%.

Key word

asymmetric catalysis - ligands - imidazoline - copper - cyclopropanation

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References

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