1
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García-Lacuna J, Baumann M. Continuous Flow Synthesis of Nitrosoarenes via Photochemical Rearrangement of Aryl Imines. J Org Chem 2024; 89:617-623. [PMID: 38131303 PMCID: PMC10777388 DOI: 10.1021/acs.joc.3c02362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/20/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023]
Abstract
Nitrosoarenes are versatile organic building blocks; however, their intrinsic instability and limited synthetic accessibility have so far restricted their widespread use. Herein, we present a new continuous flow route toward these entities that is based on a direct photochemical rearrangement process using o-nitrophenylimines as starting materials. Due to the underlying redox mechanism, a new amide group accompanies the formation of the nitroso group. Crucial to the success of this approach is the use of trifluoroethanol as a solvent and high-power light-emitting diodes (365 nm) as light sources that provide uniform irradiation and high efficiency of the resulting continuous flow method. The process is fast and robust, with high functional group tolerance and high throughput. The formation of the nitroso moiety is supported by full spectroscopic analysis, including X-ray crystallography. The scalability of this flow approach allows access to gram quantities of nitroso species for which we highlight a small set of derivatization reactions underlining their synthetic utility.
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Affiliation(s)
- Jorge García-Lacuna
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland
| | - Marcus Baumann
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland
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2
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Panjacharam P, Ulabala V, Jayakumar J, Rajasekhara Reddy S. Emerging trends in the sustainable synthesis of N-N bond bearing organic scaffolds. Org Biomol Chem 2023; 21:2632-2652. [PMID: 36883312 DOI: 10.1039/d3ob00300k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
N-N bond bearing organic frameworks such as azos, hydrazines, indazoles, triazoles and their structural moieties have piqued the interest of organic chemists due to the intrinsic nitrogen electronegativity. Recent methodologies with atom efficacy and a greener approach have overcome the synthetic obstacles of N-N bond construction from N-H. As a result, a wide range of amine oxidation methods have been reported early on. This review's vision emphasizes the emerging methods of N-N bond formation, particularly photo, electro, organo and transition metal free chemical methods.
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Affiliation(s)
| | - Vijayasree Ulabala
- Department of Chemistry, Rajiv Gandhi University of Knowledge Technology (RGUKT), Nuzvid 521202, India.
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3
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Chandran R, Sharma A, Tiwari KN. Molecular Rearrangement of 2‐Substituted Indazolones: Unorthodox Access to 2‐Carboxylate‐2,3‐dihydroquinazolin‐4‐(1H)‐one Scaffold. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- R. Chandran
- National Institute of Pharmaceutical Education and Research Raebareli Department of Medicinal Chemistry INDIA
| | - Abha Sharma
- National Institute of Pharmaceutical Education and Research Raebareli Department of Medicinal Chemistry INDIA
| | - Keshri Nath Tiwari
- Sanjay Ghodawat University Kolhapur Department of Chemistry Atigre 416118 Kolhapur INDIA
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4
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Bieniek JC, Grünewald M, Winter J, Schollmeyer D, Waldvogel SR. Electrochemical Synthesis of
N
,
N
’‑ Disubstituted Indazolin-3-ones via Intramolecular Anodic DehydrogenativeN-NCoupling Reaction. Chem Sci 2022; 13:8180-8186. [PMID: 35919432 PMCID: PMC9278119 DOI: 10.1039/d2sc01827f] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/10/2022] [Indexed: 11/30/2022] Open
Abstract
The use of electricity as a traceless oxidant enables a sustainable and novel approach to N,N′-disubstituted indazolin-3-ones by an intramolecular anodic dehydrogenative N–N coupling reaction. This method is characterized by mild reaction conditions, an easy experimental setup, excellent scalability, and a high atom economy. It was used to synthesize various indazolin-3-one derivatives in yields up to 78%, applying inexpensive and sustainable electrode materials and a low supporting electrolyte concentration. Mechanistic studies, based on cyclic voltammetry experiments, revealed a biradical pathway. Furthermore, the access to single 2-aryl substituted indazolin-3-ones by cleavage of the protecting group could be demonstrated. A novel sustainable electrochemical synthetic route to N,N′-disubstituted indazolin-3-ones by direct anodic oxidation with mild reaction conditions, a simple galvanostatic setup, broad scope and excellent scalability is established.![]()
