1
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Ruyet L, Roblick C, Häfliger J, Wang ZX, Stoffels TJ, Daniliuc CG, Gilmour R. Catalytic Ring Expanding Difluorination: An Enantioselective Platform to Access β,β-Difluorinated Carbocycles. Angew Chem Int Ed Engl 2024; 63:e202403957. [PMID: 38482736 DOI: 10.1002/anie.202403957] [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: 02/26/2024] [Indexed: 04/11/2024]
Abstract
Cyclic β,β-difluoro-carbonyl compounds have a venerable history as drug discovery leads, but limitations in the synthesis arsenal continue to impede chemical space exploration. This challenge is particularly acute in the arena of fluorinated medium rings where installing the difluoromethylene unit subtly alters the ring conformation by expanding the internal angle (∠C-CF2-C>∠C-CH2-C): this provides a handle to modulate physicochemistry (e.g. pKa). To reconcile this disparity, a highly modular ring expansion has been devised that leverages simple α,β-unsaturated esters and amides, and processes them to one-carbon homologated rings with concomitant geminal difluorination (6 to 10 membered rings, up to 95 % yield). This process is a rare example of the formal difluorination of an internal alkene and is enabled by sequential I(III)-enabled O-activation. Validation of enantioselective catalysis in the generation of unprecedented medium ring scaffolds is reported (up to 93 : 7 e.r.) together with X-ray structural analyses and product derivatization.
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Affiliation(s)
- Louise Ruyet
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Christoph Roblick
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Joel Häfliger
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Zi-Xuan Wang
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Tobias Jürgen Stoffels
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Constantin G Daniliuc
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Ryan Gilmour
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
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2
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Yang R, Zhou Z, Jiang H, Kam TS, Chen K, Ma Z. Asymmetric Synthesis of Arboduridine. Angew Chem Int Ed Engl 2024; 63:e202316016. [PMID: 38038685 DOI: 10.1002/anie.202316016] [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: 10/23/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/02/2023]
Abstract
The first asymmetric total synthesis of the monoterpenoid indole alkaloid arboduridine has been accomplished. The tricyclic A/B/D ring system was constructed by an enantioselective Michael reaction followed by intramolecular nucleophilic addition. Intramolecular α-amination of a ketone forged the piperidine ring, while a Horner-Wadsworth-Emmons (HWE) reaction was used to form the pyrrolidine ring. A reduction cyclization cascade led to formation of the tetrahydrofuran ring.
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Affiliation(s)
- Rui Yang
- Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry & Chemical Engineering, South China University of Technology, Wushan Road-381, Guangzhou, 510641, P. R. China
| | - Zeyu Zhou
- Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry & Chemical Engineering, South China University of Technology, Wushan Road-381, Guangzhou, 510641, P. R. China
| | - Huanfeng Jiang
- Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry & Chemical Engineering, South China University of Technology, Wushan Road-381, Guangzhou, 510641, P. R. China
| | - Toh-Seok Kam
- Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Kai Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China
| | - Zhiqiang Ma
- Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry & Chemical Engineering, South China University of Technology, Wushan Road-381, Guangzhou, 510641, P. R. China
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, Guangdong, 518055, P.R. China
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3
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Chen B, Yang Y, Zhang X, Xu D, Sun Y, Chen Y, Wang L. Total Syntheses of Brassicicenes A, R, and T. Org Lett 2023. [PMID: 37994662 DOI: 10.1021/acs.orglett.3c03355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
Here, we report concise and divergent total syntheses of fusicoccane members brassicicenes A, R, and T. The key feature of the synthesis is the rapid construction of the 5/8/5 tricyclic core via four steps: aldol reaction, Stork-Danheiser transposition, and ring-closing metathesis from known compounds followed by concise oxidation state adjustment.
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Affiliation(s)
- Bolin Chen
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Yufen Yang
- College of Pharmacy, Nankai University, Tianjin 300350, China
| | - Xijing Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Dongdong Xu
- College of Pharmacy, Nankai University, Tianjin 300350, China
| | - Yuanjun Sun
- Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
| | - Yue Chen
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Liang Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
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4
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Fu P, Liu T, Shen Y, Lei X, Xiao T, Chen P, Qiu D, Wang Z, Zhang Y. Divergent Total Syntheses of Illicium Sesquiterpenes through Late-Stage Skeletal Reorganization. J Am Chem Soc 2023; 145:18642-18648. [PMID: 37562030 DOI: 10.1021/jacs.3c06442] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
We disclose unified, protecting-group-free, bioinspired divergent total syntheses of eight allo-cedrane and seco-prezizaane Illicium sesquiterpenes and formal syntheses of five anislactone sesquiterpenes. The efficiency of our approach derives from rapid access to the 15-carbon tricyclic carboxylic acid through cationic epoxide-ene cyclization and HAT oxygenation, transformation of this intermediate into three distinct tricyclic precursors via Lewis acid-mediated skeletal reorganizations, subsequent programmed oxidation level enhancement, and a biomimetic oxidation-initiated skeletal rearrangement cascade. Consequently, we created a synthetic correlation map of the three most prevalent Illicium sesquiterpene families.
