Adding a structural context to the deprotometalation and trans-metal trapping chemistry of phenyl-substituted benzotriazole

M. Ángeles Fuentes, Alan R. Kennedy, Robert E. Mulvey, John A. Parkinson, Toni Rantanen, Stuart D. Robertson, Victor Snieckus

Research output: Contribution to journalArticle

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Abstract

Organometallic bases are becoming increasingly complex, because mixing components can lead to bases superior to single-component bases. To better understand this superiority, it is useful to study metalated intermediate structures prior to quenching. This study is on 1-phenyl-1H-benzotriazole, which was previously deprotonated by an in situ ZnCl2• TMEDA/LiTMP (TMEDA=N,N,N′,N′-tetramethylethylenediamine; TMP=2,2,6,6-tetramethylpiperidide) mixture and then iodinated. Herein, reaction with LiTMP exposes the deficiency of the single-component base as the crystalline product obtained was [{4-R-1-(2-lithiophenyl)-1H-benzotriazole• 3THF}2], [R=2-C6H4(Ph)NLi], in which ring opening of benzotriazole and N2 extrusion had occurred. Supporting lithiation by adding iBu2Al(TMP) induces trans-metal trapping, in which C-Li bonds transform into C-Al bonds to stabilise the metalated intermediate. X-ray diffraction studies revealed homodimeric [(4-R′-1-phenyl-1H-benzotriazole)2], [R′=(iBu)2Al(μ-TMP)Li], and its heterodimeric isomer [(4-R′-1-phenyl-1H-benzotriazole){2-R′-1-phenyl-1H-benzotriazole}], whose structure and slow conformational dynamics were probed by solution NMR spectroscopy.

Original languageEnglish
Pages (from-to)14812-14822
Number of pages11
JournalChemistry - A European Journal
Volume21
Issue number42
Early online date21 Sep 2015
DOIs
Publication statusPublished - 12 Oct 2015

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Organometallics
Isomers
Nuclear magnetic resonance spectroscopy
Extrusion
Quenching
Metals
Thymidine Monophosphate
Crystalline materials
X ray diffraction
benzotriazole

Keywords

  • lithium
  • metalation
  • structure elucidation
  • triazoles
  • zinc

Cite this

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title = "Adding a structural context to the deprotometalation and trans-metal trapping chemistry of phenyl-substituted benzotriazole",
abstract = "Organometallic bases are becoming increasingly complex, because mixing components can lead to bases superior to single-component bases. To better understand this superiority, it is useful to study metalated intermediate structures prior to quenching. This study is on 1-phenyl-1H-benzotriazole, which was previously deprotonated by an in situ ZnCl2• TMEDA/LiTMP (TMEDA=N,N,N′,N′-tetramethylethylenediamine; TMP=2,2,6,6-tetramethylpiperidide) mixture and then iodinated. Herein, reaction with LiTMP exposes the deficiency of the single-component base as the crystalline product obtained was [{4-R-1-(2-lithiophenyl)-1H-benzotriazole• 3THF}2], [R=2-C6H4(Ph)NLi], in which ring opening of benzotriazole and N2 extrusion had occurred. Supporting lithiation by adding iBu2Al(TMP) induces trans-metal trapping, in which C-Li bonds transform into C-Al bonds to stabilise the metalated intermediate. X-ray diffraction studies revealed homodimeric [(4-R′-1-phenyl-1H-benzotriazole)2], [R′=(iBu)2Al(μ-TMP)Li], and its heterodimeric isomer [(4-R′-1-phenyl-1H-benzotriazole){2-R′-1-phenyl-1H-benzotriazole}], whose structure and slow conformational dynamics were probed by solution NMR spectroscopy.",
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author = "Fuentes, {M. {\'A}ngeles} and Kennedy, {Alan R.} and Mulvey, {Robert E.} and Parkinson, {John A.} and Toni Rantanen and Robertson, {Stuart D.} and Victor Snieckus",
note = "This is the peer reviewed version of the following article: Fuentes, M. {\'A}., Kennedy, A. R., Mulvey, R. E., Parkinson, J. A., Rantanen, T., Robertson, S. D., & Snieckus, V. (2015). Adding a structural context to the deprotometalation and trans-metal trapping chemistry of phenyl-substituted benzotriazole. Chemistry - A European Journal , 21(42), 14812-14822, which has been published in final form at http://dx.doi.org/10.1002/chem.201502534. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.",
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Adding a structural context to the deprotometalation and trans-metal trapping chemistry of phenyl-substituted benzotriazole. / Fuentes, M. Ángeles; Kennedy, Alan R.; Mulvey, Robert E.; Parkinson, John A.; Rantanen, Toni; Robertson, Stuart D.; Snieckus, Victor.

In: Chemistry - A European Journal , Vol. 21, No. 42, 12.10.2015, p. 14812-14822.

Research output: Contribution to journalArticle

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AU - Fuentes, M. Ángeles

AU - Kennedy, Alan R.

AU - Mulvey, Robert E.

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AU - Rantanen, Toni

AU - Robertson, Stuart D.

AU - Snieckus, Victor

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N2 - Organometallic bases are becoming increasingly complex, because mixing components can lead to bases superior to single-component bases. To better understand this superiority, it is useful to study metalated intermediate structures prior to quenching. This study is on 1-phenyl-1H-benzotriazole, which was previously deprotonated by an in situ ZnCl2• TMEDA/LiTMP (TMEDA=N,N,N′,N′-tetramethylethylenediamine; TMP=2,2,6,6-tetramethylpiperidide) mixture and then iodinated. Herein, reaction with LiTMP exposes the deficiency of the single-component base as the crystalline product obtained was [{4-R-1-(2-lithiophenyl)-1H-benzotriazole• 3THF}2], [R=2-C6H4(Ph)NLi], in which ring opening of benzotriazole and N2 extrusion had occurred. Supporting lithiation by adding iBu2Al(TMP) induces trans-metal trapping, in which C-Li bonds transform into C-Al bonds to stabilise the metalated intermediate. X-ray diffraction studies revealed homodimeric [(4-R′-1-phenyl-1H-benzotriazole)2], [R′=(iBu)2Al(μ-TMP)Li], and its heterodimeric isomer [(4-R′-1-phenyl-1H-benzotriazole){2-R′-1-phenyl-1H-benzotriazole}], whose structure and slow conformational dynamics were probed by solution NMR spectroscopy.

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KW - triazoles

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