1
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Pereira J, Casaretto N, Frison G, Nay B. Bio-inspired total synthesis of daphnepapytone A. Chem Sci 2025:d5sc02953h. [PMID: 40417298 PMCID: PMC12096516 DOI: 10.1039/d5sc02953h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2025] [Accepted: 05/16/2025] [Indexed: 05/27/2025] Open
Abstract
Daphnepapytone A (1) is an unprecedented guaiane-derived sesquiterpene characterized by a bridged and highly substituted cyclobutane. We describe its total synthesis through a bio-inspired sequence of skeleton construction and late-stage oxidation. After the Eschenmoser-Tanabe fragmentation of (R)-carvone epoxide, the allenylation of the resulting aldehyde was followed by an allenic Pauson-Khand reaction with distal regioselectivity in the presence of [Rh(CO)2Cl]2 to give the guaiane skeleton. Oleodaphnone (3) was identified as a key intermediate of this strategy and was engaged in a biomimetic [2 + 2]-photocycloaddition, leading to the bridged cyclobutane of the title compound. Finally, a late-stage C-H oxidation chemoselectively released a triketone intermediate (15), which was reduced in a remarkably chemo- and stereoselective manner to furnish target compound 1. During this work, complex rearrangements of the bridged skeleton were observed. Beside the total synthesis of daphnepapytone A, this paper also describes the total synthesis of three guaiane natural products (oleodaphnone, diarthroncha C, daphnenicillata W), one of them being structurally revised.
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Affiliation(s)
- Joan Pereira
- Laboratoire de Synthèse Organique, Ecole Polytechnique, ENSTA Paris, CNRS, Institut Polytechnique de Paris Route de Saclay F-91128 Palaiseau Cedex France
| | - Nicolas Casaretto
- Laboratoire de Chimie Moléculaire, Ecole Polytechnique, ENSTA Paris, CNRS, Institut Polytechnique de Paris Route de Saclay F-91128 Palaiseau Cedex France
| | - Gilles Frison
- Laboratoire de Chimie Théorique, Sorbonne Université, CNRS F-75005 Paris France
| | - Bastien Nay
- Laboratoire de Synthèse Organique, Ecole Polytechnique, ENSTA Paris, CNRS, Institut Polytechnique de Paris Route de Saclay F-91128 Palaiseau Cedex France
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2
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Zhang Y, Yu P, Chen W, Li J, Liu K, Xie X, Li H, She X. Bioinspired Stereoselective Total Synthesis of the Caged Sesquiterpenoid Daphnepapytone A. Org Lett 2025. [PMID: 40372148 DOI: 10.1021/acs.orglett.5c01509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2025]
Abstract
The first total synthesis of the novel caged sesquiterpenoid daphnepapytone A is disclosed. Key reactions include a Pauson-Khand cycloaddition to provide oleodaphone, a bioinspired photoinduced [2 + 2] cycloaddition to forge the cyclobutane-containing caged skeleton, and a C-H oxidation and reduction protocol to generate daphnepapytone A. Finally, the 17-step synthetic sequence is shortened to 4 steps in protecting group-free and exclusively stereoselective fashion.
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Affiliation(s)
- Yan Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Pengfei Yu
- 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
| | - Jia Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Kai Liu
- 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
| | - Huilin Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
- State Key Laboratory of Green Pesticide, Guizhou University, Guiyang 550025, 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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3
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Molina Betancourt R, Leutzsch M, Fürstner A. Total Synthesis of the Marine Diterpenoids Caucanolide E and F by Alkyne gem-Hydrogenation: Rigorous Reassignment of Two Almost Indistinguishable Diastereomers. Angew Chem Int Ed Engl 2025; 64:e202500124. [PMID: 39936386 DOI: 10.1002/anie.202500124] [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: 01/02/2025] [Revised: 02/03/2025] [Accepted: 02/11/2025] [Indexed: 02/13/2025]
Abstract
As the spectra of the diastereomeric marine seco-cembranoids caucanolide E and F are almost identical, the isolation team had not been able to firmly assign their stereostructure. The puzzle has now been solved by a synthetic approach predicated on biogenetic considerations, which suggested that both natural products are 10S configured but differ in the configuration of their C8 stereocenter. Under this proviso, they can be distinguished by comparison with synthetic samples that are deliberately 8S,10S and 8S,10R configured: only one natural product can match sign and magnitude of the [α]D of one of these reference compounds; this particular caucanolide must be the 8S,10S isomer. Both reference compounds needed for this benchmarking exercise were accessible from a single precursor via ruthenium catalyzed gem-hydrogenation of an enyne to furnish an alkoxyfuran in the first place, followed by hydrolysis; this key transformation leverages the electrophilic character of the pianostool ruthenium carbene intermediates passed through. The recorded data showed that the assignment proposed in the literature is incorrect and needs to be reversed; this conclusion was independently confirmed by a combined NMR/DFT approach using a CP3 probability analysis.
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Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der Ruhr, Germany
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4
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Gao X, Shen H, Chen P, Huo L, Li H, Xie X, Zhao G, She X. Construction of the Tetracyclic Skeleton of Polycyclic Norcembranoids Sinudenoids B-D Via Ireland-Claisen Rearrangement. J Org Chem 2025; 90:4776-4780. [PMID: 40111397 DOI: 10.1021/acs.joc.5c00317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2025]
Abstract
Sinudenoids B-D represent a biologically significant and structurally intricate family of natural products distinguished by their unique [5-5-6-6] tetracyclic skeleton. Herein, we present an efficient strategy for the asymmetric synthesis of their [5-5-6-6] tetracyclic framework. Key features of our approach include a convergent synthetic strategy driven by esterification, a pivotal Ireland-Claisen rearrangement to construct a C11-C12 bond, followed by efficient lactonization and isomerization, and a ring-closing metathesis to complete the [5-5-6-6] tetracyclic skeleton.
