1
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Watanabe Y, Morozumi H, Mutoh H, Hagiwara K, Inoue M. Total Synthesis of (-)-Batrachotoxin Enabled by a Pd/Ag-Promoted Suzuki-Miyaura Coupling Reaction. Angew Chem Int Ed Engl 2023; 62:e202309688. [PMID: 37582693 DOI: 10.1002/anie.202309688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/17/2023]
Abstract
Batrachotoxin is an extremely potent cardio- and neurotoxic steroidal alkaloid found in certain species of frogs, birds, and beetles. The steroidal 6/6/6/5-membered carbocycle (ABCD-ring) is U-shaped and functionalized with two double bonds, a six-membered C3-hemiacetal across the AB-ring, a seven-membered oxazepane on the CD-ring, and a dimethylpyrrolecarboxy group at the D-ring carbon chain. These structural features present an unusual and formidable synthetic challenge. Herein we report a total synthesis of batrachotoxin based on a newly devised convergent strategy through a 22-step sequence. Enantiopure AB-ring and D-ring fragments were prepared and subjected to a crucial C(sp2 )-C(sp2 ) coupling reaction. Although both C(sp2 ) centers were sterically encumbered by proximal tetrasubstituted carbon atoms, Ag2 O strongly promoted the Pd(PPh3 )4 -catalyzed Suzuki-Miyaura coupling reaction at room temperature, thereby connecting the two fragments without damaging their preexisting functionalities. Subsequent treatment with t-BuOK induced Dieckmann condensation to cyclize the C-ring. The judiciously optimized functionalizations realized oxazepane formation, carbon chain extension, and pyrrole carboxylic acid condensation to deliver batrachotoxin.
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Affiliation(s)
- Yuuki Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisahiro Morozumi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroyuki Mutoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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2
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Cho S, McLaren EJ, Wang Q. Three‐Component Difunctionalization of Cyclohexenyl Triflates: Direct Access to Versatile Cyclohexenes via Cyclohexynes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202109482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Seoyoung Cho
- Department of Chemistry Duke University Durham NC 27708 USA
| | - E. J. McLaren
- Department of Chemistry Duke University Durham NC 27708 USA
| | - Qiu Wang
- Department of Chemistry Duke University Durham NC 27708 USA
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3
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Cho S, McLaren EJ, Wang Q. Three-Component Difunctionalization of Cyclohexenyl Triflates: Direct Access to Versatile Cyclohexenes via Cyclohexynes. Angew Chem Int Ed Engl 2021; 60:26332-26336. [PMID: 34644004 DOI: 10.1002/anie.202109482] [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: 07/15/2021] [Revised: 09/27/2021] [Indexed: 11/06/2022]
Abstract
Difunctionalization of strained cyclic alkynes presents a powerful strategy to build richly functionalized cyclic alkenes in an expedient fashion. Herein we disclose an efficient and flexible approach to achieve carbohalogenation, dicarbofunctionalization, aminohalogenation and aminocarbonation of readily available cyclohexenyl triflates. We have demonstrated the novel use of zincate base/nucleophile system for effective formation of key cyclohexyne intermediates and selective addition of various carbon and nitrogen nucleophiles. Importantly, leveraging the resulting organozincates enables the incorporation of a broad range of electrophilic partners to deliver structurally diverse cyclohexene motifs. The importance and utility of this method is also exemplified by the modularity of this approach and the ease in which even highly complex polycyclic scaffolds can be accessed in one step.
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Affiliation(s)
- Seoyoung Cho
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
| | - E J McLaren
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
| | - Qiu Wang
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
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4
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Affiliation(s)
- Jiarong Shi
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, P. R. China, 400030
| | - Lianggui Li
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, P. R. China, 400030
| | - Yang Li
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, P. R. China, 400030
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5
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Yoshioka E, Kakigi K, Miyoshi S, Kawasaki Y, Miyabe H. Aryne Precursors for Selective Generation of 3-Haloarynes: Preparation and Application to Synthetic Reactions. J Org Chem 2020; 85:13544-13556. [PMID: 32985890 DOI: 10.1021/acs.joc.0c01669] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The synthesis and reaction of new 3-haloaryne precursors 2a-2h were studied. The ortho-(trimethylsilyl)aryl triflate precursors 2a-2h were prepared by a simple procedure involving O-trimethylsilylation and migration of a trimethylsilyl group followed by triflation. The remarkable feature of new precursors is the selective generation of 3-haloarynes by suppressing the competitive thia-Fries rearrangement, which is the problem in the reaction using the well-known 3-haloaryne precursors. The advantage of new precursor 2a over a typical precursor 1 was confirmed by the direct comparisons in several reactions. The application of precursors 2a-2h to the syntheses of heterocycles was also reported.