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Affiliation(s)
- Jessica C Bieniek
- Department of Chemistry, Johannes Gutenberg University Duesbergweg 10-14 Mainz 55128 Germany https://www.aksw.uni-mainz.de/
| | - Michele Grünewald
- Department of Chemistry, Johannes Gutenberg University Duesbergweg 10-14 Mainz 55128 Germany https://www.aksw.uni-mainz.de/
| | - Johannes Winter
- Department of Chemistry, Johannes Gutenberg University Duesbergweg 10-14 Mainz 55128 Germany https://www.aksw.uni-mainz.de/
| | - Dieter Schollmeyer
- Department of Chemistry, Johannes Gutenberg University Duesbergweg 10-14 Mainz 55128 Germany https://www.aksw.uni-mainz.de/
| | - Siegfried R Waldvogel
- Department of Chemistry, Johannes Gutenberg University Duesbergweg 10-14 Mainz 55128 Germany https://www.aksw.uni-mainz.de/
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5
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Wang H, Ball ZT. A photochemical C=C cleavage process: toward access to backbone N-formyl peptides. Beilstein J Org Chem 2021; 17:2932-2938. [PMID: 34956413 PMCID: PMC8685554 DOI: 10.3762/bjoc.17.202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/30/2021] [Indexed: 11/23/2022] Open
Abstract
Photo-responsive modifications and photo-uncaging concepts are useful for spatiotemporal control of peptides structure and function. While side chain photo-responsive modifications are relatively common, access to photo-responsive modifications of backbone N-H bonds is quite limited. This letter describes a new photocleavage pathway, affording N-formyl amides from vinylogous nitroaryl precursors under physiologically relevant conditions via a formal oxidative C=C cleavage. The N-formyl amide products have unique properties and reactivity, but are difficult or impossible to access by traditional synthetic approaches.
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Affiliation(s)
- Haopei Wang
- Department of Chemistry, Rice University, Houston TX, USA
| | - Zachary T Ball
- Department of Chemistry, Rice University, Houston TX, USA
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6
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Ou Y, Yang T, Tang N, Yin SF, Kambe N, Qiu R. Photo-Induced N-N Coupling of o-Nitrobenzyl Alcohols and Indolines To Give N-Aryl-1-amino Indoles. Org Lett 2021; 23:6417-6422. [PMID: 34355914 DOI: 10.1021/acs.orglett.1c02227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel method to synthesize N-aryl-1-amino indoles was established by the photoinduced N-N coupling reaction. This protocol is by treatment of o-nitrobenzyl alcohols and indolines in the presence of TEAI and acetic acid with a 24 W ultraviolet (UV) light-emitting diode (LED) (385-405 nm) irradiation. The products bearing an aldehyde group can be further transformed to fluorescent probes based on Rhodamine 6G derivative 11, which shows a high specificity and sensitivity for Fe3+.
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Affiliation(s)
- Yifeng Ou
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China
| | - Tianbao Yang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China
| | - Niu Tang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China
| | - Shuang-Feng Yin
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China
| | - Nobuaki Kambe
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China.,The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Renhua Qiu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China
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7
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Liu J, Liu N, Yang Q, Wang L. Visible-light-driven photocyclization reaction: photocatalyst-free mediated intramolecular N–N coupling for the synthesis of 2 H-indazole-3-carboxamides from aryl azides. Org Chem Front 2021. [DOI: 10.1039/d1qo00777g] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A visible-light-driven photocyclization reaction of aryl azides to access 2H-indazole-3-carboxamides in moderate to excellent yields has been realized efficiently under photocatalyst-free and external additive-free conditions.
