Toggle Main Menu Toggle Search

Open Access padlockePrints

Regioselective metalation of a tertiary phosphine. Synthesis and structural characterization of an unusual tetramerie lithium phosphinomethanide

Lookup NU author(s): Dr Keith Izod, Paul O'Shaughnessy, Emeritus Professor Bill CleggORCiD, Dr Stephen Liddle


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


The tertiary phosphine MeP(C6H4-2-CH2NMe2)2 (3) is conveniently prepared by the reaction of MePCl2 with Li(C6H4-2-CH2NMe2) in high yields. Treatment of 3 with n-BuLi in light petroleum yields the tetrameric lithium phosphinomethanide complex [Li{CH2P(C6H4-2-CH2NMe 2)2}]4·(PhMe)3 (5a) after recrystallization from toluene, whereas treatment of 3 with t-BuLi under similar conditions yields the benzyllithium complex [MeP(C6H4-2-CH2NMe2)-{C 6H4-2-CH(Li)NMe2}]2 (4). Complex 5a has been characterized by elemental analyses, multielement NMR spectroscopy, and X-ray crystallography. Complex 5 can also be accessed by moderate thermal treatment of 4 in toluene solution. The kinetics of this conversion were followed by 31P NMR spectroscopy and show a first-order dependence upon the concentration of 4 and are independent of the concentration of 3. Analysis of the temperature dependence of the reaction over the range T = 308-338 K yielded ΔH‡ = 68.1 ± 4.0 kJ mol-1 and ΛS‡ = -124 ± 30 J K-1 mol-1 for this reaction, consistent with the reaction proceeding via a concerted intramolecular H-Li exchange mechanism. © 2001 American Chemical Society.

Publication metadata

Author(s): Izod K, O'Shaughnessy P, Clegg W, Liddle ST

Publication type: Article

Publication status: Published

Journal: Organometallics

Year: 2001

Volume: 20

Issue: 4

Pages: 648-653

ISSN (print): 0276-7333

ISSN (electronic): 1520-6041

Publisher: American Chemical Society


DOI: 10.1021/om000876e


Altmetrics provided by Altmetric