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Affiliation(s)
- Xiaofei Gao
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Hui Shen
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Peng Chen
- 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
| | - 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
| | - Gaoyuan Zhao
- 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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5
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Poonswat K, Attanonchai S, Batsomboon P, Theppitak C, Chainok K, Ruchirawat S, Ploypradith P. All-Carbon Quaternary Center Containing Tetrahydro-5H-benzo[c]fluorenes via Highly Stereoselective Transannular Carbocation Cyclization. Chem Asian J 2025. [PMID: 40095775 DOI: 10.1002/asia.202500300] [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: 02/19/2025] [Revised: 03/16/2025] [Accepted: 03/17/2025] [Indexed: 03/19/2025]
Abstract
Transannular carbocation cyclization of the achiral benzannulated cyclononene tertiary alcohols under acid catalysis furnished the [5/6]-fused tetracycles with three contiguous stereogenic centers, one of which is an all-carbon C11b quaternary center, in good-to-excellent yields and diastereoselectivity. Hydride, water, azide, allyl, and electron-rich (hetero)arenes could be employed as nucleophiles. The reaction is under both substrate- and condition-control. Further, functionalization of some selected substrates was also demonstrated. Computational chemistry delineated different competing reaction pathways such as direct substitution at the bisbenzylic position for other related systems-the benzannulated cyclooctene/cyclononene secondary alcohols and provided further evidence for the observed stereoselectivity.
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Affiliation(s)
- Kasam Poonswat
- Program in Chemical Sciences, Chulabhorn Graduate Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Sineenart Attanonchai
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Paratchata Batsomboon
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Chatphorn Theppitak
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Kittipong Chainok
- Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-MCMA), Faculty of Science and Technology, Thammasat University, Pathum Thani, 12121, Thailand
| | - Somsak Ruchirawat
- Program in Chemical Sciences, Chulabhorn Graduate Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology, Office of the Permanent Secretary (OPS), Ministry of Higher Education, Science, Research, and Innovation (MHESI), Bangkok, 10400, Thailand
| | - Poonsakdi Ploypradith
- Program in Chemical Sciences, Chulabhorn Graduate Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology, Office of the Permanent Secretary (OPS), Ministry of Higher Education, Science, Research, and Innovation (MHESI), Bangkok, 10400, Thailand
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6
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Lin DS, Späth G, Meng Z, Wieske LHE, Farès C, Fürstner A. Total Synthesis of the Norcembranoid Scabrolide B and Its Transformation into Sinuscalide C, Ineleganolide, and Horiolide. J Am Chem Soc 2024; 146:24250-24256. [PMID: 39167047 PMCID: PMC11378282 DOI: 10.1021/jacs.4c09467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
It was recognized only recently that the sister norcembranoids scabrolides A and B have notably different carbotricyclic scaffolds. Therefore, our synthesis route leading to scabrolide A could not be extended to its sibling. Rather, a conceptually new approach had to be devised that relied on a challenging intramolecular alkenylation of a ketone to forge the congested central cycloheptene ring at the bridgehead enone site; the required cyclization precursor was attained by a lanthanide-catalyzed Mukaiyama-Michael addition. The dissonant 1,4-oxygenation pattern was then installed by allylic rearrangement/oxidation of the enone, followed by suprafacial 1,3-transposition. Synthetic scabrolide B was transformed into sinuscalide C by dehydration and into ineleganolide by base-mediated isomerization/oxa-Michael addition, which has potential biosynthetic implications; under basic conditions, the latter compound converts into horiolide by an intricate biomimetic cascade.
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Affiliation(s)
- Davy S Lin
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Georg Späth
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Zhanchao Meng
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Lianne H E Wieske
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Christophe Farès
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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7
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Lee JR, Hwang SJ, Choi Y, Kim J, Lee GS, Lee BS, Kim KH, Kang KB, Lee HJ, Kim CS. Structural Diversification of Pyrazinone Metabolites via Spontaneous Oxa-Michael Addition in Staphylococcus xylosus. JOURNAL OF NATURAL PRODUCTS 2024; 87:1881-1887. [PMID: 38950087 DOI: 10.1021/acs.jnatprod.4c00252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
A family of pyrazinone metabolites (1-11) were characterized from Staphylococcus xylosus ATCC 29971. Six of them were hydroxylated or methoxylated, which were proposed to be produced by the rare noncatalytic oxa-Michael addition reaction with a water or methanol molecule. It was confirmed that isopropyl alcohol can also be the Michael donor of the reaction. 1-7 and the synthetic precursor 2a showed significant inhibition of breast cancer cell migration.
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Affiliation(s)
- Ju Ryeong Lee
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Su Jung Hwang
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yukyung Choi
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Jonghwan Kim
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Gyu Sung Lee
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Bum Soo Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Ki Hyun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kyo Bin Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Hyo-Jong Lee
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Chung Sub Kim
- Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
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8
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Kuo CH, Hsieh WT, Yang YH, Hwang TL, Cheng YS, Lin YA. Cesium Carbonate Promoted Direct Amidation of Unactivated Esters with Amino Alcohol Derivatives. J Org Chem 2024; 89:4958-4970. [PMID: 38523317 PMCID: PMC11002823 DOI: 10.1021/acs.joc.4c00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/13/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024]
Abstract
Cesium carbonate promoted direct amidation of unactivated esters with amino alcohols was developed without the use of transition-metal catalysts and coupling reagents. This method enabled the synthesis of several serine-containing oligopeptides and benzamide derivatives with yields up to 90%. The methodology proceeds under mild reaction conditions and exhibits no racemization for most naturally occurring amino acid substrates. The reaction demonstrates good compatibility with primary alkyl and benzyl esters and broad tolerance for a range of amino acid substrates with nonpolar and protected side chains. The hydroxy group on the amine nucleophile was found to be critical for the reaction to be successful. A likely mechanism involving cesium coordination to the substrates enabling the subsequent proximity-driven acyl transfer was proposed. The practicality of this approach was demonstrated in the preparation of a biologically active nicotinamide derivative in a reasonable yield.
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Affiliation(s)
- Chih-Hung Kuo
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Wen-Tsai Hsieh
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Ya-Hsu Yang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Teng-Li Hwang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Yu-Shan Cheng
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Yuya A. Lin
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Medicinal and Applied Chemistry, Kaohsiung
Medical University, Kaohsiung 807, Taiwan
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9
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Yahata K, Fürstner A. Total Synthesis of the Guangnanmycin A Alcohol. Angew Chem Int Ed Engl 2024; 63:e202319070. [PMID: 38226793 DOI: 10.1002/anie.202319070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/14/2024] [Accepted: 01/16/2024] [Indexed: 01/17/2024]
Abstract
Guangnanmycin A is a recently discovered congener of the well-known antitumor drug lead leinamycin; its macrolactam ring, however, is even more strained than that of the parent compound. The first synthetic foray towards this challenging target is reported, which relies on molybdenum-catalyzed macrocyclization by ring closing alkyne metathesis (RCAM) followed by ruthenium-catalyzed redox isomerization of the propargyl alcohol thus formed; the resulting enone enabled the introduction of the yet missing exo-methylene group by a modified Peterson olefination. The signature disulfide moiety of guangnanmycin A was installed by strain-driven thia-Michael addition followed by conversion of the thioether thus formed into an unsymmetric disulfide with the aid of (methylthio)dimethylsulfonium tetrafluoroborate and MeSSMe. While this sequence furnished racemic guangnanmycin A alcohol in good overall yield, the final oxidation to the corresponding acid failed, most likely because of the exceptional sensitivity of the strained scaffold.