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Affiliation(s)
- Pengfei Fu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Tao Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yang Shen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Xin Lei
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Tianjie Xiao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Peng Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Dongsheng Qiu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Zhen Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yandong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, iCHEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
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5
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Zhao H, Brånalt J, Perry M, Tyrchan C. The Role of Allylic Strain for Conformational Control in Medicinal Chemistry. J Med Chem 2023. [PMID: 37285219 DOI: 10.1021/acs.jmedchem.3c00446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
It is axiomatic in medicinal chemistry that optimization of the potency of a small molecule at a macromolecular target requires complementarity between the ligand and target. In order to minimize the conformational penalty on binding, both enthalpically and entropically, it is therefore preferred to have the ligand preorganized in the bound conformation. In this Perspective, we highlight the role of allylic strain in controlling conformational preferences. Allylic strain was originally described for carbon-based allylic systems, but the same principles apply to other types of structure with sp2 or pseudo-sp2 arrangements. These systems include benzylic (including heteroaryl methyl) positions, amides, N-aryl groups, aryl ethers, and nucleotides. We have derived torsion profiles from small molecule X-ray structures for these systems. Through multiple examples, we show how these effects have been applied in drug discovery and how they can be used prospectively to influence conformation in the design process.
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Affiliation(s)
- Hongtao Zhao
- Medicinal Chemistry, Research and Early Development, Respiratory and Immunology (R&I), BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Jonas Brånalt
- Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Matthew Perry
- Medicinal Chemistry, Research and Early Development, Respiratory and Immunology (R&I), BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
| | - Christian Tyrchan
- Medicinal Chemistry, Research and Early Development, Respiratory and Immunology (R&I), BioPharmaceuticals R&D, AstraZeneca, Gothenburg 43183, Sweden
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6
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Chen XW, Hou ZC, Chen C, Zhang LH, Chen ME, Zhang FM. Enantioselective total syntheses of six natural and two proposed meroterpenoids from Psoralea corylifolia. Chem Sci 2023; 14:5699-5704. [PMID: 37265714 PMCID: PMC10231314 DOI: 10.1039/d3sc00582h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/01/2023] [Indexed: 06/03/2023] Open
Abstract
The first enantioselective total syntheses of six natural and two proposed meroterpenoids isolated from Psoralea corylifolia have been achieved in 7-9 steps from 2-methylcyclohexanone. The current synthetic approaches feature a high level of synthetic flexibility, stereodivergent fashion and short synthetic route, thereby providing a potential platform for the preparation of numerous this-type meroterpenoids and their pseudo-natural products.
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Affiliation(s)
- Xiao-Wei Chen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Zi-Chao Hou
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Chi Chen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Ling-Hui Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Meng-En Chen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Fu-Min Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University Shanghai 200062 China
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7
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Yang H, Zhang Y, Chen W, Shi H, Huo L, Li J, Li H, Xie X, She X. Scalable Total Syntheses of (±)-Catellatolactams A and B. Org Lett 2023; 25:1003-1007. [PMID: 36748956 DOI: 10.1021/acs.orglett.3c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The first total syntheses of (±)-catellatolactams A and B, two novel ansamacrolactams, are described in 5 and 8 steps, respectively. The strategy relies on an amidation reaction to couple the acylated Meldrum's acid and an aryl amine, a regioselective C-H insertion to construct the γ-lactam moiety, and an RCM reaction to forge the macrocycles with E-olefin. This concise and scalable synthesis provided over 200 mg of the target molecules.
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Affiliation(s)
- Hesi Yang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Yan Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Wei Chen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Hongliang Shi
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Liang Huo
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Jia Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Huilin Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Xingang Xie
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
| | - Xuegong She
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China
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8
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Yang P, Li YY, Tian H, Qian GL, Wang Y, Hong X, Gui J. Syntheses of Bufospirostenin A and Ophiopogonol A by a Conformation-Controlled Transannular Prins Cyclization. J Am Chem Soc 2022; 144:17769-17775. [PMID: 36125970 DOI: 10.1021/jacs.2c07944] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Controlling the conformation of medium-sized rings is challenging because of their flexibility and ring strain effects. Herein, we report non-Curtin-Hammett conditions for the precise control of the conformation of cyclodecenones to effect the first cis-selective transannular Prins cyclization, which enabled concise syntheses of the 5(10→1)abeo-steroids bufospirostenin A and ophiopogonol A in only seven steps from inexpensive starting materials. Computational results indicated that the key cyclization was kinetically controlled and proceeded via either a Prins pathway or a carbonyl-ene pathway, depending on the reaction conditions. Moreover, conformational isomerization played a critical role in determining the stereochemistry of the products.
