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Mechanistic Aspects of the Electrochemical Oxidation of Aliphatic Amines and Aniline Derivatives. Molecules 2023; 28:molecules28020471. [PMID: 36677530 PMCID: PMC9864799 DOI: 10.3390/molecules28020471] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 12/30/2022] [Accepted: 01/01/2023] [Indexed: 01/05/2023] Open
Abstract
The electrochemical oxidation of amines is an essential alternative to the conventional chemical transformation that provides critical routes for synthesising and modifying a wide range of chemically useful molecules, including pharmaceuticals and agrochemicals. As a result, the anodic reactivity of these compounds has been extensively researched over the past seven decades. However, the different mechanistic aspects of the electrochemical oxidation of amines have never been discussed from a comprehensive and general point of view. This review examines the oxidation mechanism of aliphatic amines, amides, aniline and aniline derivatives, carbamates, and lactams, either directly oxidised at different electrode surfaces or indirectly oxidised by a reversible redox molecule, in which the reactive form was generated in situ. The mechanisms are compared and simplified to understand all possible pathways for the oxidation of amines using only a few general mechanisms. Examples of the application of these oxidation reactions are also provided.
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Mu BS, Cui XY, Zeng XP, Yu JS, Zhou J. Modular synthesis of chiral 1,2-dihydropyridines via Mannich/Wittig/cycloisomerization sequence that internally reuses waste. Nat Commun 2021; 12:2219. [PMID: 33833227 PMCID: PMC8032725 DOI: 10.1038/s41467-021-22374-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/05/2021] [Indexed: 12/18/2022] Open
Abstract
1,2-Dihydropyridines are valuable and reactive synthons, and particularly useful precursors to synthesize piperidines and pyridines that are among the most common structural components of pharmaceuticals. However, the catalytic enantioselective synthesis of structurally diverse 1,2-dihydropyridines is limited to enantioselective addition of nucleophiles to activated pyridines. Here, we report a modular organocatalytic Mannich/Wittig/cycloisomerization sequence as a flexible strategy to access chiral 1,2-dihydropyridines from N-Boc aldimines, aldehydes, and phosphoranes, using a chiral amine catalyst. The key step in this protocol, cycloisomerization of chiral N-Boc δ-amino α,β-unsaturated ketones recycles the waste to improve the yield. Specifically, recycling by-product water from imine formation to gradually release the true catalyst HCl via hydrolysis of SiCl4, whilst maintaining a low concentration of HCl to suppress side reactions, and reusing waste Ph3PO from the Wittig step to modulate the acidity of HCl. This approach allows facile access to enantioenriched 2-substituted, 2,3- or 2,6-cis-disubstituted, and 2,3,6-cis-trisubstituted piperidines.
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Affiliation(s)
- Bo-Shuai Mu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Xiao-Yuan Cui
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Xing-Ping Zeng
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Jin-Sheng Yu
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China. .,Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University, Haikou, 571158, China.
| | - Jian Zhou
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China. .,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, CAS, Shanghai, 200032, China.
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Mu BS, Zhang ZH, Wu WB, Yu JS, Zhou J. Recent Advances in Synthesis of Chiral 1,2-Dihydropyridines. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21040131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Yamamoto K, Kuriyama M, Onomura O. Anodic Oxidation for the Stereoselective Synthesis of Heterocycles. Acc Chem Res 2020; 53:105-120. [PMID: 31872753 DOI: 10.1021/acs.accounts.9b00513] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stereodefined aliphatic heterocycles are one of the fundamental structural motifs observed in natural products and biologically active compounds. Various strategies for the synthesis of these building blocks based on transition metal catalysis, organocatalysis, and noncatalytic conditions have been developed. Although electrosynthesis has also been utilized for the functionalization of aliphatic heterocycles, stereoselective transformations under electrochemical conditions are still a challenging field in electroorganic chemistry. This Account consists of four main topics related to our recent efforts on the diastereo- and/or enantioselective synthesis of aliphatic heterocycles, especially N-heterocycles, using anodic oxidations as key steps. The first topic is the development of stereoselective synthetic methods for multisubstituted piperidines and pyrrolidines from anodically prepared α-methoxy cyclic