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Kashyap S, Singh B, Ghorai MK. Magic Blue-Initiated S N2-Type Ring Opening of Activated Aziridines: Friedel-Crafts-Type Alkylation of Electron-Rich Arenes/Heteroarenes. J Org Chem 2024; 89:11429-11445. [PMID: 39088802 DOI: 10.1021/acs.joc.4c01101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
A transition metal-free, atom-economical, and highly stereospecific synthetic approach to Friedel-Crafts-type alkylation of arenes/heteroarenes has been developed. The protocol involves the catalytic aminium radical-cation salt (Magic Blue)-initiated SN2-type nucleophilic ring opening of activated aziridines with arenes/heteroarenes to give the corresponding 2,2-diarylethylamines up to 99% yield and 85% ee (for nonracemic aziridines) in a very short reaction time. Moreover, on reaction with 1,3-dimethylindole and benzofuran, aziridines undergo domino-ring-opening cyclization (DROC) to give the various biologically significant heterocyclic scaffolds in moderate to good yields.
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Affiliation(s)
- Suraj Kashyap
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Bharat Singh
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Manas K Ghorai
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
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Singh B, Kashyap S, Singh S, Gupta S, Ghorai MK. Catalytic Aminium Radical-Cation Salt (Magic Blue)-Initiated S N2-Type Nucleophilic Ring-Opening Transformations of Aziridines. J Org Chem 2024; 89:2247-2263. [PMID: 38323416 DOI: 10.1021/acs.joc.3c02194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
A simple and atom economic protocol for the construction of C-X/C-C bonds via catalytic aminium radical-cation salt (Magic Blue)-initiated SN2-type nucleophilic ring-opening transformations of racemic and nonracemic aziridines with different hetero and carbon nucleophiles to afford various amino ethers, thioethers, and amines in up to 99% yield, and with perfect enantiospecificity for some substrates but reduced ee with others (for nonracemic aziridines), is developed. This aminium radical-cation salt-initiated, SN2-type nucleophilic ring-opening strategy, along with various cyclization protocols, is employed to synthesize various biologically significant compounds.
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Affiliation(s)
- Bharat Singh
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Suraj Kashyap
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Shishir Singh
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Sikha Gupta
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
| | - Manas K Ghorai
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
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Miyajima R, Ooe Y, Miura T, Ikoma T, Iwamoto H, Takizawa SY, Hasegawa E. Triarylamine-Substituted Benzimidazoliums as Electron Donor-Acceptor Dyad-Type Photocatalysts for Reductive Organic Transformations. J Am Chem Soc 2023; 145:10236-10248. [PMID: 37127911 DOI: 10.1021/jacs.3c01264] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Triarylamine-substituted benzimidazoliums (BI+-PhNAr2), new electron donor-acceptor dyad molecules, were synthesized. Their photocatalytic properties for reductive organic transformations were explored using absorption and fluorescence spectroscopy, redox potential determinations, density functional theory calculations, transient absorption spectroscopy, and reduction reactions of selected substrates. The results show that irradiation of BI+-PhNAr2 promotes photoinduced intramolecular electron transfer to form a long-lived (∼300 μs) charge shifted state (BI•-PhN•+Ar2). In the pathway for photocatalysis of reduction reactions of substrates, BI•-PhN•+Ar2 is subsequently transformed to the neutral benzimidazolyl radical (BI•-PhNAr2) by single-electron transfer from the donor 1,3-dimethyl-2-phenylbenzimidazoline (BIH-Ph) serving as a cooperative agent. Among the benzimidazoliums explored, the bromo-substituted analogue BI+-PhN(C6H4Br-p)2 in conjunction with BIH-Ph demonstrates the most consistent catalytic performance.