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Affiliation(s)
- Peicheng Yang
- Shanghai Frontiers Science Center for TCM Chemical Biology, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.,CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Yan-Yu Li
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
| | - Hailong Tian
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Gan-Lu Qian
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
| | - Yun Wang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Xin Hong
- Center of Chemistry for Frontier Technologies, Department of Chemistry, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.,Beijing National Laboratory for Molecular Sciences, Zhongguancun North First Street No. 2, Beijing 100190, PR China.,Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Jinghan Gui
- Shanghai Frontiers Science Center for TCM Chemical Biology, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.,CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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9
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Cui H, Shen Y, Wang R, Wei H, Lei X, Chen Y, Fu P, Wang H, Bi R, Zhang Y. Synthesis of Clionastatins A and B through Enhancement of Chlorination and Oxidation Levels of Testosterone. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202200425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hao Cui
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Yang Shen
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Ruifeng Wang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Haoxiang Wei
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Xin Lei
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Yanyu Chen
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Pengfei Fu
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Haoxiang Wang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Ruihao Bi
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
| | - Yandong Zhang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
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10
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Tu J, Ripa RA, Kelley SP, Harmata M. Intramolecular (4+3) Cycloadditions of Oxidopyridinium Ions: Towards Daphnicyclidin A. Chemistry 2022; 28:e202200370. [PMID: 35612968 DOI: 10.1002/chem.202200370] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Indexed: 12/15/2022]
Abstract
N-alkylation of 5-hydroxynicotinic acid esters with electrophiles containing diene functionality produces salts that undergo intramolecular (4+3) cycloaddition reactions upon heating in the presence of base. Initial studies used a three-carbon tether to join the pyridinium ion and diene, revealing some aspects of the inherent selectivity of the reaction with such substrates. Much more challenging was the synthesis of related species possessing only a two-carbon tether. Nevertheless, the cycloaddition of such compounds was successful, leading directly to the ABC ring system of the alkaloid daphnicyclidin A.
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Affiliation(s)
- Jianzhuo Tu
- Department of Chemistry, University of Missouri-Columbia, 601 S. College Avenue, Columbia, Missouri, 65211, USA
| | - Rawshan A Ripa
- Department of Chemistry, University of Missouri-Columbia, 601 S. College Avenue, Columbia, Missouri, 65211, USA
| | - Steven P Kelley
- Department of Chemistry, University of Missouri-Columbia, 601 S. College Avenue, Columbia, Missouri, 65211, USA
| | - Michael Harmata
- Department of Chemistry, University of Missouri-Columbia, 601 S. College Avenue, Columbia, Missouri, 65211, USA
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11
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Cicetti S, Maestre E, Spanevello RA, Sarotti A. Towards the Synthesis of Highly Hindered Pyrrolidines by Intramolecular AAC Click Reactions: What Can Be Learned from DFT Calculations? European J Org Chem 2022. [DOI: 10.1002/ejoc.202200478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Soledad Cicetti
- IQUIR: Instituto de Quimica Rosario Organic Chemistry Department ARGENTINA
| | - Eugenia Maestre
- IQUIR: Instituto de Quimica Rosario Organic Chemistry Department ARGENTINA
| | | | - Ariel Sarotti
- IQUIR Química Orgánica Suipacha 570 2000 Rosario ARGENTINA
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12
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Cui H, Shen Y, Chen Y, Wang R, Wei H, Fu P, Lei X, Wang H, Bi R, Zhang Y. Two-Stage Syntheses of Clionastatins A and B. J Am Chem Soc 2022; 144:8938-8944. [PMID: 35576325 DOI: 10.1021/jacs.2c03872] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A concise and divergent synthesis of the polychlorinated marine steroids clionastatin A and B from inexpensive testosterone has been achieved through a unique two-stage chlorination-oxidation strategy. Key features of the two-stage synthesis include (1) conformationally controlled, highly stereoselective dichlorination at C1 and C2 and C4-OH-directed C19 oxygenation followed by a challenging neopentyl chlorination to install three chlorine atoms; (2) desaturation through one-pot photochemical dibromination-reductive debromination and anti-Markovnikov olefin oxidation by photoredox-metal dual catalysis to enhance the oxidation level of the backbone; and (3) Wharton transposition to furnish the D-ring enone. This synthesis proved that the introduction of the C19 chloride in the early stage of the synthesis secured the stability of the backbone against susceptibility to aromatization during the oxidation stage.
