Synthesis 2005(10): 1689-1692  
DOI: 10.1055/s-2005-869896
SPECIALTOPIC
© Georg Thieme Verlag Stuttgart · New York

Chiral Diamine-Copper(I) Complexes as Asymmetric Catalysts in the Enantioselective Addition of Phenylacetylene to Imines

Simonetta Orlandi, Federica Colombo, Maurizio Benaglia*
Centro di Eccellenza CISI, and Dipartimento di Chimica Organica e Industriale, Universita’ degli Studi di Milano, via Golgi 19, 20133 Milano, Italy
Fax: +39(0250)314159; e-Mail: maurizio.benaglia@unimi.it;
Further Information

Publication History

Received 24 March 2005
Publication Date:
18 May 2005 (online)

Abstract

The stereoselective addition of phenyl acetylene to im­ines, catalysed by chiral bis-amine-Cu(I) complexes was studied. The chiral ligands are either commercially available or easily prepared in one or two steps. This very convenient and extremely simple experimental procedure at room temperature allowed optically active propargyl amines to be obtained in good yields with enantio­selectivities up to 70%.

16

(1R,2R)-1,2-trans-Diaminocyclohexane and (1R,2R)-1,2-diaminodiphenylethylenediamine were also tested as chiral ligands, but with modest results.

17

For reactions promoted by chiral diamine complexes in aqueous solvents, see ref. 15c and 15d.

18

The reaction also worked in MeCN-H2O, 9:1 (51% yield, 18% ee).

21

N-Benzyl- and N-alkylimines did not react under our reaction conditions.