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Sample HC, Senge MO. Nucleophilic Aromatic Substitution (S NAr) and Related Reactions of Porphyrinoids: Mechanistic and Regiochemical Aspects. European J Org Chem 2021; 2021:7-42. [PMID: 33519299 PMCID: PMC7821298 DOI: 10.1002/ejoc.202001183] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Indexed: 12/29/2022]
Abstract
The nucleophilic substitution of aromatic moieties (SNAr) has been known for over 150 years and found wide use for the functionalization of (hetero)aromatic systems. Currently, several "types" of SNAr reactions have been established and notably the area of porphyrinoid macrocycles has seen many uses thereof. Herein, we detail the SNAr reactions of seven types of porphyrinoids with differing number and type of pyrrole units: subporphyrins, norcorroles, corroles, porphyrins, azuliporphyrins, N-confused porphyrins, and phthalocyanines. For each we analyze the substitution dependent upon: a) the type of nucleophile and b) the site of substitution (α, β, or meso). Along with this we evaluate this route as a synthetic strategy for the generation of unsymmetrical porphyrinoids. Distinct trends can be identified for each type of porphyrinoid discussed, regardless of nucleophile. The use of nucleophilic substitution on porphyrinoids is found to often be a cost-effective procedure with the ability to yield complex substituent patterns, which can be conducted in non-anhydrous solvents with easily accessible simple porphyrinoids.
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Affiliation(s)
- Harry C. Sample
- School of ChemistryTrinity Biomedical Sciences InstituteThe University of Dublin152‐160 Pearse StreetDublin 2Ireland
| | - Mathias O. Senge
- Institute for Advanced Study (TUM‐IAS)Technical University of MunichLichtenbergstrasse 2a85748GarchingGermany
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Yang N, Fang Y, Xu F, Zhou R, Jin X, Zhang L, Shi J, Fang J, Wu H, Zhang Z. Application of the stabilization effect of a silyl group in radical-polar crossover reactions enabled by photoredox-neutral catalysis. Org Chem Front 2021. [DOI: 10.1039/d1qo00738f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Taking advantage of the stabilization effect of a silyl group, with a bulky but positive nature, a range of less investigated organosilanes could be generally accessed via photoredox-catalysed radical-polar crossover reactions.
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Affiliation(s)
- Naiyuan Yang
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, No. 79 West Street Yingze, Taiyuan 030024, China
| | - Yewen Fang
- School of Materials and Chemical Engineering, Ningbo University of Technology, No. 201 Fenghua Road, Ningbo 315211, China
- Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, No. 345 Lingling Road, Shanghai 200032, China
| | - Fenfen Xu
- School of Materials and Chemical Engineering, Ningbo University of Technology, No. 201 Fenghua Road, Ningbo 315211, China
| | - Rong Zhou
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, No. 79 West Street Yingze, Taiyuan 030024, China
| | - Xiaoping Jin
- Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, No. 888 Yinxian Avenue East, Ningbo 315100, China
| | - Li Zhang
- Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, No. 888 Yinxian Avenue East, Ningbo 315100, China
| | - Jianxun Shi
- Department of Pharmaceutical Engineering, Zhejiang Pharmaceutical College, No. 888 Yinxian Avenue East, Ningbo 315100, China
| | - Jianghua Fang
- School of Materials and Chemical Engineering, Ningbo University of Technology, No. 201 Fenghua Road, Ningbo 315211, China
| | - Hao Wu
- School of Materials and Chemical Engineering, Ningbo University of Technology, No. 201 Fenghua Road, Ningbo 315211, China
