Contrasting synergistic heterobimetallic (Na-Mg) and homometallic (Na or Mg) bases in metalation reactions of dialkylphenylphosphines and dialkylanilines: lateral vs ring selectivities

MIchael A Stevens, Fairuz H. Hashim, Eunice S. H. Gwee, Ekaterina I. Izgorodina, Robert E. Mulvey, Victoria L. Blair

Research output: Contribution to journalArticle

Abstract

A series of dialkyl phenylphosphines and their analogous aniline substrates have been metallated with the synergistic mixedmetal base [(TMEDA)Na(TMP)(CH2SiMe3)Mg(TMP)] 1. Different metallation regioselectivities for the substrates were observed, with predominately lateral or meta-magnesiated products isolated from solution. Three novel heterobimetallic complexes [(TMEDA)Na(TMP)(CH2PCH3Ph)Mg(TMP)] 2, [(TMEDA)Na(TMP)(m- C6H4PiPr2)Mg(TMP)] 3 and [(TMEDA)Na(TMP)(m- C6H4NEt2)Mg(TMP)] 4 and two homometallic complexes [{(TMEDA)Na(EtNC6H5)}2] 5 and [(TMEDA)Na2(TMP)(C6H5PEt)]2 6 derived from homometallic metalation have been crystallographically characterised. Complex 6 is an unprecedented sodium-amide, sodium-phosphide hybrid with a rare (NaNNaP)2 ladder motif. These products reveal contrasting heterobimetallic deprotonation with homometallic induced ethene elimination reactivity. Solution studies of metallation mixtures and electrophilic iodine quenching reactions confirmed the metallation sites. In an attempt to rationalise the regioselectivity of the magnesiation reactions the C-H acidities of the six substrates were determined in THF solution using DFT calculations employing the M06-2X functional and cc-pVTZ Dunning’s basis set.
LanguageEnglish
Number of pages10
JournalChemistry - A European Journal
StateAccepted/In press - 3 Aug 2018

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Thymidine Monophosphate
Regioselectivity
Substrates
Sodium
Deprotonation
Ladders
Acidity
Discrete Fourier transforms
Amides
Iodine
Quenching
phenyllithium

Keywords

  • organic molecules
  • organo-alkali chemistry
  • ortho-metallation

Cite this

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title = "Contrasting synergistic heterobimetallic (Na-Mg) and homometallic (Na or Mg) bases in metalation reactions of dialkylphenylphosphines and dialkylanilines: lateral vs ring selectivities",
abstract = "A series of dialkyl phenylphosphines and their analogous aniline substrates have been metallated with the synergistic mixedmetal base [(TMEDA)Na(TMP)(CH2SiMe3)Mg(TMP)] 1. Different metallation regioselectivities for the substrates were observed, with predominately lateral or meta-magnesiated products isolated from solution. Three novel heterobimetallic complexes [(TMEDA)Na(TMP)(CH2PCH3Ph)Mg(TMP)] 2, [(TMEDA)Na(TMP)(m- C6H4PiPr2)Mg(TMP)] 3 and [(TMEDA)Na(TMP)(m- C6H4NEt2)Mg(TMP)] 4 and two homometallic complexes [{(TMEDA)Na(EtNC6H5)}2] 5 and [(TMEDA)Na2(TMP)(C6H5PEt)]2 6 derived from homometallic metalation have been crystallographically characterised. Complex 6 is an unprecedented sodium-amide, sodium-phosphide hybrid with a rare (NaNNaP)2 ladder motif. These products reveal contrasting heterobimetallic deprotonation with homometallic induced ethene elimination reactivity. Solution studies of metallation mixtures and electrophilic iodine quenching reactions confirmed the metallation sites. In an attempt to rationalise the regioselectivity of the magnesiation reactions the C-H acidities of the six substrates were determined in THF solution using DFT calculations employing the M06-2X functional and cc-pVTZ Dunning’s basis set.",
keywords = "organic molecules, organo-alkali chemistry, ortho-metallation",
author = "Stevens, {MIchael A} and Hashim, {Fairuz H.} and Gwee, {Eunice S. H.} and Izgorodina, {Ekaterina I.} and Mulvey, {Robert E.} and Blair, {Victoria L.}",
year = "2018",
month = "8",
day = "3",
language = "English",
journal = "Chemistry - A European Journal",
issn = "0947-6539",

}

Contrasting synergistic heterobimetallic (Na-Mg) and homometallic (Na or Mg) bases in metalation reactions of dialkylphenylphosphines and dialkylanilines : lateral vs ring selectivities. / Stevens, MIchael A; Hashim, Fairuz H.; Gwee, Eunice S. H.; Izgorodina, Ekaterina I.; Mulvey, Robert E.; Blair, Victoria L.

