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Miyaji T, Kujime M, Hikichi S, Moro-oka Y, Akita M. Synthesis and characterization of a series of (hydroperoxo)-, (alkylperoxo)-, and (mu-peroxo)palladium complexes containing the hydrotris(3,5-diisopropylpyrazolyl)borato ligand (Tp(iPr2)): (Tp(iPr2))(py)Pd-OO-X [X = H, t-Bu, Pd(Tp(iPr2))(py)] and (Tp(iPr2))(py)Pd-(mu-kappa(1):kappa(2)-OO)-PdTp(iPr2). Inorg Chem 2002; 41:5286-95. [PMID: 12354063 DOI: 10.1021/ic020355e] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dehydrative condensation of the hydroxopalladium complex (Tp(iPr2))(py)Pd-OH (1) with hydroperoxides (XOOH: X = H, t-Bu) produces the corresponding (hydroperoxo)-, (Tp(iPr2))(py)Pd-OOH (2a), and (tert-butylperoxo)palladium complexes, (Tp(iPr2))(py)Pd-OOBu(t) (3). Treatment of 2a with PPh(3) results in concomitant ligand displacement giving (Tp(i)(Pr2))(Ph(3)P)Pd-OOH (2b) and oxygenation of PPh(3) giving O=PPh(3). Further condensation between 1 and 2a gives the mu-kappa(1):kappa(1)-peroxo complex (Tp(iPr2))(py)Pd-OO-Pd(Tp(iPr2))(py) (4), while condensation between the bis(mu-hydroxo)dipalladium complex (PdTp(iPr2))(2)(mu-OH)(2) (7) with 2a affords the unsymmetrical mu-kappa(1):kappa(2)-peroxo complex (Tp(iPr2))(py)Pd-OO-PdTp(iPr2) (5). These peroxopalladium complexes 2-5 have been fully characterized by a combination of spectroscopic and crystallographic analyses, which lead to description of the O-O moieties in these complexes as peroxide (O(2)(2-)) with sp(3)-hybridized oxygen atoms. The OOH moiety in 2b is found to interact with the noncoordinated nitrogen atom of the pendant pyrazolyl group through hydrogen bond. The O(2) moieties in 2-5 turn out to be so nucleophilic (basic) as to add across carbon-heteroatom multiple bonds in acetonitrile and acetaldehyde to give the peroxometallacycle Tp(iPr2)Pd[OOC(Me)=N)]Pd(iPr2)(py)(8) (from 2, 4, and 5) and the acetato complex (Tp(iPr2))(py)Pd-OC(=O)CH(3) (9) (from 2-4), respectively. Methyl vinyl ether and styrene, CH(2)=CHY (Y = OMe, Ph), are converted to the corresponding methyl ketones, CH(3)C(=O)Y, upon treatment with 2-4.
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Affiliation(s)
- Taichi Miyaji
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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52
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Akita M, Hikichi S. Inorganic Chemistry Based on Tp Ligands —From Dioxygen Complexes to Organometallic Systems—. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2002. [DOI: 10.1246/bcsj.75.1657] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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53
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Hikichi S, Sasakura Y, Yoshizawa M, Ohzu Y, Moro-oka Y, Akita M. Selective Synthesis, Characterization, and Configurational Flexibility of the Coordinatively Unsaturated Metal Center of Half-Sandwich Type Complexes with the Less-Hindered Hydrotris(3, 5-dimethyl-4-X-1-pyrazolyl)borate Ligands [TpMe2,XMII(κ2-O,O′-L)] (M = Ni, Co; L = NO3, OAc; X = Me, H, Br). BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2002. [DOI: 10.1246/bcsj.75.1255] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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54
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Yamahara R, Ogo S, Masuda H, Watanabe Y. (Catecholato)iron(III) complexes: structural and functional models for the catechol-bound iron(III) form of catechol dioxygenases. J Inorg Biochem 2002; 88:284-94. [PMID: 11897342 DOI: 10.1016/s0162-0134(01)00353-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Catechol dioxygenases are mononuclear non-heme iron enzymes that catalyze the oxygenation of catechols to aliphatic acids via the cleavage of aromatic rings. In the last 20 years, a number of (catecholato)iron(III) complexes have been synthesized and characterized as structural and functional models for the catechol-bound iron(III) form of catechol dioxygenases. This review focuses on the structural and spectroscopic characteristics and oxygenation activity of the title complexes.
