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Steinborn C, Huber T, Lichtenegger J, Plangger I, Höfler D, Schnell SD, Weisheit L, Mayer P, Wurst K, Magauer T. Synthesis of Waixenicin A: Exploring Strategies for Nine-Membered Ring Formation. Chemistry 2024; 30:e202303489. [PMID: 37942708 PMCID: PMC7615592 DOI: 10.1002/chem.202303489] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/10/2023]
Abstract
We present a comprehensive account on our efforts behind the recently published synthesis of waixenicin A. Our approach for constructing the dihydropyran ring relied on an Achmatowicz rearrangement. For the assembly of the nine-membered ring, four distinct strategies were investigated. Our initial attempts using radical-based addition/fragmentation reactions targeting the C7-C11 bond proved unsuitable for accessing the 6/9-bicycle. By employing anionic fragmentation conditions at the furfuryl alcohol stage, we successfully reached a 5/9-bicycle. However, subsequent ring-expansion was unsuccessful. Alternative approaches, such as Nozaki-Hiyama-Kishi or Heck reactions to connect the C6-C7 bond, also encountered difficulties, with no nine-membered ring formation observed. Our first breakthrough came from our attempts to install the C5-C6 bond via an intramolecular alkylation. Surprisingly, subsequent functional group modifications proved unexpectedly challenging, necessitating a redesign of our synthetic route. Drawing from all our investigations, we concluded that construction of the C9-C10 bond would enable efficient nine-membered ring alkylation and would facilitate the installation of the desired substitution pattern along the southern periphery. Exploration of this strategy yielded further surprises but ultimately led to the successful synthesis of waixenicin A and 9-deacetoxy-14,15-deepoxyxeniculin. For the latter compound, a bioinspired one-step rearrangement to xeniafauranol A was achieved.
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Affiliation(s)
- Christian Steinborn
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Tatjana Huber
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Julian Lichtenegger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Immanuel Plangger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Denis Höfler
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Simon D Schnell
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Lara Weisheit
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Peter Mayer
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Klaus Wurst
- Institute of General, Inorganic & Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - Thomas Magauer
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
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2
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Steinborn C, Huber T, Lichtenegger J, Plangger I, Wurst K, Magauer T. Total Syntheses of (+)-Waixenicin A, (+)-9-Deacetoxy-14,15-deepoxyxeniculin, and (-)-Xeniafaraunol A. J Am Chem Soc 2023; 145:11811-11817. [PMID: 37192136 DOI: 10.1021/jacs.3c03366] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The first asymmetric total synthesis of the Xenia diterpenoid waixenicin A, a potent and highly selective TRPM7 inhibitor, is reported. The characteristic trans-fused oxabicyclo[7.4.0]tridecane ring system was constructed via a diastereoselective conjugate addition/trapping sequence, followed by an intramolecular alkylation to forge the 9-membered ring. While a β-keto sulfone motif enabled efficient ring-closure, the subsequent radical desulfonylation suffered from (E)/(Z)-isomerization of the C7/C8-alkene. Conducting the sequence with a trimethylsilylethyl ester allowed for a fluoride-mediated decarboxylation that proceeded without detectable isomerization. The acid-labile enol acetal of the delicate dihydropyran core was introduced at an early stage and temporarily deactivated by a triflate function. The latter was critical for the introduction of the side chain. Diverting from a common late-stage intermediate provided access to waixenicin A and 9-deacetoxy-14,15-deepoxyxeniculin. A high-yielding base-mediated dihydropyran-cyclohexene rearrangement of 9-deacetoxy-14,15-deepoxyxeniculin led to xeniafaraunol A in one step.
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Affiliation(s)
- Christian Steinborn
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Tatjana Huber
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Julian Lichtenegger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Immanuel Plangger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Klaus Wurst
- Institute of General, Inorganic & Theoretical Chemistry, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Thomas Magauer
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
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Tong R, Liu S, Zhao C, Jiang D, Gao L, Wang W, Ye B, Song Z. 3-Silyl-3-Borylhex-4-Enoate: A Chiral Reagent for Asymmetric Crotylboration of Aldehydes. Org Lett 2022; 24:7822-7827. [PMID: 36250588 DOI: 10.1021/acs.orglett.2c03195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A nonracemic 3-silyl-3-borylhex-4-enoate reagent has been developed. Its asymmetric crotylboration of aldehydes provides Z-anti-homoallylic alcohols possessing a trisubstituted vinylsilane in high yields with excellent stereo- and enantioselectivity. Diverse decoration of vinylsilane and ester groups, as well as formation of functionalized THF rings, showcase the potential of the approach in the synthesis of polyketide natural products.