In: Chemistry - A European Journal, 03.08.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Contrasting synergistic heterobimetallic (Na-Mg) and homometallic (Na or Mg) bases in metalation reactions of dialkylphenylphosphines and dialkylanilines

T2 - Chemistry - A European Journal

AU - Stevens,MIchael A

AU - Hashim,Fairuz H.

AU - Gwee,Eunice S. H.

AU - Izgorodina,Ekaterina I.

AU - Mulvey,Robert E.

AU - Blair,Victoria L.

PY - 2018/8/3

Y1 - 2018/8/3

N2 - A series of dialkyl phenylphosphines and their analogous aniline substrates have been metallated with the synergistic mixedmetal base [(TMEDA)Na(TMP)(CH2SiMe3)Mg(TMP)] 1. Different metallation regioselectivities for the substrates were observed, with predominately lateral or meta-magnesiated products isolated from solution. Three novel heterobimetallic complexes [(TMEDA)Na(TMP)(CH2PCH3Ph)Mg(TMP)] 2, [(TMEDA)Na(TMP)(m- C6H4PiPr2)Mg(TMP)] 3 and [(TMEDA)Na(TMP)(m- C6H4NEt2)Mg(TMP)] 4 and two homometallic complexes [{(TMEDA)Na(EtNC6H5)}2] 5 and [(TMEDA)Na2(TMP)(C6H5PEt)]2 6 derived from homometallic metalation have been crystallographically characterised. Complex 6 is an unprecedented sodium-amide, sodium-phosphide hybrid with a rare (NaNNaP)2 ladder motif. These products reveal contrasting heterobimetallic deprotonation with homometallic induced ethene elimination reactivity. Solution studies of metallation mixtures and electrophilic iodine quenching reactions confirmed the metallation sites. In an attempt to rationalise the regioselectivity of the magnesiation reactions the C-H acidities of the six substrates were determined in THF solution using DFT calculations employing the M06-2X functional and cc-pVTZ Dunning’s basis set.

AB - A series of dialkyl phenylphosphines and their analogous aniline substrates have been metallated with the synergistic mixedmetal base [(TMEDA)Na(TMP)(CH2SiMe3)Mg(TMP)] 1. Different metallation regioselectivities for the substrates were observed, with predominately lateral or meta-magnesiated products isolated from solution. Three novel heterobimetallic complexes [(TMEDA)Na(TMP)(CH2PCH3Ph)Mg(TMP)] 2, [(TMEDA)Na(TMP)(m- C6H4PiPr2)Mg(TMP)] 3 and [(TMEDA)Na(TMP)(m- C6H4NEt2)Mg(TMP)] 4 and two homometallic complexes [{(TMEDA)Na(EtNC6H5)}2] 5 and [(TMEDA)Na2(TMP)(C6H5PEt)]2 6 derived from homometallic metalation have been crystallographically characterised. Complex 6 is an unprecedented sodium-amide, sodium-phosphide hybrid with a rare (NaNNaP)2 ladder motif. These products reveal contrasting heterobimetallic deprotonation with homometallic induced ethene elimination reactivity. Solution studies of metallation mixtures and electrophilic iodine quenching reactions confirmed the metallation sites. In an attempt to rationalise the regioselectivity of the magnesiation reactions the C-H acidities of the six substrates were determined in THF solution using DFT calculations employing the M06-2X functional and cc-pVTZ Dunning’s basis set.

KW - organic molecules

KW - organo-alkali chemistry

KW - ortho-metallation

UR - https://onlinelibrary.wiley.com/journal/15213765

M3 - Article

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

ER -