1
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Samanta S, Biswas P, O'Bannon BC, Powers DC. β-Phenethylamine Synthesis: N-Pyridinium Aziridines as Latent Dual Electrophiles. Angew Chem Int Ed Engl 2024; 63:e202406335. [PMID: 38699820 PMCID: PMC11262962 DOI: 10.1002/anie.202406335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/05/2024]
Abstract
β-Phenethylamines are widely represented in biologically and pharmacologically active organic small molecules. Here, we introduce N-pyridinium aziridines as latent dual electrophiles for the synthesis of β-phenethylamines. Bromide-promoted ring opening generates β-halopyridinium amines. Selective Ni-catalyzed C-C cross-coupling between organozinc nucleophiles and the benzylic C-Br electrophile affords a diverse family of β-functionalized phenethylaminopyridinium salts, and coupling is stereoconvergent in the presence of chiral ligands. Subsequent Ni-catalyzed reductive N-N bond activation within the β-functionalized phenethylaminopyridinium salts furnishes the products of formal olefin carboamination. Other reductive N-N cleavage reactions are demonstrated to provide access to free primary amines, alkylated amines, heterocycles, and products derived from N-centered radical chemistry. The developed reaction sequence can be implemented in the context of complex molecules and natural product derivatives. Together, the described results provide a general and modular synthesis of β-phenethylamines and significantly expand the utility of N-pyridinium aziridines as linchpins in chemical synthesis.
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Affiliation(s)
- Samya Samanta
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
| | - Promita Biswas
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
| | - Braeden C O'Bannon
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
| | - David C Powers
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
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2
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Roychowdhury P, Waheed S, Sengupta U, Herrera RG, Powers DC. Synthesis of Secondary Amines via Self-Limiting Alkylation. Org Lett 2024; 26:4926-4931. [PMID: 38832812 PMCID: PMC11187628 DOI: 10.1021/acs.orglett.4c01430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/27/2024] [Accepted: 05/29/2024] [Indexed: 06/06/2024]
Abstract
N-centered nucleophilicity increases upon alkylation, and thus selective partial alkylation of ammonia and primary amines can be challenging: Poor selectivity and overalkylation are often observed. Here we introduce N-aminopyridinium salts as ammonia surrogates for the synthesis of secondary amines via self-limiting alkylation chemistry. Readily available N-aryl-N-aminopyridinium salts engage in N-alkylation and in situ depyridylation to afford secondary aryl-alkyl amines without any overalkylation products. The method overcomes classical challenges in selective amine alkylation by accomplishing alkylation via transient, highly nucleophilic pyridinium ylide intermediates and can be applied in the context of complex molecular scaffolds. These findings establish N-aminopyridinium salts as ammonia synthons in synthetic chemistry and a strategy to control the extent of amine alkylation.
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Affiliation(s)
- Pritam Roychowdhury
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Saim Waheed
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Uddalak Sengupta
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Roberto G. Herrera
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - David C. Powers
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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3
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Wen L, Tan Q, Pi C, Yuan J, Zhang J, Mi X. Visible-light-mediated C-H amidation of imidazoheterocycles with N-amidopyridiniums. Org Biomol Chem 2024; 22:4647-4650. [PMID: 38787700 DOI: 10.1039/d4ob00461b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
C-3 amidated imidazoheterocycles were synthesized via a visible light-promoted reaction of imidazoheterocycles with N-amidopyridinium salts catalyzed by 4CzIPN under mild conditions. For imidazoheterocycles and N-amidopyridinium salts with various substituents, the reaction proceeded smoothly to give the corresponding products in moderate to good yields. The reaction provides a new strategy for the synthesis of secondary amides with the imidazo[1,2-a]pyridine core.
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Affiliation(s)
- Lili Wen
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Qiannan Tan
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Chao Pi
- Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou 450052, China.
| | - Juan Yuan
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Jingyu Zhang
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
| | - Xia Mi
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou 450046, China.
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4
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Wang P, Lin L, Huang Y, Zhang H, Liao S. Radical Fluorosulfonamidation: A Facile Access to Sulfamoyl Fluorides. Angew Chem Int Ed Engl 2024:e202405944. [PMID: 38837324 DOI: 10.1002/anie.202405944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 06/07/2024]
Abstract
Recently, the introduction of fluorosulfonyl (-SO2F) groups have attracted considerable research interests, as this moiety could often afford enhanced activities and new functions in the context of chemical biology and drug discovery. Herein, we report the design and synthesis of 1-fluorosulfamoyl-pyridinium (FSAP) salts, which could serve as an effective photoredox-active precursor to fluorosulfamoyl radicals and enable the direct radical C-H fluorosulfonamidation of a variety of (hetero)arenes. This method features mild conditions, visible light, broad substrate scope, good group tolerance, etc., and a metal-free protocol is also viable by using organic photocatalysts. Further, FSAP can also be applied to the radical functionalization of alkenes via 1,2-difunctionalization, radical distal migration, tandem radical-polar crossover reactions, etc. In addition, a formal C-H methylamination of (hetero)arenes by combining this radical C-H fluorosulfonamidation with subsequent hydrolysis as well as product derivatization are also demonstrated.
