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Tendera L, Krummenacher I, Radius U. Cationic Nickel d9‐Metalloradicals [Ni(NHC)2]+. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lukas Tendera
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Ivo Krummenacher
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Udo Radius
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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Omer H, Liu P. Computational Study of the Ni-Catalyzed C-H Oxidative Cycloaddition of Aromatic Amides with Alkynes. ACS OMEGA 2019; 4:5209-5220. [PMID: 31459693 PMCID: PMC6648058 DOI: 10.1021/acsomega.9b00030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 02/01/2019] [Indexed: 06/10/2023]
Abstract
The mechanism of Ni-catalyzed ortho C(sp2)-H oxidative cycloaddition of aromatic amides with internal alkynes containing 2-pyridinylmethylamine directing group was investigated using density functional theory (DFT) calculations. The C-H cleavage step proceeds via σ-complex-assisted metathesis (σ-CAM) with an alkenyl-Ni(II) complex. This is in contrast to the more common carboxylate/carbonate-assisted concerted metalation-deprotonation mechanism in related Ni-catalyzed C-H bond functionalization reactions with N,N-bidentate directing groups. In this reaction, the alkyne not only serves as the coupling partner, but also facilitates the σ-CAM C-H metalation both kinetically and thermodynamically. The subsequent functionalization of the five-membered nickelacycle proceeds via alkyne insertion into the Ni-C bond to form a seven-membered nickelacycle. This process proceeds with high levels of regioselectivity to form a C-C bond with sterically more encumbered alkyne terminus. This unusual regioselectivity is due to steric repulsions with the directing group that is coplanar with the alkyne in the migratory insertion transition state. The C-N bond reductive elimination to form the isoquinolone cycloadduct is promoted by PPh3 complexation to the Ni center and the use of flexible 2-pyridinylmethylamine directing group. The origin of the cis-trans isomerism of alkene byproduct was also explained by computations.
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Affiliation(s)
- Humair
M. Omer
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Peng Liu
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
- Department
of Chemical and Petroleum Engineering, University
of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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Desnoyer AN, He W, Behyan S, Chiu W, Love JA, Kennepohl P. The Importance of Ligand-Induced Backdonation in the Stabilization of Square Planar d 10 Nickel π-Complexes. Chemistry 2019; 25:5259-5268. [PMID: 30693581 DOI: 10.1002/chem.201805987] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 01/06/2023]
Abstract
The electronic nature of Ni π-complexes is underexplored even though these complexes have been widely postulated as intermediates in organometallic chemistry. Herein, the geometric and electronic structure of a series of nickel π-complexes, Ni(dtbpe)(X) (dtbpe=1,2-bis(di-tert-butyl)phosphinoethane; X=alkene or carbonyl containing π-ligands), is probed using a combination of 31 P NMR, Ni K-edge XAS, Ni Kβ XES, and DFT calculations. These complexes are best described as square planar d10 complexes with π-backbonding acting as the dominant contributor to M-L bonding to the π-ligand. The degree of backbonding correlates with 2 JPP from NMR and the energy of the Ni 1s→4pz pre-edge in the Ni K-edge XAS data, and is determined by the energy of the π*ip ligand acceptor orbital. Thus, unactivated olefinic ligands tend to be poor π-acids whereas ketones, aldehydes, and esters allow for greater backbonding. However, backbonding is still significant even in cases in which metal contributions are minor. In such cases, backbonding is dominated by charge donation from the diphosphine, which allows for strong backdonation, although the metal centre retains a formal d10 electronic configuration. This ligand-induced backbonding can be formally described as a 3-centre-4-electron (3c-4e) interaction, in which the nickel centre mediates charge transfer from the phosphine σ-donors to the π*ip ligand acceptor orbital. The implications of this bonding motif are described with respect to both structure and reactivity.
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Affiliation(s)
- Addison N Desnoyer
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Weiying He
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Shirin Behyan
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Weiling Chiu
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Jennifer A Love
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Pierre Kennepohl
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
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Xu H, White PB, Hu C, Diao T. Structure and Isotope Effects of the β‐H Agostic (α‐Diimine)Nickel Cation as a Polymerization Intermediate. Angew Chem Int Ed Engl 2017; 56:1535-1538. [DOI: 10.1002/anie.201611282] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Hongwei Xu
- ChemistryNew York University 100 Washington Square E. New York NY USA
| | - Paul B. White
- Institute for Molecules and MaterialsRadboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Chunhua Hu
- ChemistryNew York University 100 Washington Square E. New York NY USA
| | - Tianning Diao
- ChemistryNew York University 100 Washington Square E. New York NY USA
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Xu H, White PB, Hu C, Diao T. Structure and Isotope Effects of the β-H Agostic (α-Diimine)Nickel Cation as a Polymerization Intermediate. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201611282] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hongwei Xu
- Chemistry; New York University; 100 Washington Square E. New York NY USA
| | - Paul B. White
- Institute for Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Chunhua Hu
- Chemistry; New York University; 100 Washington Square E. New York NY USA
| | - Tianning Diao
- Chemistry; New York University; 100 Washington Square E. New York NY USA
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Lavoie CM, MacQueen PM, Stradiotto M. Nickel-Catalyzed N-Arylation of Primary Amides and Lactams with Activated (Hetero)aryl Electrophiles. Chemistry 2016; 22:18752-18755. [DOI: 10.1002/chem.201605095] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 12/23/2022]
Affiliation(s)
| | - Preston M. MacQueen
- Department of Chemistry; Dalhousie University; Halifax Nova Scotia B3H 4R2 Canada
| | - Mark Stradiotto
- Department of Chemistry; Dalhousie University; Halifax Nova Scotia B3H 4R2 Canada
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