1
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Kim JY, Davies TQ, Fürstner A. Aminoalcohol derivatives by nickel-catalyzed enantioselective coupling of imines and dienol ethers. Chem Commun (Camb) 2023; 59:12613-12616. [PMID: 37791515 DOI: 10.1039/d3cc04582j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The reductive coupling of dienol ethers with N-tosylimines catalyzed by Ni(0) in the presence of a VAPOL-derived phosphoramidite ligand follows an unprecedented regiochemical course; it furnishes syn-configured 1,2-aminoalcohol derivatives in good chemical yields with up to 94% ee.
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Affiliation(s)
- Jae Yeon Kim
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
| | - Thomas Q Davies
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
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2
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Zachmann R, Yahata K, Holzheimer M, Jarret M, Wirtz C, Fürstner A. Total Syntheses of Nominal and Actual Prorocentin. J Am Chem Soc 2023; 145:2584-2595. [PMID: 36652728 PMCID: PMC9896551 DOI: 10.1021/jacs.2c12529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The dinoflagellate-derived polyether prorocentin is a co-metabolite of the archetypical serine/threonine phosphatase inhibitor okadaic acid. Whereas a structural relationship cannot be missed and a biosynthetic link was proposed, it is currently unknown whether there is any parallel in the bioactivity profile of these natural products. However, it was insinuated in the past that the structure assigned to prorocentin might need to be revised. Indeed, re-examination of the published spectra cast doubts as to the constitution of the fused/spirotricyclic BCD-ring system in the core. To clarify this issue, a flexible synthesis blueprint was devised that allowed us to obtain the originally proposed structure as well as the most plausible amended structure. The key to success was late-stage gold-catalyzed spirocyclization reactions that furnished the isomeric central segments with excellent selectivity. The lexicon of catalytic transformations used to make the required cyclization precursors comprised a titanium-mediated ester methylenation/metathesis cascade, a rare example of a gold-catalyzed allylic substitution, and chain extensions via organocatalytic asymmetric aldehyde propargylation. A wing sector to be attached to the isomeric cores was obtained by Krische allylation, followed by a superbly selective cobalt-catalyzed oxidative cyclization of the resulting di-unsaturated alcohol with the formation of a 2,5-trans-disubstituted tetrahydrofuran; the remaining terminal alkene was elaborated into an appropriate handle for fragment coupling by platinum-catalyzed asymmetric diboration/oxidation. The assembly of the different building blocks to the envisaged isomeric target compounds proved that the structure of prorocentin needs to be revised as disclosed herein.
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3
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Gribble GW. Naturally Occurring Organohalogen Compounds-A Comprehensive Review. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2023; 121:1-546. [PMID: 37488466 DOI: 10.1007/978-3-031-26629-4_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.
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Affiliation(s)
- Gordon W Gribble
- Department of Chemistry, Dartmouth College, Hanover, NH, 03755, USA.
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4
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Momeni T, Zadsirjan V, Hadi Meshkatalsadat M, Pourmohammadi‐Mahunaki M. Applications of Cobalt‐Catalyzed Reactions in the Total Synthesis of Natural Products. ChemistrySelect 2022. [DOI: 10.1002/slct.202202816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tayebeh Momeni
- Department of Chemistry Qom University of Technology Qom Iran 3718146645
- Department of Chemistry School of Science Alzahra University Vanak Tehran Iran
| | - Vahideh Zadsirjan
- Department of Chemistry Malek Ashtar University of Technology Tehran Iran
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5
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Davies TQ, Kim JY, Fürstner A. Nickel-Catalyzed Enantioselective Coupling of Aldehydes and Electron-Deficient 1,3-Dienes Following an Inverse Regiochemical Course. J Am Chem Soc 2022; 144:18817-18822. [PMID: 36194199 PMCID: PMC9585590 DOI: 10.1021/jacs.2c09328] [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] [Indexed: 11/29/2022]
Abstract
The nickel catalyzed reductive coupling of aldehydes with sorbate esters and related electron-deficient 1,3-dienes are known in the literature to occur at the π-bond proximal to the ester to afford aldol-type products. In stark contrast to this established path, a VAPOL-derived phosphoramidite ligand in combination with a bench-stable nickel precatalyst brokers a regiocomplementary course in that C-C bond formation proceeds exclusively at the distal alkene site to give deoxypropionate type products carrying an acrylate handle; they can be made in either anti- or syn-configured form. In addition to this enabling reverse pathway, the reaction is distinguished by excellent levels of chemo-, diastereo-, and enantioselectivity; moreover, it can be extended to the catalytic formation of F3C-substituted stereogenic centers. The use of a dienyl pinacolboronate instead of a sorbate ester is also possible, which opens access to valuable chiral borylated building blocks in optically active form.