| | - Zongyong Zhang
- School of Materials and Chemical Engineering, Ningbo University of Technology, No. 201 Fenghua Road, Ningbo 315211, China
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Kong Y, Wang Z. Nickel‐Catalyzed Reaction of Aryl 2‐Pyridyl Ethers with Silylzinc Chlorides: Silylation of Aryl 2‐Pyridyl Ethers via Cleavage of the Carbon−Oxygen Bond. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900949] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Ying‐Ying Kong
- CAS Key Laboratory of Soft Matter Chemistry and Department of ChemistryUniversity of Science and Technology of China, Hefei Anhui 230026 People's Republic of China
| | - Zhong‐Xia Wang
- CAS Key Laboratory of Soft Matter Chemistry and Department of ChemistryUniversity of Science and Technology of China, Hefei Anhui 230026 People's Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072 People's Republic of China
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Lo HJ, Lin CY, Tseng MC, Chein RJ. Lithiation of a Silyl Ether: Formation of anortho-Fries Hydroxyketone. Angew Chem Int Ed Engl 2014; 53:9026-9. [DOI: 10.1002/anie.201404495] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 05/21/2014] [Indexed: 11/10/2022]
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Griesbeck AG, Reckenthäler M. Homogeneous and heterogeneous photoredox-catalyzed hydroxymethylation of ketones and keto esters: catalyst screening, chemoselectivity and dilution effects. Beilstein J Org Chem 2014; 10:1143-50. [PMID: 24991265 PMCID: PMC4077468 DOI: 10.3762/bjoc.10.114] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/22/2014] [Indexed: 11/23/2022] Open
Abstract
The homogeneous titanium- and dye-catalyzed as well as the heterogeneous semiconductor particle-catalyzed photohydroxymethylation of ketones by methanol were investigated in order to evaluate the most active photocatalyst system. Dialkoxytitanium dichlorides are the most efficient species for chemoselective hydroxymethylation of acetophenone as well as other aromatic and aliphatic ketones. Pinacol coupling is the dominant process for semiconductor catalysis and ketone reduction dominates the Ti(OiPr)4/methanol or isopropanol systems. Application of dilution effects on the TiO2 catalysis leads to an increase in hydroxymethylation at the expense of the pinacol coupling.
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Affiliation(s)
- Axel G Griesbeck
- University of Cologne, Department of Chemistry, Organic Chemistry, Greinstr. 4, D-50939 Köln, Germany; Fax: +49(221)470 5057
| | - Melissa Reckenthäler
- University of Cologne, Department of Chemistry, Organic Chemistry, Greinstr. 4, D-50939 Köln, Germany; Fax: +49(221)470 5057
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Schlosser M. Reactions of Pyridines, Benzopyridines, and Azapyridines with Organomagnesiums and Organolithiums. In: Schnürch M, Mihovilovic MD, editors. Metalation of Azines and Diazines. Berlin: Springer Berlin Heidelberg; 2013. pp. 171-222. [DOI: 10.1007/7081_2012_96] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
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Unkelbach C, Abele BC, Lehmen K, Schildbach D, Waerder B, Wild K, Strohmann C. A diastereomerically enriched, dimeric organolithium compound and the stereochemical course of its transformations. Chem Commun (Camb) 2012; 48:2492-4. [PMID: 22113228 DOI: 10.1039/c1cc15872d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A dimeric α-silylated ethyllithium compound is presented featuring stereogenic metalated carbon centres with defined configurations. It can be generated by diastereoselective deprotonation of the corresponding ethylsilane. Reaction with Me(3)SnCl proceeds under inversion and the transfer of the stereoinformation is possible with dr's of up to 97:3.