amines. Our strategies were based primarily on N-acyliminium ion chemistry, and the key electrochemical transformations were diastereoselective anodic methoxylation, diastereoselective arylation, and anodic deallylative methoxylation. Furthermore, we found a unique property of the N-cyano protecting group that enabled the electrochemical α-methoxylation of α-substituted cyclic amines. The second topic of investigation is memory of chirality in electrochemical decarboxylative methoxylation. We observed that the electrochemical decarboxylative methoxylation of oxazolidine and thiazolidine derivatives with the appropriate N-protecting group occurred in a stereospecific manner even though the reaction proceeded through an sp2 planar carbon center. Our findings demonstrated the first example of memory of chirality in N-acyliminium ion chemistry. The third topic is the synthesis of chiral azabicyclo-N-oxyls and their application to chiral organocatalysis in the electrochemical oxidative kinetic resolution of secondary alcohols. The final topic is stereoselective transformations utilizing anodically generated halogen cations. We investigated the oxidative kinetic resolution of amino alcohol derivatives using anodically generated bromo cations. We also developed an intramolecular C-C bond formation of keto amides, a diastereoselective bromoiminolactonization of α-allyl malonamides, and an oxidative ring expansion reaction of allyl alcohols. It is noteworthy that most of the electrochemical reactions were performed in undivided cells under constant-current conditions, which avoided a complicated reaction setup and was beneficial for a large-scale reaction. In addition, we developed some enantioselective electrochemical transformations that are still challenges in electroorganic chemistry. We hope that our research will contribute to the further development of diastereo- and/or enantioselective transformations and the construction of valuable heterocyclic compounds using an electrochemical approach.
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Affiliation(s)
- Kosuke Yamamoto
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
| | - Masami Kuriyama
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
| | - Osamu Onomura
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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Golub T, Becker JY. Anodic oxidation of bisamides from diaminoalkanes by constant current electrolysis. Beilstein J Org Chem 2018; 14:861-868. [PMID: 29765466 PMCID: PMC5942381 DOI: 10.3762/bjoc.14.72] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/27/2018] [Indexed: 11/23/2022] Open
Abstract
In general, bisamides derived from diamines and involving 3 and 4 methylene groups as spacers between the two amide functionalities behave similar to monoamides upon anodic oxidation in methanol/LiClO4 because both types undergo majorly mono- and dimethoxylations at the α-position to the N atom. However, in cases where the spacer contains two methylene groups only the anodic process leads mostly to CH2-CH2 bond cleavage to afford products of type RCONHCH2OCH3. Moreover, upon replacing LiClO4 with Et4NBF4 an additional fragmentation type of product was generated from the latter amides, namely RCONHCHO. Also, the anodic process was found to be more efficient with C felt as the anode, and in a mixture of 1:1 methanol/acetonitrile co-solvents.
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Affiliation(s)
- Tatiana Golub
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - James Y Becker
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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Sharma VK, Singh SK. Synthesis, utility and medicinal importance of 1,2- & 1,4-dihydropyridines. RSC Adv 2017. [DOI: 10.1039/c6ra24823c] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The present review aims to describe various methodologies that have been used for the synthesis of 1,2- & 1,4-dihydropyridines (DHPs) and also highlight their medicinal significance.
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Affiliation(s)
- Vivek K. Sharma
- RNA Therapeutics Institute
- University of Massachusetts Medical School
- Worcester
- USA
| | - Sunil K. Singh
- Department of Chemistry
- Kirori Mal College
- University of Delhi
- Delhi-110007
- India
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Abstract
A Ni-catalyzed cross coupling of arylzinc reagents with pyridinium ions provides enantioenriched dihydropyridines, which are precursors to diverse piperidine derivatives.
We report an enantioselective Ni-catalyzed cross coupling of arylzinc reagents with pyridinium ions formed in situ from pyridine and a chloroformate. This reaction provides enantioenriched 2-aryl-1,2-dihydropyridine products that can be elaborated to numerous piperidine derivatives with little or no loss in ee. This method is notable for its use of pyridine, a feedstock chemical, to build a versatile, chiral heterocycle in a single synthetic step.
