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Semeniuchenko V, Sharif S, Rana N, Chandrasoma N, Braje WM, Baker RT, Manthorpe JM, Pietro WJ, Organ MG. Experimental Evidence for Zerovalent Pd(NHC) as a Competent Catalyst in C-N Cross-Coupling (NHC = DiMeIHept Cl). J Am Chem Soc 2024. [PMID: 39388666 DOI: 10.1021/jacs.4c12203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
Use of the branched N-heterocyclic carbene (NHC) ligand 1,3-bis(2,6-bis(3-methyl-1-(2-methylpropyl)butyl)phenyl)-4,5-dichloro-1,3-dihydro-2H-imidazole-2-ylidene (DiMeIHeptCl) facilitated the stabilization of several relevant intermediates for Pd(NHC)-catalyzed C-N cross-coupling reactions. Complexes [Pd(DiMeIHeptCl)]2(μ-N2), [Pd(DiMeIHeptCl)]2(μ-η2-1,2-η2-4,5-C6H6), and Pd(DiMeIHeptCl)(pyridine), representing zerovalent Pd(NHC) bearing labile ligands, were isolated and structurally characterized, along with divalent PdCl(Ph)(DiMeIHeptCl) and PdCl(Ph)(DiMeIHeptCl)(n-propylamine). The former is a 14-electron Pd complex, which is stable under air and chromatography on silica gel or neutral alumina. One possible reason for this exceptional stability is the numerous dispersion interactions between the NHC alkyl chains and the Pd-Ph group. Detailed investigations of catalyst activation and oxidative addition confirmed that "Pd(NHC)" is formed from many known Pd(II)(NHC) precatalysts and provided activation rates for these different precatalysts.
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Affiliation(s)
- Volodymyr Semeniuchenko
- Centre for Catalysis Research and Innovation (CCRI), Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
- NMR Core Facility, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Sepideh Sharif
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Neha Rana
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Nalin Chandrasoma
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Wilfried M Braje
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Discovery Research, Knollstrasse, Ludwigshafen 67061, Germany
| | - R Tom Baker
- Centre for Catalysis Research and Innovation (CCRI), Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Jeffrey M Manthorpe
- Department of Chemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - William J Pietro
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Michael G Organ
- Centre for Catalysis Research and Innovation (CCRI), Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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Malakar S, Gordon BM, Mandal S, Emge TJ, Goldman AS. Ruthenium Complexes of a Triphosphorus-Coordinating Pincer Ligand: Ru-P Ligand-Substituent Exchange Reactions Driven by Large Variations of Bond Energies. Inorg Chem 2023; 62:4525-4532. [PMID: 36881741 DOI: 10.1021/acs.inorgchem.2c04416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
The reaction of [(p-cymene)RuCl2]2 with the triphosphine ligand bis(2-di-tert-butylphosphinophenyl)phosphine (tBuPHPP) results in an unusual exchange reaction in which a chloride ligand and a phosphorus-bound H atom are exchanged ("H-P/Ru-Cl exchange") to give the (chlorophosphine)ruthenium hydride complex (tBuPClPP)RuHCl [1Cl-HCl; tBuPClPP = bis(2-di-tert-butylphosphinophenyl)chlorophosphine]. Density functional theory calculations indicate that the presumed initial product of metalation, (tBuPHPP)RuCl2 (1H-Cl2), undergoes an H-P/Ru-Cl exchange via sequential P-to-Ru α-H migration to give the intermediate (tBuPPP)RuHCl2, followed by Ru-to-P α-Cl migration to give the observed product 1Cl-HCl (crystallographically characterized). Dehydrochlorination of 1Cl-HCl under a H2 atmosphere gives (tBuPClPP)RuH4 (1Cl-H4), which then can undergo a second dehydrochlorination and addition of H2 to give (tBuPHPP)RuH4 (1H-H4). This reaction may proceed via the reverse of the intramolecular exchange by 1H-Cl2, i.e., loss of H2 from 1Cl-H4 to give 1Cl-H2, which could undergo Cl-P/Ru-H exchange to give (tBuPHPP)RuHCl (1H-HCl). Accordingly, the thermodynamics of Cl-P/Ru-H exchange are found to be highly dependent on the nature of the ancillary anionic ligand (H or Cl), which is not directly involved in the exchange. The origin of this thermodynamic dependence can be explained in terms of the high stability of complexes (RPXPP)RuHCl (X = H, Cl; R = Me, tBu), in which the hydride is approximately trans to a vacant coordination site and the central phosphine group is approximately trans to the weak-trans-influence chloride ligand. This conclusion has general implications for five-coordinate d6 complexes, both pincer- and nonpincer-ligated.
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Affiliation(s)
- Santanu Malakar
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Benjamin M Gordon
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Souvik Mandal
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Thomas J Emge
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Alan S Goldman
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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Grünwald A, Heinemann FW, Munz D. Oxidative Addition of Water, Alcohols, and Amines in Palladium Catalysis. Angew Chem Int Ed Engl 2020; 59:21088-21095. [PMID: 32745317 PMCID: PMC7692900 DOI: 10.1002/anie.202008350] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/22/2020] [Indexed: 11/25/2022]
Abstract
The homolytic cleavage of O-H and N-H or weak C-H bonds is a key elementary step in redox catalysis, but is thought to be unfeasible for palladium. In stark contrast, reported here is the room temperature and reversible oxidative addition of water, isopropanol, hexafluoroisopropanol, phenol, and aniline to a palladium(0) complex with a cyclic (alkyl)(amino)carbene (CAAC) and a labile pyridino ligand, as is also the case in popular N-heterocyclic carbene (NHC) palladium(II) precatalysts. The oxidative addition of protic solvents or adventitious water switches the chemoselectivity in catalysis with alkynes through activation of the terminal C-H bond. Most salient, the homolytic activation of alcohols and amines allows atom-efficient, additive-free cross-coupling and transfer hydrogenation under mild reaction conditions with usually unreactive, yet desirable reagents, including esters and bis(pinacolato)diboron.
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Affiliation(s)
- Annette Grünwald
- Department of Chemistry and Pharmacy, General and Inorganic ChemistryFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
| | - Frank W. Heinemann
- Department of Chemistry and Pharmacy, General and Inorganic ChemistryFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
| | - Dominik Munz
- Inorganic Chemistry: Coordination ChemistrySaarland UniversityCampus, Geb. C4.166123SaarbrückenGermany
- Department of Chemistry and Pharmacy, General and Inorganic ChemistryFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
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Grünwald A, Heinemann FW, Munz D. Oxidative Addition of Water, Alcohols, and Amines in Palladium Catalysis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Annette Grünwald
- Department of Chemistry and Pharmacy, General and Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Frank W. Heinemann
- Department of Chemistry and Pharmacy, General and Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Dominik Munz
- Inorganic Chemistry: Coordination Chemistry Saarland University Campus, Geb. C4.1 66123 Saarbrücken Germany
- Department of Chemistry and Pharmacy, General and Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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Rama RJ, Martín MT, Peloso R, Nicasio MC. Low-coordinate M(0) complexes of group 10 stabilized by phosphorus(III) ligands and N-heterocyclic carbenes. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2020. [DOI: 10.1016/bs.adomc.2020.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kukowski JE, Smoliakova IP. Steric and electronic effect of secondary phosphines in reactions with cyclopalladated complexes. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.11.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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