Jump to main content
Jump to site search

Issue 10, 2011
Previous Article Next Article

Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

Author affiliations

Abstract

In this paper, we report a novel synthesis of anhydrous 1-hydroxy-2,2,6,6-tetramethyl-piperidine (TEMPO-H). An X-ray crystal structure and full characterization of the compound are included. Compared to hydrated TEMPO-H, its anhydrous form exhibits improved stability and a differing chemical reactivity. The reactions of anhydrous TEMPO-H with a variety of low-valent carbon centres are described. For example, anhydrous TEMPO-H was reacted with 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), an unsaturated NHC. Crystals of [CHNC6H2(CH3)3]2C⋯HO(NC5H6(CH3)4), IMes⋯TEMPO-H, were isolated and a crystal structure determined. The experimental structure is compared to the results of theoretical calculations on the hydrogen-bonded dimer. Anhydrous TEMPO-H was also reacted with the saturated NHC, 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene (SIPr), giving the product [CH2Ni-Pr2C6H3]2CH⋯O(NC5H6(CH3)4). In contrast, the reaction of hydrated TEMPO-H with 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene gave small amounts of the hydrolysis product, N-(2,6-diisopropylphenyl)-N-[2-(2,6-diisopropylphenylamino)ethyl]formamide. Finally, anhydrous TEMPO-H was reacted with (triphenylphosphoranylidene)ketene to generate Ph3PC(H)C([double bond, length as m-dash]O)O(NC5H6(CH3)4). A full characterization of the product, including an X-ray crystal structure, is described.

Graphical abstract: Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

Back to tab navigation

Supplementary files

Publication details

The article was received on 09 Nov 2010, accepted on 11 Feb 2011 and first published on 06 Apr 2011


Article type: Paper
DOI: 10.1039/C0OB00999G
Citation: Org. Biomol. Chem., 2011,9, 3672-3680
  •   Request permissions

    Anhydrous TEMPO-H: reactions of a good hydrogen atom donor with low-valent carbon centres

    N. A. Giffin, M. Makramalla, A. D. Hendsbee, K. N. Robertson, C. Sherren, C. C. Pye, J. D. Masuda and J. A. C. Clyburne, Org. Biomol. Chem., 2011, 9, 3672
    DOI: 10.1039/C0OB00999G

Search articles by author

Spotlight

Advertisements