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Son JH, Cheung A, Zhu JS, Haddadin MJ, Kurth MJ. Davis-Beirut Reaction Inspired Nitroso Diels-Alder Reaction. Tetrahedron Lett 2021; 69:152951. [PMID: 33854257 PMCID: PMC8039969 DOI: 10.1016/j.tetlet.2021.152951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A Davis-Beirut reaction inspired nitroso Diels-Alder protocol is reported. The starting material for the procedure is a nitrophenyl moiety with the para position appropriately substituted with a 2°-amine (see 5) or 2°-alcohol (see 6). Deprotonation at the benzylic position followed by concomitant oxidation of the benzylic position and reduction of the nitro moiety delivers a nitrosophenyl intermediate, which subsequently undergoes a nitroso Diels-Alder reaction. This one-pot procedure delivers aryldihydro-1,2-oxazines in moderate yields.
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Affiliation(s)
- Jung-Ho Son
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616
| | - Amy Cheung
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616
| | - Jie S Zhu
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616
| | - Makhluf J Haddadin
- Department of Chemistry, American University of Beirut, Riad El Solh, 1107 2020, Beirut, Lebanon
| | - Mark J Kurth
- Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616
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2
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Abstract
Imines, versatile intermediates for organic synthesis, can be exploited for the
preparation of diverse classes of biologically active benzazoles. Because of the special
characteristics of the C=N bond, imines can be simultaneously used in the synthesis of
1,3-benzazoles and 1,2-benzazoles. With the development of imine synthesis, a variety of
novel cascade reactions for benzazole synthesis have been reported in the last decade.
Therefore, there is a strong need to elucidate the recent progress in the formation of various
classes of benzazoles, including benzimidazoles, benzoxazoles, benzothiazoles, indazoles,
and benzisoxazoles, via imines obtained by condensation reactions or oxidative/
redox coupling reactions In this review, we provide a comprehensive survey of this
area. In particular, various green and mild synthetic methodologies are summarized, and
the multiple roles of novel catalysts and significant mechanisms for several transformations are highlighted in
detail. We believe that this review will aid researchers studying the synthesis of complex molecules containing
the benzazole motif via imines.
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Affiliation(s)
- Ran An
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Mengbi Guo
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yingbo Zang
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Hang Xu
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Zhuang Hou
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Chun Guo
- Key Laboratory of Structure-Based Drugs Design and Discovery (Ministry of Education), School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China
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Zhu JS, Haddadin MJ, Kurth MJ. Davis-Beirut Reaction: Diverse Chemistries of Highly Reactive Nitroso Intermediates in Heterocycle Synthesis. Acc Chem Res 2019; 52:2256-2265. [PMID: 31328502 DOI: 10.1021/acs.accounts.9b00220] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Indazoles are an important class of nitrogen heterocycles because of their excellent performance in biologically relevant applications, such as in chemical biology and medicinal chemistry. In these applications, convenient synthesis using commercially available and diverse building blocks is highly desirable. Within this broad class, 2H-indazoles are relatively underexploited when compared to 1H-indazole, perhaps because of regioselectivity issues associated with the synthesis of 2H-indazoles. This Account describes our unfolding of the synthetic utility of the Davis-Beirut reaction (DBR) for the construction of 2H-indazoles and their derivatives; parallel unfoldings of mechanistic models for these interrelated N-N bond forming reactions are also summarized. The Davis-Beirut reaction is a robust method that exploits the diverse chemistries of a key nitroso imine or nitroso benzaldehyde intermediate generated in situ under redox neutral conditions. The resulting N-N bond-forming heterocyclization between nucleophilic and electrophilic nitrogens can be leveraged for the synthesis of multiple classes of indazoles and their derivatives, such as simple or fused indazolones, thiazolo-indazoles, 3-alkoxy-2H-indazoles, 2H-indazole N-oxides, and 2H-indazoles with various substitutions on the ring system or the nitrogens. These diverse products can all be synthesized under alkaline conditions and the various strategies for accessing these heterocycles are discussed. Alternatively, we have also developed methods involving mild photochemical conditions for the nitrobenzyl → aci-nitro → nitroso imine sequence. Solvent consideration is especially important for modulating the chemistry of the reactive intermediates in these reactions; the presence of water is critically important in some cases, but water's beneficial effect has a ceiling because of the alternative reaction pathways it enables. Fused 2H-indazoles readily undergo ring opening reactions to give indazolones when treated with nucleophiles or electrophiles. Furthermore, palladium-catalyzed cross coupling, the Sonagashira reaction, EDC amide coupling, 1,3-dipolar cycloadditions with nitrile oxides, copper-catalyzed alkyne-azide cycloadditions (click reaction), as well as copper-free click reactions, can all be used late-stage to modify 2H-indazoles and indazolones. The continued development and applications of the Davis-Beirut reaction has provided many insights for taming the reactivity of highly reactive nitro and nitroso groups, which still has a plethora of underexplored chemistries and challenges. For example, there is currently a limited number of nonfused 2H-indazole examples containing an aryl substitution at nitrogen. This is caused by relatively slow N-N bond formation between N-aryl imine and nitroso reactants, which allows water to add to the key nitroso imine intermediate causing imine bond cleavage to be a competitive reaction pathway rather than proceeding through the desired N-N bond-forming heterocyclization.