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Affiliation(s)
- Eito Yoshioka
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Kengo Kakigi
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Shouta Miyoshi
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Yuichi Kawasaki
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
| | - Hideto Miyabe
- School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Chuo-ku, Kobe 650-8530, Japan
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6
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Hioki Y, Mori A, Okano K. Steric effects on deprotonative generation of cyclohexynes and 1,2-cyclohexadienes from cyclohexenyl triflates by magnesium amides. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Guo Y, Guo Z, Lu JT, Fang R, Chen SC, Luo T. Total Synthesis of (-)-Batrachotoxinin A: A Local-Desymmetrization Approach. J Am Chem Soc 2020; 142:3675-3679. [PMID: 32036656 DOI: 10.1021/jacs.9b12882] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An enantioselective total synthesis of (-)-batrachotoxinin A is accomplished based on a key photoredox coupling reaction and the subsequent local-desymmetrization operation. After the expedient assembly of the highly oxidized steroid skeleton, a delicate sequence of redox manipulations was carried out to deliver a late-stage intermediate on gram scale-and ultimately (-)-batrachotoxinin A in an efficient manner.
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Affiliation(s)
- Yinliang Guo
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Zhixian Guo
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Jia-Tian Lu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Runting Fang
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Si-Cong Chen
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Tuoping Luo
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies , Peking University , Beijing 100871 , China
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8
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Synthetic Approaches to Zetekitoxin AB, a Potent Voltage-Gated Sodium Channel Inhibitor. Mar Drugs 2019; 18:md18010024. [PMID: 31888062 PMCID: PMC7024329 DOI: 10.3390/md18010024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (NaVs) are membrane proteins that are involved in the generation and propagation of action potentials in neurons. Recently, the structure of a complex made of a tetrodotoxin-sensitive (TTX-s) NaV subtype with saxitoxin (STX), a shellfish toxin, was determined. STX potently inhibits TTX-s NaV, and is used as a biological tool to investigate the function of NaVs. More than 50 analogs of STX have been isolated from nature. Among them, zetekitoxin AB (ZTX) has a distinctive chemical structure, and is the most potent inhibitor of NaVs, including tetrodotoxin-resistant (TTX-r) NaV. Despite intensive synthetic studies, total synthesis of ZTX has not yet been achieved. Here, we review recent efforts directed toward the total synthesis of ZTX, including syntheses of 11-saxitoxinethanoic acid (SEA), which is considered a useful synthetic model for ZTX, since it contains a key carbon-carbon bond at the C11 position.
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9
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Meguro T, Chen S, Kanemoto K, Yoshida S, Hosoya T. Modular Synthesis of Unsymmetrical Doubly-ring-fused Benzene Derivatives Based on a Sequential Ring Construction Strategy Using Oxadiazinones as a Platform Molecule. CHEM LETT 2019. [DOI: 10.1246/cl.190118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Tomohiro Meguro
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Shengnan Chen
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Kazuya Kanemoto
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Suguru Yoshida
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Takamitsu Hosoya
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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10
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Li ZY, Chaminda Lakmal HH, Cui X. Enabling Catalytic Arene C–H Amidomethylation via Bis(tosylamido)methane as a Sustainable Formaldimine Releaser. Org Lett 2019; 21:3735-3740. [DOI: 10.1021/acs.orglett.9b01183] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhong-Yuan Li
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | | | - Xin Cui
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
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11
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Walker JR, Merit JE, Thomas-Tran R, Tang DTY, Du Bois J. Divergent Synthesis of Natural Derivatives of (+)-Saxitoxin Including 11-Saxitoxinethanoic Acid. Angew Chem Int Ed Engl 2019; 58:1689-1693. [PMID: 30488599 PMCID: PMC6426452 DOI: 10.1002/anie.201811717] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Indexed: 11/06/2022]
Abstract
The bis-guanidinium toxins are a collection of natural products that display nanomolar potency against select isoforms of eukaryotic voltage-gated Na+ ion channels. We describe a synthetic strategy that enables access to four of these poisons, namely 11-saxitoxinethanoic acid, C13-acetoxy saxitoxin, decarbamoyl saxitoxin, and saxitoxin. Highlights of this work include an unusual Mislow-Evans rearrangement and a late-stage Stille ketene acetal coupling. The IC50 value of 11-saxitoxinethanoic acid was measured against rat NaV 1.4, and found to be 17.0 nm, similar to those of the sulfated toxins gonyautoxin II and III.