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Affiliation(s)
- Kenzo Yahata
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
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10
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Spohr S, Fürstner A. Studies toward Providencin: The Furanyl-Cyclobutanol Segment. Org Lett 2023; 25:1536-1540. [PMID: 36847332 PMCID: PMC10012265 DOI: 10.1021/acs.orglett.3c00327] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Indexed: 03/01/2023]
Abstract
The furanocembranoid providencin remains an unconquered bastion, although the synthesis of 17-deoxyprovidencin─lacking a single -OH group─has been accomplished in the past. This paper describes a practical approach to a properly hydroxylated building block via an iridium-catalyzed photosensitized intramolecular [2 + 2] cycloaddition as the key step. While an attempt to convert this compound into providencin via RCAM failed, it might well be elaborated into the natural product by adopting the literature route.
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Affiliation(s)
- Simon
M. Spohr
- Max-Planck-Institut
für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut
für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
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11
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Fürstner A. How to Break the Law:
trans
‐Hydroboration and
gem
‐Hydroboration of Alkynes. Isr J Chem 2023. [DOI: 10.1002/ijch.202300004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Affiliation(s)
- Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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12
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d’Aleman A, Gayraud O, Fressigné C, Petit E, Bailly L, Maddaluno J, De Paolis M. Organocatalyzed enantio- and diastereoselective isomerization of prochiral 1,3-cyclohexanediones into nonalactones bearing distant stereocenters. Chem Sci 2023; 14:2107-2113. [PMID: 36845928 PMCID: PMC9945243 DOI: 10.1039/d2sc06842g] [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: 12/12/2022] [Accepted: 01/27/2023] [Indexed: 01/30/2023] Open
Abstract
The lactonization of 2-(2-nitrophenyl)-1,3-cyclohexanediones containing an alcohol side chain and up to three distant prochiral elements is reported by isomerization under the mediation of simple organocatalysts such as quinidine. Through a process of ring expansion, strained nonalactones and decalactone are produced with up to three stereocenters in high er and dr (up to 99 : 1). Distant groups, including alkyl, aryl, carboxylate and carboxamide moieties, were examined.
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13
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Tuccinardi J, Wood JL. Total Syntheses of (+)-Ineleganolide and (-)-Sinulochmodin C. J Am Chem Soc 2022; 144:20539-20547. [PMID: 36283051 PMCID: PMC9651135 DOI: 10.1021/jacs.2c09826] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Indexed: 11/29/2022]
Abstract
Described herein are the first total syntheses of the nor-furanocembranoid natural products (+)-ineleganolide (1) and (-)-sinulochmodin C (2). The synthetic strategy is predicated on a transannular Michael reaction that provides both natural products from a common macrocyclic intermediate and leverages a diastereoselective radical cyclization to furnish a key bicyclic lactone. The latter is further advanced to a macrocyclic precursor via a Nozaki-Hiyama-Kishi cyclization and a one-pot furan oxidation/oxa-Michael cascade. Unexpected stereochemical nuances that guided the evolution and eventual completion of the total synthesis are discussed.
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Affiliation(s)
- Joseph
P. Tuccinardi
- Department of Chemistry and
Biochemistry, Baylor University, One Bear Place 97348, Waco, Texas 76798, United States
| | - John L. Wood
- Department of Chemistry and
Biochemistry, Baylor University, One Bear Place 97348, Waco, Texas 76798, United States
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14
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Zhang K, Li C, Jia Y, Zhao W. Asymmetric Oxidative Lactonization of Enynyl Boronates. Angew Chem Int Ed Engl 2022; 61:e202209004. [DOI: 10.1002/anie.202209004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Kezhuo Zhang
- State Key Laboratory of Chemo/Biosensing and Chemometrics Advanced Catalytic Engineering Research Center of the Ministry of Education College of Chemistry and Chemical Engineering Hunan University 410082 Changsha Hunan P. R. China
| | - Chenchen Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics Advanced Catalytic Engineering Research Center of the Ministry of Education College of Chemistry and Chemical Engineering Hunan University 410082 Changsha Hunan P. R. China
| | - Yining Jia
- State Key Laboratory of Chemo/Biosensing and Chemometrics Advanced Catalytic Engineering Research Center of the Ministry of Education College of Chemistry and Chemical Engineering Hunan University 410082 Changsha Hunan P. R. China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics Advanced Catalytic Engineering Research Center of the Ministry of Education College of Chemistry and Chemical Engineering Hunan University 410082 Changsha Hunan P. R. China
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15
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Zhang K, Li C, Jia Y, Zhao W. Asymmetric Oxidative Lactonization of Enynyl Boronates. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209004] [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)
| | | | | | - Wanxiang Zhao
- Hunan University chemistry Yuelushan, Changsha 410082 changsha CHINA
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16
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Radkowski K, Fürstner A. A Sphingolipid Fatty Acid Constituent Made by Alkyne trans‐Hydrogenation: Total Synthesis of Symbioramide. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Ali R, Ahmed W, Jayant V, alvi S, Ahmed N, Ahmed A. Metathesis reactions in total‐ and natural product fragments syntheses. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Rashid Ali
- Jamia Millia Islamia New Delhi India 110025 Department of Chemistry Jamia Nagar,New Delhi india110025 110025 New Delhi INDIA
| | - Waqar Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Vikrant Jayant
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - shakeel alvi
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Nadeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Azeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
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18
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Abstract
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The marine natural
product scabrolide A was obtained by isomerization
of the vinylogous 1,4-diketone entity of nominal scabrolide B as the
purported pivot point of the biosynthesis of these polycyclic norcembranoids.
Despite the success of this maneuver, the latter compound itself turned
out not to be identical with the natural product of that name. The
key steps en route to the carbocyclic core of these targets were a
[2,3]-sigmatropic rearrangement of an allylic sulfur ylide to forge
the overcrowded C12–C13 bond, an RCM reaction to close the
congested central six-membered ring, and a hydroxy-directed epoxidation/epoxide
opening/isomerization sequence to set the “umpoled”
1,4-dicarbonyl motif and the correct angular configuration at C12.