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Affiliation(s)
- Ruiqi Tong
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Song Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Chen Zhao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Dongyang Jiang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Lu Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Wanshu Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Bengui Ye
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Zhenlei Song
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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4
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Ma WW, Yang C, Xie Q, Xu YH. Dienylation of N-benzoylhydrazones with CF 3-substituted homoallenylboronates in water. Org Biomol Chem 2022; 20:1386-1390. [PMID: 35088801 DOI: 10.1039/d1ob02335g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A convenient method for the dienylation of N-benzoylhydrazones in water has been developed. This protocol expanded the synthetic application of functionalized homoallenylboronates to provide the useful 2-aminomethyl-1,3-diene derivatives with high efficiency (up to 99% yield) and stereoselectivity without using any catalyst, additive or inert atmosphere. Furthermore, the transformation of a 2-aminomethyl-1,3-diene derivative to synthesize a functionalized pyrrolidine derivative was also explored.
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Affiliation(s)
- Wei-Wei Ma
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R China.
| | - Chao Yang
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R China.
| | - Qiang Xie
- Department of Nuclear Medicine the First Affiliated Hospital of USTC; the Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, P. R China.
| | - Yun-He Xu
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, P. R China. .,State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R China
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del Corte X, Martínez de Marigorta E, Palacios F, Vicario J, Maestro A. An overview of the applications of chiral phosphoric acid organocatalysts in enantioselective additions to CO and CN bonds. Org Chem Front 2022. [DOI: 10.1039/d2qo01209j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Since 2004, chiral phosphoric acids (CPAs) have emerged as highyl efficient organocatalysts, providing excellent results in a wide reaction scope. In this review, the applications of CPA for enantioselective additions to CO and CN bonds are covered.
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Affiliation(s)
- Xabier del Corte
- Department of Organic Chemistry I, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
| | - Edorta Martínez de Marigorta
- Department of Organic Chemistry I, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
| | - Francisco Palacios
- Department of Organic Chemistry I, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
| | - Javier Vicario
- Department of Organic Chemistry I, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
| | - Aitor Maestro
- Department of Organic Chemistry I, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
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Berger M, Carboni D, Melchiorre P. Photochemical Organocatalytic Regio- and Enantioselective Conjugate Addition of Allyl Groups to Enals. Angew Chem Int Ed Engl 2021; 60:26373-26377. [PMID: 34695283 PMCID: PMC9298816 DOI: 10.1002/anie.202111648] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/18/2021] [Indexed: 11/18/2022]
Abstract
We report the first catalytic enantioselective conjugate addition of allyl groups to α,β‐unsaturated aldehydes. The chemistry exploits the visible‐light‐excitation of chiral iminium ions to activate allyl silanes towards the formation of allylic radicals, which are then intercepted stereoselectively. The underlying radical mechanism of this process overcomes the poor regio‐ and chemoselectivity that traditionally affects the conjugate allylation of enals proceeding via polar pathways. We also demonstrate how this organocatalytic strategy could selectively install a valuable prenyl fragment at the β‐carbon of enals.
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Affiliation(s)
- Martin Berger
- ICIQ-Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain
| | - Davide Carboni
- ICIQ-Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain
| | - Paolo Melchiorre
- ICREA-Passeig Lluís Companys 23, 08010, Barcelona, Spain.,ICIQ-Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avenida Països Catalans 16, 43007, Tarragona, Spain
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7
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Berger M, Carboni D, Melchiorre P. Photochemical Organocatalytic Regio‐ and Enantioselective Conjugate Addition of Allyl Groups to Enals. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111648] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Martin Berger
- ICIQ—Institute of Chemical Research of Catalonia the Barcelona Institute of Science and Technology Avenida Països Catalans 16 43007 Tarragona Spain
| | - Davide Carboni
- ICIQ—Institute of Chemical Research of Catalonia the Barcelona Institute of Science and Technology Avenida Països Catalans 16 43007 Tarragona Spain
| | - Paolo Melchiorre
- ICREA—Passeig Lluís Companys 23 08010 Barcelona Spain
- ICIQ—Institute of Chemical Research of Catalonia the Barcelona Institute of Science and Technology Avenida Països Catalans 16 43007 Tarragona Spain
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8
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Xie YW, Zhao ZN, Lin ZW, Wang YH, Liu YQ, Huang YY. Asymmetric Petasis reaction for the synthesis of chiral α- and β-butadienyl amines. Chem Commun (Camb) 2021; 57:2364-2367. [PMID: 33533779 DOI: 10.1039/d0cc08241d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Petasis reaction using (1S,2R)-1-amino-2-indanol as the substrate and an activator to construct α- and β-butadienyl amines in optically pure forms was realized, which are otherwise difficult to prepare. The reactions feature a metal-free nature, broad substrate scope, complete regioselectivities (γ-selectivity of pinacol homoallenyl- and isoprenylboronates), and high to excellent chirality induction (up to >20 : 1 dr). The favored nucleophilic addition across the Si-face of the imine intermediate was explained using DFT calculations of the six-membered chair-like transition state.
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Affiliation(s)
- Yi-Wen Xie
- Department of Chemistry, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China.
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