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Affiliation(s)
- Peng Wang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- Key Laboratory of Green and Precise Synthetic Chemistry and Application, Ministry of Education, College of Chemistry and Materials Science, Huaibei Normal University, Huaibei, Anhui, 235000, China
| | - Lu Lin
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yao Huang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Honghai Zhang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Saihu Liao
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou, 350108, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
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5
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Liu J, Du J, Zhang LB, Li M, Guo W. Electrochemical Benzylic C-H Amination via N-Aminopyridinium. J Org Chem 2024; 89:6465-6473. [PMID: 38644574 DOI: 10.1021/acs.joc.4c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
An electrochemical protocol for benzylic C(sp3)-H aminopyridylation via direct C-H/N-H cross-coupling of alkylarenes with N-aminopyridinium triflate has been developed. This method features excellent site-selectivity, broad substrate scope, redox reagent-free and facile scalability. The generated benzylaminopyridiniums can be readily converted to benzylamines via electroreductive N-N bond cleavage.
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Affiliation(s)
- Jingwei Liu
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Jinyao Du
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Lin-Bao Zhang
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Ming Li
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Weisi Guo
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
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6
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Liu J, Guo L, Chen Z, Guo Y, Zhang W, Peng X, Wang Z, Zeng YF. Photoredox-catalyzed unsymmetrical diamination of alkenes for access to vicinal diamines. Chem Commun (Camb) 2024; 60:3413-3416. [PMID: 38441256 DOI: 10.1039/d4cc00330f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
A photoredox-catalyzed unsymmetrical diamination of alkenes by using N-aminopyridinium salts and nitriles as the amination reagents has been developed. Various vicinal diamines were obtained in moderate to excellent yields under mild reaction conditions. Furthermore, this protocol could be applied in the late-stage modification of pharmaceuticals and natural products. Preliminary mechanistic studies suggested that this methodology may undergo a radical pathway followed by a Ritter-type reaction.
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Affiliation(s)
- Jie Liu
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Lu Guo
- Department of Sports Medicine, Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Zhang Chen
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Yu Guo
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Wei Zhang
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Xue Peng
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
| | - Zhen Wang
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
- MOE Key Lab of Rare Pediatric Diseases, University of South China, Hengyang, Hunan, 421001, China
| | - Yao-Fu Zeng
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
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7
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Han G, You J, Choi J, Kang EJ. N-Iminopyridinium Compounds in Giese Reaction: Photoinduced Homolytic N-N and C-C Bond Cleavage for Cyanoalkyl Radical Generation. Org Lett 2024. [PMID: 38489286 DOI: 10.1021/acs.orglett.4c00565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
We present an innovative photoinduced cyanoalkyl radical addition methodology using N-iminopyridinium reagents derived from cyclic ketones. Mechanistic investigations reveal the association of the excited Hantzsch ester and iminopyridinium with pyridyl radical generation. The ensuing cascade involving homolytic N-N bond and C-C bond cleavage of the pyridyl radical ultimately leads to the formation of cyanoalkyl radical species, leading to diverse Giese-type products. The method showcases versatility and synthetic utility in late-stage functionalization.
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Affiliation(s)
- Gyuri Han
- Department of Applied Chemistry, Kyung Hee University, Yongin 17104, Korea
| | - Jihyun You
- Department of Applied Chemistry, Kyung Hee University, Yongin 17104, Korea
| | - Junhyeon Choi
- Department of Applied Chemistry, Kyung Hee University, Yongin 17104, Korea
| | - Eun Joo Kang
- Department of Applied Chemistry, Kyung Hee University, Yongin 17104, Korea
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8
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Puttreddy R, Kumar P, Rissanen K. Pyridine Iodine(I) Cations: Kinetic Trapping as a Sulfonate Complexes. Chemistry 2024; 30:e202304178. [PMID: 38193788 DOI: 10.1002/chem.202304178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 01/10/2024]
Abstract
Seven pyridine iodine(I) sulfonate complexes were prepared and isolated at low temperatures and characterized by X-ray diffraction analysis. The inherently instable pyridine iodine(I) cations are stabilized by an oxygen of sulfonate anions via the I⋅⋅⋅O halogen bond. In these complexes, the iodine atom of the pyridine iodine(I) cation acts as an electron acceptor and the sulfonate oxygen as the electron donor. These complexes are stable enough in the crystalline state, yet decompose rapidly under ambient conditions, also being unstable in solution. The (pyridine)N-I bond lengths [2.140(3)-2.197(2) Å] and the I⋅⋅⋅O halogen bonds [2.345(6)-2.227(3) Å] are analogous to (imide)N-I⋅⋅⋅O-N-pyridine uncharged halogen-bonded complexes formed from N-haloimides and pyridine N-oxides, thus confirming the existence of elusive pyridine iodine(I) cation.
