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Moustafa ME, Fard MA, Puddephatt RJ. Oxidative Addition of Halogens to a Dineophylplatinum(II) Complex: Halogen Complexes and Fluxional Platinum(IV) Complexes. J Organomet Chem 2023. [DOI: 10.1016/j.jorganchem.2023.122706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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2
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Rettig ID, Xu J, Knight EA, Truong PT, Bowring MA. Variable Kinetic Isotope Effect Reveals a Multistep Pathway for Protonolysis of a Pt–Me Bond. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Irving D. Rettig
- Department of Chemistry, Reed College, Portland, Oregon97202, United States
| | - Jingtong Xu
- Department of Chemistry, Reed College, Portland, Oregon97202, United States
| | | | - Phan T. Truong
- Department of Chemistry, Reed College, Portland, Oregon97202, United States
| | - Miriam A. Bowring
- Department of Chemistry, Reed College, Portland, Oregon97202, United States
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3
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Gubler J, Radić M, Stöferle Y, Chen P. 2‐Aminoalkylgold Complexes: The Putative Intermediate in Au‐Catalyzed Hydroamination of Alkenes Does Not Protodemetalate. Chemistry 2022; 28:e202200332. [PMID: 35319803 PMCID: PMC9401602 DOI: 10.1002/chem.202200332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Indexed: 11/30/2022]
Abstract
Au‐catalyzed hydroamination proceeds well for alkynes but not alkenes. We report gas‐phase binding energies of alkenes and alkynes to a cationic Au center, which indicate that differences in binding are not the origin of the disparate chemical behavior. We further report the synthesis and characterization of 2‐aminoalkylgold complexes, which would be the intermediates in a hypothetical Au‐catalyzed hydroamination of styrene. The reactivity of the well‐characterized and isolable complexes reveals that protonation or alkylation of the 2‐aminoalkylgold complexes results in amine elimination in solution, and in the gas phase, indicating that the failure of Au‐catalyzed alkene hydroamination derives from a non‐competitive protodeauration step. We analyze possible transition states for the protodeauration, and identify an insufficiently strong Au‐proton interaction as the reason that the transition states lie too high in energy to compete.
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Affiliation(s)
- Joël Gubler
- Laboratorium für Organische Chemie ETH Zürich Rämistrasse 101 8092 Zürich Switzerland
| | - Mitar Radić
- Laboratorium für Organische Chemie ETH Zürich Rämistrasse 101 8092 Zürich Switzerland
| | - Yannick Stöferle
- Laboratorium für Organische Chemie ETH Zürich Rämistrasse 101 8092 Zürich Switzerland
| | - Peter Chen
- Laboratorium für Organische Chemie ETH Zürich Rämistrasse 101 8092 Zürich Switzerland
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4
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Moustafa ME, Boyle PD, Puddephatt RJ. Reactivity and mechanism in reactions of methylene halides with cycloneophylplatinum(II) complexes: Oxidative addition and methylene insertion. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Farasat Z, Nabavizadeh SM, Niroomand Hosseini F, Hoseini SJ, Abu-Omar MM. Ligand-Controlled C sp2-H versus C sp3-H Bond Formation in Cycloplatinated Complexes: A Joint Experimental and Theoretical Mechanistic Investigation. Inorg Chem 2021; 60:1998-2008. [PMID: 33476136 DOI: 10.1021/acs.inorgchem.0c03502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cyclometalated platinum(II) complexes [PtMe(C∧N)(L)] [1PS: C∧N = 2-phenylpyridinate (ppy), L = SMe2; 1BS: C∧N = benzo[h]quinolate (bhq), L = SMe2; 1PP: C∧N = ppy, L = PPh3; and 1BP: C∧N = bhq, L = PPh3] containing two different cyclometalated ligands and two different ancillary ligands have been investigated in the reaction with CX3CO2H (X = F or H). When L = SMe2, the Pt-Me bond rather than the Pt-C bond of the cycloplatinated complex is cleaved to give the complexes [Pt(C∧N)(CX3CO2)(SMe2)]. When L = PPh3, the selectivity of the reaction is reversed. In the reaction of [PtMe(C∧N)(PPh3)] with CF3CO2H, the Pt-C∧N bond is cleaved rather than the Pt-Me bond. The latter reaction gave [PtMe(κ1N-Hppy)(PPh3)(CF3CO2)] as an equilibrium mixture of two isomers. For L = PPh3, no reaction was observed with CH3CO2H. The reasons for this difference in selectivity for complexes 1 are computationally discussed based on the energy barrier needed for the protonolysis of the Pt-Csp3 bond versus the Pt-Csp2 bond. Two pathways including the direct one-step acid attack at the Pt-C bond (SE2) and stepwise oxidative-addition on the Pt(II) center followed by reductive elimination [SE(ox)] are proposed. A detailed density functional theory (DFT) study of these protonations along with experimental UV-vis kinetics suggests that a one-step electrophilic attack (SE2) at the Pt-C bond is the most likely mechanism for complexes 1, and changing the nature of the ancillary ligand can influence the selectivity in the Pt-C bond cleavage. The effect of the nature of the acid and cyclometalated ligand (C∧N) is also discussed.