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Affiliation(s)
- J Patrick Lutz
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
| | - Stephen T Chau
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
| | - Abigail G Doyle
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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Matsumura Y, Asano T, Nakagiri T, Onomura O. Diastereoselective Cyclopropanation Utilizing a New ChiralN,O-Acetals Prepared by Electrochemical Oxidation of Carbamates. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.199800047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nocquet-Thibault S, Retailleau P, Cariou K, Dodd RH. Iodine(III)-Mediated Umpolung of Bromide Salts for the Ethoxybromination of Enamides. Org Lett 2013; 15:1842-5. [DOI: 10.1021/ol400453b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Sophie Nocquet-Thibault
- Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
| | - Pascal Retailleau
- Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
| | - Kevin Cariou
- Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
| | - Robert H. Dodd
- Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
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Alix A, Lalli C, Retailleau P, Masson G. Highly enantioselective electrophilic α-bromination of enecarbamates: chiral phosphoric acid and calcium phosphate salt catalysts. J Am Chem Soc 2012; 134:10389-92. [PMID: 22686436 DOI: 10.1021/ja304095z] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Metal-free chiral phosphoric acids and chiral calcium phosphates both catalyze highly enantio- and diastereoselective electrophilic α-bromination of enecarbamates to provide an atom-economical synthesis of enantioenriched vicinal haloamines. Either enantiomer can be formed in good yield with excellent diastereo- and enantioselectivity simply by switching the catalyst from a phosphoric acid to its calcium salt.
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Affiliation(s)
- Aurélien Alix
- Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
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12
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Mizuta S, Onomura O. Diastereoselective addition to N-acyliminium ions with aryl- and alkenyl boronic acids via a Petasis-type reaction. RSC Adv 2012. [DOI: 10.1039/c2ra01254e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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O’Connor PD, Marino MG, Guéret SM, Brimble MA. Synthesis and Reactivity of β-Methoxymethyl Enecarbamates. J Org Chem 2009; 74:8893-6. [DOI: 10.1021/jo901992z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Patrick D. O’Connor
- Department of Chemistry, The University of Auckland, 23 Symonds Street, Auckland, New Zealand
| | - Michael G. Marino
- Department of Chemistry, The University of Auckland, 23 Symonds Street, Auckland, New Zealand
| | - Stéphanie M. Guéret
- Department of Chemistry, The University of Auckland, 23 Symonds Street, Auckland, New Zealand
| | - Margaret A. Brimble
- Department of Chemistry, The University of Auckland, 23 Symonds Street, Auckland, New Zealand
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Le Corre L, Kizirian JC, Levraud C, Boucher JL, Bonnet V, Dhimane H. Diastereoselective functionalizations of enecarbamates derived from pipecolic acid towards 5-guanidinopipecolates as arginine mimetics. Org Biomol Chem 2008; 6:3388-98. [DOI: 10.1039/b805811c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Highly enantioselective introduction of bis(alkoxycarbonyl)methyl group into the 2-position of piperidine skeleton. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2006.04.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Minato D, Imai M, Kanda Y, Onomura O, Matsumura Y. Copper ion-catalyzed regioselective introduction of active methylene groups into the γ-position of piperidine skeleton and its application to the synthesis of (−)-cincholoiponic acid. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.05.158] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Onomura O, Kanda Y, Imai M, Matsumura Y. Stereoselective synthesis of optically active 2-alkylpiperidines utilizing electrochemical oxidation as a key step. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2005.01.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Girard N, Hurvois JP, Moinet C, Toupet L. Total Synthesis of (±)-Pumiliotoxin C: An Electrochemical Approach. European J Org Chem 2005. [DOI: 10.1002/ejoc.200400846] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Botman PNM, Dommerholt FJ, de Gelder R, Broxterman QB, Schoemaker HE, Rutjes FPJT, Blaauw RH. Diastereoselective Synthesis of (2S,5R)-5-Hydroxypipecolic Acid and 6-Substituted Derivatives. Org Lett 2004; 6:4941-4. [PMID: 15606105 DOI: 10.1021/ol047774v] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] Herein, we report a diastereoselective synthesis of the natural product (2S,5R)-5-hydroxypipecolic acid and 6-substituted derivatives thereof. The key step in the synthetic sequence is a novel highly diastereoselective epoxidation reaction of an enantiomerically pure cyclic enamide intermediate.