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Affiliation(s)
- James R. Walker
- James R. Walker, SAFC, Inc., 645 Science Dr., Madison, WI 53711
| | - Jeffrey E. Merit
- Jeffrey E. Merit, Gilead Sciences, 333 Lakeside Dr., Foster City, CA 94404
| | - Rhiannon Thomas-Tran
- Rhiannon Thomas-Tran, Arcus Biosciences, Inc., 3928 Point Eden Way, Hayward, CA 94545
| | - Doris T. Y. Tang
- Doris T. Y. Tang and J. Du Bois, Department of Chemistry, Stanford University, Stanford, CA 94305,
| | - J. Du Bois
- Doris T. Y. Tang and J. Du Bois, Department of Chemistry, Stanford University, Stanford, CA 94305,
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12
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Walker JR, Merit JE, Thomas‐Tran R, Tang DTY, Du Bois J. Divergent Synthesis of Natural Derivatives of (+)‐Saxitoxin Including 11‐Saxitoxinethanoic Acid. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201811717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | | | - Doris T. Y. Tang
- Department of ChemistryStanford University Stanford CA 94305 USA
| | - J. Du Bois
- Department of ChemistryStanford University Stanford CA 94305 USA
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13
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Korb M, Lang H. The anionic Fries rearrangement: a convenient route to ortho-functionalized aromatics. Chem Soc Rev 2019; 48:2829-2882. [DOI: 10.1039/c8cs00830b] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The scope and mechanism of anionic (hetero-) Fries rearrangements are summarized for various migrating groups and arenes, including applications and computational studies.
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Affiliation(s)
- Marcus Korb
- Technische Universität Chemnitz
- Faculty of Natural Sciences
- Institute of Chemistry
- Inorganic Chemistry
- Chemnitz
| | - Heinrich Lang
- Technische Universität Chemnitz
- Faculty of Natural Sciences
- Institute of Chemistry
- Inorganic Chemistry
- Chemnitz
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14
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Lee CJ, Swain M, Kwon O. Synthesis of Cyclic β-Silylalkenyl Triflates via an Alkenyl Cation Intermediate. Org Lett 2018; 20:5474-5477. [PMID: 30118234 PMCID: PMC6133754 DOI: 10.1021/acs.orglett.8b02398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trimethylsilylalkyne derivatives are transformed into cyclic β-silylalkenyl triflates through cationic cyclization and subsequent trapping of the alkenyl cation by a triflate anion. β-Silylcyclohexenyl triflates and 3-trimethylsilyl-1,4-dihydronaphth-2-yl triflates are generated efficiently using this methodology. These products provide ready access to substituted cyclohexynes, exemplified by a concise total synthesis of β-apopicropodophyllin.
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Affiliation(s)
- Craig J. Lee
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
| | - Manisha Swain
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
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15
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Inoue K, Nakura R, Okano K, Mori A. One-Pot Synthesis of Silylated Enol Triflates from Silyl Enol Ethers for Cyclohexynes and 1,2-Cyclohexadienes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800353] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kazuki Inoue
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai 657-8501 Nada, Kobe Japan
| | - Ryo Nakura
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai 657-8501 Nada, Kobe Japan
| | - Kentaro Okano
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai 657-8501 Nada, Kobe Japan
| | - Atsunori Mori
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai 657-8501 Nada, Kobe Japan
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16
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Hioki Y, Yukioka T, Okano K, Mori A. Deprotonative Generation of Cyclohexynes from Cyclic Enol Triflates Using Aluminate Bases. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201800205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yuto Hioki
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai Nada Kobe 657-8501 Japan
| | - Taro Yukioka
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai Nada Kobe 657-8501 Japan
| | - Kentaro Okano
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai Nada Kobe 657-8501 Japan
| | - Atsunori Mori
- Department of Chemical Science and Engineering; Kobe University; 1-1 Rokkodai Nada Kobe 657-8501 Japan
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17
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Lv C, Wan C, Liu S, Lan Y, Li Y. Aryne Trifunctionalization Enabled by 3-Silylaryne as a 1,2-Benzdiyne Equivalent. Org Lett 2018; 20:1919-1923. [DOI: 10.1021/acs.orglett.8b00469] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chunjie Lv
