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Investigation of macrocyclisation routes to 1,4,7-triazacyclononanes : efficient syntheses from 1,2-ditosylamides

Stones, G. and Tripoli, Régis and McDavid, Colin L. and Roux-Duplatre, Kewin and Kennedy, A.R. and Sherrington, D.C. and Gibson, C.L. (2008) Investigation of macrocyclisation routes to 1,4,7-triazacyclononanes : efficient syntheses from 1,2-ditosylamides. Organic and Biomolecular Chemistry, 6 (2). pp. 374-384. ISSN 1477-0520

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    Abstract

    Two routes to the synthesis of a cyclohexyl-fused 1,4,7-triazacyclononane involving macrocyclisations of tosamides have been investigated. In the first approach, using a classic Richman-Atkins-type cyclisation of a cyclohexyl-substituted 1,4,7-tritosamide with ethylene glycol ditosylate, afforded the cyclohexyl-fused 1,4,7-triazacyclononane in 5.86% overall yield in four steps. The second, more concise, approach involving the macrocyclisation of trans-cyclohexane-1,2-ditosamide with the tritosyl derivative of diethanolamine initially gave poor yields (< 25%). The well-documented problems with efficiencies in macrocyclisations using 1,2-ditosamides led to the use of a wider range of 1,2-ditosamides including ethane-1,2-ditosamide and propane-1,2-ditosamide. These extended studies led to the development of an efficient macrocyclisation protocol using lithium hydride. This new method afforded 1,4,7-tritosyl-1,4,7-triazacyclononanes in good yield (57-90%) from 1,2-ditosamides in a single step. These efficient methods were then applied to the preparation of a chiral cyclohexyl-fused 1,4,7-tritosyl-1,4,7-triazacyclononane (65-70%). This key chiral intermediate was then converted into a copper(II) complex following detosylation and N-methylation. The resulting chiral copper(II) complex catalysed the aziridination of styrene but it did so in a racemic fashion.

    Item type: Article
    ID code: 19843
    Keywords: chiral aziridines, crystal structure, dynamic behavior, model complexes, ring closure, ligands, Chemistry
    Subjects: Science > Chemistry
    Department: Faculty of Science > Pure and Applied Chemistry
    Related URLs:
      Depositing user: Strathprints Administrator
      Date Deposited: 04 Jun 2010 14:49
      Last modified: 18 Jul 2013 11:31
      URI: http://strathprints.strath.ac.uk/id/eprint/19843

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