| Autor: |
Barrett AN; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom., Woof CR; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom., Goult CA; Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom., Gasperini D; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom., Mahon MF; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom., Webster RL; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. |
| Abstrakt: |
The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton "donor phosphine" makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines (ArP) 5 have been formed in good conversion, with the crystal structures presented. The use of catalytic quantities of iron(III) acetylacetonate provides significant improvements in conversion in the context of diphosphine (Ar 2 P) 2 and alkyl-substituted cyclotetra- or cyclopentaphosphine ((AlkylP) n , where n = 4 or 5) formation. Both iron-free and iron-mediated reactions show high levels of selectivity for one specific ring size. Finally, investigations into the reactivity of Fe(acac) 3 suggest that the iron species is acting as a sink for the hydrochloric acid byproduct of the reaction. |