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Affiliation(s)
- Thomas Q Davies
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Jae Yeon Kim
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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6
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García-Domínguez P, de Lera AR. Puzzling Out the Structure of Novofumigatamide: Total Synthesis of Constitutional Isomers. Part II. J Org Chem 2022; 87:12528-12546. [PMID: 36129245 PMCID: PMC9552235 DOI: 10.1021/acs.joc.2c01228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
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The total synthesis
of several constitutional isomers
showing a
different connectivity of the macrolactam ring with the hexahydropyrrolo[2,3-b]indole core, as well as those arising from the positional
exchange of the valine and the anthranilate units of the structure
originally proposed for (−)-novofumigatamide, has been carried
out. The constitutional isomers with 12-membered ring macrolactam
connected with the pyrroloindoline framework through the indole nitrogen,
and the acetyl group at the pyrrole nitrogen, of endo relative configuration, were prepared through the condensation between
the tryptophan and valine edges derived from l- or d-tryptophan and l-valine amino acids. The corresponding exo products are highly unstable structures difficult to
isolate and characterize. A second group of isomeric structures synthesized
considered the positional exchange between the valine and the anthranilate
residues within the macrolactam ring in the originally proposed macrocyclic
structure. Comparison of the spectroscopic data allowed us to discard
these alternative structures for the natural product.
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7
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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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8
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Späth G, Fürstner A. Total Synthesis of Mycinamicin IV as Integral Part of a Collective Approach to Macrolide Antibiotics. Chemistry 2021; 28:e202104400. [PMID: 34910333 PMCID: PMC9305142 DOI: 10.1002/chem.202104400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Indexed: 11/09/2022]
Abstract
The total synthesis of the 16‐membered macrolide mycinamicin IV is outlined, which complements our previously disclosed, largely catalysis‐based route to the aglycone. This work must also be seen in the context of our recent conquest of aldgamycin N, a related antibiotic featuring a similar core but a distinctly different functionalization pattern. Taken together, these projects prove that the underlying blueprint is integrative and hence qualifies for a collective approach to this prominent class of natural products. In both cases, the final glycosylation phase mandated close attention and was accomplished only after robust de novo syntheses of the (di)deoxy sugars of the desosamine, chalcose, mycinose and aldgarose types had been established. Systematic screening of the glycosidation promoter was also critically important for success.
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Affiliation(s)
- Georg Späth
- Max-Planck-Institut für Kohlenforschung, Organometallic Chemistry, 45470, Mülheim/Ruhr, GERMANY
| | - Alois Fürstner
- Max-Planck-Institut fur Kohlenforschung, Organometallic Chemistry, Kaiser-Wilhelm-Platz 1, 45470, Mülheim/Ruhr, GERMANY
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9
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Schmidt AC, Hiersemann M. Total Synthesis and Structural Assignment of (-)-Fusaequisin A. Chemistry 2021; 28:e202103558. [PMID: 34762322 PMCID: PMC9299783 DOI: 10.1002/chem.202103558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Indexed: 11/09/2022]
Abstract
(-)-Fusaequisin A is an irregularly assembled polyketide isolated from the ascomycete Fusarium equiseti. Fusaequisin A shares a carbon backbone with curvicollide C from the ascomycete Podospora curvicolla but its absolute configuration remained hitherto unsettled. Herein, we document the total synthesis of (-)-fusaequisin A and its 4-O-desmethyl derivative following a central-to-lateral building block strategy. Catalytic asymmetric Claisen rearrangement, Julia-Kocienski olefination and olefin cross-metathesis served as key C/C-connecting transformations. The constitution and absolute configuration of (-)-fusaequisin A was deduced and the original structural assignment was adjusted.