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Affiliation(s)
- Hao Cui
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yang Shen
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yanyu Chen
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Ruifeng Wang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Haoxiang Wei
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Pengfei Fu
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Xin Lei
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Haoxiang Wang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Ruihao Bi
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yandong Zhang
- Department of Chemistry and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.,Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao 266000, China
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13
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Uprety B, Chandran R, Arderne C, Abrahamse H. Anticancer Activity of Urease Mimetic Cobalt (III) Complexes on A549-Lung Cancer Cells: Targeting the Acidic Microenvironment. Pharmaceutics 2022; 14:pharmaceutics14010211. [PMID: 35057107 PMCID: PMC8780642 DOI: 10.3390/pharmaceutics14010211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/23/2021] [Accepted: 01/11/2022] [Indexed: 12/30/2022] Open
Abstract
Tumour cells maintain a local hypoxic and acidic microenvironment which plays a crucial role in cancer progression and drug resistance. Urease is a metallohydrolases that catalyses the hydrolysis of urea into ammonia and carbon dioxide, causing an abrupt increase of pH. This enzymatic activity can be employed to target the acidic tumour microenvironment. In this study, we present the anticancer activities of urease mimetic cobalt (III) complexes on A549 cells. The cells were treated with different doses of cobalt (III) complexes to observe the cytotoxicity. The change in cellular morphology was observed using an inverted microscope. The cell death induced by these complexes was analysed through ATP proliferation, LDH release and caspase 3/7 activity. The effect of extracellular alkalinization by the cobalt (III) complexes on the efficacy of the weakly basic drug, doxorubicin (dox) was also evaluated. This combination therapy of dox with cobalt (III) complexes resulted in enhanced apoptosis in A549 cells, as evidenced by elevated caspase 3/7 activity in treated groups. The study confirms the urease mimicking anticancer activity of cobalt (III) complexes by neutralizing the tumour microenvironment. This study will motivate the applications of transition metal-based enzyme mimics in targeting the tumour microenvironment for effective anticancer treatments.
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Affiliation(s)
- Bhawna Uprety
- Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa;
- Correspondence: (B.U.); (R.C.); Tel.: +27-11-559-6926 (R.C.)
| | - Rahul Chandran
- Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa;
- Correspondence: (B.U.); (R.C.); Tel.: +27-11-559-6926 (R.C.)
| | - Charmaine Arderne
- Research Centre for Synthesis and Catalysis, Department of Chemical Sciences, University of Johannesburg, P.O. Box 524, Johannesburg 2092, South Africa;
| | - Heidi Abrahamse
- Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa;
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14
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Belen’kii LI, Gazieva GA, Evdokimenkova YB, Soboleva NO. The literature of heterocyclic chemistry, Part XX, 2020. ADVANCES IN HETEROCYCLIC CHEMISTRY 2022. [DOI: 10.1016/bs.aihch.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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15
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Guillade L, Mora P, Villar P, Alvarez R, R de Lera A. Total synthesis of nahuoic acid A via a putative biogenetic intramolecular Diels-Alder (IMDA) reaction. Chem Sci 2021; 12:15157-15169. [PMID: 34909158 PMCID: PMC8612404 DOI: 10.1039/d1sc04524e] [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: 08/17/2021] [Accepted: 10/26/2021] [Indexed: 11/21/2022] Open
Abstract
Inspired by the biogenetic proposal of an intramolecular Diels–Alder (IMDA) cycloaddition, the total synthesis of natural product nahuoic acid A, a cofactor-competitive inhibitor of the epigenetic enzyme lysine methyl transferase SETD8, has been carried out. A non-conjugated pentaenal precursor was synthesized with high levels of stereoselectivity at seven stereogenic centers and with the appropriate control of double bond geometries. Although the IMDA reaction of the non-conjugated pentaenal using Me2AlCl for catalysis at −40 °C selectively afforded the trans-fused diastereomer corresponding to the Re-endo mode of cycloaddition, under thermal reaction conditions it gave rise to a mixture of diastereomers, that preferentially formed through the exo mode, including the cis-fused angularly-methylated octahydronaphthalene diastereomer precursor of nahuoic acid A. The natural product could be obtained upon oxidation and overall deprotection of the hydroxyl groups present in the Si-exo IMDA diastereomer. The total synthesis of natural product nahuoic acid A, a cofactor-competitive inhibitor of the epigenetic enzyme lysine methyl transferase SETD8, has been carried out based on the biogenetic proposal of an intramolecular Diels–Alder (IMDA) cycloaddition.![]()
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Affiliation(s)
- Lucía Guillade
- Departamento de Química Orgánica, Facultade de Química, CINBIO, IIS Galicia Sur, Universidade de Vigo 36310 Vigo Spain
| | - Paula Mora
- Departamento de Química Orgánica, Facultade de Química, CINBIO, IIS Galicia Sur, Universidade de Vigo 36310 Vigo Spain
| | - Pedro Villar
- Departamento de Química Orgánica, Facultade de Química, CINBIO, IIS Galicia Sur, Universidade de Vigo 36310 Vigo Spain
| | - Rosana Alvarez
- Departamento de Química Orgánica, Facultade de Química, CINBIO, IIS Galicia Sur, Universidade de Vigo 36310 Vigo Spain
| | - Angel R de Lera
- Departamento de Química Orgánica, Facultade de Química, CINBIO, IIS Galicia Sur, Universidade de Vigo 36310 Vigo Spain
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16
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Deng T, Mazumdar W, Yoshinaga Y, Patel PB, Malo D, Malo T, Wink DJ, Driver TG. Rh 2(II)-Catalyzed Intermolecular N-Aryl Aziridination of Olefins Using Nonactivated N Atom Precursors. J Am Chem Soc 2021; 143:19149-19159. [PMID: 34748699 DOI: 10.1021/jacs.1c09229] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The development of the first intermolecular Rh2(II)-catalyzed aziridination of olefins using anilines as nonactivated N atom precursors and an iodine(III) reagent as the stoichiometric oxidant is reported. This reaction requires the transfer of an N-aryl nitrene fragment from the iminoiodinane intermediate to a Rh2(II) carboxylate catalyst; in the absence of a catalyst only diaryldiazene formation was observed. This N-aryl aziridination is general and can be successfully realized by using as little as 1 equiv of the olefin. Di-, tri-, and tetrasubstituted cyclic or acylic olefins can be employed as substrates, and a range of aniline and heteroarylamine N atom precursors are tolerated. The Rh2(II)-catalyzed N atom transfer to the olefin is stereospecific as well as chemo- and diastereoselective to produce the N-aryl aziridine as the only amination product. Because the chemistry of nonactivated N-aryl aziridines is underexplored, the reactivity of N-aryl aziridines was explored toward a range of nucleophiles to stereoselectively access privileged 1,2-stereodiads unavailable from epoxides, and removal of the N-2,4-dinitrophenyl group was demonstrated to show that functionalized primary amines can be constructed.