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Affiliation(s)
- Zahra Farasat
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - S Masoud Nabavizadeh
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran.,Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | | | - S Jafar Hoseini
- Professor Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Mahdi M Abu-Omar
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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6
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Bavi M, Nabavizadeh SM, Hosseini FN, Niknam F, Hamidizadeh P, Hoseini SJ, Raoof F, Abu-Omar MM. Ligand-Mediated C-Br Oxidative Addition to Cycloplatinated(II) Complexes and Benzyl-Me C-C Bond Reductive Elimination from a Cycloplatinated(IV) Complex. ACS OMEGA 2020; 5:28621-28631. [PMID: 33195914 PMCID: PMC7658948 DOI: 10.1021/acsomega.0c03573] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Reaction of the Pt(II) complexes [PtMe2(pbt)], 1a, (pbt = 2-(2-pyridyl)benzothiazole) and [PtMe(C^N)(PPh2Me)] [C^N = deprotonated 2-phenylpyridine (ppy), 1b, or deprotonated benzo[h]quinoline (bhq), 1c] with benzyl bromide, PhCH2Br, is studied. The reaction of 1a with PhCH2Br gave the Pt(IV) product complex [PtBr(CH2Ph)Me2(pbt)]. The major trans isomer is formed in a trans oxidative addition (2a), while the minor cis products (2a' and 2a″) resulted from an isomerization process. A solution of Pt(II) complex 1a in the presence of benzyl bromide in toluene at 70 °C after 7 days gradually gave the dibromo Pt(IV) complex [Pt(Br)2Me2(pbt)], 4a, as determined by NMR spectroscopy and single-crystal XRD. The reaction of complexes 1b and 1c with PhCH2Br gave the Pt(IV) complexes [PtMeBr(CH2Ph)(C^N)(PPh2Me)] (C^N = ppy; 2b; C^N = bhq, 2c), in which the phosphine and benzyl ligands are trans. Multinuclear NMR spectroscopy ruled out other isomers. Attempts to grow crystals of the cycloplatinated(IV) complex 2b yielded a previously reported Pt(II) complex [PtBr(ppy)(PPh2Me)], 3b, presumably from reductive elimination of ethylbenzene. UV-vis spectroscopy was used to study the kinetics of reaction of Pt(II) complexes 1a-1c with benzyl bromide. The data are consistent with a second-order SN2 mechanism and the first order in both the Pt complex and PhCH2Br. The rate of reaction decreases along the series 1a ≫ 1c > 1b. Density functional theory calculations were carried out to support experimental findings and understand the formation of isomers.
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Affiliation(s)
- Marzieh Bavi
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - S. Masoud Nabavizadeh
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | | | - Fatemeh Niknam
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Peyman Hamidizadeh
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - S. Jafar Hoseini
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Fatemeh Raoof
- Professor Rashidi
Laboratory of Organometallic Chemistry, Department of Chemistry, College
of Sciences, Shiraz University, Shiraz 71467-13565, Iran
| | - Mahdi M. Abu-Omar
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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Ujjval R, Deepa M, Thomas JM, Sivasankar C, Thirupathi N. Unusual [Pt{κ 2( C, N)}] + → [Pt{κ 2( N, N)}] + Coordination Mode Flip of the Guanidinate(1−) Ligand in Cationic N, N′, N″-Tris(3,5-xylyl)guanidinatoplatinum(II) Bis(phosphine) Complexes. Syntheses, Structural and Theoretical Studies. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rishabh Ujjval
- Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Masilamani Deepa
- Postgraduate and Research Department of Chemistry, Muthurangam Government Arts College (Autonomous), Vellore 632 002, Tamil Nadu, India
| | - Jisha Mary Thomas
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), R. V. Nagar, Kalapet, Pondicherry 605 014, India
| | - Chinnappan Sivasankar
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), R. V. Nagar, Kalapet, Pondicherry 605 014, India
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Fard MA, Puddephatt RJ. Oxidative addition of halogens to a Cycloneophylplatinum(II) complex and evidence for C–H bond activation at Platinum(IV). J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2020.121139] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Neugebauer M, Schmitz S, Brünink D, Doltsinis NL, Klein A. Dynamics of the efficient cyclometalation of the undercoordinated organoplatinum complex [Pt(COD)(neoPh)] + (neoPh = 2-methyl-2-phenylpropyl). NEW J CHEM 2020. [DOI: 10.1039/d0nj04811a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD)(κ2-neoPh)] was studied experimentally and mechanistically using DFT and MD simulations.