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Affiliation(s)
- Ann-Christin Schmidt
- Fakultät für Chemie und Chemische Biologie, TU Dortmund, 44227, Dortmund, Germany
| | - Martin Hiersemann
- Fakultät für Chemie und Chemische Biologie, TU Dortmund, 44227, Dortmund, Germany
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10
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Davies TQ, Murphy JJ, Dousset M, Fürstner A. Nickel-Catalyzed Enantioselective Synthesis of Pre-Differentiated Homoallylic syn- or anti-1,2-Diols from Aldehydes and Dienol Ethers. J Am Chem Soc 2021; 143:13489-13494. [PMID: 34410708 PMCID: PMC8414482 DOI: 10.1021/jacs.1c07042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Nickel catalysis
allied with cyclodiphosphazane or VAPOL-derived
phosphoramidite ligands provides selective access to monoprotected
vicinal diols by reductive coupling of dienol ethers and aldehydes.
The observed regioselectivity is unprecedented, in that the diene
reacts at the least nucleophilic and most hindered C atom that is
attached to the oxygen substituent rather than at the terminal position.
Notably, both syn and anti diastereomers
of the products can be accessed depending on the configuration of
the diene partner with usually excellent diastereo- and enantioselectivity.
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Affiliation(s)
- Thomas Q Davies
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - John J Murphy
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Maxime Dousset
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany
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11
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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: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [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 Bu3SnH in the presence of [Cp*RuCl]4 as the catalyst. The addition follows a stereochemically unorthodox trans‐selective course; in terms of regioselectivity, the Bu3Sn‐ 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 Bu3Sn‐ 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 Kohlenforschung, 45470, Mülheim an der RuhrMülheim/Ruhr, Germany
| | - Tomas J Saiegh
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der RuhrMülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der RuhrMülheim/Ruhr, Germany
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12
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Ohta M, Kato S, Sugai T, Fuwa H. Cobalt-Catalyzed Hartung-Mukaiyama Cyclization of γ-Hydroxy Olefins: Stereocontrolled Synthesis of the Tetrahydrofuran Moiety of Amphidinolide N. J Org Chem 2021; 86:5584-5615. [PMID: 33769047 DOI: 10.1021/acs.joc.1c00085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Cobalt-catalyzed Mukaiyama-type cyclization of γ-hydroxy olefins is known as an atom- and step-economical means for stereoselective synthesis of 2,5-trans-substituted tetrahydrofuran derivatives. In this study, we investigated the synthesis of a series of 2,5-substituted tetrahydrofuran derivatives by means of a cobalt-catalyzed Hartung-Mukaiyama cyclization. The stereochemical consequence of the reaction was found to be largely dependent on the substitution pattern and relative configuration of γ-hydroxy olefins. 2,5-cis-Substituted tetrahydrofuran derivatives could be obtained diastereoselectively from appropriately substituted γ-hydroxy olefins. Additionally, relatively bulky olefin substituents and unprotected hydroxy groups at non-interfering positions (e.g., α and δ) were well tolerated in the reaction. Finally, the synthetic versatility of the Hartung-Mukaiyama cyclization was demonstrated through a stereocontrolled synthesis of the tetrahydrofuran moiety of amphidinolide N, a potent cytotoxic macrolide of marine origin. This study expands the capacity of Mukaiyama-type cyclization in that it can be used in convergent assembly of complex tetrahydrofuran motifs from internal olefins.
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Affiliation(s)
- Masaki Ohta
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Shota Kato
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Tomoya Sugai
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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13
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Herlé B, Späth G, Schreyer L, Fürstner A. Total Synthesis of Mycinolide IV and Path‐Scouting for Aldgamycin N. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Bart Herlé
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Georg Späth
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Lucas Schreyer
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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14
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Späth G, Fürstner A. Scalable De Novo Synthesis of Aldgarose and Total Synthesis of Aldgamycin N. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Georg Späth
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim/Ruhr Germany
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15
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Herlé B, Späth G, Schreyer L, Fürstner A. Total Synthesis of Mycinolide IV and Path-Scouting for Aldgamycin N. Angew Chem Int Ed Engl 2021; 60:7893-7899. [PMID: 33448619 PMCID: PMC8048839 DOI: 10.1002/anie.202016475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/13/2021] [Indexed: 12/19/2022]
Abstract
Proof-of-concept is provided that a large estate of 16-membered macrolide antibiotics can be reached by a "unified" approach. The key building block was formed on scale by an asymmetric vinylogous Mukaiyama aldol reaction; its alkene terminus was then converted either into the corresponding methyl ketone by Wacker oxidation or into a chain-extended aldehyde by catalyst-controlled branch-selective asymmetric hydroformylation. These transformations ultimately opened access to two structurally distinct series of macrolide targets. Notable late-stage maneuvers comprise a rare example of a ruthenium-catalyzed redox isomerization of an 1,3-enyne-5-ol into a 1,3-diene-5-one derivative, as well as the elaboration of a tertiary propargylic alcohol into an acyloin by trans-hydrostannation/Chan-Lam-type coupling. Moreover, this case study illustrates the underutilized possibility of forging complex macrolactone rings by transesterification under essentially neutral conditions.