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Affiliation(s)
- Ryo Yamahara
- Institute for Molecular Science, Myodaiji-cho, Okazaki 444-8585, Japan
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55
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Hikichi S, Yoshizawa M, Sasakura Y, Komatsuzaki H, Moro-oka Y, Akita M. Structural Characterization and Intramolecular Aliphatic C−H Oxidation Ability of MIII(μ-O)2MIII Complexes of Ni and Co with the Hydrotris(3,5-dialkyl-4-X-pyrazolyl)borate Ligands TpMe2,X (X=Me, H, Br) and TpiPr2. Chemistry 2001. [DOI: 10.1002/1521-3765(20011203)7:23%3c5011::aid-chem5011%3e3.0.co;2-c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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56
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Hikichi S, Yoshizawa M, Sasakura Y, Komatsuzaki H, Moro-oka Y, Akita M. Structural characterization and intramolecular aliphatic C-H oxidation ability of M(III)(mu-O)2M(III) complexes of Ni and Co with the hydrotris-(3,5-dialkyl-4-X-pyrazolyl)borate ligands TpMe2,X (X = Me, H, Br) and TpiPr2. Chemistry 2001; 7:5011-28. [PMID: 11775675 DOI: 10.1002/1521-3765(20011203)7:23<5011::aid-chem5011>3.0.co;2-c] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Reaction of the dinuclear M(II)-bis(mu-hydroxo) complexes of nickel and cobalt, [(M(II)(TpR)]2(mu-OH)2] (M = Ni; 3Ni M = Co: 3Co), with one equivalent of H2O2 yields the corresponding M(III)-bis(mu-oxo) complexes, [[M(III)(TpR)]2-(mu-O)2] (M=Ni; 2Ni, M=Co: 2Co). The employment of a series of TpMe2,X (TpMe2,X = hydrotris(3,5-dimethyl-4-X-1-pyrazolyl)borate; X = Me, H, Br) as a metal supporting ligand makes it possible to isolate and structurally characterize the thermally unstable M(III)-bis-(mu-oxo) complexes 2Ni and 2Co. Both the starting (3Ni and 3Co) and resulting complexes (2Ni and 2Co) contain five-coordinate metal centers with a slightly distorted square-pyramidal geometry. Characteristic features of the nickel complexes 2Ni, such as the two intense absorptions around 400 and 300 nm in the UV-visible spectra and the apparent diamagnetism, are very similar to those of the previously reported bis(mu-oxo) species of Cu(III) and Ni(III) with ligands other than TpR, whereas the spectroscopic properties of the cobalt complexes 2Co (i.e., paramagnetically shifted NMR signals and a single intense absorption appearing at 350 nm) are clearly distinct from those of the isostructural nickel compounds 2Ni. Thermal decomposition of 2Ni and 2Co results in oxidation of the inner saturated hydrocarbyl substituents of the TpR ligand. Large kH/kD values obtained from the first-order decomposition rates of the TpMe3 and Tp(CD3)2,Me derivatives of 2 evidently indicate that the rate-determining step is an hydrogen abstraction from the primary C-H bond of the methyl substituents. mediated by the M(III)2-(mu-O)2 species. The nickel complex 2Ni shows reactivity about 10(3) times greater than that of the cobalt analogue 2Co. The oxidation ability of the M(III)(mu-O)2M(III) core should be affected by the hindered TpR ligand system, which can stabilize the +2 oxidation state of the metal centers.
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Affiliation(s)
- S Hikichi
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
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57
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Ogo S, Yamahara R, Funabiki T, Masuda H, Watanabe Y. Biomimetic Intradiol-Cleavage of Catechols with Incorporation of Both Atoms of O2: The Role of the Vacant Coordination Site on the Iron Center. CHEM LETT 2001. [DOI: 10.1246/cl.2001.1062] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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58
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Raffard N, Carina R, Simaan A, Sainton J, Rivière E, Tchertanov L, Bourcier S, Bouchoux G, Delroisse M, Banse F, Girerd JJ. Biomimetic Catalysis of Catechol Cleavage by O2 in Organic Solvents − Role of Accessibility of O2 to FeIII in 2,11-Diaza[3,3](2,6)pyridinophane-Type Catalysts. Eur J Inorg Chem 2001. [DOI: 10.1002/1099-0682(200109)2001:9<2249::aid-ejic2249>3.0.co;2-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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59
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Jo DH, Chiou YM, Que L. Models for extradiol cleaving catechol dioxygenases: syntheses, structures, and reactivities of iron(II)-monoanionic catecholate complexes. Inorg Chem 2001; 40:3181-90. [PMID: 11399191 DOI: 10.1021/ic001185d] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystallographic and spectroscopic studies of extradiol cleaving catechol dioxygenases indicate that the enzyme-substrate complexes have both an iron(II) center and a monoanionic catecholate. Herein we report a series of iron(II)-monoanionic catecholate complexes, [(L)Fe(II)(catH)](X) (1a, L = 6-Me(3)-TPA (tris(6-methyl-2-pyridylmethyl)amine), catH = CatH (1,2-catecholate monoanion); 1b, L = 6-Me(3)-TPA, catH = DBCH (3,5-di-tert-butyl-1,2-catecholate monoanion); 1c, L = 6-Me(2)-bpmcn (N,N'-dimethyl-N,N'-bis(6-methyl-2-pyridylmethyl)-trans-1,2-diaminocyclohexane), catH = CatH; 1d, L = 6-Me(2)-bpmcn, catH = DBCH), that model such enzyme complexes. The crystal structure of [(6-Me(2)-bpmcn)Fe(II)(DBCH)](+) (1d) shows that the DBCH ligand binds to the iron asymmetrically as previously reported for 1b, with two distinct