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Fontana LA, Rigolin VH, Ribeiro MA, Barros WP, Megiatto JD. A synthetic tactic to substitute axial ligands in sterically demanding Ru(II)porphyrinates. Dalton Trans 2022; 51:9971-9977. [PMID: 35708623 DOI: 10.1039/d2dt01095j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a synthetic strategy that allows for the preparation of sterically encumbered heteroleptic Ru(II)porphyrinates with the desired configuration of stable/inert and weak/labile axial ligands to direct reactions between substrates to exclusively occur at the sterically encumbered face. To demonstrate the method, we describe the synthesis of a strapped-Ru(II)porphyrinate bearing a stable/inert triphenylphosphine (PPh3) bulky axial ligand coordinated exo to the central cavity and a weak/labile methanol molecule coordinated at the internal axial position. With this axial ligand configuration, the reported Ru(II)porphyrinate exclusively promotes carbene transfer reactions to olefins through the central cavity, which has been verified by the selective formation of cycloprane-linked [2]rotaxanes.
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Affiliation(s)
- Liniquer A Fontana
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
| | - Vitor H Rigolin
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
| | - Marcos A Ribeiro
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
| | - Wdeson P Barros
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
| | - Jackson D Megiatto
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
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Gouré E, Gerey B, Astudillo CN, Pécaut J, Sirach S, Molton F, Fortage J, Collomb MN. Self-Assembled Heterometallic Complexes by Incorporation of Calcium or Strontium Ion into a Manganese(II) 12-Metallacrown-3 Framework Supported by a Tripodal Ligand with Pyridine-Carboxylate Motifs: Stability in Their Manganese(III) Oxidized Form. Inorg Chem 2021; 60:7922-7936. [PMID: 34014651 DOI: 10.1021/acs.inorgchem.1c00457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report on the isolation of a new family of μ-carboxylato-bridged metallocrown (MC) compounds by self-assembly of the recently isolated hexadentate tris(2-pyridylmethyl)amine ligand tpada2- incorporating two carboxylate units with metal cations. Twelve-membered MCs of manganese of the type 12-MC-3, namely, [{MnII(tpada)}3(M)(H2O)n]2+ (Mn3M) (M = Mn2+ (n = 0), Ca2+ (n = 1), or Sr2+ (n = 2)), were structurally characterized. The metallamacrocycles connectivity consisting in three -[Mn-O-C-O]- repeating units is provided by one carboxylate unit of the three tpada2- ligands, while the second carboxylate coordinated a fourth cation in the central cavity of the MC, Mn2+ or an alkaline earth metal, Ca2+ or Sr2+. Mn3Ca and {Mn3Sr}2 join the small family of heterometallic manganese-calcium complexes and even rarer manganese-strontium complexes as models of the OEC of photosystem II (PSII). A 8-MC-4 of strontium of the molecular wheel type with four -[Sr-O]- repeating unit was also isolated by self-assembly of the tpada2- ligand with Sr2+. This complex, namely, [Sr(tpada)(OH2)]4 (Sr4), does not incorporate any cation in the central cavity but instead four water molecules coordinated to each Sr2+. Electrochemical investigations coupled to UV-visible absorption and EPR spectroscopies as well as electrospray mass spectrometry reveal the stability of the 12-MC-3 tetranuclear structures in solution, both in the initial oxidation state, MnII3M, as well as in the three-electrons oxidized state, MnIII3M. Indeed, the cyclic voltammogram of all these complexes exhibits three-successive reversible oxidation waves between +0.5 and +0.9 V corresponding to the successive one-electron oxidation of the Mn(II) ion into Mn(III) of the three {Mn(tpada)} units constituting the ring, which are fully maintained after bulk electrolysis.
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Affiliation(s)
- Eric Gouré
- Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France
| | - Bertrand Gerey
- Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France.,Univ. Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, 38000 Grenoble, France
| | | | - Jacques Pécaut
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, 38000 Grenoble, France
| | - Selim Sirach
- Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France
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Fontana LA, Almeida MP, Alcântara AFP, Rigolin VH, Ribeiro MA, Barros WP, Megiatto JD. Ru(II)Porphyrinate-based molecular nanoreactor for carbene insertion reactions and quantitative formation of rotaxanes by active-metal-template syntheses. Nat Commun 2020; 11:6370. [PMID: 33311502 PMCID: PMC7733472 DOI: 10.1038/s41467-020-20046-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 10/29/2020] [Indexed: 12/28/2022] Open
Abstract
Selectivity in N–H and S–H carbene insertion reactions promoted by Ru(II)porphyrinates currently requires slow addition of the diazo precursor and large excess of the primary amine and thiol substrates in the reaction medium. Such conditions are necessary to avoid the undesirable carbene coupling and/or multiple carbene insertions. Here, the authors demonstrate that the synergy between the steric shielding provided by a Ru(II)porphyrinate-based macrocycle with a relatively small central cavity and the kinetic stabilization of otherwise labile coordinative bonds, warranted by formation of the mechanical bond, enables single carbene insertions to occur with quantitative efficiency and perfect selectivity even in the presence of a large excess of the diazo precursor and stoichiometric amounts of the primary amine and thiol substrates. As the Ru(II)porphyrinate-based macrocycle bears a confining nanospace and alters the product distribution of the carbene insertion reactions when compared to that of its acyclic version, the former therefore functions as a nanoreactor. Selectivity in carbene insertion reactions promoted by Ru(II)porphyrinates is achieved only upon careful control of substrate stoichiometry. Here, the authors demonstrate that endotopic catalysis and formation of mechanical bonds enables carbene insertions to occur selectively and in quantitative yield regardless of substrate stoichiometry.
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Affiliation(s)
- Liniquer A Fontana
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil
| | - Marlon P Almeida
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil
| | - Arthur F P Alcântara
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.,Instituto Federal do Sertão Pernambucano, Estrada do Tamboril, 56200-000, Ouricuri, Brazil
| | - Vitor H Rigolin
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil
| | - Marcos A Ribeiro
- Departamento de Química, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, 29075-910, Vitória, Brazil
| | - Wdeson P Barros
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil
| | - Jackson D Megiatto
- Institute of Chemistry, University of Campinas (UNICAMP), POBox 6154, 13083-970, Campinas, Brazil.
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Hutchinson DJ, Clauss R, Sárosi MB, Hey-Hawkins E. Supramolecular self-assembly of heterobimetallic complexes: a new N,P-based, selective heteroditopic ligand. Dalton Trans 2018; 47:1053-1061. [PMID: 29300413 DOI: 10.1039/c7dt04449f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Pyrimidine-hydrazone and phosphole architectures have been combined to create a new heteroditopic ligand capable of forming heterobimetallic ZnII/PdII, PbII/PdII and CuII/PdII complexes in high yielding stepwise or one pot reactions. The catalytic activity of these complexes in Heck coupling and Miyaura borylation reactions was investigated.
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Affiliation(s)
- Daniel John Hutchinson
- Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Leipzig University, D-04103 Leipzig, Germany.
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