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Affiliation(s)
- Christian Unkelbach
- Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44227 Dortmund, Germany
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Takanami T, Hayashi S, Iso K, Matsumoto J, Hino F. An efficient one-pot protocol for asymmetric bifunctionalization of 5,15-disubstituted porphyrins: direct access to meso activated alkenyl-substituted meso-formylporphyrins. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.08.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Huang C, Chernyak N, Dudnik AS, Gevorgyan V. The Pyridyldiisopropylsilyl Group: A Masked Functionality and Directing Group for Monoselective ortho-Acyloxylation and ortho-Halogenation Reactions of Arenes. Adv Synth Catal 2011; 353:10.1002/adsc.201000975. [PMID: 24363640 PMCID: PMC3866842 DOI: 10.1002/adsc.201000975] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A novel, easily removable and modifiable silicon-tethered pyridyldiisopropylsilyl directing group for C-H functionalizations of arenes has been developed. The installation of the pyridyldiisopropylsilyl group can efficiently be achieved via two complementary routes using easily available 2-(diisopropylsilyl)pyridine (5). The first strategy features a nucleophilic hydride substitution at the silicon atom in 5 with aryllithium reagents generated in situ from the corresponding aryl bromides or iodides. The second milder route exploits a highly efficient room-temperature rhodium(I)-catalyzed cross-coupling reaction between 5 and aryl iodides. The latter approach can be applied to the preparation of a wide range of pyridyldiisopropylsilyl-substituted arenes possessing a variety of functional groups, including those incompatible with organometallic reagents. The pyridyldiisopropylsilyl directing group allows for a highly efficient, regioselective palladium(II)-catalyzed mono-ortho-acyloxylation and ortho-halogenation of various aromatic compounds. Most impor-tantly, the silicon-tethered directing group in both acyloxylated and halogenated products can easily be removed or efficiently converted into an array of other valuable functionalities. These transformations include protio-, deuterio-, halo-, boro-, and alkynyldesilylations, as well as a conversion of the directing group into the hydroxy functionality. In addition, the construction of aryl-aryl bonds via the Hiyama-Denmark cross-coupling reaction is feasible for the acetoxylated products. Moreover, the ortho-halogenated pyridyldiisopropylsilylarenes, bearing both nucleophilic pyridyldiisopropylsilyl and electrophilic aryl halide moieties, represent synthetically attractive 1,2-ambiphiles. A unique reactivity of these ambiphiles has been demonstrated in efficient syntheses of arylenediyne and benzosilole derivatives, as well as in a facile generation of benzyne. In addition, preliminary mechanistic studies of the acyloxylation and halogenation reactions have been performed. A trinuclear palladacycle intermediate has been isolated from a stoichiometric reaction between diisopropyl-(phenyl)pyrid-2-ylsilane (3a) and palladium acetate. Furthermore, both C-H functionalization reactions exhibited equally high values of the intramolecular primary kinetic isotope effect (kH/kD = 6.7). Based on these observations, a general mechanism involving the formation of a palladacycle via a C-H activation process as the rate-determining step has been proposed.
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Affiliation(s)
- Chunhui Huang
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA
| | - Natalia Chernyak
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA
| | - Alexander S. Dudnik
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA
| | - Vladimir Gevorgyan
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA
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Unkelbach C, Strohmann C. Low-Temperature Addition of Organolithiums to Functionalized Vinylsilanes under Formation of Secondary α-Lithiated Alkylsilanes. J Am Chem Soc 2009; 131:17044-5. [DOI: 10.1021/ja9076167] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christian Unkelbach
- Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
| | - Carsten Strohmann
- Anorganische Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