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Affiliation(s)
- Michael Neugebauer
- University of Cologne
- Department of Chemistry
- Institute for Inorganic Chemistry
- D-50939 Cologne
- Germany
| | - Simon Schmitz
- University of Cologne
- Department of Chemistry
- Institute for Inorganic Chemistry
- D-50939 Cologne
- Germany
| | - Dana Brünink
- Westfälische Wilhelms-Universität Münster
- Institut für Festkörpertheorie and Center for Multiscale Theory and Computation
- 48149 Münster
- Germany
| | - Nikos L. Doltsinis
- Westfälische Wilhelms-Universität Münster
- Institut für Festkörpertheorie and Center for Multiscale Theory and Computation
- 48149 Münster
- Germany
| | - Axel Klein
- University of Cologne
- Department of Chemistry
- Institute for Inorganic Chemistry
- D-50939 Cologne
- Germany
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Behnia A, Fard MA, Puddephatt RJ. Stereochemistry of oxidative addition of methyl iodide and hydrogen peroxide to organoplatinum(II) complexes having an appended phenol group and the supramolecular chemistry of the platinum(IV) products. J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2019.120962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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11
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Stereochemistry of oxidative addition reactions of cycloneophyl complexes of Platinum(II): A methylene insertion reaction from dichloromethane. J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2019.03.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Puddephatt RJ. Selectivity in carbon–carbon coupling reactions at palladium(IV) and platinum(IV). CAN J CHEM 2019. [DOI: 10.1139/cjc-2019-0015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The isomerization and reductive elimination reactions from octahedral organometallic complexes of palladium(IV) and platinum(IV) usually occur through five-coordinate intermediates that cannot be directly detected. This paper reports a computational study of five-coordinate complexes of formulae [PtMe3(bipy)]+, [PtMe2Ph(bipy)]+, and [PtMe(CH2CMe2C6H4)(bipy)]+ (M = Pd or Pt, bipy = 2,2′-bipyridine), particularly with respect to reactivity and selectivity in reductive elimination. All of the complexes are predicted to have square pyramidal structures with the bipy and two R groups in the equatorial positions and one R group in the axial position, and axial–equatorial exchange occurs by a pairwise mechanism, with the transition state having a pinched trigonal bipyramidal (PTBP) stereochemistry, with one nitrogen and two R groups in the trigonal plane. The activation energy for isomerization is lower than that for reductive elimination in all cases. For the complexes [MMe2Ph(bipy)]+, the activation energies for reductive elimination with Me–Me or Me–Ph coupling are similar. For the complexes [MMe(CH2CMe2C6H4)(bipy)]+, the reductive elimination with Me–C6H4 bond formation from the isomer with the methyl group in the axial position is predicted and is attributed to it having the best conformation of the Me and C6H4 groups for C–C bond formation. In all cases, the selectivity for reductive elimination is similar for M = Pd or Pt, but reactivity is higher for M = Pd. The relevance of this work to selectivity in catalysis is discussed.
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Affiliation(s)
- Richard J. Puddephatt
- Department of Chemistry, University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Chemistry, University of Western Ontario, London, ON N6A 5B7, Canada
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Behnia A, Fard MA, Boyle PD, Puddephatt RJ. Complexes Containing a Phenol–Platinum(II) Hydrogen Bond: Synthons for Supramolecular Self‐Assembly and Precursors for Hydridoplatinum(IV) Complexes. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900480] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ava Behnia
- Department of Chemistry The University of Western Ontario London N6A 5B7 Canada
| | | | - Paul D. Boyle
- Department of Chemistry The University of Western Ontario London N6A 5B7 Canada
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Mrózek O, Dostál L, Císařová I, Honzíček J, Vinklárek J. Propene complexes of molybdenum and tungsten stabilized by intramolecular coordination of the 1-(quinol-8-yl)indenyl ligand. Dalton Trans 2019; 48:12210-12218. [DOI: 10.1039/c9dt02229e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Synthesis, reactivity and properties of unusually stable propene complexes of molybdenum and tungsten are reported.
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Affiliation(s)
- Ondřej Mrózek
- Department of General and Inorganic Chemistry
- Faculty of Chemical Technology
- University of Pardubice
- 532 10 Pardubice
- Czech Republic
| | - Libor Dostál
- Department of General and Inorganic Chemistry
- Faculty of Chemical Technology
- University of Pardubice
- 532 10 Pardubice
- Czech Republic
| | - Ivana Císařová
- Department of Inorganic Chemistry
- Faculty of Science
- Charles University in Prague
- 128 43 Prague 2
- Czech Republic
| | - Jan Honzíček
- Institute of Chemistry and Technology of Macromolecular Materials
- Faculty of Chemical Technology
- University of Pardubice
- 532 10 Pardubice
- Czech Republic
| | - Jaromír Vinklárek
- Department of General and Inorganic Chemistry
- Faculty of Chemical Technology
- University of Pardubice
- 532 10 Pardubice
- Czech Republic
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