Iminophosphorane-based [P2N2] rhodium complexes: synthesis, reactivity, and application in catalysed transfer hydrogenation of polar bonds

Antoine Buchard, Elina Payet, Audrey Auffrant, Xavier Le Goff, Pascal Le Floch

Research output: Contribution to journalArticle

12 Citations (Scopus)
87 Downloads (Pure)

Abstract

[Rh(P2N2)X] complexes (2-X, X = Cl, BF4) featuring a tetradentate iminophosphorane phosphine ligand were synthesised and characterised. X-Ray analysis provides evidence for a square planar geometry without coordination of the chloride anion. These complexes proved to be air-sensitive, and their oxidation to Rh(iii) complexes 3-X was observed in air. The controlled reaction of 2-BF4 with one equivalent of hexachloroethane yielded [Rh(P2N2)Cl2(BF4)] (3-BF4). Direct synthesis of 3-Cl can also be achieved by coordination of the [P2N2] ligand to [RhCl(THT)3] (THT = tetrahydrothiophene). The reactivity of Rh(i) complexes 2 was further investigated, and no reaction was observed with silanes, aryl halides, or pinacolborane, although decomposition was observed under 1 atm of H2 upon prolonged heating. Interestingly, reduction of complex 3-Cl was observed by NMR upon treatment with silanes or sodium isopropoxide. Therefore, complex 3-Cl was used for catalytic transfer hydrogenation of polar bonds. The reduction of aromatic and aliphatic ketones can be carried out using 1% catalyst and 10% sodium isopropoxide, while imines are partially reduced under these conditions.
Original languageEnglish
Pages (from-to)2943-2949
Number of pages7
JournalNew Journal of Chemistry
Volume34
Issue number12
Early online date19 Sep 2010
DOIs
Publication statusPublished - 2010

Fingerprint

Silanes
Rhodium
phosphine
Hydrogenation
Sodium
Ligands
Imines
X ray analysis
Air
Ketones
Anions
Chlorides
Negative ions
Nuclear magnetic resonance
Decomposition
Heating
Oxidation
Catalysts
Geometry
4,4,5,5-tetramethyl(1,3,2)dioxaborolane

Cite this

Iminophosphorane-based [P2N2] rhodium complexes: synthesis, reactivity, and application in catalysed transfer hydrogenation of polar bonds. / Buchard, Antoine; Payet, Elina; Auffrant, Audrey; Goff, Xavier Le; Floch, Pascal Le.

In: New Journal of Chemistry, Vol. 34, No. 12, 2010, p. 2943-2949.

Research output: Contribution to journalArticle

Buchard, Antoine ; Payet, Elina ; Auffrant, Audrey ; Goff, Xavier Le ; Floch, Pascal Le. / Iminophosphorane-based [P2N2] rhodium complexes: synthesis, reactivity, and application in catalysed transfer hydrogenation of polar bonds. In: New Journal of Chemistry. 2010 ; Vol. 34, No. 12. pp. 2943-2949.
@article{72a6368075324d049367a261cdfb7af5,
title = "Iminophosphorane-based [P2N2] rhodium complexes: synthesis, reactivity, and application in catalysed transfer hydrogenation of polar bonds",
abstract = "[Rh(P2N2)X] complexes (2-X, X = Cl, BF4) featuring a tetradentate iminophosphorane phosphine ligand were synthesised and characterised. X-Ray analysis provides evidence for a square planar geometry without coordination of the chloride anion. These complexes proved to be air-sensitive, and their oxidation to Rh(iii) complexes 3-X was observed in air. The controlled reaction of 2-BF4 with one equivalent of hexachloroethane yielded [Rh(P2N2)Cl2(BF4)] (3-BF4). Direct synthesis of 3-Cl can also be achieved by coordination of the [P2N2] ligand to [RhCl(THT)3] (THT = tetrahydrothiophene). The reactivity of Rh(i) complexes 2 was further investigated, and no reaction was observed with silanes, aryl halides, or pinacolborane, although decomposition was observed under 1 atm of H2 upon prolonged heating. Interestingly, reduction of complex 3-Cl was observed by NMR upon treatment with silanes or sodium isopropoxide. Therefore, complex 3-Cl was used for catalytic transfer hydrogenation of polar bonds. The reduction of aromatic and aliphatic ketones can be carried out using 1{\%} catalyst and 10{\%} sodium isopropoxide, while imines are partially reduced under these conditions.",
author = "Antoine Buchard and Elina Payet and Audrey Auffrant and Goff, {Xavier Le} and Floch, {Pascal Le}",
year = "2010",
doi = "10.1039/C0NJ00299B",
language = "English",
volume = "34",
pages = "2943--2949",
journal = "New Journal of Chemistry",
issn = "1144-0546",
publisher = "Royal Society of Chemistry",
number = "12",

