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Chen C, Wu F, Ji J, Jia AQ, Zhang QF. Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2020. [DOI: 10.1515/znb-2020-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Treatment of [(η
6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η
6-p-cymene)RuCl2(κ
1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ
1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ
3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]
n
with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ
3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.
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Affiliation(s)
- Chong Chen
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Fule Wu
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Jiao Ji
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Ai-Quan Jia
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
| | - Qian-Feng Zhang
- Institute of Molecular Engineering and Applied Chemistry , Anhui University of Technology , Ma’anshan , Anhui 243002 , PR China
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2
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Nikitin K, O'Gara R. Mechanisms and Beyond: Elucidation of Fluxional Dynamics by Exchange NMR Spectroscopy. Chemistry 2019; 25:4551-4589. [PMID: 30421834 DOI: 10.1002/chem.201804123] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Indexed: 12/31/2022]
Abstract
Detailed mechanistic information is crucial to our understanding of reaction pathways and selectivity. Dynamic exchange NMR techniques, in particular 2D exchange spectroscopy (EXSY) and its modifications, provide indispensable intricate information on the mechanisms of organic and inorganic reactions and other phenomena, for example, the dynamics of interfacial processes. In this Review, key results from exchange NMR studies of small molecules over the last few decades are systemised and discussed. After a brief introduction to the theory, the key types of dynamic processes are identified and fundamental examples given of intra- and intermolecular reactions, which, in turn, could involve, or not, bond-making and bond-breaking events. Following that logic, internal molecular rotation, intramolecular stereomutation and molecular recognition will first be considered because they do not typically involve bond breaking. Then, rearrangements, substitution-type reactions, cyclisations, additions and other processes affecting chemical bonds will be discussed. Finally, interfacial molecular dynamics and unexpected combinations of different types of fluxional processes will also be highlighted. How exchange NMR spectroscopy helps to identify conformational changes, coordination and molecular recognition processes as well as quantify reaction energy barriers and extract detailed mechanistic information by using reaction rate theory in conjunction with computational techniques will be shown.
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Affiliation(s)
- Kirill Nikitin
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
| | - Ryan O'Gara
- School of Chemistry, University College Dublin, Belfield, Dublin, Ireland
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3
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Huber R, Bigler R, Mezzetti A. Chiral Iron(II) NPPN Complexes: Synthesis and Application in the Asymmetric Strecker Reaction of Azomethine Imines. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00357] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raffael Huber
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Raphael Bigler
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Antonio Mezzetti
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
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4
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Naidu KS, Patil YP, Nethaji M, Jagirdar BR. Synthesis, characterization and reactivity studies of electrophilic ruthenium(II) complexes: a study of H₂ activation and labilization. Dalton Trans 2014; 43:13410-23. [PMID: 25077596 DOI: 10.1039/c4dt00295d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Reaction of 2,2'-bipyridine (bpy) with dinuclear complexes [RuCl(dfppe)(μ-Cl)3Ru(dmso-S)3] (dfppe = 1,2-bis(dipentafluorophenyl phosphino)ethane (C6F5)2PCH2CH2P(C6F5)2; dmso = dimethyl sulfoxide) (1) or [RuCl(dfppe)(μ-Cl)3RuCl(dfppe)] (2) affords the mononuclear species trans-[RuCl2(bpy)(dfppe)] (3). Using this precursor complex (3), a series of new cationic Ru(II) electrophilic complexes [RuCl(L)(bpy)(dfppe)][Z] (L = P(OMe)3 (5), PMe3 (6), CH3CN (7), CO (8), H2O (9); Z = OTf (5, 6, 7, 8), BAr(F)4 (9) have been synthesized via abstraction of chloride by AgOTf or NaBAr(F)4 in the presence of L. Complexes 5 and 6 were converted into the corresponding isomeric hydride derivatives [RuH(PMe3)(bpy)(dfppe)][OTf] (10a, 10b) and [RuH(P(OMe)3)(bpy)(dfppe)][OTf] (11a, 11b) respectively, when treated with NaBH4. Protonation of the cationic monohydride complex (11a) with HOTf at low temperatures resulted in H2 evolution accompanied by the formation of either solvent or triflate bound six coordinated species [Ru(S)(P(OMe)3)(bpy)(dfppe)][OTf]n [(S = solvent (n = 2), triflate (n = 1)] (13a/13b); these species have not been isolated and could not be established with certainty. They (13a/13b) were not isolated, instead the six-coordinated isomeric aqua complexes cis-[Ru(bpy)(dfppe)(OH2)(P(OMe)3)][OTf]2 (14a/14b) were isolated. Reaction of the aqua complexes (14a/14b) with 1 atm of H2 at room temperature in acetone-d6 solvent resulted in heterolytic cleavage of the H-H bond. Results of the studies on H2 lability and heterolytic activation using these complexes are discussed. The complexes 3, 5, 11a, and 14a have been structurally characterized.
