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Luo J, Kar S, Rauch M, Montag M, Ben-David Y, Milstein D. Efficient Base-Free Aqueous Reforming of Methanol Homogeneously Catalyzed by Ruthenium Exhibiting a Remarkable Acceleration by Added Catalytic Thiol. J Am Chem Soc 2021; 143:17284-17291. [PMID: 34617436 PMCID: PMC8532156 DOI: 10.1021/jacs.1c09007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 12/11/2022]
Abstract
Production of H2 by methanol reforming is of particular interest due the low cost, ready availability, and high hydrogen content of methanol. However, most current methods either require very high temperatures and pressures or strongly rely on the utilization of large amounts of base. Here we report an efficient, base-free aqueous-phase reforming of methanol homogeneously catalyzed by an acridine-based ruthenium pincer complex, the activity of which was unexpectedly improved by a catalytic amount of a thiol additive. The reactivity of this system is enhanced by nearly 2 orders of magnitude upon addition of the thiol, and it can maintain activity for over 3 weeks, achieving a total H2 turnover number of over 130 000. On the basis of both experimental and computational studies, a mechanism is proposed which involves outer-sphere dehydrogenations promoted by a unique ruthenium complex with thiolate as an assisting ligand. The current system overcomes the need for added base in homogeneous methanol reforming and also highlights the unprecedented acceleration of catalytic activity of metal complexes achieved by the addition of a catalytic amount of thiol.
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Affiliation(s)
- Jie Luo
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
| | - Sayan Kar
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
| | - Michael Rauch
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
| | - Michael Montag
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
| | - Yehoshoa Ben-David
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
| | - David Milstein
- Department of Molecular Chemistry
and Materials Science, Weizmann Institute
of Science, Rehovot, 76100, Israel
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2
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Ning Y, Tian H, Gui J. Biogenesis-Guided Synthesis and Structural Revision of Sarocladione Enabled by Ruthenium-Catalyzed Endoperoxide Fragmentation. Angew Chem Int Ed Engl 2021; 60:11222-11226. [PMID: 33682234 DOI: 10.1002/anie.202101451] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/21/2021] [Indexed: 11/11/2022]
Abstract
Sarocladione is the first 5,10:8,9-diseco-steroid with a 14-membered macrocyclic diketone framework to have been isolated from a natural source. Herein we report a biomimetic synthesis of sarocladione in only two or seven steps from inexpensive, commercially available ergosterol. The key feature of this synthesis was a novel ruthenium-catalyzed endoperoxide fragmentation, which transformed various saturated endoperoxides into olefinic diketones by cleavage of two C-C bonds. This synthesis allowed us to unambiguously determine the structure of sarocladione and provided experimental support for its revised biosynthetic origin. This work also vividly demonstrates that consideration of the biogenesis is a powerful tool for elucidating the structures of natural products.
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Affiliation(s)
- Yuhan Ning
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Hailong Tian
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Jinghan Gui
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
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3
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Ning Y, Tian H, Gui J. Biogenesis‐Guided Synthesis and Structural Revision of Sarocladione Enabled by Ruthenium‐Catalyzed Endoperoxide Fragmentation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yuhan Ning
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Hailong Tian
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Jinghan Gui
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
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4
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Shirakawa Y, Yano Y, Niwa Y, Inabe K, Umezawa N, Kato N, Hisamatsu Y, Higuchi T. Stable Iron Porphyrin Intramolecularly Coordinated by Alcoholate Anion: Synthesis and Evaluation of Axial Ligand Effect of Alcoholate on Spectroscopy and Catalytic Activity. Inorg Chem 2019; 58:4268-4274. [PMID: 30896162 DOI: 10.1021/acs.inorgchem.8b03384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We synthesized intramolecularly aliphatic alcoholate-coordinated iron porphyrins (1a, 1b) that retain their axial coordination in the presence of another ligand or oxidant. The electron-donative character of alcoholate was less than that of thiolate, and the coordination ability of a sixth ligand to 1a and 1b was very much lower than in the case of the thiolate-coordinated compounds. Density functional theory calculations indicated that the marked difference in coordination ability could be explained in terms of thermodynamic and steric factors. The catalytic oxidizing ability of the thiolate-coordinated compound, SR complex, was much higher than that of 1a.