}

TY - JOUR

T1 - Iminophosphorane-based [P2N2] rhodium complexes: synthesis, reactivity, and application in catalysed transfer hydrogenation of polar bonds

AU - Buchard, Antoine

AU - Payet, Elina

AU - Auffrant, Audrey

AU - Goff, Xavier Le

AU - Floch, Pascal Le

PY - 2010

Y1 - 2010

N2 - [Rh(P2N2)X] complexes (2-X, X = Cl, BF4) featuring a tetradentate iminophosphorane phosphine ligand were synthesised and characterised. X-Ray analysis provides evidence for a square planar geometry without coordination of the chloride anion. These complexes proved to be air-sensitive, and their oxidation to Rh(iii) complexes 3-X was observed in air. The controlled reaction of 2-BF4 with one equivalent of hexachloroethane yielded [Rh(P2N2)Cl2(BF4)] (3-BF4). Direct synthesis of 3-Cl can also be achieved by coordination of the [P2N2] ligand to [RhCl(THT)3] (THT = tetrahydrothiophene). The reactivity of Rh(i) complexes 2 was further investigated, and no reaction was observed with silanes, aryl halides, or pinacolborane, although decomposition was observed under 1 atm of H2 upon prolonged heating. Interestingly, reduction of complex 3-Cl was observed by NMR upon treatment with silanes or sodium isopropoxide. Therefore, complex 3-Cl was used for catalytic transfer hydrogenation of polar bonds. The reduction of aromatic and aliphatic ketones can be carried out using 1% catalyst and 10% sodium isopropoxide, while imines are partially reduced under these conditions.

AB - [Rh(P2N2)X] complexes (2-X, X = Cl, BF4) featuring a tetradentate iminophosphorane phosphine ligand were synthesised and characterised. X-Ray analysis provides evidence for a square planar geometry without coordination of the chloride anion. These complexes proved to be air-sensitive, and their oxidation to Rh(iii) complexes 3-X was observed in air. The controlled reaction of 2-BF4 with one equivalent of hexachloroethane yielded [Rh(P2N2)Cl2(BF4)] (3-BF4). Direct synthesis of 3-Cl can also be achieved by coordination of the [P2N2] ligand to [RhCl(THT)3] (THT = tetrahydrothiophene). The reactivity of Rh(i) complexes 2 was further investigated, and no reaction was observed with silanes, aryl halides, or pinacolborane, although decomposition was observed under 1 atm of H2 upon prolonged heating. Interestingly, reduction of complex 3-Cl was observed by NMR upon treatment with silanes or sodium isopropoxide. Therefore, complex 3-Cl was used for catalytic transfer hydrogenation of polar bonds. The reduction of aromatic and aliphatic ketones can be carried out using 1% catalyst and 10% sodium isopropoxide, while imines are partially reduced under these conditions.

UR - http://www.scopus.com/inward/record.url?scp=78649364658&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1039/C0NJ00299B

U2 - 10.1039/C0NJ00299B

DO - 10.1039/C0NJ00299B

M3 - Article

VL - 34

SP - 2943

EP - 2949

JO - New Journal of Chemistry

JF - New Journal of Chemistry

SN - 1144-0546

IS - 12

ER -