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, 400030, P. R. China
| | - Caiwen Wan
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, 400030, P. R. China
| | - Song Liu
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, 400030, P. R. China
| | - Yu Lan
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, 400030, P. R. China
| | - Yang Li
- School of Chemistry and Chemical Engineering, Chongqing University, 174 Shazheng Street, Chongqing, 400030, P. R. China
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18
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Sakata K, Wang Y, Urabe D, Inoue M. Synthesis of the Tetracyclic Structure of Batrachotoxin Enabled by Bridgehead Radical Coupling and Pd/Ni-Promoted Ullmann Reaction. Org Lett 2017; 20:130-133. [PMID: 29232148 DOI: 10.1021/acs.orglett.7b03482] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The steroidal ABCD-ring system of the potent neurotoxin batrachotoxin was efficiently assembled in a convergent fashion. Bridgehead radical coupling between the simple AB-ring and D-ring fragments (3 and 4) formed the sterically congested linkage at the C9-oxygen-attached tetrasubstituted carbon. The C-ring was then cyclized by the Pd/Ni-promoted Ullmann reaction of the vinyl triflate and vinyl bromide of 19, giving rise to tetracyclic structure 1.
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Affiliation(s)
- Komei Sakata
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yinghua Wang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Daisuke Urabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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19
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Shih JL, Jansone-Popova S, Huynh C, May JA. Synthesis of azasilacyclopentenes and silanols via Huisgen cycloaddition-initiated C-H bond insertion cascades. Chem Sci 2017; 8:7132-7137. [PMID: 29147544 PMCID: PMC5637360 DOI: 10.1039/c7sc03130k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/21/2017] [Indexed: 12/29/2022] Open
Abstract
An unusual transition metal-free cascade reaction of alkynyl carbonazidates was discovered to form azasilacyclopentenes. Mild thermolysis afforded the products via a series of cyclizations, rearrangements, and an α-silyl C-H bond insertion (rather than the more common Wolff rearrangement, 1,2-shift, or β-silyl C-H insertion) to form silacyclopropanes. A mechanistic proposal for the sequence was informed by control experiments and the characterization of reaction intermediates. The substrate scope and post-cascade transformations were also explored.
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Affiliation(s)
- Jiun-Le Shih
- Department of Chemistry , University of Houston , Fleming Building Room 112, 3585 Cullen Blvd , Houston , TX 77204-5003 , USA .
| | - Santa Jansone-Popova
- Department of Chemistry , University of Houston , Fleming Building Room 112, 3585 Cullen Blvd , Houston , TX 77204-5003 , USA .
| | - Christopher Huynh
- Department of Chemistry , University of Houston , Fleming Building Room 112, 3585 Cullen Blvd , Houston , TX 77204-5003 , USA .
| | - Jeremy A May
- Department of Chemistry , University of Houston , Fleming Building Room 112, 3585 Cullen Blvd , Houston , TX 77204-5003 , USA .
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20
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Zhou H, Chaminda Lakmal HH, Baine JM, Valle HU, Xu X, Cui X. Catalytic [2 + 2 + 2] cycloaddition with indium(iii)-activated formaldimines: a practical and selective access to hexahydropyrimidines and 1,3-diamines from alkenes. Chem Sci 2017; 8:6520-6524. [PMID: 28989677 PMCID: PMC5628582 DOI: 10.1039/c7sc02576a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 07/20/2017] [Indexed: 02/02/2023] Open
Abstract
Catalytic [2 + 2 + 2] cycloaddition with three double bond systems has been developed for construction of hexahydropyrimidine and 1,3-diamine derivatives.
Catalytic [2 + 2 + 2] cycloaddition with imines has, for the first time, been developed as a practical and selective approach for direct construction of hexahydropyrimidine derivatives from various alkenes. With formaldimines as reagents and simple InCl3 as the catalyst, this ionic [2 + 2 + 2] approach is applicable for a wide scope of alkenes and allenes with various electronic and steric properties, as well as substitution patterns. Through facile hydrolysis of the resulting hexahydropyrimidines, this catalytic process also provides a new synthetic strategy for the aminomethylamination of alkenes and allenes to practically access 1,3-diamine derivatives.