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Affiliation(s)
- K S Naidu
- Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560012, India.
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5
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Egloff J, Ranocchiari M, Schira A, Schotes C, Mezzetti A. Highly Enantioselective Ruthenium/PNNP-Catalyzed Imine Aziridination: Evidence of Carbene Transfer from a Diazoester Complex. Organometallics 2013. [DOI: 10.1021/om400735p] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joël Egloff
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Marco Ranocchiari
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Amata Schira
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Christoph Schotes
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Antonio Mezzetti
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
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6
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Ma ESF, Patrick BO, James BR. Reversible binding of water, methanol, and ethanol to a five-coordinate ruthenium(II) complex. Dalton Trans 2013; 42:4291-8. [PMID: 23344393 DOI: 10.1039/c3dt32909g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The known green, five-coordinate, square-pyramidal trans-RuCl(2)(P-N)(PPh(3)) complex reversibly binds water, MeOH and EtOH in the vacant coordination site in the solid state and in CH(2)Cl(2) solution to give pink adducts (P-N = o-diphenylphosphino-N,N'-dimethylaniline). The adducts are well characterized, including X-ray analysis of the aqua complex, trans-RuCl(2)(P-N)(PPh(3))(H(2)O), which crystallizes in two different benzene-solvated forms. Comparison of the structural data with those determined previously for the binding of H(2)S, thiols, and H(2), which form cis-RuX(2)(P-N)(PPh(3))L products (X = Cl, Br; L = a S-ligand or H(2)) reveals the trans-influence trend P > H(2)S ~ thiols > H(2) > Cl ~ Br > H(2)O. Thermodynamic data for the binding of water were estimated in solution by UV-Vis spectroscopy, and ΔH(o) data for the aqua and alcohol adducts in the solid state were obtained by differential scanning calorimetry. Inclusion of published data for the S-ligand adducts reveals the thermal stability trend of the solid complexes as MeSH > MeOH > H(2)S > H(2)O > EtSH > EtOH.
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Affiliation(s)
- Erin S F Ma
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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7
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Schotes C, Mezzetti A. Alkylidene β-Ketoesters in Asymmetric Catalysis: Recent Developments. ACS Catal 2012. [DOI: 10.1021/cs300035m] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christoph Schotes
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093
Zürich, Switzerland
| | - Antonio Mezzetti
- Department of Chemistry and Applied
Biosciences, ETH Zürich, CH-8093
Zürich, Switzerland
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8
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Schotes C, Althaus M, Aardoom R, Mezzetti A. Asymmetric Diels-Alder and Ficini reactions with alkylidene β-ketoesters catalyzed by chiral ruthenium PNNP complexes: mechanistic insight. J Am Chem Soc 2012; 134:1331-43. [PMID: 22191539 DOI: 10.1021/ja210372u] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydride abstraction from the β-position of the enolato ligand of the previously reported complex [Ru(3a-H)(PNNP)]PF(6) (5a; 3a-H is the enolate of 2-tert-butoxycarbonylcyclopentanone) with (Ph(3)C)PF(6) gives the dicationic complex [Ru(6a)(PNNP)](2+) (7a) as a single diastereoisomer, which contains the unsaturated β-ketoester 2-tert-butoxycarbonyl-2-cyclopenten-1-one (6a) as a chelating ligand. The methyl analogue 2-methoxycarbonylcyclopentanone (3b) gives [Ru(3b-H)(PNNP)]PF(6) as a mixture of noninterconverting diastereoisomers (ester group of 3b trans to P, 5b; or to N, 5c), which were separated by column chromatography. Hydride abstraction from 5b (or 5c) yields diastereomerically pure [Ru(6b)(PNNP)](2+) (7b or 7c). Complexes 7b and 7c do not interconvert at room temperature in CD(2)Cl(2) and form opposite enantiomers of the Diels-Alder adduct upon reaction with Dane's diene (1 equiv). X-ray studies of 7a, 5b, and 5c give insight into the origin of enantioselection and the sense of asymmetric induction in the previously reported asymmetric Diels-Alder and Ficini cycloaddition reactions with 2,3-disubstituted butadienes and ynamides, respectively. Stoichiometric reactions (substrate coordination, cycloaddition, and product displacement) between [Ru(OEt(2))(2)(PNNP)](2+) (2), 6b (or 6a), and Dane's diene (15, to give estrone derivatives) or N-benzyl-N-(cyclohexylethynyl)-4-methylbenzenesulfonamide (17, to give cyclobutenamides) suggest that product displacement from the catalyst is turnover limiting.
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Affiliation(s)
- Christoph Schotes
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
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