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Affiliation(s)
- Jinni Liu
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, Hubei 443002, China
| | - Na Liu
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, Hubei 443002, China
| | - Qingqing Yang
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, Hubei 443002, China
| | - Long Wang
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, Hubei 443002, China
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8
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Guo AD, Wei D, Nie HJ, Hu H, Peng C, Li ST, Yan KN, Zhou BS, Feng L, Fang C, Tan M, Huang R, Chen XH. Light-induced primary amines and o-nitrobenzyl alcohols cyclization as a versatile photoclick reaction for modular conjugation. Nat Commun 2020; 11:5472. [PMID: 33122644 PMCID: PMC7596520 DOI: 10.1038/s41467-020-19274-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 09/30/2020] [Indexed: 12/31/2022] Open
Abstract
The advent of click chemistry has had a profound impact on many fields and fueled a need for reliable reactions to expand the click chemistry toolkit. However, developing new systems to fulfill the click chemistry criteria remains highly desirable yet challenging. Here, we report the development of light-induced primary amines and o-nitrobenzyl alcohols cyclization (PANAC) as a photoclick reaction via primary amines as direct click handle, to rapid and modular functionalization of diverse small molecules and native biomolecules. With intrinsic advantages of temporal control, good biocompatibility, reliable chemoselectivity, excellent efficiency, readily accessible reactants, operational simplicity and mild conditions, the PANAC photoclick is robust for direct diversification of pharmaceuticals and biorelevant molecules, lysine-specific modifications of unprotected peptides and native proteins in vitro, temporal profiling of endogenous kinases and organelle-targeted labeling in living systems. This strategy provides a versatile platform for organic synthesis, bioconjugation, medicinal chemistry, chemical biology and materials science.
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Affiliation(s)
- An-Di Guo
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Dan Wei
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Hui-Jun Nie
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hao Hu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Chengyuan Peng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Shao-Tong Li
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Ke-Nian Yan
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Bin-Shan Zhou
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Lei Feng
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Chao Fang
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Minjia Tan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ruimin Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Xiao-Hua Chen
- Chinese Academy of Sciences Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China.
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9
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Bao Y, Deng Z, Feng J, Zhu W, Li J, Wan J, Liu G. A B 2(OH) 4-Mediated Synthesis of 2-Substituted Indazolone and Its Application in a DNA-Encoded Library. Org Lett 2020; 22:6277-6282. [PMID: 32806212 DOI: 10.1021/acs.orglett.0c02032] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Indazolone cores are among the most common structural components in medicinal chemistry and can be found in many biologically active molecules. In this report, a mild and efficient approach to 2-substituted indazolones via B2(OH)4-mediated reductive N-N bond formation is developed. This strategy features mild conditions, no request for a metal catalyst, and a wide scope for both aliphatic and aromatic amines. Meanwhile, this method was further successfully applied on DNA to construct indazolone cores for a DNA-encoded library. This will enable the production of a very attractive indazolone-cored library from simple amines and scaffolds, which will provide considerable diversity.
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Affiliation(s)
- Yapeng Bao
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Zongfa Deng
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Jing Feng
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Weiwei Zhu
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Jin Li
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Jinqiao Wan
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
| | - Guansai Liu
- Discovery Chemistry Unit, HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China
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10
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Zhu JS, Larach JM, Tombari RJ, Gingrich PW, Bode SR, Tuck JR, Warren HT, Son JH, Duim WC, Fettinger JC, Haddadin MJ, Tantillo DJ, Kurth MJ, Olson DE. A Redox Isomerization Strategy for Accessing Modular Azobenzene Photoswitches with Near Quantitative Bidirectional Photoconversion. Org Lett 2019; 21:8765-8770. [PMID: 31638403 DOI: 10.1021/acs.orglett.9b03387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Photoswitches capable of accessing two geometric states are highly desirable, especially if their design is modular and incorporates a pharmacophore tethering site. We describe a redox isomerization strategy for synthesizing p-formylazobenzenes from p-nitrobenzyl alcohol. The resulting azo-aldehydes can be readily converted to photoswitchable compounds with excellent photophysical properties using simple hydrazide click chemistry. As a proof of principle, we synthesized a photoswitchable surfactant enabling the photocontrol of an emulsion with exceptionally high spatiotemporal precision.
