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Li C, Shi K, Zhao S, Liu J, Zhai Q, Hou X, Xu J, Wang X, Liu J, Wu X, Fan W. Natural-source payloads used in the conjugated drugs architecture for cancer therapy: Recent advances and future directions. Pharmacol Res 2024; 207:107341. [PMID: 39134188 DOI: 10.1016/j.phrs.2024.107341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/30/2024] [Accepted: 08/02/2024] [Indexed: 08/15/2024]
Abstract
Drug conjugates are obtained from tumor-located vectors connected to cytotoxic agents via linkers, which are designed to deliver hyper-toxic payloads directly to targeted cancer cells. These drug conjugates include antibody-drug conjugates (ADCs), peptide-drug conjugates (PDCs), small molecule-drug conjugates (SMDCs), nucleic acid aptamer-drug conjugates (ApDCs), and virus-like drug conjugate (VDCs), which show great therapeutic value in the clinic. Drug conjugates consist of a targeting carrier, a linker, and a payload. Payloads are key therapy components. Cytotoxic molecules and their derivatives derived from natural products are commonly used in the payload portion of conjugates. The ideal payload should have sufficient toxicity, stability, coupling sites, and the ability to be released under specific conditions to kill tumor cells. Microtubule protein inhibitors, DNA damage agents, and RNA inhibitors are common cytotoxic molecules. Among these conjugates, cytotoxic molecules of natural origin are summarized based on their mechanism of action, conformational relationships, and the discovery of new derivatives. This paper also mentions some cytotoxic molecules that have the potential to be payloads. It also summarizes the latest technologies and novel conjugates developed in recent years to overcome the shortcomings of ADCs, PDCs, SMDCs, ApDCs, and VDCs. In addition, this paper summarizes the clinical trials conducted on conjugates of these cytotoxic molecules over the last five years. It provides a reference for designing and developing safer and more efficient conjugates.
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Affiliation(s)
- Cuiping Li
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Kourong Shi
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Siyuan Zhao
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Juan Liu
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Qiaoli Zhai
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Xiaoli Hou
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Jie Xu
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
| | - Xinyu Wang
- Shanghai Wei Er Lab, Shanghai 201707, China.
| | - Jiahui Liu
- Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China.
| | - Xin Wu
- Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China; Shanghai Wei Er Lab, Shanghai 201707, China.
| | - Wei Fan
- Department of Pharmacy, Seventh People's Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200137, China.
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Deng YH, Chu WD, Shang YH, Yu KY, Jia ZL, Fan CA. P(NMe2)3-Mediated Umpolung Spirocyclopropanation Reaction of p-Quinone Methides: Diastereoselective Synthesis of Spirocyclopropane-Cyclohexadienones. Org Lett 2020; 22:8376-8381. [DOI: 10.1021/acs.orglett.0c02998] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yu-Hua Deng
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Research & Development Center for Natural Products, and School of Chemical Science and Technology, Yunnan University, No. 2 Cuihu North Road, Kunming 650091, China
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Wen-Dao Chu
- College of Chemistry and Chemical Engineering, China West Normal University, No. 1 Shida Road, Nanchong 637002, China
| | - Yun-Han Shang
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Research & Development Center for Natural Products, and School of Chemical Science and Technology, Yunnan University, No. 2 Cuihu North Road, Kunming 650091, China
| | - Ke-Yin Yu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Zhi-Long Jia
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Chun-An Fan
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
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Su Y, Zhao Y, Chang B, Ling Q, Feng Y, Zhao X, Huang D, Wang KH, Huo C, Hu Y. Diastereoselective synthesis of spiro-cyclopropanyl-cyclohexadienones via direct sulfide-catalyzed [2 + 1] annulation of para-quinone methides with bromides. Org Biomol Chem 2020; 18:4257-4266. [DOI: 10.1039/d0ob00778a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A sulfide-catalyzed [2 + 1] annulation of para-quinone methides with diverse bromides was disclosed to access appealing spiro-cyclopropanyl-cyclohexadienones with high diastereoselectivity.