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Affiliation(s)
- Rakesh Puttreddy
- University of Jyvaskyla, Department of Chemistry, P.O. BOX 35, FI-40014, Jyväskylä, Finland
| | - Parveen Kumar
- University of Jyvaskyla, Department of Chemistry, P.O. BOX 35, FI-40014, Jyväskylä, Finland
| | - Kari Rissanen
- University of Jyvaskyla, Department of Chemistry, P.O. BOX 35, FI-40014, Jyväskylä, Finland
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9
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Yang LF, Xiong ZQ, Ouyang XH, Wang QA, Li JH. Cobalt-Promoted Photoredox 1,2-Amidoamination of Alkenes with N-Sulfonamidopyridin-1-ium Salts and Free Amines. Org Lett 2024; 26:1667-1671. [PMID: 38380904 DOI: 10.1021/acs.orglett.4c00155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
A cobalt-promoted photoredox 1,2-amidoamination of alkenes with N-sulfonamidopyridin-1-ium salts and free amines for the synthesis of unsymmetrical vicinal diamines has been developed. The reaction handles N-(sulfonamido)pyridin-1-ium salts as the sulfonamidyl radical precursors and free amines as the nucleophilic terminating reagents to enable the formation of two new C(sp3)-N bonds in a single reaction step and offers a route to selectively producing unsymmetrical vicinal diamines with an exquisite selectivity and a good compatibility of functional groups.
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Affiliation(s)
- Liang-Feng Yang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China
| | - Zhi-Qiang Xiong
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
| | - Xuan-Hui Ouyang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
| | - Qiu-An Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China
| | - Jin-Heng Li
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China
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10
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Shi X, Wang Q, Tang Z, Huang H, Cao T, Cao H, Liu X. Divergent Synthesis of F- and CF 3-Containing N-Fused Heterocycles Enabled by Fragmentation Cycloaddition of β-CF 3-1,3-Enynes with N-Aminopyridiniums Ylides. Org Lett 2024; 26:1255-1260. [PMID: 38323865 DOI: 10.1021/acs.orglett.4c00088] [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
The two novel cyclization modes of β-CF3-1,3-enynes are presented herein for the divergent construction of F- and CF3-containing N-fused heterocycles. Fluorinated pyrazolo[1,5-a]pyridines were afforded from β-CF3-1,3-enynes with N-aminopyridiniums ylides via detrifluoromethylative [2 + 3] cyclizations, followed by fluorine transfer from a CF3 unit. Whereas reaction with N-aminoisoquinoliniums ylides gave CF3-substituted pyrrolo[2,1-a]isoquinoline by unprecedented fragmentation [3 + 2]-cycloadditions. Additionally, gram-scale experiments and synthetic utility are demonstrated by further derivatization of fluorinated heterocycles.
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Affiliation(s)
- Xiaotian Shi
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Qiong Wang
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Zhiqing Tang
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Huilin Huang
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Tongxin Cao
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Hua Cao
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
| | - Xiang Liu
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, P. R. of China
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11
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Boudry E, Bourdreux F, Marrot J, Moreau X, Ghiazza C. Dearomatization of Pyridines: Photochemical Skeletal Enlargement for the Synthesis of 1,2-Diazepines. J Am Chem Soc 2024; 146:2845-2854. [PMID: 38235671 DOI: 10.1021/jacs.3c14467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In this report, we developed a unified and standardized one-pot sequence that converts pyridine derivatives into 1,2-diazepines by inserting a nitrogen atom. This skeletal transformation capitalizes on the in situ generation of 1-aminopyridinium ylides, which rearrange under UV light irradiation. A thorough evaluation of the key parameters (wavelength, reaction conditions, activating agent) allowed us to elaborate on a simple, mild, and user-friendly protocol. The model reaction was extrapolated to more than 40 examples, including drug derivatives, affording unique 7-membered structures. Mechanistic evidence supports the transient presence of a diazanorcaradiene species. Finally, pertinent transformations of the products, including ring contraction reactions to form pyrazoles, were conducted and paved the way to a broad application of the developed protocol.