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Affiliation(s)
- Peter N M Botman
- Chiralix B.V., P.O. Box 31070, 6503 CB Nijmegen, The Netherlands
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Furukubo S, Moriyama N, Onomura O, Matsumura Y. Stereoselective synthesis of azasugars by electrochemical oxidation. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.09.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Matsumura Y, Onomura O, Suzuki H, Furukubo S, Maki T, Li CJ. Indium-mediated nucleophilic substitution reaction of β,γ-unsaturated α-methoxypiperidine derivative in water. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01042-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kanda Y, Onomura O, Maki T, Matsumura Y. Asymmetric carbon-carbon bond-forming reaction at the 2-position of a piperidine skeleton. Chirality 2003; 15:89-94. [PMID: 12467049 DOI: 10.1002/chir.10151] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An asymmetric carbon-carbon bond-forming reaction at the 2-position of a piperidine skeleton was exploited. This method consisted of a reaction between 1-(4-methoxybenzoyl)-3,4-didehydro-2-methoxypiperidines and dimethyl malonate catalyzed by Cu(II)-chiral 2,2'-isopropylidenebis(4-phenyl-2-oxazoline) to afford a 2-substituted piperidine skeleton with moderate enantioselectivity.
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Affiliation(s)
- Yasuhisa Kanda
- Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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Abstract
Some methods for innovative molecular transformations using optically active alpha-amino acids have been exploited. 1) The non-Kolbe reaction of the N-benzoyloxazoline derivative 1 derived from L-serine gave the optically active N,O-acetal 2 when graphite was used an anode material. This reaction represents the first example of "memory of chirality" in the carbenium ion chemistry. 2) The optically active pipecolic acid derivative 13, prepared from L-lysine by using electrochemical oxidation, was cyclopropanated with high diastereoselectivity (96.6%de), and the product 14 was transformed into (2S,3R)-metanopipecolic acid (7). 3) An enantiomerically pure 1,2-dihydropyridine 23 was prepared from L-lysine using electrochemical oxidation as a key step and was utilized as a chiral diene synthon in the Diels-Alder reaction. That is, in the presence of AlCl3, the Diels-Alder reaction between 23 and N-acryloyloxazolidinone 24 gave a cycloadduct with high stereoselectivity, which was converted to an optically active isoquinuclidine derivative 26 (96.8% ee). 4) The Hofmann rearrangement of the L-glutamine derivative 27 to the enantiomerically pure 2-aminobutyric acid derivative 28 was successfully achieved with an electrochemical method using a trifluoroethanol-MeCN solvent system. 5) Some types of N-formyl cyclic amine derivatives were found to be effective activators of trichlorosilane to reduce ketones and imines. Namely, the reduction of ketones and imines by trichlorosilane with a catalytic amount of L-proline derivatives 30 and 32 gave enantiomerically enriched sec-alcohols and amines, respectively, to some extent of optical yields.
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Affiliation(s)
- Osamu Onomura
- Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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25
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Copper ion-catalyzed asymmetric carbon–carbon bond-forming reaction at the 2-position of a piperidine skeleton. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)00449-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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26
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A Convenient Method for Synthesis of Optically Active Methylphenidate from N-Methoxycarbonylpiperidine by Utilizing Electrochemical Oxidation and Evans Aldol-type Reaction. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00653-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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Matsumura Y, Nakamura Y, Maki T, Onomura O. New enantiomerically pure 1,2-dihydropyridine and its use for construction of optically active 2-azabicyclo[2.2.2]octane. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(00)01342-3] [Citation(s) in RCA: 23] [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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28
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Reactivity of 2-cyano-1,4,5,6-tetrahydro-1-pyridinecarboxylic acid esters towards various nucleophiles: Regio- and stereoselectivity of the attack. MONATSHEFTE FUR CHEMIE 1997. [DOI: 10.1007/bf00806971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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29
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30
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Streith J, Boiron A, Paillaud JL, Rodriguez-Perez EM, Strehler C, Tschamber T, Zehnder M. Chelate-Controlled Asymmetric Synthesis of 2-Substituted 2,3-Dihydropyridin-4(1H)-ones: Synthesis ofD- andL-aminodeoxyaltrose derivatives. Helv Chim Acta 1995. [DOI: 10.1002/hlca.19950780106] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Electroorganic chemistry 139. Electroreductive decyanation of nitriles and its application to synthesis of α-alkylamines. Tetrahedron 1992. [DOI: 10.1016/s0040-4020(01)80493-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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32
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Regioselective introduction of alkyl groups to the position α or γ to nitrogen atom of piperidine skeletons using anodic oxidation in a key step. Tetrahedron Lett 1990. [DOI: 10.1016/s0040-4039(00)97071-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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33
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