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Shteinman AA, Mitra M. Nonheme mono- and dinuclear iron complexes in bio-inspired C H and C C bond hydroxylation reactions: Mechanistic insight. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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2
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Kalra A, Bagchi V, Paraskevopoulou P, Das P, Ai L, Sanakis Y, Raptopoulos G, Mohapatra S, Choudhury A, Sun Z, Cundari TR, Stavropoulos P. Is the Electrophilicity of the Metal Nitrene the Sole Predictor of Metal-Mediated Nitrene Transfer to Olefins? Secondary Contributing Factors as Revealed by a Library of High-Spin Co(II) Reagents. Organometallics 2021; 40:1974-1996. [PMID: 35095166 PMCID: PMC8797515 DOI: 10.1021/acs.organomet.1c00267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent research has highlighted the key role played by the electron affinity of the active metal-nitrene/imido oxidant as the driving force in nitrene additions to olefins to afford valuable aziridines. The present work showcases a library of Co(II) reagents that, unlike the previously examined Mn(II) and Fe(II) analogues, demonstrate reactivity trends in olefin aziridinations that cannot be solely explained by the electron affinity criterion. A family of Co(II) catalysts (17 members) has been synthesized with the assistance of a trisphenylamido-amine scaffold decorated by various alkyl, aryl, and acyl groups attached to the equatorial amidos. Single-crystal X-ray diffraction analysis, cyclic voltammetry and EPR data reveal that the high-spin Co(II) sites (S = 3/2) feature a minimal [N3N] coordination and span a range of 1.4 V in redox potentials. Surprisingly, the Co(II)-mediated aziridination of styrene demonstrates reactivity patterns that deviate from those anticipated by the relevant electrophilicities of the putative metal nitrenes. The representative L4Co catalyst (-COCMe3 arm) is operating faster than the L8Co analogue (-COCF3 arm), in spite of diminished metal-nitrene electrophilicity. Mechanistic data (Hammett plots, KIE, stereocontrol studies) reveal that although both reagents follow a two-step reactivity path (turnover-limiting metal-nitrene addition to the C b atom of styrene, followed by product-determining ring-closure), the L4Co catalyst is associated with lower energy barriers in both steps. DFT calculations indicate that the putative [L4Co]NTs and [L8Co]NTs species are electronically distinct, inasmuch as the former exhibits a single-electron oxidized ligand arm. In addition, DFT calculations suggest that including London dispersion corrections for L4Co (due to the polarizability of the tert-Bu substituent) can provide significant stabilization of the turnover-limiting transition state. This study highlights how small ligand modifications can generate stereoelectronic variants that in certain cases are even capable of overriding the preponderance of the metal-nitrene electrophilicity as a driving force.
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Affiliation(s)
- Anshika Kalra
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Vivek Bagchi
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States; Institute of Nano Science and Technology, Mohali, Punjab 160062, India
| | - Patrina Paraskevopoulou
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Purak Das
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Lin Ai
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States; College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Yiannis Sanakis
- Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, NCSR "Demokritos", Athens 15310, Greece
| | - Grigorios Raptopoulos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Sudip Mohapatra
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Amitava Choudhury
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Zhicheng Sun
- Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, Texas 76203, United States
| | - Thomas R Cundari
- Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, Texas 76203, United States
| | - Pericles Stavropoulos
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
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Bhoumik NC, Joy MTR, Ghosh S, Richmond MG, Kabir SE. Thermolysis of [HOs3(CO)8{µ3-Ph2PCH2P(Ph)C6H4}]: New Os2- and Os3- cluster products based on multiple C H bond activation of the bis(diphenylphosphino)methane ligand. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Baulina ТV, Kudryavtsev IY, Sykat GY, Brel’ VK. Synthesis of Functionalized Tris(2-propoxyphenyl)phosphine Oxides as Precursors of Tripodal Propeller-Shaped Ligands. RUSS J GEN CHEM+ 2018. [DOI: 10.1134/s1070363218090281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Bagchi V, Kalra A, Das P, Paraskevopoulou P, Gorla S, Ai L, Wang Q, Mohapatra S, Choudhury A, Sun Z, Cundari TR, Stavropoulos P. Comparative Nitrene-Transfer Chemistry to Olefinic Substrates Mediated by a Library of Anionic Mn(II) Triphenylamido-Amine Reagents and M(II) Congeners (M = Fe, Co, Ni) Favoring Aromatic over Aliphatic Alkenes. ACS Catal 2018. [DOI: 10.1021/acscatal.8b01941] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Vivek Bagchi
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Anshika Kalra
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Purak Das
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Patrina Paraskevopoulou
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou 15771, Athens, Greece
| | - Saidulu Gorla
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Lin Ai
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
- College of Chemistry, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Qiuwen Wang
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Sudip Mohapatra
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Amitava Choudhury
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Zhicheng Sun
- Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, Texas 76203, United States
| | - Thomas R. Cundari
- Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, Texas 76203, United States
| | - Pericles Stavropoulos
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
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Mondal D, Bhattacharya K. Synthesis and structural characterization of a hemiacetal and aldehyde bound diiron(III) complex with two different coordination numbers: A product by oxidative cleavage of carbon nitrogen single bond. INORG CHEM COMMUN 2017. [DOI: 10.1016/j.inoche.2017.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Drover MW, Love JA, Schafer LL. 1,3-N,O-Complexes of late transition metals. Ligands with flexible bonding modes and reaction profiles. Chem Soc Rev 2017; 46:2913-2940. [DOI: 10.1039/c6cs00715e] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
1,3-N,O-Chelating ligands are ubiquitous in nature owing to their occurrence as α-chiral amino acids in metalloproteins.
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Affiliation(s)
- Marcus W. Drover
- Department of Chemistry
- The University of British Columbia Vancouver
- Canada
| | - Jennifer A. Love
- Department of Chemistry
- The University of British Columbia Vancouver
- Canada
| | - Laurel L. Schafer
- Department of Chemistry
- The University of British Columbia Vancouver
- Canada
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Abstract
Two new Eu(II)-containing cryptates were prepared with a new nitrogenous cryptand functionalized with three benzo groups. The introduction of three aromatic rings into the ligand backbone imparts lopsided geometrical features on the resulting Eu(II) coordination environments. In both complexes, the interactions between Eu and the amines on the aromatic side of the molecule are weaker than those on the nonaromatic side, resulting in one discrete unit with two distinct faces. One of the new complexes is, to the best of our knowledge, the first direct observation of a bis-aquo Eu(II)-containing cryptate with two nonadjacent inner-sphere water molecules. In addition to solid-phase structure, the electronic UV-visible and emission spectra of the new complexes were studied in acetonitrile. Experimental results show that the decreased Lewis basicity of the aromatic face hypsochromically shifts absorbances and emissions from a structurally related compound without the benzo groups.
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Affiliation(s)
- Guo-Xia Jin
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University , Jinan 250014, P. R. China.,Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States
| | - Matthew D Bailey
- Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States
| | - Matthew J Allen
- Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States
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Ryken SA, Schafer LL. N,O-Chelating Four-Membered Metallacyclic Titanium(IV) Complexes for Atom-Economic Catalytic Reactions. Acc Chem Res 2015; 48:2576-86. [PMID: 26247696 DOI: 10.1021/acs.accounts.5b00224] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Titanium, as the second most abundant transition metal in the earth's crust, lends itself as a sustainable and inexpensive resource in catalysis. Its nontoxicity and biocompatibility are also attractive features for handling and disposal. Titanium has excelled as a catalyst for a broad range of transformations, including ethylene and α-olefin polymerizations. However, many reactions relevant to fine chemical synthesis have preferrentially employed late transition metals, and reactive, inexpensive early transition metals have been largely overlooked. In addition to promising reactivity, titanium complexes feature more robust character compared with some other highly Lewis-acidic metals such as those found in the lanthanide series. Since the advent of modulating ligand scaffolds, titanium has found use in a growing variety of reactions as a versatile homogeneous catalyst. These catalytic transformations include hydrofunctionalization reactions (adding an element-hydrogen (E-H) bond across a C-C multiple bond), as well as the ring-opening polymerization of cyclic esters, all of which are atom-economic transformations. Our investigations have focused on tight bite angle monoanionic N,O-chelating ligands, forming four-membered metallacycles. These ligand sets, including amidates, ureates, pyridonates, and sulfonamidates, have flexible binding modes offering a range of stable and reactive intermediates necessary for catalytic activity. Additionally, the simple form of these ligands leads to easily prepared proligands, along with facile tuning of steric and electronic factors. A sterically bulky titanium amidate complex has proven to be a leading catalyst for the selective formation of anti-Markovnikov addition products via intermolecular hydroamination of terminal alkynes, while sterically less demanding titanium pyridonates have opened the path to the selective formation of amine substituted cycloalkanes via the intramolecular hydroaminoalkylation of aminoalkenes over the competing hydroamination pathway. Sulfonamidates have boosted reactivity for hydrofunctionalization and polymerization reactions compared with amide ligands not bearing a sulfonyl group. N,O-Chelated titanium complexes have been used to synthesize ultrahigh molecular weight polyethylene and have been utilized in the challenging task of realizing equal incorporation of two different cyclic esters in a random ring-opening copolymerization. These discrete complexes have allowed for careful study of fundamental coordination chemistry and stoichiometric organometallic investigations. With inexpensive starting materials and modular ligands, titanium N,O-chelated complexes are well-suited to address the challenges of achieving greener chemical processes while accessing useful reaction manifolds for sustainable synthesis.