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Affiliation(s)
- Ryo Miyajima
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
| | - Yuuki Ooe
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
| | - Tomoaki Miura
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
| | - Tadaaki Ikoma
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
| | - Hajime Iwamoto
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
| | - Shin-Ya Takizawa
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Eietsu Hasegawa
- Department of Chemistry, Faculty of Science, Niigata University, 8050 Ikarashi-2, Nishi-ku, Niigata 950-2181, Japan
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Chen ME, Gan ZY, Hu YH, Zhang FM. Tandem Oxidative Ritter Reaction/Hydration/Aldol Condensation of α-Arylketones with Propiolonitriles for the Construction of 3-Acyl-3-pyrrolin-2-ones. J Org Chem 2023; 88:3954-3964. [PMID: 36881939 DOI: 10.1021/acs.joc.2c02935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
A novel tandem oxidative Ritter reaction/hydration/aldol condensation of α-arylketones with substituted propiolonitriles has been developed. This protocol conveniently affords a wide range of functionalized 3-acyl-3-pyrrolin-2-ones through the efficient construction of four chemical bonds, a C-N bond, a C═C bond, and two C═O bonds, and the formation of one ring bearing an aza-quaternary center, which is ascribed to the strategical introduction of functionalized nitriles to this transformation. A reaction mechanism was proposed based on some control experiments.
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Affiliation(s)
- Meng-En Chen
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Zhang-Yan Gan
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Yue-Hong Hu
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
| | - Fu-Min Zhang
- State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
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Kato N, Nanjo T, Takemoto Y. Electron Donor-Acceptor (EDA) Complex between a Triarylamine and B(C 6F 5) 3 for the Photocatalytic Dehydrogenative Cross-Coupling of Phenols. Chem Pharm Bull (Tokyo) 2023; 71:747-750. [PMID: 37661381 DOI: 10.1248/cpb.c23-00409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
In this article, an electron donor-acceptor (EDA) complex between a triarylamine and B(C6F5)3 that catalyzes the dehydrogenative cross-coupling of phenols is described. We demonstrate, for the first time, that the use of both components of the radical ion pairs generated by the photoexcitation of the EDA complex as co-catalysts, and the triarylaminium radical cation (+·NAr3) successfully promotes dehydrogenative cross-coupling between electron-rich phenols and 2-naphthols to provide electron-rich biphenol motifs using molecular oxygen as a terminal oxidant.
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Affiliation(s)
- Natsuki Kato
- Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Takeshi Nanjo
- Graduate School of Pharmaceutical Sciences, Kyoto University
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Samanta A, Pramanik S, Mondal S, Maity S. Zinc acetate-promoted blocking of the ATRA process with alkyl halides enabling photochemical alkylamination of olefins. Chem Commun (Camb) 2022; 58:8400-8403. [PMID: 35796040 DOI: 10.1039/d2cc02574d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Organic photoredox-catalyzed alkylamination of olefins is performed with alkyl halides and nitrile solvent by blocking the traditional photoredox-ATRA process with Zn(OAc)2. A range of carbon-centered radicals (α-alkylcarbonyl, benzyl, cyanomethyl) are effectively participating in this strategy giving rise to versatile carboamination products with high synthetic value.
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Affiliation(s)
- Apurba Samanta
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
| | - Shyamal Pramanik
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
| | - Subhashis Mondal
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
| | - Soumitra Maity
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
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Cremer C, Patureau FW. O 2-Mediated Te(II)-Redox Catalysis for the Cross-Dehydrogenative Coupling of Indoles. JACS AU 2022; 2:1318-1323. [PMID: 35783164 PMCID: PMC9241012 DOI: 10.1021/jacsau.2c00193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 05/09/2023]
Abstract
Very few elements in the periodic system can catalytically activate O2, such as in the context of cross-dehydrogenative couplings. The development of O2-activating catalysts is essential to enable new and sustainable reactivity concepts to emerge, because these catalysts also often feature specific activating interactions with the target substrates. In this context, the unprecedented Te(II)/Te(III) catalyzed dehydrogenative C3-C2 dimerization of indoles is described herein. The fact that O2 can be directly utilized as a terminal oxidant in this reaction, as well as the absence of any background reactivity without the redox-active Te catalyst, constitute very important milestones for the fields of cross-dehydrogenative couplings and tellurium catalysis.
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