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Affiliation(s)
- Tianning Deng
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
| | - Wrickban Mazumdar
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
| | - Yuki Yoshinaga
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
| | - Pooja B Patel
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
| | - Dana Malo
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States.,Hinsdale South High School, 7401 Clarendon Hills Road, Darien, Illinois 60561, United States
| | - Tala Malo
- Hinsdale South High School, 7401 Clarendon Hills Road, Darien, Illinois 60561, United States
| | - Donald J Wink
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
| | - Tom G Driver
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, Illinois 60607, United States
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17
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Subbaiah MAM, Meanwell NA. Bioisosteres of the Phenyl Ring: Recent Strategic Applications in Lead Optimization and Drug Design. J Med Chem 2021; 64:14046-14128. [PMID: 34591488 DOI: 10.1021/acs.jmedchem.1c01215] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The benzene moiety is the most prevalent ring system in marketed drugs, underscoring its historic popularity in drug design either as a pharmacophore or as a scaffold that projects pharmacophoric elements. However, introspective analyses of medicinal chemistry practices at the beginning of the 21st century highlighted the indiscriminate deployment of phenyl rings as an important contributor to the poor physicochemical properties of advanced molecules, which limited their prospects of being developed into effective drugs. This Perspective deliberates on the design and applications of bioisosteric replacements for a phenyl ring that have provided practical solutions to a range of developability problems frequently encountered in lead optimization campaigns. While the effect of phenyl ring replacements on compound properties is contextual in nature, bioisosteric substitution can lead to enhanced potency, solubility, and metabolic stability while reducing lipophilicity, plasma protein binding, phospholipidosis potential, and inhibition of cytochrome P450 enzymes and the hERG channel.
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Affiliation(s)
- Murugaiah A M Subbaiah
- Department of Medicinal Chemistry, Biocon-Bristol Myers Squibb Research and Development Centre, Biocon Park, Bommasandra IV Phase, Jigani Link Road, Bangalore, Karnataka 560099, India
| | - Nicholas A Meanwell
- Department of Small Molecule Drug Discovery, Bristol Myers Squibb Research and Early Development, P.O. Box 4000, Princeton, New Jersey 08543-4000, United States
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18
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Weng GG, Hong BK, Bao SS, Wen Y, Wu LQ, Huang XD, Jia JG, Wen GH, Li SH, Peng L, Zheng LM. From helices to superhelices: hierarchical assembly of homochiral van der Waals 1D coordination polymers. Chem Sci 2021; 12:12619-12630. [PMID: 34703547 PMCID: PMC8494031 DOI: 10.1039/d1sc01913a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/13/2021] [Indexed: 11/21/2022] Open
Abstract
Chiral transcription from the molecular level to the macroscopic level by self-organization has been a topic of considerable interest for mimicking biological systems. Homochiral coordination polymers (CPs) are intriguing systems that can be applied in the construction of artificial helical architectures, but they have scarcely been explored to date. Herein, we propose a new strategy for the generation of superhelices of 1D CPs by introducing flexible cyclohexyl groups on the side chains to simultaneously induce interchain van der Waals interactions and chain misalignment due to conformer interconversion. Superhelices of S- or R-Tb(cyampH)3·3H2O (S-1H, R-1H) [cyampH2 = S- or R-(1-cyclohexylethyl)aminomethylphosphonic acid] were obtained successfully, the formation of which was found to follow a new type of "chain-twist-growth" mechanism that had not been described previously. The design strategy used in this work may open a new and general route to the hierarchical assembly and synthesis of helical CP materials.