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Affiliation(s)
- Yingpeng Su
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Yanan Zhao
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Bingbing Chang
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Qinqin Ling
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Yawei Feng
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Xiaolong Zhao
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Danfeng Huang
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Ke-Hu Wang
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Congde Huo
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
| | - Yulai Hu
- College of Chemistry and Chemical Engineering
- Northwest Normal University
- Lanzhou 730070
- P. R. China
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Tsuji Y, Richard JP. Formation and Mechanism for Reactions of Ring-Substituted Phenonium Ions in Aqueous Solution. J PHYS ORG CHEM 2016; 29:557-564. [PMID: 27812239 PMCID: PMC5087973 DOI: 10.1002/poc.3510] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The results of studies on the structure and reactivity of spiro[5.2]oct-5,7-diene-4yl carbocation [phenonium ion] have had a significant impact on the course of discussion about the distinction between classical and nonclassical carbocations. This minireview will present a brief overview of the structure, bonding and reactivity of ring substituted phenonium ions (X-4+), with an emphasis on work completed since 2004. The discussion will focus on the development of new experimental protocol for determination of the selectivity for addition of nucleophilic anions to X-4+ in aqueous solution. The existing relationships between carbocation lifetime and nucleophilic selectivity, and the known lifetime of ca 140 sec for spiro[2.5]oct-4,7-diene-6-one provide rough estimates of the lifetimes for 4-Me-X-4+ and 4-MeO-X-4+ in aqueous solution. Evidence is presented that nucleophile addition to X-4+ proceeds through an "exploded" transition state, with relatively weak bonding the nucleophile and leaving group, and the development of significant positive charge at the reacting primary cyclopropyl carbon.
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Affiliation(s)
- Yutaka Tsuji
- Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Komorinomachi, Kurume 830-8555, Japan
| | - John P. Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260, USA
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Zhang XZ, Du JY, Deng YH, Chu WD, Yan X, Yu KY, Fan CA. Spirocyclopropanation Reaction of para-Quinone Methides with Sulfonium Salts: The Synthesis of Spirocyclopropanyl para-Dienones. J Org Chem 2016; 81:2598-606. [DOI: 10.1021/acs.joc.5b02725] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Xiang-Zhi Zhang
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Ji-Yuan Du
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Yu-Hua Deng
- State
Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou
Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Wen-Dao Chu
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Xu Yan
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Ke-Yin Yu
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Chun-An Fan
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
- State
Key Laboratory of Natural and Biomimetic Drugs, Peking University, 38
Xueyuan Lu, Beijing 100191, China
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6
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Chari RVJ, Miller ML, Widdison WC. Antibody-drug conjugates: an emerging concept in cancer therapy. Angew Chem Int Ed Engl 2014; 53:3796-827. [PMID: 24677743 DOI: 10.1002/anie.201307628] [Citation(s) in RCA: 703] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Indexed: 01/17/2023]
Abstract
Traditional cancer chemotherapy is often accompanied by systemic toxicity to the patient. Monoclonal antibodies against antigens on cancer cells offer an alternative tumor-selective treatment approach. However, most monoclonal antibodies are not sufficiently potent to be therapeutically active on their own. Antibody-drug conjugates (ADCs) use antibodies to deliver a potent cytotoxic compound selectively to tumor cells, thus improving the therapeutic index of chemotherapeutic agents. The recent approval of two ADCs, brentuximab vedotin and ado-trastuzumab emtansine, for cancer treatment has spurred tremendous research interest in this field. This Review touches upon the early efforts in the field, and describes how the lessons learned from the first-generation ADCs have led to improvements in every aspect of this technology, i.e., the antibody, the cytotoxic compound, and the linker connecting them, leading to the current successes. The design of ADCs currently in clinical development, and results from mechanistic studies and preclinical and clinical evaluation are discussed. Emerging technologies that seek to further advance this exciting area of research are also discussed.
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Affiliation(s)
- Ravi V J Chari
- ImmunoGen, Inc. 830 Winter St, Waltham, MA 02451 (USA) http://www.immunogen.com.