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Affiliation(s)
- Zhanchao Meng
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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19
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Melot R, Saiegh TJ, Fürstner A. Regioselective trans-Hydrostannation of Boron-Capped Alkynes. Chemistry 2021; 27:17002-17011. [PMID: 34240757 PMCID: PMC9291331 DOI: 10.1002/chem.202101901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Indexed: 01/16/2023]
Abstract
Alkynyl-B(aam) (aam=anthranilamidato) derivatives are readily available bench-stable compounds that undergo remarkably selective reactions with Bu3 SnH in the presence of [Cp*RuCl]4 as the catalyst. The addition follows a stereochemically unorthodox trans-selective course; in terms of regioselectivity, the Bu3 Sn- unit is delivered with high fidelity to the C-atom of the triple bond adjacent to the boracyclic head group ("alpha,trans-addition"). This outcome is deemed to reflect a hydrogen bonding interaction between the protic -NH groups of the benzo-1,3,2-diazaborininone ring system and the polarized [Ru-Cl] bond in the loaded catalyst, which locks the substrate in place in a favorable orientation relative to the incoming reagent. The resulting isomerically (almost) pure gem-dimetalated building blocks are amenable to numerous downstream functionalizations; most remarkable is the ability to subject the -B(aam) moiety to Suzuki-Miyaura cross coupling without need for prior hydrolysis while keeping the adjacent Bu3 Sn- group intact. Alternatively, the tin residue can be engaged in selective tin/halogen exchange without touching the boron substituent; the fact that the two -NH entities of -B(aam) do not protonate organozinc reagents and hence do not interfere with Negishi reactions of the alkenyl halides thus formed is another virtue of this so far underutilized boracycle. Overall, the ruthenium catalyzed trans-hydrostannation of alkynyl-B(aam) derivatives opens a practical gateway to isomerically pure trisubstituted alkenes of many different substitution patterns by sequential functionalization of the 1-alkenyl-1,1-heterobimetallic adducts primarily formed.
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Affiliation(s)
- Romain Melot
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - Tomas J. Saiegh
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
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20
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Hillenbrand J, Korber JN, Leutzsch M, Nöthling N, Fürstner A. Canopy Catalysts for Alkyne Metathesis: Investigations into a Bimolecular Decomposition Pathway and the Stability of the Podand Cap. Chemistry 2021; 27:14025-14033. [PMID: 34293239 PMCID: PMC8518412 DOI: 10.1002/chem.202102080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Indexed: 11/28/2022]
Abstract
Molybdenum alkylidyne complexes with a trisilanolate podand ligand framework ("canopy catalysts") are the arguably most selective catalysts for alkyne metathesis known to date. Among them, complex 1 a endowed with a fence of lateral methyl substituents on the silicon linkers is the most reactive, although fairly high loadings are required in certain applications. It is now shown that this catalyst decomposes readily via a bimolecular pathway that engages the Mo≡CR entities in a stoichiometric triple-bond metathesis event to furnish RC≡CR and the corresponding dinuclear complex, 8, with a Mo≡Mo core. In addition to the regular analytical techniques, 95 Mo NMR was used to confirm this unusual outcome. This rapid degradation mechanism is largely avoided by increasing the size of the peripheral substituents on silicon, without unduly compromising the activity of the resulting complexes. When chemically challenged, however, canopy catalysts can open the apparently somewhat strained tripodal ligand cages; this reorganization leads to the formation of cyclo-tetrameric arrays composed of four metal alkylidyne units linked together via one silanol arm of the ligand backbone. The analogous tungsten alkylidyne complex 6, endowed with a tripodal tris-alkoxide (rather than siloxide) ligand framework, is even more susceptible to such a controlled and reversible cyclo-oligomerization. The structures of the resulting giant macrocyclic ensembles were established by single-crystal X-ray diffraction.
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Affiliation(s)
- Julius Hillenbrand
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - J. Nepomuk Korber
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim an der RuhrMülheim/RuhrGermany
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21
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Martínez-García L, Prado G, Góñez KV, Paleo MR, Sardina FJ. Stereoselective Synthesis of Hydrindane and Hydroazulene Derivatives by Transannular Cyclization of Nine- and Ten-Membered Carbocycles. J Org Chem 2021; 86:13684-13692. [PMID: 34519499 DOI: 10.1021/acs.joc.1c01751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Treatment of cis-fused bicyclic diene dicarboxylates with Li/naphthalene triggers a tandem ring-opening and transannular cyclization process that stereoselectively yields hydroazulenes and hydrindanes derivatives. Cyclononadienyl diesters, which can be isolated after the ring-opening step by judicious choice of the reaction conditions, undergo a tandem conjugate addition/intramolecular Michael addition upon treatment with chiral lithium amides to give bicyclic β-amino esters in a process where 4 contiguous stereocenters are formed with high diastereocontrol. A concise route toward the highly enantioenriched AEF ring core of the aconitine-type alkaloids has been developed as an application of this methodology. The starting cis-fused bicyclic dicarboxylates are easily prepared in one step by reductive alkylation of diisopropyl phthalate (Na/THF, followed by the appropriate bis-electrophiles).
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Affiliation(s)
- Lucas Martínez-García
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Gustavo Prado
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Karen V Góñez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M Rita Paleo
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - F Javier Sardina
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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22
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Abstract
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For numerous enabling features and strategic virtues, contemporary
alkyne metathesis is increasingly recognized as a formidable synthetic
tool. Central to this development was the remarkable evolution of
the catalysts during the past decades. Molybdenum alkylidynes carrying
(tripodal) silanolate ligands currently set the standards; their functional
group compatibility is exceptional, even though they comprise an early
transition metal in its highest oxidation state. Their performance
is manifested in case studies in the realm of dynamic covalent chemistry,
advanced applications to solid-phase synthesis, a revival of transannular
reactions, and the assembly of complex target molecules at sites,
which one may not intuitively trace back to an acetylenic ancestor.
In parallel with these innovations in material science and organic
synthesis, new insights into the mode of action of the most advanced
catalysts were gained by computational means and the use of unconventional
analytical tools such as 95Mo and 183W NMR spectroscopy.
The remaining shortcomings, gaps, and desiderata in the field are
also critically assessed.
