Reaction of metallated tert-butyl(phenyl)phosphane oxide with electrophiles as a route to functionalized tertiary phosphane oxides: Alkylation reactions

Richard K. Haynes, Tin Lok Au-Yeung, Wai Kuen Chan, Wai Lun Lam, Zhi Yi Li, Lam Lung Yeung, Albert S.C. Chan, Pei Li, Mark Koen, Craig R. Mitchell, Simone C. Vonwiller

Research output: Journal article publicationJournal articleAcademic researchpeer-review

72 Citations (Scopus)

Abstract

P-Chiral tertiary phosphane oxides have been prepared from each of the secondary phosphane oxides racemic 1, (S(p))-(-)-4 and (Rp)-(+)-tert-butylphenylphosphane oxide (5) by lithiation with LDA or nBuLi, or sodiation with sodium hydride, in THF, and then by treatment with a series of primary alkyl halides. Doubly P-chiral ditertiary bis(phosphane oxides) are also obtained from these metallated secondary phosphane oxides by treatment with electrophiles based on straight-chain, tartrate-derived, and bishalomethylarene dihalides. In general, the bis-phosphane oxides are obtained in good yields. However, when the α,ω-dihalide bears an embedded heteroatom (O or Si), yields are diminished. The enantiomeric purity of each of the products was assessed through admixture with (R(p))- and (S(p))-tert-butyl(phenyl)phosphanylthioic acids and measurement of the tert-butyl resonances in the1H-NMR spectra. In all cases, the act of metallation of the enantiomerically pure secondary phosphane oxide followed by its alkylation is not accompanied by detectable racemization. This method for preparing P-chiral tertiary phosphane oxides is therefore more straightforward than those described previously.
Original languageEnglish
Pages (from-to)3205-3216
Number of pages12
JournalEuropean Journal of Organic Chemistry
Issue number18
DOIs
Publication statusPublished - 1 Jan 2000

Keywords

  • Alkylations
  • Halides
  • Metallations
  • P-Chiral phosphane oxides

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Organic Chemistry

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