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Affiliation(s)
- Guo-Guo Weng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Ben-Kun Hong
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 People's Republic of China
| | - Song-Song Bao
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Yujie Wen
- Key Laboratory of Mesoscopic Chemistry of MOE, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 People's Republic of China
| | - Lan-Qing Wu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Xin-Da Huang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Jia-Ge Jia
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Ge-Hua Wen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
| | - Shu-Hua Li
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 People's Republic of China
| | - Luming Peng
- Key Laboratory of Mesoscopic Chemistry of MOE, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 People's Republic of China
| | - Li-Min Zheng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University Nanjing 210023 People's Republic of China
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19
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Hewitt KA, Herbert CA, Matus AC, Jarvo ER. Nickel-Catalyzed Kumada Cross-Coupling Reactions of Benzylic Sulfonamides. Molecules 2021; 26:5947. [PMID: 34641491 PMCID: PMC8512530 DOI: 10.3390/molecules26195947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/22/2021] [Accepted: 09/25/2021] [Indexed: 11/29/2022] Open
Abstract
Herein, we report a Kumada cross-coupling reaction of benzylic sulfonamides. The scope of the transformation includes acyclic and cyclic sulfonamide precursors that cleanly produce highly substituted acyclic fragments. Preliminary data are consistent with a stereospecific mechanism that allows for a diastereoselective reaction.
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Affiliation(s)
| | | | | | - Elizabeth R. Jarvo
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA; (K.A.H.); (C.A.H.); (A.C.M.)
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20
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Chen R, Qiu D, Lei X, Niu Y, Hua Y, Peng H, Zeng T, Zhang Y. Total Synthesis and Assignment of the Absolute Configuration of (+)-Omphalic Acid. Org Lett 2021; 23:6972-6976. [PMID: 34397211 DOI: 10.1021/acs.orglett.1c02599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Omphalane diterpenoids usually contain a cyclohexane-fused bicyclo[3.2.1]octane scaffold embedded with two continuous quaternary carbon centers, which pose considerable challenges to synthetic chemists. Herein, we reported the first total synthesis of omphalic acid with high stereochemical control, featuring an intermolecular Diels-Alder cycloaddition, ring reorganization through Criegee oxidative cleavage and programmed aldol condensations, conformationally controlled hydrogenation, and Pd-catalyzed carboxylation. The absolute configuration of omphalic acid was defined for the first time via the asymmetric total synthesis facilitated by a derivatization resolution protocol.
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Affiliation(s)
- Renzhi Chen
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Dongsheng Qiu
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Xin Lei
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Yujie Niu
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Yuhui Hua
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Huayu Peng
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Tao Zeng
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Yandong Zhang
- Department of Chemistry, Department of Chemical Biology, and Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
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21
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Scesa PD, West LM, Roche SP. Role of Macrocyclic Conformational Steering in a Kinetic Route toward Bielschowskysin. J Am Chem Soc 2021; 143:7566-7577. [PMID: 33945689 DOI: 10.1021/jacs.1c03336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Macrocyclic furanobutenolide-derived cembranoids (FBCs) are the biosynthetic precursors to a wide variety of highly congested and oxygenated polycyclic (nor)diterpenes (e.g. plumarellide, verrillin, and bielschowskysin). These architecturally complex metabolites are thought to originate from site-selective oxidation of the macrocycle backbone and a series of intricate transannular reactions. Yet the development of a common biomimetic route has been hampered by a lack of synthetic methods for the pivotal furan dearomatization in a regio- and stereoselective manner. To address these shortcomings, a concise strategy of epoxidation followed by a kinetically controlled furan dearomatization is reported. The surprising switch of facial α:β-discrimination observed in the epoxidation of the most strained E-acerosolide versus E-deoxypukalide and E-bipinnatin J derived macrocycles has been rationalized by the variation of the 3D conformational landscape between macrocyclic scaffolds. A careful conformational analysis of these macrocycles by VT-NMR and NOESY experiments at low temperature was supported by DFT calculations to characterize these equilibrating macrocyclic conformers. The shift in conformational topology associated with a swing of the butenolide ring in E-deoxypukalide is in general agreement with the reversal of β-selectivity observed in the epoxidation. We also describe the downstream functionalization of FBC-macrocycles and how the C-7 epoxide configuration is retentively translated to the C-3 stereogenicity in dearomatized products under kinetic control to secure the requisite 3S,7S,8S configurations for the bielschowskysin synthesis. Unlike previously speculated, our results suggest that the most strained FBC-macrocycles bearing a E-(Δ7,8)-alkene moiety may stand as the true biosynthetic precursors to bielschowskysin and several other polycyclic natural products of this class.
