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Xu LC, Ma XD, Liu KM, Duan XF. Chemo- and Regioselective Alkylation of Pyridine N-Oxides with Titanacyclopropanes. Org Lett 2023. [PMID: 38016093 DOI: 10.1021/acs.orglett.3c03469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
While titanacyclopropanes are used to react mainly with ester, amide, and cyano to undergo cyclopropanation, herein they react preferentially with pyridine N-oxide to accomplish C2-H alkylation beyond these functionalities with double regioselectivity. After being pyridylated at the less hindered C-Ti bond, the remaining C-Ti bond of titanacyclopropanes can be further functionalized by various electrophiles, allowing facile introduction of complex alkyls onto the C2 of pyridines. Its synthetic potential has been demonstrated by late-stage diversification of drugs.
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Affiliation(s)
- Li-Chen Xu
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Xiao-Di Ma
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Kun-Ming Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Xin-Fang Duan
- College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
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2
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Lee Y, Nam YS, Kim SY, Ki JE, Lee HG. Mechanistic duality of indolyl 1,3-heteroatom transposition. Chem Sci 2023; 14:7688-7698. [PMID: 37476715 PMCID: PMC10355096 DOI: 10.1039/d3sc00716b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 06/15/2023] [Indexed: 07/22/2023] Open
Abstract
A novel mechanistic duality has been revealed from the indolyl 1,3-heteroatom transposition (IHT) of N-hydroxyindole derivatives. A series of in-depth mechanistic investigations suggests that two separate mechanisms are operating simultaneously. Moreover, the relative contribution of each mechanistic pathway, the energy barrier for each pathway, and the identity of the primary pathway were shown to be the functions of the electronic properties of the substrate system. Based on the mechanistic understanding obtained, a mechanism-driven strategy for the general and efficient introduction of a heteroatom at the 3-position of indole has been developed. The reaction developed exhibits a broad substrate scope to provide the products in various forms of the functionalised indole. Moreover, the method is applicable to the introduction of both oxygen- and nitrogen-based functional groups.
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Affiliation(s)
- Yujin Lee
- Department of Chemistry, Seoul National University 1, Gwanak-ro, Gwanak-gu Seoul 08826 South Korea
| | - Yun Seung Nam
- Department of Chemistry, Seoul National University 1, Gwanak-ro, Gwanak-gu Seoul 08826 South Korea
| | - Soo Young Kim
- Department of Chemistry, Seoul National University 1, Gwanak-ro, Gwanak-gu Seoul 08826 South Korea
| | - Jeong Eun Ki
- Department of Chemistry, Seoul National University 1, Gwanak-ro, Gwanak-gu Seoul 08826 South Korea
| | - Hong Geun Lee
- Department of Chemistry, Seoul National University 1, Gwanak-ro, Gwanak-gu Seoul 08826 South Korea
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3
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Dong G, Jiang M, Wu N, Zhang S, Zhu H, Xu Z. An umpolung strategy for chemically selective intermolecular cross-enolate-type coupling of N-alkenoxypyridinium salts with aldehydes. Chem Commun (Camb) 2023; 59:3594-3597. [PMID: 36883526 DOI: 10.1039/d3cc00422h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
An efficient method for the synthesis of 1,4-ketoaldehydes via the cross-coupling of N-alkenoxyheteroarenium salts and primary aldehydes is developed. This method provides a broad substrate scope and excellent functional group compatibility. The utility of this method is demonstrated via the diverse transformations of heterocyclic compounds and cycloheptanone, as well as the late-stage functionalization of biorelevant molecules.
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Affiliation(s)
- Guichao Dong
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| | - Mengfei Jiang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| | - Nan Wu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| | - Shengxiang Zhang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| | - Huilong Zhu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
| | - Zhou Xu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, Jiangsu, China.
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4
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Direct photolysis of N-methoxypyridiniums for the pyridylation of carbon/heteroatom-hydrogen bonds. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1399-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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Kim M, You E, Kim J, Hong S. Site-Selective Pyridylic C-H Functionalization by Photocatalytic Radical Cascades. Angew Chem Int Ed Engl 2022; 61:e202204217. [PMID: 35481719 DOI: 10.1002/anie.202204217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Indexed: 11/08/2022]
Abstract
An efficient pyridylic C(sp3 )-H functionalization has been developed through photocatalytic radical-mediated fluoroalkylation or cascade reactions. This method is enabled by the reversible formation of alkylidene dihydropyridine intermediates via the facile enolate formation of C4-alkyl N-amidopyridinium salts in the absence of an external base, thereby establishing the conditions necessary for subsequent intermolecular radical trapping. Rapid structural diversification of the pyridylic site can be achieved through photocatalytic multicomponent cascade reactions involving alkene trifluoromethylation, SO2 -reincorporation, and sulfonyl radical addition. This operationally simple method features a broad substrate scope and high chemoselectivity and offers a unique approach for the rational modification of the heterobenzylic C-H bonds of pyridines and quinolines with uniform site-selective control. Furthermore, experimental and theoretical studies were performed to elucidate the reaction mechanism.