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Affiliation(s)
- Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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23
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Meng Z, Spohr SM, Tobegen S, Farès C, Fürstner A. A Unified Approach to Polycyclic Alkaloids of the Ingenamine Estate: Total Syntheses of Keramaphidin B, Ingenamine, and Nominal Njaoamine I. J Am Chem Soc 2021; 143:14402-14414. [PMID: 34448391 PMCID: PMC8431342 DOI: 10.1021/jacs.1c07955] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Many
polycyclic marine
alkaloids are thought to derive from partly
reduced macrocyclic alkylpyridine derivatives via a transannular Diels–Alder
reaction that forms their common etheno-bridged diaza-decaline core
(“Baldwin–Whitehead hypothesis”). Rather than
trying to emulate this biosynthesis pathway, a route to these natural
products following purely chemical logic was pursued. Specifically,
a Michael/Michael addition cascade provided rapid access to this conspicuous
tricyclic scaffold and allowed different handles to be introduced
at the bridgehead quarternary center. This flexibility opened opportunities
for the formation of the enveloping medium-sized and macrocyclic rings.
Ring closing alkyne metathesis (RCAM) proved most reliable and became
a recurrent theme en route to keramaphidin B, ingenamine, xestocyclamine
A, and nominal njaoamine I (the structure of which had to be corrected
in the aftermath of the synthesis). Best results were obtained with
molybdenum alkylidyne catalysts endowed with (tripodal) silanolate
ligands, which proved fully operative in the presence of tertiary
amines, quinoline, and other Lewis basic sites. RCAM was successfully
interlinked with macrolactamization, an intricate hydroboration/protonation/alkyl-Suzuki
coupling sequence, or ring closing olefin metathesis (RCM) for the
closure of the second lateral ring; the use of RCM for the formation
of an 11-membered cycle is particularly noteworthy. Equally rare are
RCM reactions that leave a pre-existing triple bond untouched, as
the standard ruthenium catalysts are usually indiscriminative vis-à-vis
the different π-bonds. Of arguably highest significance, however,
is the use of two consecutive or even concurrent RCAM reactions en
route to nominal njaoamine I as the arguably most complex of the chosen
targets.
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Affiliation(s)
- Zhanchao Meng
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Simon M Spohr
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Sandra Tobegen
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Christophe Farès
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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24
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Haack A, Hillenbrand J, van Gastel M, Fürstner A, Neese F. Spectroscopic and Theoretical Study on Siloxy-Based Molybdenum and Tungsten Alkylidyne Catalysts for Alkyne Metathesis. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01587] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Alexander Haack
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | | | | | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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25
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Thompson RR, Rotella ME, Zhou X, Fronczek FR, Gutierrez O, Lee S. Impact of Ligands and Metals on the Formation of Metallacyclic Intermediates and a Nontraditional Mechanism for Group VI Alkyne Metathesis Catalysts. J Am Chem Soc 2021; 143:9026-9039. [PMID: 34110130 PMCID: PMC8227475 DOI: 10.1021/jacs.1c01843] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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The
intermediacy of metallacyclobutadienes as part of a [2 + 2]/retro-[2
+ 2] cycloaddition-based mechanism is a well-established paradigm
in alkyne metathesis with alternative species viewed as off-cycle
decomposition products that interfere with efficient product formation.
Recent work has shown that the exclusive intermediate isolated from
a siloxide podand-supported molybdenum-based catalyst was not the
expected metallacyclobutadiene but instead a dynamic metallatetrahedrane.
Despite their paucity in the chemical literature, theoretical work
has shown these species to be thermodynamically more stable as well
as having modest barriers for cycloaddition. Consequentially, we report
the synthesis of a library of group VI alkylidynes as well as the
roles metal identity, ligand flexibility, secondary coordination sphere,
and substrate identity all have on isolable intermediates. Furthermore,
we report the disparities in catalyst competency as a function of
ligand sterics and metal choice. Dispersion-corrected DFT calculations
are used to shed light on the mechanism and role of ligand and metal
on the intermediacy of metallacyclobutadiene and metallatetrahedrane
as well as their implications to alkyne metathesis.
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Affiliation(s)
- Richard R Thompson
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Madeline E Rotella
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Xin Zhou
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Frank R Fronczek
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Semin Lee
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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26
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Löffler LE, Wirtz C, Fürstner A. Collective Total Synthesis of Casbane Diterpenes: One Strategy, Multiple Targets. Angew Chem Int Ed Engl 2021; 60:5316-5322. [PMID: 33289954 PMCID: PMC7986786 DOI: 10.1002/anie.202015243] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Indexed: 11/29/2022]
Abstract
Of the more than 100 casbane diterpenes known to date, only the eponymous parent hydrocarbon casbene itself has ever been targeted by chemical synthesis. Outlined herein is a conceptually new approach that brings not a single but a variety of casbane derivatives into reach, especially the more highly oxygenated and arguably more relevant members of this family. The key design elements are a catalyst-controlled intramolecular cyclopropanation with or without subsequent equilibration, chain extension of the resulting stereoisomeric cyclopropane building blocks by chemoselective hydroboration/cross-coupling, and the efficient closure of the strained macrobicyclic framework by ring-closing alkyne metathesis. A hydroxy-directed catalytic trans-hydrostannation allows for late-stage diversity. These virtues are manifested in the concise total syntheses of depressin, yuexiandajisu A, and ent-pekinenin C. The last compound turned out to be identical to euphorhylonal A, the structure of which had clearly been misassigned.
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Affiliation(s)
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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27
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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: 43] [Impact Index Per Article: 10.8] [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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28
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Löffler LE, Wirtz C, Fürstner A. Collective Total Synthesis of Casbane Diterpenes: One Strategy, Multiple Targets. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015243] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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29
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Schulthoff S, Hamilton JY, Heinrich M, Kwon Y, Wirtz C, Fürstner A. The Formosalides: Structure Determination by Total Synthesis. Angew Chem Int Ed Engl 2021; 60:446-454. [PMID: 32946141 PMCID: PMC7821135 DOI: 10.1002/anie.202011472] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Indexed: 01/08/2023]
Abstract
Total synthesis allowed the constitution of the cytotoxic marine macrolides of the formosalide family to be confirmed and their previously unknown stereostructure to be assigned with confidence. The underlying blueprint was inherently modular to ensure that each conceivable isomer could be reached. This flexibility derived from the use of strictly catalyst controlled transformations to set the stereocenters, except for the anomeric position, which is under thermodynamic control; as an extra safety measure, all stereogenic centers were set prior to ring closure to preclude any interference of the conformation adopted by the macrolactone rings of the different diastereomers. Late-stage macrocyclization by ring-closing alkyne metathesis was followed by a platinum-catalyzed transannular 6-exo-dig hydroalkoxylation/ketalization to craft the polycyclic frame. The side chain featuring a very labile unsaturation pattern was finally attached to the core by Stille coupling.
