Intramolecular Cyclization Reactions in Haloalkyl-Cobalt Complexes with Macrocyclic Equatorial Ligands

Dreos, Renata and Randaccio, Lucio and Siega, Patrizia and Vrdoljak, Višnja (2009) Intramolecular Cyclization Reactions in Haloalkyl-Cobalt Complexes with Macrocyclic Equatorial Ligands. Croatica Chemica Acta, 82 (2). pp. 455-461. ISSN 0011-1643

[img]
Preview
PDF - Published Version
Language: English

Download (1MB) | Preview

Abstract

Organocobalt complexes containing axial haloalkyl groups afford metallacycles of different size by N or O alkylation of the macrocyclic equatorial ligands. The reaction mechanism involves the intra-molecular nucleophilic attack of a negatively charged atom of the equatorial ligand on the axial XCH2 haloalkyl group with simultaneous detachment of a halide ion, X−. In imino/oxime and amino/oxime derivatives, the generation of the negatively charged nitrogen requires the abstraction of a proton and the reaction occurs only in alkaline medium. In bis(dimethylglioximato) and Schiff base complexes, a negatively charged oxygen is present in the equatorial ligand and the reaction occurs even in neutral medium. Three-, six- and seven- membered metallacycles are obtained, with the common feature that the Co–C bond is shorter and more resistant toward homolysis than in parent complexes or in closely related derivatives.

Item Type: Article
Keywords: intramolecular metallacyclization; haloalkyl-cobalt; reaction mechanism; X-ray structures
Date: 2009
Subjects: NATURAL SCIENCES > Chemistry
Divisions: Faculty of Science > Department of Chemistry
Publisher: Hrvatsko kemijsko društvo
Related URLs:
Depositing User: Branka Maravic
Date Deposited: 09 May 2014 13:18
Last Modified: 09 May 2014 13:18
URI: http://digre.pmf.unizg.hr/id/eprint/1115

Actions (login required)

View Item View Item