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Affiliation(s)
- Myojeong Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Euna You
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Jieun Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Sungwoo Hong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
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6
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Kim M, You E, Kim J, Hong S. Site‐Selective Pyridylic C–H Functionalization by Photocatalytic Radical Cascades. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Myojeong Kim
- KAIST: Korea Advanced Institute of Science and Technology Chemistry KOREA, REPUBLIC OF
| | - Euna You
- KAIST: Korea Advanced Institute of Science and Technology Chemistry KOREA, REPUBLIC OF
| | - Jieun Kim
- KAIST: Korea Advanced Institute of Science and Technology Chemistry KOREA, REPUBLIC OF
| | - Sungwoo Hong
- Korea Advanced Institute of Science and Technology KAIST Department of Chemistry Yusung Gu (KAIST) 34141 Daejeon KOREA, REPUBLIC OF
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7
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Sheng H, Liu Q, Chen F, Wang Z, Chen X. Visible-light-induced N-heterocyclic carbene mediated cascade transformation of N-alkenoxypyridinium salts. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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8
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Huang M, Ma J, Zou Z, Li H, Liu J, Kong L, Pan Y, Zhang W, Liang Y, Wang Y. A photoinduced transient activating strategy for late-stage chemoselective C(sp 3)–H trifluoromethylation of azines. Chem Sci 2022; 13:11312-11319. [PMID: 36320576 PMCID: PMC9533475 DOI: 10.1039/d2sc03989c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/24/2022] [Indexed: 11/23/2022] Open
Abstract
The direct functionalization of C(sp3)–H bonds is an ultimately ideal synthetic strategy with high atom economy and step efficiency. However, the direct trifluoromethylation of electron-deficient heteroaryl adjacent C(sp3)–H bonds remains a formidable challenge. We have described a transient activating strategy involving a Tf-shift process and π–π stacking interaction for catalyst-free direct benzylic C(sp3)–H trifluoromethylation of azines, such as pyridine, pyrimidine, quinoline, dihydropyridinone, tetrahydroisoquinoline and tetrahydroquinazoline, with an air-stable crystalline imidazolium sulfonate reagent IMDN-Tf. This bench-stable cationic reagent offers a scalable and practical protocol for the late-stage modification of drug molecules with high site selectivity, which avoids the prefunctionalization and the use of stoichiometric metals and strong oxidants. Furthermore, comprehensive mechanistic studies revealed the determining effect of π–π stacking for the activation of azinylic C(sp3)–H bonds. Late-stage C(sp3)–H functionalization of unactivated azines: the traceless Tf switching process offers ample opportunities for site-selective derivatization of heteroaryls, allowing for the rapid increase of molecular complexity.![]()
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Affiliation(s)
- Mengjun Huang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jiawei Ma
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zhenlei Zou
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Heyin Li
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jiyang Liu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Lingyu Kong
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yi Pan
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Weigang Zhang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yi Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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9
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Kumar R, Nguyen QH, Um TW, Shin S. Recent Progress in Enolonium Chemistry under Metal-Free Conditions. CHEM REC 2021; 22:e202100172. [PMID: 34418282 DOI: 10.1002/tcr.202100172] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/08/2021] [Accepted: 08/11/2021] [Indexed: 11/09/2022]
Abstract
Umpolung approach through inversion of the polarity of conventional enolates, has opened up an unprecedented opportunity in the cross-coupling via alkylation. The enolonium equivalents can be accessed either by hypervalent iodine reagents, activation/oxidation of amides, or the oxidation of alkynes. Under umpolung conditions, highly basic conditions required for classical enolate chemistry can be avoided, and they can couple with unmodified nucleophiles such as heteroatom donors and electron-rich arenes.
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Affiliation(s)
- Ravi Kumar
- Department of Chemistry, Center for New Directions in Organic Chemistry (CNOS), and Institute for Natural Sciences, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Korea
| | - Quynh H Nguyen
- Department of Chemistry, Center for New Directions in Organic Chemistry (CNOS), and Institute for Natural Sciences, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Korea
| | - Tae-Woong Um
- Department of Chemistry, Center for New Directions in Organic Chemistry (CNOS), and Institute for Natural Sciences, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Korea
| | - Seunghoon Shin
- Department of Chemistry, Center for New Directions in Organic Chemistry (CNOS), and Institute for Natural Sciences, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Korea
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10
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Li H, Xia HC, Nie FY, Song QH. Rapid and Effective Reaction of 2-Methylpyridin- N-oxides with Triphosgene via a [3,3]-Sigmatropic Rearrangement: Mechanism and Applications. J Org Chem 2021; 86:8308-8318. [PMID: 34042446 DOI: 10.1021/acs.joc.1c00749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A facile and effective synthesis of 2-chloromethylpyridines was developed by a one-pot reaction of 2-alkylpyridin-N-oxides and triphosgene at room temperature. As starting materials, N-oxides of 2-alkylpyridine derivatives, including 2-alkylpyridines, 2-methyl quinolines, and phenanthroline, can react rapidly with triphosgene in the presence of triethylamine, affording 2-chloromethylpyridines in good to excellent yields (52-95%). Using the 2-methylquinoline substrate for the mechanistic study, it has been well demonstrated that the chlorination reaction undergoes a [3,3]-sigmatropic rearrangement, which can be observed as a reversible process by monitoring the intermediates. Moreover, the chlorination reaction can be used to construct a rapid and sensitive fluorescent probe for the detection of phosgene.
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Affiliation(s)
- Hao Li
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Hong-Cheng Xia
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Fang-Yuan Nie
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Qin-Hua Song
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, P. R. China
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11
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Sheng H, Liu Q, Su XD, Lu Y, Wang ZX, Chen XY. Visible-Light-Triggered Iodinations Facilitated by Weak Electrostatic Interaction of N-Heterocyclic Carbenes. Org Lett 2020; 22:7187-7192. [DOI: 10.1021/acs.orglett.0c02523] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- He Sheng
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Liu
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Di Su
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Lu
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhi-Xiang Wang
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang-Yu Chen
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
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