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Kisten P, Manoury E, Lledós A, Whitwood AC, Lynam JM, Slattery JM, Duckett SB, Poli R. Ir I(η 4-diene) precatalyst activation by strong bases: formation of an anionic Ir III tetrahydride. Dalton Trans 2023; 52:2495-2505. [PMID: 36727834 DOI: 10.1039/d2dt04036k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The reaction between [IrCl(COD)]2 and dppe in a 1 : 2 ratio was investigated in detail under three different conditions. [IrCl(COD)(dppe)], 1, is formed at room temperature in the absence of base. In the presence of a strong base at room temperature, hydride complexes that retain the carbocyclic ligand in the coordination sphere are generated. In isopropanol, 1 is converted into [IrH(1,2,5,6-η2:η2-COD)(dppe)] (2) on addition of KOtBu, with k12 = (1.11 ± 0.02) × 10-4 s-1, followed by reversible isomerisation to [IrH(1-κ-4,5,6-η3-C8H12)(dppe)] (3) with k23 = (3.4 ± 0.2) × 10-4 s-1 and k32 = (1.1 ± 0.3) × 10-5 s-1 to yield an equilibrium 5 : 95 mixture of 2 and 3. However, when no hydride source is present in the strong base (KOtBu in benzene or toluene), the COD ligand in 1 is deprotonated, followed by β-H elimination of an IrI-C8H11 intermediate, which leads to complex [IrH(1-κ-4,5,6-η3-C8H10)(dppe)] (4) selectively. This is followed by its reversible isomerisation to 5, which features a different relative orientation of the same ligands (k45 = (3.92 ± 0.11) × 10-4 s-1; k5-4 = (1.39 ± 0.12) × 10-4 s-1 in C6D6), to yield an equilibrated 32 : 68 mixture of 4 and 5. DFT calculations assisted in the full rationalization of the selectivity and mechanism of the reactions, yielding thermodynamic (equilibrium) and kinetic (isomerization barriers) parameters in excellent agreement with the experimental values. Finally, in the presence of KOtBu and isopropanol at 80 °C, 1 is transformed selectively to K[IrH4(dppe)] (6), a salt of an anionic tetrahydride complex of IrIII. This product is also selectively generated from 2, 3, 4 and 5 and H2 at room temperature, but only when a strong base is present. These results provide an insight into the catalytic action of [IrCl(COD)(LL)] complexes in the hydrogenation of polar substrates in the presence of a base.
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Affiliation(s)
- Paven Kisten
- Department of Chemistry, University of York, Heslington, York, YO10 5DD UK. .,CNRS, LCC (Laboratoire de Chimie de Coordination), Université de Toulouse, UPS, INPT, 205 route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France CNRS.
| | - Eric Manoury
- CNRS, LCC (Laboratoire de Chimie de Coordination), Université de Toulouse, UPS, INPT, 205 route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France CNRS.
| | - Agustí Lledós
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - Adrian C Whitwood
- Department of Chemistry, University of York, Heslington, York, YO10 5DD UK.
| | - Jason M Lynam
- Department of Chemistry, University of York, Heslington, York, YO10 5DD UK.
| | - John M Slattery
- Department of Chemistry, University of York, Heslington, York, YO10 5DD UK.
| | - Simon B Duckett
- Department of Chemistry, University of York, Heslington, York, YO10 5DD UK.
| | - Rinaldo Poli
- CNRS, LCC (Laboratoire de Chimie de Coordination), Université de Toulouse, UPS, INPT, 205 route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France CNRS. .,Institut Universitaire de France, 1, rue Descartes, 75231 Paris Cedex 05, France
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2
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Peppas A, Papadaki E, Schnakenburg G, Magrioti V, Philippopoulos AI. Heteroleptic copper(I) complexes incorporating sterically demanding diazabutadiene ligands (DABs). Synthesis, spectroscopic characterization and solid state structural analysis. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.07.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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4
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Eiβler A, Kläring P, Emmerling F, Braun T. α‐Dialdimine Complexes of Rhodium(I) and Iridium(I): Their Reactivity with Dioxygen and Dihydrogen. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300625] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anna Eiβler
- Humboldt‐Universität zu Berlin, Department of Chemistry, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany, Fax: +49‐30‐2093‐7468, http://www2.hu‐berlin.de/chemie/braun/
| | - Paul Kläring
- Humboldt‐Universität zu Berlin, Department of Chemistry, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany, Fax: +49‐30‐2093‐7468, http://www2.hu‐berlin.de/chemie/braun/
| | - Franziska Emmerling
- BAM Federal Institute for Materials Research and Testing, Richard‐Willstätter‐Str. 11, 12489 Berlin, Germany
| | - Thomas Braun
- Humboldt‐Universität zu Berlin, Department of Chemistry, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany, Fax: +49‐30‐2093‐7468, http://www2.hu‐berlin.de/chemie/braun/
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Penner A, Braun T. Rhodium and Iridium Complexes with α‐Diketimine Ligands: Oxidative Addition of H
2
and O
2. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anna Penner
- Humboldt‐Universität zu Berlin, Department of Chemistry, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany, Fax: +49‐30‐2093‐6939
| | - Thomas Braun
- Humboldt‐Universität zu Berlin, Department of Chemistry, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany, Fax: +49‐30‐2093‐6939
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Hillier AC, Lee HM, Stevens ED, Nolan SP. Cationic Iridium Complexes Bearing Imidazol-2-ylidene Ligands as Transfer Hydrogenation Catalysts. Organometallics 2001. [DOI: 10.1021/om0103456] [Citation(s) in RCA: 193] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna C. Hillier
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Hon Man Lee
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Edwin D. Stevens
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
| | - Steven P. Nolan
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148
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Bikrani M, Garralda MA, Ibarlucea L, Pinilla E, Torres MR. Pentacoordinated cationic rhodium(I) and iridium(I) organocomplexes with α-diimine ligands derived from glyoxal: crystal structure of [Rh(norbornadiene)(glyoxalbis(4-dimethylamino-anil))-(PPh3)]BF4 · 1/2CH2Cl2. Inorganica Chim Acta 1998. [DOI: 10.1016/s0020-1693(98)00237-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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