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Affiliation(s)
| | | | - Marc Heinrich
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Yonghoon Kwon
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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30
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Carroll AR, Copp BR, Davis RA, Keyzers RA, Prinsep MR. Marine natural products. Nat Prod Rep 2021; 38:362-413. [PMID: 33570537 DOI: 10.1039/d0np00089b] [Citation(s) in RCA: 220] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review covers the literature published in 2019 for marine natural products (MNPs), with 719 citations (701 for the period January to December 2019) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1490 in 440 papers for 2019), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. Methods used to study marine fungi and their chemical diversity have also been discussed.
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Affiliation(s)
- Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Australia. and Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia
| | - Brent R Copp
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia and School of Enivironment and Science, Griffith University, Brisbane, Australia
| | - Robert A Keyzers
- Centre for Biodiscovery, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Michèle R Prinsep
- Chemistry, School of Science, University of Waikato, Hamilton, New Zealand
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31
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Hillenbrand J, Leutzsch M, Gordon CP, Copéret C, Fürstner A. 183 W NMR Spectroscopy Guides the Search for Tungsten Alkylidyne Catalysts for Alkyne Metathesis. Angew Chem Int Ed Engl 2020; 59:21758-21768. [PMID: 32820864 PMCID: PMC7756321 DOI: 10.1002/anie.202009975] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/21/2020] [Indexed: 12/12/2022]
Abstract
Triarylsilanolates are privileged ancillary ligands for molybdenum alkylidyne catalysts for alkyne metathesis but lead to disappointing results and poor stability in the tungsten series. 1 H,183 W heteronuclear multiple bond correlation spectroscopy, exploiting a favorable 5 J-coupling between the 183 W center and the peripheral protons on the alkylidyne cap, revealed that these ligands upregulate the Lewis acidity to an extent that the tungstenacyclobutadiene formed in the initial [2+2] cycloaddition step is over-stabilized and the catalytic turnover brought to a halt. Guided by the 183 W NMR shifts as a proxy for the Lewis acidity of the central atom and by an accompanying chemical shift tensor analysis of the alkylidyne unit, the ligand design was revisited and a more strongly π-donating all-alkoxide ligand prepared. The new expanded chelate complex has a tempered Lewis acidity and outperforms the classical Schrock catalyst, carrying monodentate tert-butoxy ligands, in terms of rate and functional-group compatibility.
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Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Christopher P. Gordon
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 1–58093ZürichSwitzerland
| | - Christophe Copéret
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 1–58093ZürichSwitzerland
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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32
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From Target-Oriented to Motif-Oriented: A Case Study on Nannocystin Total Synthesis. Molecules 2020; 25:molecules25225327. [PMID: 33203102 PMCID: PMC7697126 DOI: 10.3390/molecules25225327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 01/14/2023] Open
Abstract
Natural product total synthesis is in essence target-oriented in that a set of organic transformations are orchestrated into a workable process, leading ultimately to the target molecule with a predefined architecture. For a bioactive lead, proof of synthetic viability is merely the beginning. Ensuing effort repurposes the initial synthesis for structural diversification in order to probe structure-activity relationship (SAR). Yet accessibility is not equal to flexibility; moving from convergency to divergency, it is not always feasible to explore the chemical space around a particular substructure of interest simply by tweaking an established route. In this situation, the motif-oriented strategy becomes a superior choice, which gives priority to synthetic flexibility at the concerned site such that a route is adopted only if it is capable of implementing diversification therein. This strategy was recently devised by Fürstner et al., enabling them to achieve total synthesis of both natural and non-natural nannocystins varied at an otherwise challenging position. The present review examines seven distinctive nannocystin total syntheses reported thus far and showcases the merits of conventional (target-oriented) as well as motif-oriented strategies, concluding that these two approaches complement each other and are both indispensable for natural product based drug discovery.
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33
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Schulthoff S, Hamilton JY, Heinrich M, Kwon Y, Wirtz C, Fürstner A. The Formosalides: Structure Determination by Total Synthesis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011472] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
| | | | - Marc Heinrich
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Yonghoon Kwon
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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34
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Peil S, Bistoni G, Goddard R, Fürstner A. Hydrogenative Metathesis of Enynes via Piano-Stool Ruthenium Carbene Complexes Formed by Alkyne gem-Hydrogenation. J Am Chem Soc 2020; 142:18541-18553. [PMID: 33073575 PMCID: PMC7596760 DOI: 10.1021/jacs.0c07808] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Indexed: 12/12/2022]
Abstract
The only recently discovered gem-hydrogenation of internal alkynes is a fundamentally new transformation, in which both H atoms of dihydrogen are transferred to the same C atom of a triple bond while the other position transforms into a discrete metal carbene complex. [Cp*RuCl]4 is presently the catalyst of choice: the resulting piano-stool ruthenium carbenes can engage a tethered alkene into either cyclopropanation or metathesis, and a prototypical example of such a reactive intermediate with an olefin ligated to the ruthenium center has been isolated and characterized by X-ray diffraction. It is the substitution pattern of the olefin that determines whether metathesis or cyclopropanation takes place: a systematic survey using alkenes of largely different character in combination with a computational study of the mechanism at the local coupled cluster level of theory allowed the preparative results to be sorted and an intuitive model with predictive power to be proposed. This model links the course of the reaction to the polarization of the double bond as well as to the stability of the secondary carbene complex formed, if metathesis were to take place. The first application of "hydrogenative metathesis" to the total synthesis of sinularones E and F concurred with this interpretation and allowed the proposed structure of these marine natural products to be confirmed. During this synthesis, it was found that gem-hydrogenation also provides opportunities for C-H functionalization. Moreover, silylated alkynes are shown to participate well in hydrogenative metathesis, which opens a new entry into valuable allylsilane building blocks. Crystallographic evidence suggests that the polarized [Ru-Cl] bond of the catalyst interacts with the neighboring R3Si group. Since attractive interligand Cl/R3Si contacts had already previously been invoked to explain the outcome of various ruthenium-catalyzed reactions, including trans-hydrosilylation, the experimental confirmation provided herein has implications beyond the present case.