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Chari RVJ, Miller ML, Widdison WC. Antikörper-Wirkstoff-Konjugate: ein neues Konzept in der Krebstherapie. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201307628] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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8
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Tsuji Y, Ogawa S, Richard JP. Substituent Effects on the Formation and Nucleophile Selectivity of Ring-Substituted Phenonium Ions in Aqueous Solution. J PHYS ORG CHEM 2013; 26:970-976. [PMID: 24511183 DOI: 10.1002/poc.3145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The reaction of 2-(4-methyphenyl)ethyl tosylate (Me-1-OTs) in 50/50 (v/v) trifluoroethanol/water at 25 °C is first-order in the concentration of azide anion nucleophile. A carbon-13 NMR analysis of the products of the reactions of Me-1-[α-13C]OTs in 50/50 (v/v) trifluoroethanol/water at 25 °C shows the formation of Me-1-[β-13C]OH, Me-1-[β-13C]OCH2CF3 and Me-1-[β-13C]N3 from the trapping of a symmetrical 4-methylphenonium ion reaction intermediate Me-2+. The formation of Me-1-[α-13C]N3 by concerted bimolecular displacement of azide ion at Me-1-[α-13C]OTs (kN = 3.8 × 10-6 M-1 s-1) and of Me-1-[α-13C]OH and Me-1-[α-13C]OCH2CF3 by concerted bimolecular displacement of solvent (ksolv = 1.8 × 10-8 s-1) is also observed. An analysis of the rate and product data provides a value of kaz/ks = 32 M-1 for partitioning of Me-2+ between addition of azide ion and solvent that is nearly 3-fold smaller than kaz/ks = 83 M-1 reported in an earlier study on the partitioning of MeO-2+ [J. Org. Chem.2011, 76, 9568]. This change is attributed to a decrease in nucleophile selectivity with increasing electrophile reactivity for the activation-limited addition of solvent and azide anion to X-2+. These data set a limit of 1/ks ≥ 10-7 s for the lifetime of Me-2+ in aqueous solution.
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Affiliation(s)
- Yutaka Tsuji
- Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Komorinomachi, Kurume 830-8555, Japan
| | - Shin Ogawa
- Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Komorinomachi, Kurume 830-8555, Japan
| | - John P Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, NY 14260, USA
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9
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Tsuji Y, Hara D, Hagimoto R, Richard JP. Formation and stability of the 4-methoxyphenonium ion in aqueous solution. J Org Chem 2011; 76:9568-71. [PMID: 22029847 DOI: 10.1021/jo202118s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of 2-methoxyphenylethyl tosylate (MeO-1-Ts) is first-order in [N(3)(-)]. A carbon-13 NMR analysis of the products of the reactions of MeO-1-[α-(13)C]Ts shows the formation of MeO-1-[β-(13)C]OH and MeO-1-[β-(13)C]N(3) from the trapping of a symmetrical 4-methoxyphenonium ion reaction intermediate 2(+). An analysis of the rate and product data provides a value of k(az)/k(s) = 83 M(-1) for partitioning of 2(+) between addition of azide ion and solvent. These data set a limit for the lifetime of 2(+) in aqueous solution.