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Affiliation(s)
- Elise Boudry
- Université Paris-Saclay, UVSQ, CNRS, UMR 8180 Institut Lavoisier de Versailles, 78035 Versailles Cedex, France
| | - Flavien Bourdreux
- Université Paris-Saclay, UVSQ, CNRS, UMR 8180 Institut Lavoisier de Versailles, 78035 Versailles Cedex, France
| | - Jérôme Marrot
- Université Paris-Saclay, UVSQ, CNRS, UMR 8180 Institut Lavoisier de Versailles, 78035 Versailles Cedex, France
| | - Xavier Moreau
- Université Paris-Saclay, UVSQ, CNRS, UMR 8180 Institut Lavoisier de Versailles, 78035 Versailles Cedex, France
| | - Clément Ghiazza
- Université Paris-Saclay, UVSQ, CNRS, UMR 8180 Institut Lavoisier de Versailles, 78035 Versailles Cedex, France
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12
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Li SS, Jiang YS, Chen LN, Chen DN, Luo XL, Pan CX, Xia PJ. The Merger of Halogen Atom Transfer (XAT) and Energy Transfer Catalysis (EnT) for the Modular 1,2-Iminylalkylation of Diazenes. Org Lett 2023; 25:7009-7013. [PMID: 37708359 DOI: 10.1021/acs.orglett.3c02584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
The 1,2-iminylalkylation of diazenes using alkyl iodides in combination with an O-benzoyl oxime is reported. In this transformation, O-benzoyl oxime acted as a radical precursor and XAT mediator. In addition to common alkyl iodides, other alkyl iodides such as iodomethane, iodomethane-d3, trifluoroiodomethane, ethyl difluoroiodoacetate, and iodoalkanes containing unprotected hydroxyl and amide groups can also serve as C-radical precursors in the 1,2-iminylalkylation with electrophilic diazenes as radical acceptors.
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Affiliation(s)
- Shan-Shan Li
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Yu-Shi Jiang
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Li-Ning Chen
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Dan-Na Chen
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Xue-Ling Luo
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Cheng-Xue Pan
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Peng-Ju Xia
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
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13
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Cosio MN, Alharbi WS, Sur A, Wang CH, Najafian A, Cundari TR, Powers DC. On the mechanism of intermolecular nitrogen-atom transfer from a lattice-isolated diruthenium nitride intermediate. Faraday Discuss 2023; 244:154-168. [PMID: 37186144 DOI: 10.1039/d2fd00167e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Catalyst confinement within microporous media provides the opportunity to site isolate reactive intermediates, enforce intermolecular functionalization chemistry by co-localizing reactive intermediates and substrates in molecular-scale interstices, and harness non-covalent host-guest interactions to achieve selectivities that are complementary to those accessible in solution. As part of an ongoing program to develop synthetically useful nitrogen-atom transfer (NAT) catalysts, we have demonstrated intermolecular benzylic amination of toluene at a Ru2 nitride intermediate confined within the interstices of a Ru2-based metal-organic framework (MOF), Ru3(btc)2X3 (btc = 1,3,5-benzenetricarboxylate, i.e., Ru-HKUST-1 for X = Cl). Nitride confinement within the extended MOF lattice enabled intermolecular C-H functionalization of benzylic C-H bonds in preference to nitride dimerization, which was encountered with soluble molecular analogues. Detailed study of the kinetic isotope effects (KIEs, i.e., kH/kD) of C-H amination, assayed both as intramolecular effects using partially labeled toluene and as intermolecular effects using a mixture of per-labeled and unlabeled toluene, provided evidence for restricted substrate mobility on the time scale of interstitial NAT. Analysis of these KIEs as a function of material mesoporosity provided approximate experimental values for functionalization in the absence of mass transport barriers. Here, we disclose a combined experimental and computational investigation of the mechanism of NAT from a Ru2 nitride to the C-H bond of toluene. Computed kinetic isotope effects for a H-atom abstraction (HAA)/radical rebound (RR) mechanism are in good agreement with experimental data obtained for C-H amination at the rapid diffusion limit. These results provide the first detailed analysis of the mechanism of intermolecular NAT to a C-H bond, bolster the use of KIEs as a probe of confinement effects on NAT within MOF lattices, and provide mechanistic insights unavailable by experiment because rate-determining mass transport obscured the underlying chemical kinetics.
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Affiliation(s)
- Mario N Cosio
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
| | - Waad S Alharbi
- Department of Chemistry, Center of Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, USA.
- Chemistry Department, Science College, University of Jeddah, Jeddah, Kingdom of Saudi Arabia
| | - Aishanee Sur
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
| | - Chen-Hao Wang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
| | - Ahmad Najafian
- Department of Chemistry, Center of Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, USA.
| | - Thomas R Cundari
- Department of Chemistry, Center of Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, USA.
| | - David C Powers
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
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