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Affiliation(s)
- Scott A. Ryken
- Department of Chemistry, University of British Columbia, 2036
Main Mall, Vancouver, British
Columbia V6T 1Z1, Canada
| | - Laurel L. Schafer
- Department of Chemistry, University of British Columbia, 2036
Main Mall, Vancouver, British
Columbia V6T 1Z1, Canada
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Brown JL, Jones MB, Gaunt AJ, Scott BL, MacBeth CE, Gordon JC. Lanthanide(III) Di- and Tetra-Nuclear Complexes Supported by a Chelating Tripodal Tris(Amidate) Ligand. Inorg Chem 2015; 54:4064-75. [DOI: 10.1021/acs.inorgchem.5b00299] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - Cora E. MacBeth
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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11
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Yeagle KP, Hester D, Piro NA, Dougherty WG, Kassel WS, Graves CR. Synthesis, Characterization, and Catalytic Activity of a Series of Aluminium–Amidate Complexes. Aust J Chem 2015. [DOI: 10.1071/ch14514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aluminium complexes {[κ2-N,O-(t-BuNCOPh)]AlMe2}2 (2), [κ2-N,O-(t-BuNCOPh)]2AlMe (3), and [κ2-N,O-(t-BuNCOPh)]3Al (4) were prepared through the protonolysis reaction between trimethylaluminium and one, two, or three equivalents, respectively, of N-tert-butylbenzamide. Complex 2 was also prepared via a salt metathesis reaction between K(t-BuNCOPh) and dimethylaluminium chloride. Complexes 2–4 were characterized using 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction analysis of the complexes corroborated ligand : metal stoichiometries and revealed that all the amidate ligands coordinate to the aluminium ion in a κ2 fashion. The Al–amidate complexes 2–4 were viable catalyst precursors for the Meerwein–Ponndorf–Verley–Oppenauer reduction–oxidation manifold, successfully interconverting several classes of carbonyl and alcohol substrates.
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12
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Di(alkylamido)zirconium dichlorides and tri(arylamido)zirconium monochlorides having hemilabile N, O ligands and their methyl derivatives. J Organomet Chem 2015. [DOI: 10.1016/j.jorganchem.2014.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Hu X, Lu C, Wu B, Ding H, Zhao B, Yao Y, Shen Q. Synthesis and structural diversity of lanthanide amidate complexes and their catalytic activities for the ring-opening polymerization of rac-lactide. J Organomet Chem 2013. [DOI: 10.1016/j.jorganchem.2013.02.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Bagchi V, Raptopoulos G, Das P, Christodoulou S, Wang Q, Ai L, Choudhury A, Pitsikalis M, Paraskevopoulou P, Stavropoulos P. Synthesis and characterization of a family of Co(II) triphenylamido-amine complexes and catalytic activity in controlled radical polymerization of olefins. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.11.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Maddox AF, Erickson KA, Tanski JM, Waterman R. C–N Bond formation via ligand-induced nucleophilicity at a coordinated triamidoamine ligand. Chem Commun (Camb) 2011; 47:11769-71. [DOI: 10.1039/c1cc15179g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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