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Takanami T, Wakita A, Matsumoto J, Sekine S, Suda K. An efficient one-pot procedure for asymmetric bifunctionalization of 5,15-disubstituted porphyrins: a simple preparation of mesoacyl-, alkoxycarbonyl-, and carbamoyl-substituted meso-formylporphyrins. Chem Commun (Camb) 2009:101-3. [DOI: 10.1039/b817551a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Takanami T, Matsumoto J, Kumagai Y, Sawaizumi A, Suda K. A facile one-pot preparation of meso-hydroxymethylporphyrins via a sequential SNAr reaction with (2-pyridyldimethylsilyl)methyllithium followed by hydrolysis and aerobic oxidation. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2008.10.087] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Affortunato F, Florio S, Luisi R, Musio B. α- vs Ortho-Lithiation of N-Alkylarylaziridines: Probing the Role of the Nitrogen Inversion Process. J Org Chem 2008; 73:9214-20. [DOI: 10.1021/jo8016549] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Francesco Affortunato
- Dipartimento Farmaco-Chimico, Università di Bari, Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi C.I.N.M.P.I.S., Via E. Orabona 4, I-70125, Bari, Italy
| | - Saverio Florio
- Dipartimento Farmaco-Chimico, Università di Bari, Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi C.I.N.M.P.I.S., Via E. Orabona 4, I-70125, Bari, Italy
| | - Renzo Luisi
- Dipartimento Farmaco-Chimico, Università di Bari, Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi C.I.N.M.P.I.S., Via E. Orabona 4, I-70125, Bari, Italy
| | - Biagia Musio
- Dipartimento Farmaco-Chimico, Università di Bari, Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi C.I.N.M.P.I.S., Via E. Orabona 4, I-70125, Bari, Italy
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Takanami T, Wakita A, Sawaizumi A, Iso K, Onodera H, Suda K. One-Pot Synthesis of meso-Formylporphyrins by SNAr Reaction of 5,15-Disubstituted Porphyrins with (2-Pyridyldimethylsilyl)methyllithium. Org Lett 2008; 10:685-7. [DOI: 10.1021/ol703107t] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Atsushi Wakita
- Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Aoyo Sawaizumi
- Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Kazuhiro Iso
- Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Hidetoshi Onodera
- Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Kohji Suda
- Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo 204-8588, Japan
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Abstract
[reaction: see text] We have developed an efficient copper-catalyzed allylation of carbonyl derivatives using allyl(2-pyridyl)silanes, in which the strong directing effect of the 2-pyridyl group was observed. A useful synthesis and allylation of substituted allyl(2-pyridyl)silanes is also described.
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Affiliation(s)
- Toshiyuki Kamei
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
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Berghian C, Darabantu M, Turck A, Plé N. Metallation of pyridin-2-yldiazines. Use of pyridine ring as ortho-directing group. Diazines. Part 45. Tetrahedron 2005; 61:9637-44. [DOI: 10.1016/j.tet.2005.07.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Dong Y, Chollet J, Matile H, Charman SA, Chiu FCK, Charman WN, Scorneaux B, Urwyler H, Santo Tomas J, Scheurer C, Snyder C, Dorn A, Wang X, Karle JM, Tang Y, Wittlin S, Brun R, Vennerstrom JL. Spiro and dispiro-1,2,4-trioxolanes as antimalarial peroxides: charting a workable structure-activity relationship using simple prototypes. J Med Chem 2005; 48:4953-61. [PMID: 16033274 DOI: 10.1021/jm049040u] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes the discovery of synthetic 1,2,4-trioxolane antimalarials and how we established a workable structure-activity relationship in the context of physicochemical, biopharmaceutical, and toxicological profiling. An achiral dispiro-1,2,4-trioxolane (3) in which the trioxolane is flanked by a spiroadamantane and spirocyclohexane was rapidly identified as a lead compound. Nonperoxidic 1,3-dioxolane isosteres of 3 were inactive as were trioxolanes without the spiroadamantane. The trioxolanes were substantially less effective in a standard oral suspension formulation compared to a solubilizing formulation and were more active when administered subcutaneously than orally, both of which suggest substantial biopharmaceutical liabilities. Nonetheless, despite their limited oral bioavailability, the more lipophilic trioxolanes generally had better oral activity than their more polar counterparts. In pharmacokinetic experiments, four trioxolanes had high plasma clearance values, suggesting a potential metabolic instability. The toxicological profiles of two trioxolanes were comparable to that of artesunate.