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Affiliation(s)
- Yoshinori Shirakawa
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Yuuki Yano
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Yuki Niwa
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Kanako Inabe
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Naoki Umezawa
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Nobuki Kato
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Yosuke Hisamatsu
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
| | - Tsunehiko Higuchi
- Graduate School of Pharmaceutical Sciences , Nagoya City University , 3-1 Tanabe-dori , Mizuho-ku, Nagoya 467-8603 , Japan
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5
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Uehara H, Shisaka Y, Nishimura T, Sugimoto H, Shiro Y, Miyake Y, Shinokubo H, Watanabe Y, Shoji O. Structures of the Heme Acquisition Protein HasA with Iron(III)-5,15-Diphenylporphyrin and Derivatives Thereof as an Artificial Prosthetic Group. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201707212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hiromu Uehara
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Yuma Shisaka
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Tsubasa Nishimura
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Hiroshi Sugimoto
- Core Research for Evolutional Science and Technology; Japan Science and Technology Agency; 5 Sanbancho Chiyoda-ku Tokyo 102-0075 Japan
- RIKEN SPring-8 Center; 1-1-1 Kouto Sayo Hyogo 679-5148 Japan
| | - Yoshitsugu Shiro
- Guraduate School of Life Science; University of Hyogo; 3-2-1 Kouto Sayo Hyogo 678-1297 Japan
| | - Yoshihiro Miyake
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Yoshihito Watanabe
- Research Center for Materials Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Osami Shoji
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
- Core Research for Evolutional Science and Technology; Japan Science and Technology Agency; 5 Sanbancho Chiyoda-ku Tokyo 102-0075 Japan
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6
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Uehara H, Shisaka Y, Nishimura T, Sugimoto H, Shiro Y, Miyake Y, Shinokubo H, Watanabe Y, Shoji O. Structures of the Heme Acquisition Protein HasA with Iron(III)-5,15-Diphenylporphyrin and Derivatives Thereof as an Artificial Prosthetic Group. Angew Chem Int Ed Engl 2017; 56:15279-15283. [DOI: 10.1002/anie.201707212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Hiromu Uehara
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Yuma Shisaka
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Tsubasa Nishimura
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Hiroshi Sugimoto
- Core Research for Evolutional Science and Technology; Japan Science and Technology Agency; 5 Sanbancho Chiyoda-ku Tokyo 102-0075 Japan
- RIKEN SPring-8 Center; 1-1-1 Kouto Sayo Hyogo 679-5148 Japan
| | - Yoshitsugu Shiro
- Guraduate School of Life Science; University of Hyogo; 3-2-1 Kouto Sayo Hyogo 678-1297 Japan
| | - Yoshihiro Miyake
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry; Graduate School of Engineering; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8603 Japan
| | - Yoshihito Watanabe
- Research Center for Materials Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
| | - Osami Shoji
- Department of Chemistry; Graduate School of Science; Nagoya University; Furo-cho Chikusa-ku Nagoya 464-8602 Japan
- Core Research for Evolutional Science and Technology; Japan Science and Technology Agency; 5 Sanbancho Chiyoda-ku Tokyo 102-0075 Japan
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7
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Suzuki H, Inabe K, Shirakawa Y, Umezawa N, Kato N, Higuchi T. Role of Thiolate Ligand in Spin State and Redox Switching in the Cytochrome P450 Catalytic Cycle. Inorg Chem 2017; 56:4245-4248. [DOI: 10.1021/acs.inorgchem.6b02499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hiroshi Suzuki
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
| | - Kanako Inabe
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
| | - Yoshinori Shirakawa
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
| | - Naoki Umezawa
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
| | - Nobuki Kato
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
| | - Tsunehiko Higuchi
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya 467-8603, Japan
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8
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Saint-Germes L, Bar L, Dejeu J, Spinelli N, Defrancq E, Pratviel G. The pKa value of the proximal water molecule trans to a high-valent MnVO porphyrin: towards the control of reactivity by pH. Dalton Trans 2017; 46:12088-12094. [DOI: 10.1039/c7dt01829k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In water, the protonation state of the proximal water molecule of a high-valent manganese-oxo porphyrin could be controlled by pH. While in interaction with DNA the porphyrin was able to cleave DNA, only when the proximal water molecule was in the form of a hydroxyl group.