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Affiliation(s)
- Paul D Scesa
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Lyndon M West
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Stéphane P Roche
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
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22
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Mutoh H, Nakamura S, Hagiwara K, Inoue M. Construction of Pentacyclic Limonoid Skeletons via Radical Cascade Reactions. J Org Chem 2021; 86:6869-6878. [PMID: 33905252 DOI: 10.1021/acs.joc.1c00212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Limonoids 1 and 2 share a 6/6/6/5-membered ABCD-ring system and a six-membered oxacycle and differ in their C9-stereochemistries. A new radical-based strategy was devised to construct the pentacyclic skeletons of 1 and 2. An oxacycle-fused A-ring and enyne fragments were coupled to produce radical precursors 4a-4c with different C7-oxygen functionalities. The bridgehead tertiary bromide of 4a-4c participated in a radical cascade reaction with the three unsaturated bonds to cyclize the C9-diastereomeric BCD-rings.
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Affiliation(s)
- Hiroyuki Mutoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shu Nakamura
- 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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23
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Nakayama Y, Maser MR, Okita T, Dubrovskiy AV, Campbell TL, Reisman SE. Total Synthesis of Ritterazine B. J Am Chem Soc 2021; 143:4187-4192. [PMID: 33689345 DOI: 10.1021/jacs.1c01372] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The first total synthesis of the cytotoxic alkaloid ritterazine B is reported. The synthesis features a unified approach to both steroid subunits, employing a titanium-mediated propargylation reaction to achieve divergence from a common precursor. Other key steps include gold-catalyzed cycloisomerizations that install both spiroketals and late stage C-H oxidation to incorporate the C7' alcohol.
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Affiliation(s)
- Yasuaki Nakayama
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael R Maser
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Tatsuya Okita
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Anton V Dubrovskiy
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Taryn L Campbell
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Sarah E Reisman
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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24
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Fürstner A. Lessons from Natural Product Total Synthesis: Macrocyclization and Postcyclization Strategies. Acc Chem Res 2021; 54:861-874. [PMID: 33507727 PMCID: PMC7893715 DOI: 10.1021/acs.accounts.0c00759] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Macrocyclic
natural products are plentiful in
the bacteria, archaea,
and eukaryote domains of life. For the significant advantages that
they provide to the producing organisms, evolution has learned how
to implement various types of macrocyclization reactions into the
different biosynthetic pathways and how to effect them with remarkable
ease. Mankind greatly benefits from nature’s pool, not least
because naturally occurring macrocycles or derivatives thereof serve
as important drugs for the treatment of many serious ailments. In stark contrast, macrocyclization reactions are usually perceived
as difficult to accomplish by purely chemical means. While it is true
that ring closure necessarily entails an entropic loss and may result
in the buildup of (considerable) ring strain that must be compensated
for in one way or the other, it is also fair to note tremendous methodological
advances during the last decades that greatly alleviated this traditional
“macrocycle challenge”. It is therefore increasingly
possible to explore the advantages provided by large as well as medium-size
ring systems in a more systematic manner. This venture also holds
the promise of increasing the “chemical space” amenable
to drug development to a considerable extent. In consideration
of this and other important long-term perspectives,
it is appropriate to revisit the current state of the art. To this
end, a number of vignettes are presented, each of which summarizes
a total synthesis project targeting macrocyclic natural products of
greatly different chemotypes using a variety of transformations to
reach these goals. Although we were occasionally facing “dead
ends”, which are also delineated for the sake of a complete
picture, these case studies illustrate the notion that the formation
of a certain macrocyclic perimeter is (usually) no longer seriously
limiting. In addition to substantial progress in the “classical”
repertoire (macrolactonization and macrolactamization
(pateamine A, spirastrellolide, and belizentrin)), various metal-catalyzed
reactions have arguably led to the greatest leaps forward. Among them,
palladium-catalyzed C–C bond formation (roseophilin and nominal
xestocyclamine A) and, in particular, alkene and alkyne metathesis
stand out (iejimalide, spirastrellolide, enigmazole, ingenamine, and
sinulariadiolide). In some cases, different methods were pursued in
parallel, thus allowing for a critical assessment and comparison. To the extent that the macrocyclic challenge is vanishing, the
opportunity arises to focus attention on the postmacrocyclization
phase. One may stipulate that a well-designed cyclization precursor
does not only ensure efficient ring closure but also fosters and streamlines
the steps that come after the event. One way to do so is dual (multiple)
use in that the functional groups serving the actual cyclization reaction
also find productive applications downstream from it rather than being
subject to simple defunctionalization. In this context,
better insight into the conformational peculiarities of large rings
and the growing confidence in their accessibility in a stereochemically
well defined format rejuvenate the implementation of transannular
reactions or reaction cascades that can lead to rapid and substantial
increases in molecular complexity. The examples summarized herein
showcase such possibilities, with special emphasis on tranannular
gold catalysis and the emerging ruthenium-catalyzed trans-hydrometalation chemistry for the selective functionalization of
alkynes.