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Affiliation(s)
- Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, USA
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Tang Y, Dong Y, Wang X, Sriraghavan K, Wood JK, Vennerstrom JL. Dispiro-1,2,4-trioxane analogues of a prototype dispiro-1,2,4-trioxolane: mechanistic comparators for artemisinin in the context of reaction pathways with iron(II). J Org Chem 2005; 70:5103-10. [PMID: 15960511 DOI: 10.1021/jo050385+] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single electron reduction of the 1,2,4-trioxane heterocycle of artemisinin (1) forms primary and secondary carbon-centered radicals. The complex structure of 1 does not lend itself to a satisfactory dissection of the electronic and steric effects that influence the formation and subsequent reaction of these carbon-centered free radicals. To help demarcate these effects, we characterized the reactions of achiral dispiro-1,2,4-trioxolane 4 and dispiro-1,2,4-trioxanes 5-7 with ferrous bromide and 4-oxo-TEMPO. Our results suggest a small preference for attack of Fe(II) on the nonketal peroxide oxygen atom of 1. For 4, but not for 5 and 6, there was a strong preference for attack of Fe(II) on the less hindered peroxide bond oxygen atom. The steric hindrance afforded by a spiroadamantane in a five-membered trioxolane is evidently much greater than that for a corresponding six-membered trioxane. Unlike 1, 5-7 fragment by entropically favored beta-scission pathways forming relatively stable alpha-oxa carbon-centered radicals. These data suggest that formation of either primary or secondary carbon-centered radicals is a necessary but insufficient criterion for antimalarial activity of 1 and synthetic peroxides.
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Affiliation(s)
- Yuanqing Tang
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA
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Abstract
The adjacent centres of electrophilicity and nucleophilicity lead to interesting chemical reactivity in the title reagent.
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Affiliation(s)
- Mariya V Kozytska
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
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Sadimenko AP. Organometallic Complexes of the η2 (N, C)-Coordinated Derivatives of Pyridine. Elsevier; 2005. pp. 111-74. [DOI: 10.1016/s0065-2725(04)88002-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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Kamei T, Itami K, Yoshida JI. Catalytic Carbometalation/Cross-Coupling Sequence across Alkynyl(2-pyridyl)silanes Leading to a Diversity-Oriented Synthesis of Tamoxifen-Type Tetrasubstituted Olefins. Adv Synth Catal 2004. [DOI: 10.1002/adsc.200404220] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Itami K, Mitsudo K, Fujita K, Ohashi Y, Yoshida JI. Catalytic intermolecular Pauson-Khand-type reaction: strong directing effect of pyridylsilyl and pyrimidylsilyl groups and isolation of Ru complexes relevant to catalytic reaction. J Am Chem Soc 2004; 126:11058-66. [PMID: 15339192 DOI: 10.1021/ja047484+] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Some circumstantial evidence for the directing effect of the 2-pyridylsilyl group in the Ru-catalyzed intermolecular Pauson-Khand-type reaction (PKR) of alkenyl(2-pyridyl)silane, alkyne, and carbon monoxide has been provided. Most importantly, we have succeeded in isolating several monometallic Ru complexes relevant to the catalytic reaction: Ru(vinylsilane)(CO)(3) complexes and ruthenacyclopentene. While the stoichimetric reaction of the Ru(vinylsilane)(CO)(3) complex with an alkyne led to the formation of the corresponding cyclopentenone (PKR product) at 100 degrees C, the ruthenacyclopentene intermediate was quantitatively produced at 50 degrees C. This complex was also converted to a cyclopentenone upon heating at 100 degrees C. Moreover, it was also found that the Ru(vinylsilane)(CO)(3) complex and ruthenacyclopentene serve as catalysts in intermolecular PKR.
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Affiliation(s)
- Kenichiro Itami
- Contribution from the Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
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Itami K, Terakawa K, Yoshida JI, Kajimoto O. The Carbon–Silicon Bond Cleavage of Organosilicon Compounds in Supercritical Water. BCSJ 2004. [DOI: 10.1246/bcsj.77.2071] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Affiliation(s)
- Rafael Chinchilla
- Departamento de Química Orgánica and Instituto de Síntesis Orgánica, Facultad de Ciencias, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain.
