ePrints

Chiral salen ligands designed to form polymetallic complexes

Lookup NU author(s): Thierry Achard, Emeritus Professor Bill CleggORCiD, Dr Ross Harrington, Professor Michael North

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

Chiral salen ligands capable of forming polymetallic complexes have been designed. The ligands possess substituents in the 4,4'-positions, but have no substituent in the 3,3'-positions to allow a second metal ion access to the salen oxygen atoms. Ligands in which a polyether chain links the 4,4'-positions were prepared and complexed to copper. In addition, acyclic ligands with potential metal coordinating substituents in the 4,4'-positions were prepared and complexed to copper and cobalt. The crystal structure of one of the cobalt complexes shows it to be a trimetallic complex in which a Co(II)(OAc)(2) group coordinates to the salen oxygen atoms of two Co(Ill)(salen)(OAc) units. In contrast, the crystal structure of a Co(salen) complex with tert-butyl groups attached to the 3,3'-positions is found to be mononuclear. All of the complexes were tested as asymmetric phase transfer catalysts for the asymmetric alkylation of an alanine methyl ester, forming (R)-alpha-methyl phenylalanine methyl ester with up to 85% ee. (C) 2011 Elsevier Ltd. All rights reserved.

Publication metadata

Author(s): Achard TRJ, Clegg W, Harrington RW, North M

Publication type: Article

Publication status: Published

Journal: Tetrahedron

Year: 2012

Volume: 68

Issue: 1

Pages: 133-144

Print publication date: 31/10/2011

ISSN (print): 0040-4020

ISSN (electronic): 1464-5416

Publisher: Pergamon

URL: http://dx.doi.org/10.1016/j.tet.2011.10.084

DOI: 10.1016/j.tet.2011.10.084

Altmetrics

Share