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25
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Liu XY, Wang FP, Qin Y. Synthesis of Three-Dimensionally Fascinating Diterpenoid Alkaloids and Related Diterpenes. Acc Chem Res 2021; 54:22-34. [PMID: 33351595 DOI: 10.1021/acs.accounts.0c00720] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Three-dimensional cage-like natural products represent astounding and long-term challenges in the research endeavors of total synthesis. A central issue that synthetic chemists need to address lies in how to efficiently construct the polycyclic frameworks as well as to install the requisite substituent groups. The diterpenoid alkaloids that biogenetically originate from amination of diterpenes and diversify through late-stage skeletal reorganization belong to such a natural product category. As the characteristic components of the Aconitum and Delphinium species, these molecules display a rich array of biological activities, some of which are used as clinical drugs. More strikingly, their intricate and beautiful architectures have rendered the diterpenoid alkaloids elusive targets in the synthetic community. The successful preparation of these intriguing compounds relies on the development of innovative synthetic strategies.Our laboratory has explored the total synthesis of a variety of diterpenoid alkaloids and their biogenetically related diterpenes over the past decade. In doing so, we have accessed 6 different types of skeletons (atisine-, denudatine-, arcutane-, arcutine-, napelline-, and hetidine-type) and achieved the total synthesis of 6 natural products (isoazitine, dihydroajaconine, gymnandine, atropurpuran, arcutinine, and liangshanone). Strategically, an oxidative dearomatization/Diels-Alder (OD/DA) cycloaddition sequence was widely employed in our synthesis to form the ubiquitous [2.2.2]-bicyclic ring unit and its related ring-distorted derivatives in these complex target molecules. This protocol, in combination with additional bond-forming key steps, allowed us to prepare the corresponding polycyclic alkaloids and a biogenetically associated diterpene. For example, bioinspired C-H activation, aza-pinacol, and aza-Prins cyclizations were used toward a unified approach to the atisine-, denudatine-, and hetidine-type alkaloids via ajaconine intermediates in our first work. To pursue the synthesis of atropurpuran and related arcutine alkaloids, we harnessed a ketyl-olefin radical cyclization to assemble the carbocycle and an aza-Wacker cyclization to construct the unusual pyrrolidine ring. Furthermore, a one-pot alkene cleavage/Mannich cyclization tactic, sequential Robinson annulation, and intramolecular aldol addition were developed, which facilitated the formation of the napelline alkaloid scaffold and the first total synthesis of liangshanone. Finally, the utility of the Mannich cyclization and enyne cycloisomerization reactions allowed for access to the highly functionalized A/E and C/D ring fragments of aconitine (regarded as the "Holy Grail" of diterpenoid alkaloids). This Account provides insight into our synthetic designs and approaches used toward the synthesis of diterpenoid alkaloids and relevant diterpenes. These endeavors lay a foundation for uncovering the biological profiles of associated molecules and also serve as a reference for preparing other three-dimensionally fascinating natural products.
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Affiliation(s)
- Xiao-Yu Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug, and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Feng-Peng Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug, and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Yong Qin
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug, and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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Williams CM, Dallaston MA. The Future of Retrosynthesis and Synthetic Planning: Algorithmic, Humanistic or the Interplay? Aust J Chem 2021. [DOI: 10.1071/ch20371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The practice of deploying and teaching retrosynthesis is on the cusp of considerable change, which in turn forces practitioners and educators to contemplate whether this impending change will advance or erode the efficiency and elegance of organic synthesis in the future. A short treatise is presented herein that covers the concept of retrosynthesis, along with exemplified methods and theories, and an attempt to comprehend the impact of artificial intelligence in an era when freely and commercially available retrosynthetic and forward synthesis planning programs are increasingly prevalent. Will the computer ever compete with human retrosynthetic design and the art of organic synthesis?
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Tcharkhetian AEG, Bruni AT, Rodrigues CHP. Combining experimental and theoretical approaches to study the structural and spectroscopic properties of Flakka (α-pyrrolidinopentiophenone). RESULTS IN CHEMISTRY 2021. [DOI: 10.1016/j.rechem.2021.100254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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28
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Semenova E, Lahtigui O, Scott SK, Albritton M, Abboud KA, Ghiviriga I, Roitberg AE, Grenning AJ. Selective ring-rearrangement or ring-closing metathesis of bicyclo[3.2.1]octenes. Chem Commun (Camb) 2020; 56:11779-11782. [PMID: 32940291 DOI: 10.1039/d0cc04624h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Explored was the competitive ring-closing metathesis vs. ring-rearrangement metathesis of bicyclo[3.2.1]octenes prepared by a simple and convergent synthesis from bicyclic alkylidenemalono-nitriles and allylic electrophiles. It was uncovered that ring-closing metathesis occurs exclusively on the tetraene-variant, yielding unique, stereochemically and functionally rich polycyclic bridged frameworks, whereas the reduced version (a triene) undergoes ring-rearrangement metathesis to 5-6-5 fused ring systems resembling the isoryanodane core.
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Affiliation(s)
- Evgeniya Semenova
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, FL, USA.
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