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Affiliation(s)
- Jie S Zhu
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Julio M Larach
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Robert J Tombari
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Phillip W Gingrich
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Stanley R Bode
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Jeremy R Tuck
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Hunter T Warren
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Jung-Ho Son
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Whitney C Duim
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - James C Fettinger
- Department of Chemistry , University of California, Davis , One 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 , One Shields Avenue , Davis , California 95616 , United States
| | - Mark J Kurth
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - David E Olson
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States.,Department of Biochemistry & Molecular Medicine, School of Medicine , University of California, Davis , 2700 Stockton Boulevard, Suite 2102 , Sacramento , California 95817 , United States.,Center for Neuroscience , University of California, Davis , 1544 Newton Court , Davis , California 95618 , United States
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11
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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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12
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Kraemer N, Li CJ, Zhu JS, Larach JM, Tsui KY, Tantillo DJ, Haddadin MJ, Kurth MJ. Davis-Beirut Reaction: A Photochemical Brønsted Acid Catalyzed Route to N-Aryl 2 H-Indazoles. Org Lett 2019; 21:6058-6062. [PMID: 31339318 PMCID: PMC6698363 DOI: 10.1021/acs.orglett.9b02213] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Davis-Beirut reaction provides access to 2H-indazoles from aromatic nitro compounds. However, N-aryl targets have been traditionally challenging to access due to competitive alternate reaction pathways. Previously, the key nitroso imine intermediate was generated under alkaline conditions, but as reported here, the photochemistry of o-nitrobenzyl alcohols empowered Brønsted acid catalyzed conditions for accessing N-aryl targets. Anilines and alkyl amines give different outcomes under optimized conditions; the proposed mechanism was studied using quantum chemical calculations.
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Affiliation(s)
- Niklas Kraemer
- 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
| | - Jie S. Zhu
- Department of Chemistry, University of California Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - Julio M. Larach
- 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
| | - 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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13
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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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14
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Reddy DS, Kutateladze AG. Photoinitiated Cascade for Rapid Access to Pyrroloquinazolinone Core of Vasicinone, Luotonins, and Related Alkaloids. Org Lett 2019; 21:2855-2858. [PMID: 30933523 DOI: 10.1021/acs.orglett.9b00858] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Furylimines of aromatic o-nitro aldehydes undergo a photoinduced cascade transformation offering rapid atom- and step-economical access to complex polyheterocyclic scaffolds possessing a privileged pyrroloquinazolinone core.
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Affiliation(s)
- D Sai Reddy
- Department of Chemistry and Biochemistry , University of Denver , Denver , Colorado 80208 , United States
| | - Andrei G Kutateladze
- Department of Chemistry and Biochemistry , University of Denver , Denver , Colorado 80208 , United States
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15
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Yang T, Lu H, Qiu R, Hong L, Yin S, Kambe N. Photocatalyst‐free Synthesis of Indazolones under CO
2
Atmosphere. Chem Asian J 2019; 14:1436-1442. [DOI: 10.1002/asia.201900306] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Tianbao Yang
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha 410082 P. R. China
| | - Huiai Lu
- College of BiologyHuazhong University of Science and Technology Wuhan 430074 Hubei P. R. China
| | - Renhua Qiu
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha 410082 P. R. China
- Graduate School of EngineeringOsaka University Suita Osaka 565-0871 Japan
| | - Ling Hong
- College of BiologyHuazhong University of Science and Technology Wuhan 430074 Hubei P. R. China
| | - Shuang‐Feng Yin
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha 410082 P. R. China
| | - Nobuaki Kambe
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha 410082 P. R. China
- Graduate School of EngineeringOsaka University Suita Osaka 565-0871 Japan
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16
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Nie HJ, Guo AD, Lin HX, Chen XH. Rapid and halide compatible synthesis of 2- N-substituted indazolone derivatives via photochemical cyclization in aqueous media. RSC Adv 2019; 9:13249-13253. [PMID: 35520758 PMCID: PMC9063774 DOI: 10.1039/c9ra02466b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/19/2019] [Indexed: 12/25/2022] Open
Abstract
A straightforward protocol for the rapid construction of privileged indazolone architectures suggests a new avenue of great importance to medicinal chemistry.
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Affiliation(s)
- Hui-Jun Nie
- Department of Chemistry
- Innovative Drug Research Center
- College of Sciences Shanghai University
- Shanghai
- China
| | - An-Di Guo
- Chinese Academy of Sciences Key Laboratory of Receptor Research
- Synthetic Organic & Medicinal Chemistry Laboratory
- Shanghai Institute of Materia Medica
- Chinese Academy of Sciences
- Shanghai 201203
| | - Hai-Xia Lin
- Department of Chemistry
- Innovative Drug Research Center
- College of Sciences Shanghai University
- Shanghai
- China
| | - Xiao-Hua Chen
- Chinese Academy of Sciences Key Laboratory of Receptor Research
- Synthetic Organic & Medicinal Chemistry Laboratory
- Shanghai Institute of Materia Medica
- Chinese Academy of Sciences
- Shanghai 201203
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