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Affiliation(s)
- Sebastian Peil
- Max-Planck-Institut für
Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Giovanni Bistoni
- Max-Planck-Institut für
Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Richard Goddard
- Max-Planck-Institut für
Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für
Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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35
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Hillenbrand J, Leutzsch M, Gordon CP, Copéret C, Fürstner A. 183
W NMR Spectroscopy Guides the Search for Tungsten Alkylidyne Catalysts for Alkyne Metathesis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202009975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Christopher P. Gordon
- Department of Chemistry and Applied Biosciences ETH Zürich Vladimir-Prelog-Weg 1–5 8093 Zürich Switzerland
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences ETH Zürich Vladimir-Prelog-Weg 1–5 8093 Zürich Switzerland
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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36
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Cui M, Bai W, Sung HHY, Williams ID, Jia G. Robust Alkyne Metathesis Catalyzed by Air Stable d2 Re(V) Alkylidyne Complexes. J Am Chem Soc 2020; 142:13339-13344. [DOI: 10.1021/jacs.0c06581] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mingxu Cui
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Wei Bai
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Herman H. Y. Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ian D. Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Guochen Jia
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- HKUST Shenzhen Research Institute, Shenzhen 518057, China
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37
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Meng Z, Fürstner A. Total Synthesis Provides Strong Evidence: Xestocyclamine A is the Enantiomer of Ingenamine. J Am Chem Soc 2020; 142:11703-11708. [PMID: 32544329 PMCID: PMC7467676 DOI: 10.1021/jacs.0c05347] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
Xestocyclamine
A ((−)-1) is featured prominently
in a biosynthesis pathway leading to a large family of polycyclic
alkaloids. The first total synthesis now proves that the structure
of this compound had originally been misassigned. The route to (−)-1 is based on a double Michael addition for the formation
of the bridged diazadecalin core and a palladium-catalyzed decarboxylative
allylation to install the quaternary bridgehead center. Ring-closing
alkyne metathesis allowed a 13-membered cycloalkyne to be forged,
which was selectively reduced during an involved sequence of hydroboration/selective
protodeborylation/alkyl-Suzuki coupling used to close the 11-membered
ring. Crystallographic data prove the identity of synthetic (−)-1 with nominal xestocyclamine, but the spectra differ from
those of the authentic alkaloid. To clarify the point, the synthesis
was redirected toward ingenamine (3), which is supposedly
a positional isomer of 1. The recorded data confirm the
assignment of this particular natural product and strongly suggest
that xestocyclamine A is in fact the enantiomer of ingenamine (+)-3.
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Affiliation(s)
- Zhanchao Meng
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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38
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Hillenbrand J, Leutzsch M, Yiannakas E, Gordon CP, Wille C, Nöthling N, Copéret C, Fürstner A. "Canopy Catalysts" for Alkyne Metathesis: Molybdenum Alkylidyne Complexes with a Tripodal Ligand Framework. J Am Chem Soc 2020; 142:11279-11294. [PMID: 32463684 PMCID: PMC7322728 DOI: 10.1021/jacs.0c04742] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
![]()
A new family of structurally well-defined
molybdenum alkylidyne
catalysts for alkyne metathesis, which is distinguished by a tripodal
trisilanolate ligand architecture, is presented. Complexes of type 1 combine the virtues of previous generations of silanolate-based
catalysts with a significantly improved functional group tolerance.
They are easy to prepare on scale; the modularity of the ligand synthesis
allows the steric and electronic properties to be fine-tuned and hence
the application profile of the catalysts to be optimized. This opportunity
is manifested in the development of catalyst 1f, which
is as reactive as the best ancestors but exhibits an unrivaled scope.
The new catalysts work well in the presence of unprotected alcohols
and various other protic groups. The chelate effect entails even a
certain stability toward water, which marks a big leap forward in
metal alkylidyne chemistry in general. At the same time, they tolerate
many donor sites, including basic nitrogen and numerous heterocycles.
This aspect is substantiated by applications to polyfunctional (natural)
products. A combined spectroscopic, crystallographic, and computational
study provides insights into structure and electronic character of
complexes of type 1. Particularly informative are a density
functional theory (DFT)-based chemical shift tensor analysis of the
alkylidyne carbon atom and 95Mo NMR spectroscopy; this
analytical tool had been rarely used in organometallic chemistry before
but turns out to be a sensitive probe that deserves more attention.
The data show that the podand ligands render a Mo-alkylidyne a priori
more electrophilic than analogous monodentate triarylsilanols; proper
ligand tuning, however, allows the Lewis acidity as well as the steric
demand about the central atom to be adjusted to the point that excellent
performance of the catalyst is ensured.
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Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Ektoras Yiannakas
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Christopher P Gordon
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093 Zürich, Switzerland
| | - Christian Wille
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Nils Nöthling
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093 Zürich, Switzerland
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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39
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Vargová D, Némethová I, Šebesta R. Asymmetric copper-catalyzed conjugate additions of organometallic reagents in the syntheses of natural compounds and pharmaceuticals. Org Biomol Chem 2020; 18:3780-3796. [PMID: 32391843 DOI: 10.1039/d0ob00278j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Access to enantiopure complex molecular structures is crucial for the development of new drugs as well as agents used in crop-protection. In this regard, numerous asymmetric methods have been established. Copper-catalyzed 1,4-additions of organometallic reagents are robust C-C bond formation strategies applicable in a wide range of circumstances. This review analyses the syntheses of natural products and pharmaceutical agents, which rely on the application of asymmetric Cu-catalyzed conjugate additions of various organometallic reagents. A wide range of available organometallics, e.g. dialkylzinc, trialkylaluminum, Grignard, and organozirconium, can now be used in conjugate additions to address various synthetic challenges present in targeted natural compounds. Furthermore, efficient catalysts allow high levels of stereofidelity over a diverse array of starting Michael acceptors.
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Affiliation(s)
- Denisa Vargová
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Organic Chemistry, Mlynská dolina, Ilkovičova 6, SK-84215, Bratislava, Slovakia.
| | - Ivana Némethová
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Organic Chemistry, Mlynská dolina, Ilkovičova 6, SK-84215, Bratislava, Slovakia.
| | - Radovan Šebesta
- Comenius University in Bratislava, Faculty of Natural Sciences, Department of Organic Chemistry, Mlynská dolina, Ilkovičova 6, SK-84215, Bratislava, Slovakia.