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Affiliation(s)
- Jie S. Zhu
- Department of Chemistry, University of California Davis, 1 Shields Avenue, Davis California 95616, United States
| | | | - Mark J. Kurth
- Department of Chemistry, University of California Davis, 1 Shields Avenue, Davis California 95616, United States
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4
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Zhu JS, Li CJ, Tsui KY, Kraemer N, Son JH, Haddadin MJ, Tantillo DJ, Kurth MJ. Accessing Multiple Classes of 2 H-Indazoles: Mechanistic Implications for the Cadogan and Davis-Beirut Reactions. J Am Chem Soc 2019; 141:6247-6253. [PMID: 30912441 DOI: 10.1021/jacs.8b13481] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The Cadogan cyclization is a robust but harsh method for the synthesis of 2 H-indazoles, a valuable class of nitrogen heterocycles. Although nitrene generation by exhaustive deoxygenation is widely accepted as the operating mechanism in the reductive cyclization of nitroaromatics, non-nitrene pathways have only been theorized previously. Here, 2 H-indazole N-oxides were synthesized through an interrupted Cadogan/Davis-Beirut reaction and are presented as direct evidence of competent oxygenated intermediates; mechanistic implications for both reactions are discussed. Isolation and characterization of these N-oxides enabled a formal Cadogan cyclization at room temperature for 2 H-indazole synthesis.
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Affiliation(s)
- Jie S Zhu
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Clarabella J Li
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Ka Yi Tsui
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Niklas Kraemer
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Jung-Ho Son
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Makhluf J Haddadin
- Department of Chemistry , American University of Beirut , Beirut 1107 2020 , Lebanon
| | - Dean J Tantillo
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Mark J Kurth
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
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Liu S, Xu L, Wei Y. One-Pot, Multistep Reactions for the Modular Synthesis of N,N′-Diarylindazol-3-ones. J Org Chem 2018; 84:1596-1604. [DOI: 10.1021/acs.joc.8b02548] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shuai Liu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xin-jiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Liang Xu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xin-jiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Yu Wei
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xin-jiang Bingtuan, Shihezi University, Shihezi 832003, China
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Zhu JS, Kraemer N, Shatskikh ME, Li CJ, Son JH, Haddadin MJ, Tantillo DJ, Kurth MJ. N-N Bond Formation between Primary Amines and Nitrosos: Direct Synthesis of 2-Substituted Indazolones with Mechanistic Insights. Org Lett 2018; 20:4736-4739. [PMID: 30067041 DOI: 10.1021/acs.orglett.8b01655] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A concise, one-step route to indazolones from primary alkyl amines and o-nitrobenzyl alcohols is reported. The key step in this readily scalable indazolone forming process involves base-mediated in situ o-nitrobenzyl alcohol → o-nitrosobenzaldehyde conversion. Although this functional group interconversion is known to be useful for 2 H-indazole synthesis, its reactivity was modulated for indazolone formation.
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Affiliation(s)
- Jie S Zhu
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Niklas Kraemer
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Marina E Shatskikh
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Clarabella J Li
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Jung-Ho Son
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Makhluf J Haddadin
- Department of Chemistry , American University of Beirut , Beirut , Lebanon
| | - Dean J Tantillo
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
| | - Mark J Kurth
- Department of Chemistry , University of California Davis , 1 Shields Avenue , Davis , California 95616 , United States
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