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Affiliation(s)
- Laurie Saint-Germes
- CNRS
- Laboratoire de Chimie de Coordination
- F-31077 Toulouse cedex4
- France
- Université de Toulouse
| | - Laure Bar
- Université Grenoble Alpes
- Département de Chimie Moléculaire-UMR CNRS 5250
- 38041 Grenoble Cedex 9
- France
| | - Jérôme Dejeu
- Université Grenoble Alpes
- Département de Chimie Moléculaire-UMR CNRS 5250
- 38041 Grenoble Cedex 9
- France
| | - Nicolas Spinelli
- Université Grenoble Alpes
- Département de Chimie Moléculaire-UMR CNRS 5250
- 38041 Grenoble Cedex 9
- France
| | - Eric Defrancq
- Université Grenoble Alpes
- Département de Chimie Moléculaire-UMR CNRS 5250
- 38041 Grenoble Cedex 9
- France
| | - Geneviève Pratviel
- CNRS
- Laboratoire de Chimie de Coordination
- F-31077 Toulouse cedex4
- France
- Université de Toulouse
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9
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Giovani S, Singh R, Fasan R. Efficient conversion of primary azides to aldehydes catalyzed by active site variants of myoglobin. Chem Sci 2015; 7:234-239. [PMID: 26900445 PMCID: PMC4754990 DOI: 10.1039/c5sc02857d] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/28/2015] [Indexed: 12/19/2022] Open
Abstract
The oxidation of primary azides to aldehydes constitutes a convenient but underdeveloped transformation for which no efficient methods are available. Here, we demonstrate that engineered variants of the hemoprotein myoglobin can catalyze this transformation with high efficiency (up to 8,500 turnovers) and selectivity across a range of structurally diverse aryl-substituted primary azides. Mutagenesis of the 'distal' histidine residue was particularly effective in enhancing the azide oxidation reactivity of myoglobin, enabling these reactions to proceed in good to excellent yields (37-89%) and to be carried out at a synthetically useful scale. Kinetic isotope effect, isotope labeling, and substrate binding experiments support a mechanism involving heme-catalyzed decomposition of the organic azide followed by alpha hydrogen deprotonation to generate an aldimine which, upon hydrolysis, releases the aldehyde product. This work provides the first example of a biocatalytic azide-to-aldehyde conversion and expands the range of non-native chemical transformations accessible through hemoprotein-mediated catalysis.
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Affiliation(s)
- Simone Giovani
- Department of Chemistry , University of Rochester , 120 Trustee Rd , Rochester , New York 14627 , USA .
| | - Ritesh Singh
- Department of Chemistry , University of Rochester , 120 Trustee Rd , Rochester , New York 14627 , USA .
| | - Rudi Fasan
- Department of Chemistry , University of Rochester , 120 Trustee Rd , Rochester , New York 14627 , USA .
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10
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Audran G, Brémond P, Marque SR, Siri D, Santelli M. Energetics of the biosynthesis of prostanes from arachidonate. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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11
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Cai R, Huang M, Cui X, Zhang J, Du C, Wu Y, Wu Y. Synthesis of cyclopentadienyl alkyl ethers via Pd-catalyzed cyclotrimerization of diarylacetylenes. RSC Adv 2013. [DOI: 10.1039/c3ra41326h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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12
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Baytekin HT, Baytekin B, Grzybowski BA. Mechanoradicals Created in “Polymeric Sponges” Drive Reactions in Aqueous Media. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Baytekin HT, Baytekin B, Grzybowski BA. Mechanoradicals Created in “Polymeric Sponges” Drive Reactions in Aqueous Media. Angew Chem Int Ed Engl 2012; 51:3596-600. [DOI: 10.1002/anie.201108110] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/02/2012] [Indexed: 11/10/2022]
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15
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Sun XY, Tian XY, Li ZW, Peng XS, Wong HNC. Total synthesis of plakortide E and biomimetic synthesis of plakortone B. Chemistry 2011; 17:5874-80. [PMID: 21491517 DOI: 10.1002/chem.201003309] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Indexed: 11/09/2022]
Abstract
The total synthesis of plakortide E (1a) is reported. A novel palladium-catalyzed approach towards 1,2-dioxolanes as well as an alternative substrate-controlled route leading exclusively to cis-highly substituted 1,2-dioxolanes have been developed. A lipase-catalyzed kinetic resolution was employed to provide optically pure 1,2-dioxolane central cores. Coupling of the central cores and side chains was achieved by a modified Negishi reaction. All four isomeric structures of plakortide E methyl ester, namely, 26a-d were synthesized. One of the structures, 26d, was shown to be identical with the natural plakortide E methyl ester on the basis of (1)H, (13)C NMR spectra and specific rotation comparisons. With the plakortide E methyl ester (4S,6R,10R)-(-)-cis-26d and its other three isomers in hand, we successfully converted them into (3S,4S,6R,10R)-plakortone B (2a), and its isomers ent-2a, 2b and ent-2b via an intramolecular oxa-Michael addition/lactonization cascade reaction. Finally, saponification converted 1,2-dioxolane 26d into plakortide E (1a) whose absolute configuration (4S,6R,10R) was confirmed by comparison of spectral and physical data with those reported.