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Affiliation(s)
- Yutaka Tsuji
- Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Komorinomachi, Kurume 830-8555, Japan
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Lajiness JP, Boger DL. Synthesis and characterization of a cyclobutane duocarmycin derivative incorporating the 1,2,10,11-tetrahydro-9H-cyclobuta[c]benzo[e]indol-4-one (CbBI) alkylation subunit. J Am Chem Soc 2010; 132:13936-40. [PMID: 20839806 PMCID: PMC2952436 DOI: 10.1021/ja106986f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of 1,2,10,11-tetrahydro-9H-cyclobuta[c]benzo[e]indol-4-one (17, CbBI), which contains a deep-seated fundamental structural modification in the CC-1065 and duocarmycin alkylation subunit consisting of the incorporation of a ring-expanded fused cyclobutane (vs cyclopropane), its chemical and structural characterization, and its incorporation into a key analogue of the natural products are detailed. The approach to the preparation of CbBI was based on a precedented (Ar-3' and Ar-5') but previously unknown Ar-4' spirocyclization of a phenol onto a tethered alkyl halide to form the desired cyclobutane. The conditions required for the implementation of the Ar-4' spirocyclization indicate that the entropy of activation substantially impacts the rate of reaction relative to that for the much more facile Ar-3' spirocyclization, while the higher enthalpy of activation slows the reaction relative to an Ar-5' spirocyclization. The characterization of the CbBI-based agents revealed their exceptional stability and exquisite reaction regioselectivity, and a single-crystal X-ray structure analysis of N-Boc-CbBI (13) revealed their structural origins. The reaction regioselectivity may be attributed to the stereoelectronic alignment of the two available cyclobutane bonds with the cyclohexadienone π-system, which resides in the bond that extends to the less substituted cyclobutane carbon for 13. The remarkable stability of N-Boc-CbBI (which is stable even at pH 1) relative to N-Boc-CBI containing a cyclopropane (t(1/2) = 133 h at pH 3) may be attributed to a combination of the increased extent of vinylogous amide conjugation, the nonoptimal geometric alignment of the cyclobutane with the activating cyclohexadienone, and the intrinsic but modestly lower strain energy (1.8 kcal/mol) of a cyclobutane versus a cyclopropane.
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Affiliation(s)
- James P. Lajiness
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Dale L. Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
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Rasool N, Rashid MA, Reinke H, Fischer C, Langer P. Synthesis and reactions of functionalized spirocyclopropanes by cyclization of dilithiated β-ketosulfones, α-cyanoacetone and diethyl 2-oxopropylphosphonate with 1,1-diacetylcyclopropane. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.01.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Rasool N, Rashid MA, Adeel M, Görls H, Langer P. Synthesis and reactions of hydroxyspiro[5.2]cyclooctenones based on the cyclization of the dianions of acetone and diethyl 2-oxopropylphosphonate with 1,1-diacylcyclopropanes. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.02.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Hückel W. Änderungen des Molekülbaus bei chemischen Reaktionen. XIII. Vermeintliche nichtklassische Kationen bei Umlagerungen. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/prac.19650280105] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Rys P, Vogelsanger R. Benzo[a]spiro[2, 5]octa-1, 4-dien-3-on und Derivate I. Synthese von Benzo[a]spiro[2, 5]octa-1, 4-dien-3-on und seiner 4-Arylazo-Derivate. 5. Mitteilung über reaktionsmechanistische Untersuchungen an Reaktivfarbstoffen. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19720550816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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3 Acid and Base Centers: Structure and Acid-Base Property. STUDIES IN SURFACE SCIENCE AND CATALYSIS 1989. [DOI: 10.1016/s0167-2991(08)61046-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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18
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Reactivity of sterically hindered phenols, containing the CX-CY group in the para-position. Russ Chem Bull 1971. [DOI: 10.1007/bf00869032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Belostotskaya IS, Volod'kin AA, Ershov VV. Opening of the alkane ring of cyclohexadienone spiranes. Russ Chem Bull 1968. [DOI: 10.1007/bf00910839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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23
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Atkinson RS, Dreiding AS. Synthese von Trispiro[5.2.2.5.2.2.]heneicosa-1,4,13,16-tetraen-3,15-dion durch doppelte intramolekulare C-Alkylierung eines Diphenols. Helv Chim Acta 1967. [DOI: 10.1002/hlca.19670500106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Ershov VV, Belostotskaya IS. Di-tert-butylspirocyclodienones. Russ Chem Bull 1965. [DOI: 10.1007/bf00847921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Seidl G, Huisgen R, Wimmer I. Mittlere Ringe, XXVII. Die Beteiligung methoxylierten ß-Phenyls an der Ionisation; Versuche zur Isolierung verbrückter Zwischenstufen. ACTA ACUST UNITED AC 1964. [DOI: 10.1002/jlac.19646770106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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