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Affiliation(s)
- Hui Zhou
- Department of Chemistry , Mississippi State University , Mississippi State , MS 39762 , USA .
| | | | - Jonathan M Baine
- Department of Chemistry , Mississippi State University , Mississippi State , MS 39762 , USA .
| | - Henry U Valle
- Department of Chemistry , Mississippi State University , Mississippi State , MS 39762 , USA .
| | - Xue Xu
- Department of Chemistry , Mississippi State University , Mississippi State , MS 39762 , USA .
| | - Xin Cui
- Department of Chemistry , Mississippi State University , Mississippi State , MS 39762 , USA .
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21
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Eiden CG, Aldrich CC. Synthesis of a 3-Amino-2,3-dihydropyrid-4-one and Related Heterocyclic Analogues as Mechanism-Based Inhibitors of BioA, a Pyridoxal Phosphate-Dependent Enzyme. J Org Chem 2017; 82:7806-7819. [PMID: 28682613 DOI: 10.1021/acs.joc.7b00847] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Amiclenomycin (ACM) is a chemically unstable antibiotic with selective activity against Mycobacterium tuberculosis (Mtb) due to mechanism-based inhibition of BioA, a pyridoxal 5'-phosphate (PLP)-dependent aminotransferase. The first-generation ACM analogue dihydro-2-pyridone 1 maintains a similar bioactivation mechanism concluding with covalent labeling of the PLP cofactor. To improve on 1, we report the synthesis of dihydro-4-pyranone 2, dihydro-4-pyridone 3, and dihydro-4-thiopyranone 13, which were rationally designed to boost the rate of enzyme inactivation by lowering the pKa of their α-protons. We employed a unified synthetic strategy for construction of the desired heterocycles featuring α-amino ynone generation followed by 6-endo-dig cyclization. However, competitive 5-exo-dig cyclization, β-elimination of the ynone, and dimerization of the resultant α-amino carbonyls all complicated the syntheses of the dihydro-4-pyranone and dihydro-4-pyridone scaffolds. These obstacles were overcome by Teoc protection of the β-amino group in the assembly of 3 and Boc-MOM protection of the α-amino group in the synthesis of 2, enabling the efficient construction of 2 and 3 in seven steps from commercially available starting materials. Dihydro-4-pyridone 3 possessed improved enzyme inhibition as measured by its kinact value against BioA.
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Affiliation(s)
- Carter G Eiden
- Department of Medicinal Chemistry, University of Minnesota , 308 Harvard Street SE, 8-174 WDH, Minneapolis, Minnesota 55455, United States
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota , 308 Harvard Street SE, 8-174 WDH, Minneapolis, Minnesota 55455, United States
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22
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Logan MM, Toma T, Thomas-Tran R, Du Bois J. Asymmetric synthesis of batrachotoxin: Enantiomeric toxins show functional divergence against NaV. Science 2017; 354:865-869. [PMID: 27856903 DOI: 10.1126/science.aag2981] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/14/2016] [Indexed: 01/22/2023]
Abstract
The steroidal neurotoxin (-)-batrachotoxin functions as a potent agonist of voltage-gated sodium ion channels (NaVs). Here we report concise asymmetric syntheses of the natural (-) and non-natural (+) antipodes of batrachotoxin, as well both enantiomers of a C-20 benzoate-modified derivative. Electrophysiological characterization of these molecules against NaV subtypes establishes the non-natural toxin enantiomer as a reversible antagonist of channel function, markedly different in activity from (-)-batrachotoxin. Protein mutagenesis experiments implicate a shared binding side for the enantiomers in the inner pore cavity of NaV These findings motivate and enable subsequent studies aimed at revealing how small molecules that target the channel inner pore modulate NaV dynamics.
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Affiliation(s)
- Matthew M Logan
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
| | - Tatsuya Toma
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
| | | | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA.