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Affiliation(s)
- Xiao-Yu Sun
- Department of Chemistry, Centre of Novel Functional Molecules, Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, PR China
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16
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Kumar D, Sastry GN, de Visser SP. Effect of the axial ligand on substrate sulfoxidation mediated by iron(IV)-oxo porphyrin cation radical oxidants. Chemistry 2011; 17:6196-205. [PMID: 21469227 DOI: 10.1002/chem.201003187] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Indexed: 11/09/2022]
Abstract
Cytochromes P450 catalyze a range of different oxygen-transfer processes including aliphatic and aromatic hydroxylation, epoxidation, and sulfoxidation reactions. Herein, we have investigated substrate sulfoxidation mediated by models of P450 enzymes as well as by biomimetic oxidants using density functional-theory methods and we have rationalized the sulfoxidation reaction barriers and rate constants. We carried out two sets of calculations: first, we calculated the sulfoxidation by an iron(IV)-oxo porphyrin cation radical oxidant [Fe(IV)=O(Por(+.))SH] that mimics the active site of cytochrome P450 enzymes with a range of different substrates, and second, we studied one substrate (dimethyl sulfide) with a selection of different iron(IV)-oxo porphyrin cation radical oxidants [Fe(IV)=O(Por(+.))L] with varying axial ligands L. The study presented herein shows that the barrier height for substrate sulfoxidation correlates linearly with the ionization potential of the substrate, thus reflecting the electron-transfer processes in the rate-determining step of the reaction. Furthermore, the axial ligand of the oxidant influences the pK(a) value of the iron(IV)-oxo group, and, as a consequence, the bond dissociation energy (BDE(OH) value correlates with the barrier height for the reverse sulfoxidation reaction. These studies have generalized substrate-sulfoxidation reactions and have shown how they fundamentally compare with substrate hydroxylation and epoxidation reactions.
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Affiliation(s)
- Devesh Kumar
- Molecular Modelling Group, Indian Institute of Chemical Technology, Hyderabad 500-607, India.
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17
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Efimov I, Basran J, Thackray SJ, Handa S, Mowat CG, Raven EL. Structure and reaction mechanism in the heme dioxygenases. Biochemistry 2011; 50:2717-24. [PMID: 21361337 PMCID: PMC3092302 DOI: 10.1021/bi101732n] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
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As members of the family of heme-dependent enzymes, the heme dioxygenases are differentiated by virtue of their ability to catalyze the oxidation of l-tryptophan to N-formylkynurenine, the first and rate-limiting step in tryptophan catabolism. In the past several years, there have been a number of important developments that have meant that established proposals for the reaction mechanism in the heme dioxygenases have required reassessment. This focused review presents a summary of these recent advances, written from a structural and mechanistic perspective. It attempts to present answers to some of the long-standing questions, to highlight as yet unresolved issues, and to explore the similarities and differences of other well-known catalytic heme enzymes such as the cytochromes P450, NO synthase, and peroxidases.
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Affiliation(s)
- Igor Efimov
- Department of Chemistry, George Porter Building, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
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18
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Hessenauer-Ilicheva N, Franke A, Wolak M, Higuchi T, van Eldik R. Spectroscopic and Mechanistic Studies on Oxidation Reactions Catalyzed by the Functional Model SR Complex for Cytochrome P450: Influence of Oxidant, Substrate, and Solvent. Chemistry 2009; 15:12447-59. [DOI: 10.1002/chem.200901712] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Yanai T, Mori S. Density Functional Studies on Isomerization of Prostaglandin H2to Prostacyclin Catalyzed by Cytochrome P450. Chemistry 2009; 15:4464-73. [DOI: 10.1002/chem.200802550] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Yanai TK, Mori S. Density functional studies on thromboxane biosynthesis: mechanism and role of the heme-thiolate system. Chem Asian J 2009; 3:1900-11. [PMID: 18844316 DOI: 10.1002/asia.200800253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Reaction mechanisms for the isomerization of prostaglandin H(2) to thromboxane A(2), and degradation to 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and malondialdehyde (MDA), catalyzed by thromboxane synthase, were investigated using the unrestricted Becke-three-parameter plus Lee-Yang-Parr (UB3LYP) density functional level theory. In addition to the reaction pathway through Fe(IV)-porphyrin intermediates, a new reaction pathway through Fe(III)-porphyrin pi-cation radical intermediates was found. Both reactions proceed with the homolytic cleavage of endoperoxide O-O to give an alkoxy radical. This intermediate converts into an allyl radical intermediate by a C-C homolytic cleavage, followed by the formation of thromboxane A(2) having a 6-membered ring through a one electron transfer, or the degradation into HHT and MDA. The proposed mechanism shows that an iron(III)-containing system having electron acceptor ability is essential for the 6-membered ring formation leading to thromboxane A(2). Our results suggest that the step of the endoperoxide O-O homolytic bond cleavage has the highest activation energy following the binding of prostaglandin H(2) to thromboxane synthase.
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Affiliation(s)
- Tetsuya K Yanai
- Faculty of Science, Ibaraki University, Bunkyo, Mito 310-8512, Japan
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21
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Higuchi T. Inevitable Cytochrome P450 Coordination Structure for Enzyme Function: Chemical Model Approach to Elucidation of the Axial Ligand Effect. J SYN ORG CHEM JPN 2009. [DOI: 10.5059/yukigoseikyokaishi.67.134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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