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Abstract
The representative examples of beneficial effects of hydrophilic groups in aqueous organic reactions are described, including the Diels-Alder reactions, hetero Diels-Alder reactions, Claisen rearrangement, radical reactions, and transition metal-catalyzed reactions. Although the low solubility of organic molecules in water has been a bane in aqueous organic reactions, the incorporation of hydrophilic groups into the substrate structure can overcome the solubility problem and at the same time enhance the hydrophobic effect. In some cases, interesting micellar effects are observed because of the amphiphilic natures of such molecules. The emerging concept of "removable hydrophilic group," in which the solubility problems have been alleviated, yet the initial product can still be transformed into a variety of products with the removal of the hydrophilic groups, is also described.
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Affiliation(s)
- Kenichiro Itami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan
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30
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Abstract
It is shown that t-BuLi in Et(2)O promotes an exclusive regioselective metalation of 2-aryl-6-chloropyridine compounds at the aromatic ortho position demonstrating that the 2-chloropyridyl moiety may be considered as a directing group. This functionally directed metalation group was successfully used for the selective lithiation of substituted aromatics and for the straightforward preparation of new N,P ligands.
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Affiliation(s)
- Yves Fort
- Synthèse Organique et Réactivité, UMR CNRS-UHP 7565, Faculté des Sciences, Université Henri Poincaré-Nancy I, BP 239, 54506 Vandoeuvre-Lès-Nancy, France.
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Itami K, Mineno M, Kamei T, Yoshida JI. A general and straightforward route toward diarylmethanes. Integrated cross-coupling reactions using (2-pyridyl)silylmethylstannane as an air-stable, storable, and versatile coupling platform. Org Lett 2002; 4:3635-8. [PMID: 12375906 DOI: 10.1021/ol026573t] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Pharmacologically important diarylmethane structures have been prepared in a straightforward manner through sequentially integrated Pd-catalyzed cross-coupling reactions. (2-Pyridyl)silylmethylstannane was found to be an air-stable, storable, and versatile coupling platform in this synthetic strategy.
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Affiliation(s)
- Kenichiro Itami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan
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Affiliation(s)
- Jun-Ichi Yoshida
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan.
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Abstract
Metal-catalyzed hydrosilylation of alkenes and alkynes using dimethyl(pyridyl)silane is described. The hydrosilylation of alkenes using dimethyl(2-pyridyl)silane (2-PyMe(2)SiH) proceeded well in the presence of a catalytic amount of RhCl(PPh(3))(3) with virtually complete regioselectivity. By taking advantage of the phase tag property of the 2-PyMe(2)Si group, hydrosilylation products were isolated in greater than 95% purity by simple acid-base extraction. Strategic catalyst recovery was also demonstrated. The hydrosilylation of alkynes using 2-PyMe(2)SiH proceeded with a Pt(CH(2)=CHSiMe(2))(2)O/P(t-Bu)(3) catalyst to give alkenyldimethyl(2-pyridyl)silanes in good yield with high regioselectivity. A reactivity comparison of 2-PyMe(2)SiH with other related hydrosilanes (3-PyMe(2)SiH, 4-PyMe(2)SiH, and PhMe(2)SiH) was also performed. In the rhodium-catalyzed reaction, the reactivity order of hydrosilane was 2-PyMe(2)SiH >> 3-PyMe(2)SiH, 4-PyMe(2)SiH, PhMe(2)SiH, indicating a huge rate acceleration with 2-PyMe(2)SiH. In the platinum-catalyzed reaction, the reactivity order of hydrosilane was PhMe(2)SiH, 3-PyMe(2)SiH >> 4-PyMe(2)SiH > 2-PyMe(2)SiH, indicating a rate deceleration with 2-PyMe(2)SiH and 4-PyMe(2)SiH. It seems that these reactivity differences stem primarily from the governance of two different mechanisms (Chalk-Harrod and modified Chalk-Harrod mechanisms). From the observed reactivity order, coordination and electronic effects of dimethyl(pyridyl)silanes have been implicated.