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23
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Maurer DP, Fan R, Thamattoor DM. Photochemical Generation of Strained Cycloalkynes from Methylenecyclopropanes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Daniel P. Maurer
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
| | - Rui Fan
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
| | - Dasan M. Thamattoor
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
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24
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Maurer DP, Fan R, Thamattoor DM. Photochemical Generation of Strained Cycloalkynes from Methylenecyclopropanes. Angew Chem Int Ed Engl 2017; 56:4499-4501. [DOI: 10.1002/anie.201701275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Daniel P. Maurer
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
| | - Rui Fan
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
| | - Dasan M. Thamattoor
- Department of Chemistry Colby College 5765 Mayflower Hill Waterville ME 04901 USA
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25
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Hioki Y, Okano K, Mori A. Generation of cycloalkynes through deprotonation of cyclic enol triflates with magnesium bisamides. Chem Commun (Camb) 2017; 53:2614-2617. [PMID: 28195283 DOI: 10.1039/c6cc09920c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Deprotonative generation of cyclohexynes, cycloheptynes, and cyclooctynes was achieved by controlling the reactivities of transient anionic species from the corresponding enol triflates with magnesium bis(2,2,6,6-tetramethylpiperidide) as a base. The starting enol triflates are readily obtained through triflation of the corresponding ketones, allowing direct access to the cycloalkynes.
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Affiliation(s)
- Yuto Hioki
- Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
| | - Kentaro Okano
- Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
| | - Atsunori Mori
- Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
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26
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Fan R, Wen Y, Thamattoor DM. Photochemical generation and trapping of 3-oxacyclohexyne. Org Biomol Chem 2017; 15:8270-8275. [DOI: 10.1039/c7ob01697b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The strained heterocyclic alkyne, 3-oxacyclohexyne, has been generated for the first time by a photochemical route.
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Affiliation(s)
- Rui Fan
- Department of Chemistry
- Colby College
- Waterville
- USA
| | - Yuewei Wen
- Department of Chemistry
- Colby College
- Waterville
- USA
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27
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Toma T, Logan MM, Menard F, Devlin AS, Du Bois J. Inhibition of Sodium Ion Channel Function with Truncated Forms of Batrachotoxin. ACS Chem Neurosci 2016; 7:1463-1468. [PMID: 27501251 DOI: 10.1021/acschemneuro.6b00212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
A novel family of small molecule inhibitors of voltage-gated sodium channels (NaVs) based on the structure of batrachotoxin (BTX), a well-known channel agonist, is described. Protein mutagenesis and electrophysiology experiments reveal the binding site as the inner pore region of the channel, analogous to BTX, alkaloid toxins, and local anesthetics. Homology modeling of the eukaryotic channel based on recent crystallographic analyses of bacterial NaVs suggests a mechanism of action for ion conduction block.
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Affiliation(s)
- Tatsuya Toma
- Department
of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Matthew M. Logan
- Department
of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Frederic Menard
- Department
of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - A. Sloan Devlin
- Department
of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - J. Du Bois
- Department
of Chemistry, Stanford University, Stanford, California 94305-5080, United States
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28
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Medina JM, McMahon TC, Jiménez-Osés G, Houk KN, Garg NK. Cycloadditions of cyclohexynes and cyclopentyne. J Am Chem Soc 2014; 136:14706-9. [PMID: 25283710 PMCID: PMC4207212 DOI: 10.1021/ja508635v] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
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We report the strategic use of cyclohexyne
and the more elusive
intermediate, cyclopentyne, as a tool for the synthesis of new
heterocyclic compounds. Experimental and computational studies
of a 3-substituted cyclohexyne are also described. The observed
regioselectivities are explained by the distortion/interaction
model.
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Affiliation(s)
- Jose M Medina
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States
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29
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Michel B, Greaney MF. Continuous-Flow Synthesis of Trimethylsilylphenyl Perfluorosulfonate Benzyne Precursors. Org Lett 2014; 16:2684-7. [DOI: 10.1021/ol500959e] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Boris Michel
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Michael F. Greaney
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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30
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Eberlin LS, Mulcahy JV, Tzabazis A, Zhang J, Liu H, Logan MM, Roberts HJ, Lee GK, Yeomans DC, Du Bois J, Zare RN. Visualizing dermal permeation of sodium channel modulators by mass spectrometric imaging. J Am Chem Soc 2014; 136:6401-5. [PMID: 24708172 PMCID: PMC4017602 DOI: 10.1021/ja501635u] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Determining
permeability of a given compound through human skin
is a principal challenge owing to the highly complex nature of dermal
tissue. We describe the application of an ambient mass spectrometry
imaging method for visualizing skin penetration of sodium channel
modulators, including novel synthetic analogs of natural neurotoxic
alkaloids, topically applied ex vivo to human skin. Our simple and label-free approach enables
successful mapping of the transverse and lateral diffusion of small
molecules having different physicochemical properties without the
need for extensive sample preparation.
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Affiliation(s)
- Livia S Eberlin
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States
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