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Affiliation(s)
- Bart Herlé
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Georg Späth
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Lucas Schreyer
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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16
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Späth G, Fürstner A. Scalable De Novo Synthesis of Aldgarose and Total Synthesis of Aldgamycin N. Angew Chem Int Ed Engl 2021; 60:7900-7905. [PMID: 33448589 PMCID: PMC8048874 DOI: 10.1002/anie.202016477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/13/2021] [Indexed: 12/25/2022]
Abstract
Since the accompanying study had shown that the introduction of the eponymous aldgarose sugar to the C5-OH group of the macrocyclic aglycone of aldgamycin N is most difficult, if not even impossible, the synthesis route was revised and the glycosidation performed at an earlier stage. To mitigate the "cost" of this strategic amendment, a practical and scalable de novo synthesis of this branched octose was developed. The glycoside formation required mild conditions; it commenced with the reaction of the aglycone with the trichloroacetimidate donor to give a transient orthoester, which slowly rearranged to the desired aldgaropyranoside. The presence of the polar peripheral groups in the product did not impede the selective late-stage functionalization of the macrolide ring itself: the contained propargylic alcohol entity was readily transformed into the characteristic acyloin motif of the target by a ruthenium-catalyzed trans-hydrostannation followed by a modified Chan-Lam-type coupling.
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Affiliation(s)
- Georg Späth
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung45470Mülheim/RuhrGermany
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17
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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: 2.7] [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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18
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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: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [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)
- Lorenz E Löffler
- 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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19
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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: 28] [Impact Index Per Article: 9.3] [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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20
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Fuwa H. Structure determination, correction, and disproof of marine macrolide natural products by chemical synthesis. Org Chem Front 2021. [DOI: 10.1039/d1qo00481f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Integration of chemical synthesis, NMR spectroscopy, and various analytical means is key to success in the structure elucidation of stereochemically complex marine macrolide natural products.
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Affiliation(s)
- Haruhiko Fuwa
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Chuo University
- Tokyo 112-8551
- Japan
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21
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Kato S, Mizukami D, Sugai T, Tsuda M, Fuwa H. Total synthesis and complete configurational assignment of amphirionin-2. Chem Sci 2020; 12:872-879. [PMID: 34163854 PMCID: PMC8179035 DOI: 10.1039/d0sc06021f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Amphirionin-2 is a linear polyketide metabolite that exhibits potent and selective cytotoxic activity against certain human cancer cell lines. We disclose herein the first total synthesis of amphirionin-2 and determination of its absolute configuration. Our synthesis featured an extensive use of cobalt-catalyzed Mukaiyama-type cyclization of γ-hydroxy olefins for stereoselective formation of all the tetrahydrofuran rings found in the natural product, and a late-stage Stille-type coupling for convergent assembly of the entire carbon backbone. Four candidate diastereomers of amphirionin-2 were synthesized in a unified, convergent manner, and their spectroscopic/chromatographic properties were compared with those of the authentic material. The present study culminated in the reassignment of the C5/C7 relative configuration, assignment of the C12/C18 relative configuration, and determination of the absolute configuration of amphirionin-2. An extensive application of cobalt-catalyzed Mukaiyama-type cyclization of γ-hydroxy olefins and a late-stage Stille-type reaction enabled syntheses of four diastereomers of amphirionin-2 to establish its absolute configuration.![]()
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Affiliation(s)
- Shota Kato
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Daichi Mizukami
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Tomoya Sugai
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Masashi Tsuda
- Center for Advanced Marine Core Research and Department of Agriculture and Marine Science, Kochi University Nankoku Kochi 783-8502 Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