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Affiliation(s)
- Kenichiro Itami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan
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Itami K, Nokami T, Ishimura Y, Mitsudo K, Kamei T, Yoshida J. Diversity-oriented synthesis of multisubstituted olefins through the sequential integration of palladium-catalyzed cross-coupling reactions. 2-pyridyldimethyl(vinyl)silane as a versatile platform for olefin synthesis. J Am Chem Soc 2001; 123:11577-85. [PMID: 11716711 DOI: 10.1021/ja016790+] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel strategy for the diversity-oriented synthesis of multisubstituted olefins, where 2-pyridyldimethyl(vinyl)silane functions as a versatile platform for olefin synthesis, is described. The palladium-catalyzed Heck-type coupling of 2-pyridyldimethyl(vinyl)silanes with organic iodides took place in the presence of Pd2(dba)3/tri-2-furylphosphine catalyst to give beta-substituted vinylsilanes in excellent yields. The Heck-type coupling occurred even with alpha- and beta-substituted 2-pyridyldimethyl(vinyl)silanes. The one-pot double Heck coupling of 2-pyridyldimethyl(vinyl)silane took place with two different aryl iodides to afford beta,beta-diarylated vinylsilanes in good yields. The palladium-catalyzed Hiyama-type coupling of 2-pyridyldimethyl(vinyl)silane with organic halides took place in the presence of tetrabutylammonium fluoride to give di- and trisubstituted olefins in high yields. The sequential integration of Heck-type (or double Heck) coupling and Hiyama-type coupling produced the multisubstituted olefins in regioselective, stereoselective, and diversity-oriented fashions. Especially, the one-pot sequential Heck/Hiyama coupling reaction provides an extremely facile entry into a diverse range of stereodefined multisubstituted olefins. Mechanistic considerations of both Heck-type and Hiyama-type coupling reactions are also described.
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Affiliation(s)
- K Itami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan
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Itami K, Kamei T, Yoshida J. Unusually accelerated silylmethyl transfer from tin in stille coupling: implication of coordination-driven transmetalation. J Am Chem Soc 2001; 123:8773-9. [PMID: 11535082 DOI: 10.1021/ja0160593] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The palladium-catalyzed cross-coupling reaction of 2-PyMe2SiCH2SnBu3 with aryl iodide (Ar-I) exclusively produced the 2-PyMe2SiCH2 transferred product 2-PyMe2SiCH2Ar. The relative transfer ability of organic group from tin was found to be 2-PyMe2SiCH2 >> Ph > Me > Bu >> PhMe2SiCH2, which implies the beneficial pyridyl-to-palladium coordination effect. Thus, the transfer of the silylmethyl group from tin to palladium was remarkably accelerated by simply appending the 2-pyridyl group on silicon. The pyridyl-to-palladium coordination was validated in the palladium(II) complex 2-PyMe2SiCH2PdClPPh3 by 1H NMR and X-ray crystal structure analysis. The cross-coupling product was used for further transformations. The C-Si oxidation of the cross-coupling product 2-PyMe2SiCH2Ar afforded ArCH2OH in high yield. The fluoride ion-catalyzed 1,2-addition of 2-PyMe2SiCH2Ar to carbonyl compound (RR'C=O) gave ArCH2C(OH)RR' in high yield.
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Affiliation(s)
- K Itami
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501, Japan
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Affiliation(s)
- Kenichiro Itami
- Department of Synthetic Chemistry and Biological Chemistry, Kyoto University Yoshida, Kyoto 606-8501, Japan
| | - Tooru Koike
- Department of Synthetic Chemistry and Biological Chemistry, Kyoto University Yoshida, Kyoto 606-8501, Japan
| | - Jun-ichi Yoshida
- Department of Synthetic Chemistry and Biological Chemistry, Kyoto University Yoshida, Kyoto 606-8501, Japan
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