Fe-O bonds of 1.943(1) and 2.344(1) A. Complexes 1 react with O(2) or NO to afford blue-purple iron(III)-catecholate dianion complexes, [(L)Fe(III)(cat)](+) (2). Interestingly, crystallographically characterized 2d, isolated from either reaction, has the N-methyl groups in a syn configuration, in contrast to the anti configuration of the precursor complex, so epimerization of the bound ligand must occur in the course of isolating 2d. This notion is supported by the fact that the UV-vis and EPR properties of in situ generated 2d(anti) differ from those of isolated 2d(syn). While the conversion of 1 to 2 in the presence of O(2) occurs without an obvious intermediate, that in the presence of NO proceeds via a metastable S = (3)/(2) [(L)Fe(catH)(NO)](+) adduct 3, which can only be observed spectroscopically but not isolated. Intermediates 3a and 3b subsequently disproportionate to afford two distinct complexes, [(6-Me(3)-TPA)Fe(III)(cat)](+) (2a and 2b) and [(6-Me(3)-TPA)Fe(NO)(2)](+) (4) in comparable yield, while 3d converts to 2d in 90% yield. Complexes 2b and anti-2d react further with O(2) over a 24 h period and afford a high yield of cleavage products. Product analysis shows that the products mainly derive from intradiol cleavage but with a small extent of extradiol cleavage (89:3% for 2b and 78:12% for anti-2d). The small amounts of the extradiol cleavage products observed may be due to the dissociation of an alpha-methyl substituted pyridyl arm, generating a complex with a tridentate ligand. Surprisingly, syn-2d does not react with O(2) over the course of 4 days. These results suggest that there are a number of factors that influence the mode and rate of cleavage of catechols coordinated to iron centers.
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Affiliation(s)
- D H Jo
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA
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60
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Jo DH, Que, Jr. L. Tuning the Regiospecificity of Cleavage in FeIII Catecholate Complexes: Tridentate Facial versus Meridional Ligands. Angew Chem Int Ed Engl 2000; 39:4284-4287. [DOI: 10.1002/1521-3773(20001201)39:23<4284::aid-anie4284>3.0.co;2-i] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2000] [Indexed: 11/06/2022]
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61
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Jo DH, Que, Jr. L. Tuning the Regiospecificity of Cleavage in FeIII Catecholate Complexes: Tridentate Facial versus Meridional Ligands. Angew Chem Int Ed Engl 2000. [DOI: 10.1002/1521-3757(20001201)112:23<4454::aid-ange4454>3.0.co;2-s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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62
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Solomon EI, Brunold TC, Davis MI, Kemsley JN, Lee SK, Lehnert N, Neese F, Skulan AJ, Yang YS, Zhou J. Geometric and electronic structure/function correlations in non-heme iron enzymes. Chem Rev 2000; 100:235-350. [PMID: 11749238 DOI: 10.1021/cr9900275] [Citation(s) in RCA: 1351] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E I Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305-5080
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63
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Ogihara T, Hikichi* S, Akita* M, Uchida T, Kitagawa T, Moro-oka* Y. An approach to the O2 activating mononuclear non-heme Fe enzymes: structural characterization of Fe(II)–acetato complex and formation of alkylperoxoiron(III) species with the highly hindered hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate. Inorganica Chim Acta 2000. [DOI: 10.1016/s0020-1693(99)00337-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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64
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Funabiki T, Yamazaki T. Mechanism of oxygenative cleavage of catechols by nonheme iron complexes in relevance to catechol dioxygenases studied by quantum chemical calculations. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1381-1169(99)00198-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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65
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Hikichi S, Yoshizawa M, Sasakura Y, Komatsuzaki H, Akita M, Moro-oka Y. Oxygenation of Saturated Hydrocarbyl Groups in the Dinuclear Ni(III) Bis(μ-oxo) Complexes with the Hydrotris(pyrazolyl)borate Ligands TpR(R = Me3and Pri2). CHEM LETT 1999. [DOI: 10.1246/cl.1999.979] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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66
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Kosugi M, Hikichi S, Akita M, Moro-oka Y. Inter- and Intramolecular Hydrogen-Bonding Interaction of Hydroxo Groups and Steric Effect of Alkyl Substituents on Pyrazolyl Rings in TpR Ligands: Synthesis and Structural Characterization of Chloro-, Acetylacetonato-, and Hydroxo Complexes of VO2+ with TpPri2 and TpMe2 Ligands. Inorg Chem 1999. [DOI: 10.1021/ic9806028] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Masahiro Kosugi
- Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Shiro Hikichi
- Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Munetaka Akita
- Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Yoshihiko Moro-oka
- Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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