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22
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Le Vaillant F, Reijerse EJ, Leutzsch M, Cornella J. Dialkyl Ether Formation at High-Valent Nickel. J Am Chem Soc 2020; 142:19540-19550. [PMID: 33143423 PMCID: PMC7677934 DOI: 10.1021/jacs.0c07381] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Indexed: 12/15/2022]
Abstract
In this article, we investigated the I2-promoted cyclic dialkyl ether formation from 6-membered oxanickelacycles originally reported by Hillhouse. A detailed mechanistic investigation based on spectroscopic and crystallographic analysis revealed that a putative reductive elimination to forge C(sp3)-OC(sp3) using I2 might not be operative. We isolated a paramagnetic bimetallic NiIII intermediate featuring a unique Ni2(OR)2 (OR = alkoxide) diamond-like core complemented by a μ-iodo bridge between the two Ni centers, which remains stable at low temperatures, thus permitting its characterization by NMR, EPR, X-ray, and HRMS. At higher temperatures (>-10 °C), such bimetallic intermediate thermally decomposes to afford large amounts of elimination products together with iodoalkanols. Observation of the latter suggests that a C(sp3)-I bond reductive elimination occurs preferentially to any other challenging C-O bond reductive elimination. Formation of cyclized THF rings is then believed to occur through cyclization of an alcohol/alkoxide to the recently forged C(sp3)-I bond. The results of this article indicate that the use of F+ oxidants permits the challenging C(sp3)-OC(sp3) bond formation at a high-valent nickel center to proceed in good yields while minimizing deleterious elimination reactions. Preliminary investigations suggest the involvement of a high-valent bimetallic NiIII intermediate which rapidly extrudes the C-O bond product at remarkably low temperatures. The new set of conditions permitted the elusive synthesis of diethyl ether through reductive elimination, a remarkable feature currently beyond the scope of Ni.
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Affiliation(s)
- Franck Le Vaillant
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Edward J. Reijerse
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34−36, Mülheim an der Ruhr 45470, Germany
| | - Markus Leutzsch
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Josep Cornella
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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23
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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: 2.8] [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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24
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Chan HSS, Thompson AL, Christensen KE, Burton JW. Forwards and backwards - synthesis of Laurencia natural products using a biomimetic and retrobiomimetic strategy incorporating structural reassignment of laurefurenynes C-F. Chem Sci 2020; 11:11592-11600. [PMID: 34094406 PMCID: PMC8162873 DOI: 10.1039/d0sc04120c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/25/2020] [Indexed: 11/26/2022] Open
Abstract
Laurefurenynes C-F are four natural products isolated from Laurencia species whose structures were originally determined on the basis of extensive nuclear magnetic resonance experiments. On the basis of a proposed biogenesis, involving a tricyclic oxonium ion as a key intermediate, we have reassigned the structures of these four natural products and synthesized the four reassigned structures using a biomimetic approach demonstrating that they are the actual structures of the natural products. In addition, we have developed a synthesis of the enantiomers of the natural products laurencin and deacetyllaurencin from the enantiomer of (E)-laurefucin using an unusual retrobiomimetic strategy. All of these syntheses have been enabled by the use of tricyclic oxonium ions as pivotal synthetic intermediates.
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Affiliation(s)
- Hau Sun Sam Chan
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Amber L Thompson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Kirsten E Christensen
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Jonathan W Burton
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK
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25
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Hubert P, Seibel E, Beemelmanns C, Campagne J, Figueiredo RM. Stereoselective Construction of (
E,Z
)‐1,3‐Dienes and Its Application in Natural Product Synthesis. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000730] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Pierre Hubert
- ICGM Univ Montpellier, CNRS, ENSCM Montpellier France
| | - Elena Seibel
- Hans-Knöll-Institute (HKI) Beutenbergstrasse 11a 07745 Jena Germany
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26
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Zheng K, Hong R. Postulated Biogenesis-Guided Total Synthesis and Structural Revision of 2,18-seco-Lankacidinol A. Org Lett 2020; 22:3785-3788. [DOI: 10.1021/acs.orglett.0c00993] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Kuan Zheng
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Ran Hong
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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