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40
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Abstract
The first asymmetric total synthesis of (+)-jatrophalactam was reported, which unambiguously determined the absolute configuration of the titled natural product. The key features entail a conformationally controlled cyclopropanation, a Meldrum's acid adduct-engaged macrolactam formation, and a Pd(II)-mediated oxidative cyclization.
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Affiliation(s)
- Jianhong Gao
- Department of Chemistry , Zhejiang University , Hangzhou 310058 , China
| | - Dongyu Sun
- Department of Chemistry , Zhejiang University , Hangzhou 310058 , China
| | - Kuan Yu
- Department of Chemistry , Zhejiang University , Hangzhou 310058 , China
| | - Hujun Xie
- Department of Applied Chemistry , Zhejiang Gongshang University , Hangzhou 310018 , China
| | - Hanfeng Ding
- Department of Chemistry , Zhejiang University , Hangzhou 310058 , China
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41
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Palframan MJ, Pattenden G. Biosynthetic Interrelationships within Polycyclic Cembranoids Isolated from Corals: Conjecture, Biomimetic Synthesis and Reality. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901438] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Matthew J. Palframan
- School of Chemistry; The University of Nottingham; University Park Nottingham NG7 2RD UK
| | - Gerald Pattenden
- School of Chemistry; The University of Nottingham; University Park Nottingham NG7 2RD UK
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42
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Hillenbrand J, Leutzsch M, Fürstner A. Molybdenum Alkylidyne Complexes with Tripodal Silanolate Ligands: The Next Generation of Alkyne Metathesis Catalysts. Angew Chem Int Ed Engl 2019; 58:15690-15696. [PMID: 31449713 PMCID: PMC6856820 DOI: 10.1002/anie.201908571] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/23/2019] [Indexed: 12/12/2022]
Abstract
A new type of molybdenum alkylidyne catalysts for alkyne metathesis is described, which is distinguished by an unconventional podand topology. These structurally well-defined complexes are easy to make on scale and proved to be tolerant toward numerous functional groups; even certain protic substituents were found to be compatible. The new catalysts were characterized by X-ray crystallography and by spectroscopic means, including 95 Mo NMR.
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Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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43
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Thompson RR, Rotella ME, Du P, Zhou X, Fronczek FR, Kumar R, Gutierrez O, Lee S. Siloxide Podand Ligand as a Scaffold for Molybdenum-Catalyzed Alkyne Metathesis and Isolation of a Dynamic Metallatetrahedrane Intermediate. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00430] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard R. Thompson
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Madeline E. Rotella
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Pu Du
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Xin Zhou
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Frank R. Fronczek
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Revati Kumar
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Semin Lee
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70810, United States
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44
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Wang Z, Li PL, Luo XC, Wang Q, van Ofwegen L, Tang XL, Li GQ. Terpenoids from the South China Sea soft coral Sinularia multiflora. Nat Prod Res 2019; 35:2395-2402. [PMID: 31631686 DOI: 10.1080/14786419.2019.1678615] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A rare sinulariane-type norcembranoid sinulariadiolide B (1) with a unique cyano group, and a eunicellin-based diterpenoid multifloralin (2), along with two known related analogues, sinulariadiolide (3) and sclerophytin E (4), were isolated from the extract of the South China Sea soft coral Sinularia multiflora. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with previously reported data. Compounds 2 and 4 showed potent antifouling activity against barnacle Balanus albicostatus.
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Affiliation(s)
- Zheng Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, People's Republic of China.,Laboratory of Marine Drugs and Biological Products, National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
| | - Ping-Lin Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, People's Republic of China.,Laboratory of Marine Drugs and Biological Products, National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
| | - Xiang-Chao Luo
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, People's Republic of China.,Laboratory of Marine Drugs and Biological Products, National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
| | - Qi Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, People's Republic of China.,Institutes of Chronic Disease, Qingdao University, Qingdao, People's Republic of China
| | | | - Xu-Li Tang
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, People's Republic of China
| | - Guo-Qiang Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, People's Republic of China.,Laboratory of Marine Drugs and Biological Products, National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
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45
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Hillenbrand J, Leutzsch M, Fürstner A. Molybdenum Alkylidyne Complexes with Tripodal Silanolate Ligands: The Next Generation of Alkyne Metathesis Catalysts. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908571] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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46
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Ding XB, Furkert DP, Brimble MA. Highly Diastereoselective Synthesis of Syn-1,3-Dihydroxyketone Motifs from Propargylic Alcohols via Spiroepoxide Intermediates. Angew Chem Int Ed Engl 2019; 58:11830-11835. [PMID: 31218800 DOI: 10.1002/anie.201905736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/19/2019] [Indexed: 12/29/2022]
Abstract
Syn dihydroxyketone motifs are embedded in a wide range of biologically active natural products, however the development of stereoselective synthetic methods to assemble these structures has proven a challenging task. We report a highly diastereoselective method for the synthesis of syn dihydroxyketones from propargylic alcohols, with wide scope for application in natural product synthesis. The reaction sequence involves regioselective cyclisation of propargylic alcohols with incorporation of a triketone to give enol dioxolanes that are then diastereoselectively epoxidised to form unusual spiroepoxide intermediates. Hydrolysis affords syn dihydroxyketones as essentially single diastereisomers. The reaction sequence is operationally simple, of wide substrate scope, and remarkably can be efficiently carried out as a one-pot process with no loss of overall yield or diastereoselectivity.
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Affiliation(s)
- Xiao-Bo Ding
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland, 1010, New Zealand
| | - Daniel P Furkert
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland, 1010, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland, 1010, New Zealand
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47
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Ding X, Furkert DP, Brimble MA. Highly Diastereoselective Synthesis of
Syn
‐1,3‐Dihydroxyketone Motifs from Propargylic Alcohols via Spiroepoxide Intermediates. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201905736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xiao‐Bo Ding
- School of Chemical Sciences The University of Auckland 23 Symonds Street Auckland 1010 New Zealand
| | - Daniel P. Furkert
- School of Chemical Sciences The University of Auckland 23 Symonds Street Auckland 1010 New Zealand
| | - Margaret A. Brimble
- School of Chemical Sciences The University of Auckland 23 Symonds Street Auckland 1010 New Zealand
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48
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Longobardi LE, Fürstner A. trans
‐Hydroboration of Propargyl Alcohol Derivatives and Related Substrates. Chemistry 2019; 25:10063-10068. [DOI: 10.1002/chem.201902228] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/07/2019] [Indexed: 01/04/2023]
Affiliation(s)
- Lauren E. Longobardi
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim/Ruhr Germany
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