1
|
Essayan DE, Schubach MJ, Smoot JM, Puri T, Pronin SV. Directed Hydrogen Atom Transfer for Selective Reactions of Polyenols. J Am Chem Soc 2024; 146:18224-18229. [PMID: 38917421 DOI: 10.1021/jacs.4c06601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Directed hydrogen atom transfer to alkenes is described. The process is catalyzed by iron complexes and allows for the site-selective hydrofunctionalization of polyenols. Experimental data suggest that coordination of the hydroxy group to the iron hydride intermediate plays an important role in preferential engagement of the allylic alcohol motif and provides a new basis for selectivity in radical hydrofunctionalization events. As a proof of concept, β- and γ-amino alcohols are prepared from the corresponding polyenols in a selective manner.
Collapse
Affiliation(s)
- Daniel E Essayan
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Matthew J Schubach
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Jeanelle M Smoot
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Taranee Puri
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Sergey V Pronin
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| |
Collapse
|
2
|
Yi J, He M, Zhang Y, Yu P, Xie X, Li H, She X. Total Syntheses of (±)-Acetoxymarsupellone and (±)-Marsupellins A, B, and D Enabled by a Reductive Cyclization and Semipinacol Rearrangement Strategy. Org Lett 2024; 26:5146-5150. [PMID: 38857062 DOI: 10.1021/acs.orglett.4c01572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
We report herein the total syntheses of three marsupellin-family sesquiterpenoids, (±)-acetoxymarsupellone and (±)-marsupellins B and D, in 14-19 steps from our known precursor, making marsupellin A also accessible from marsupellin B through a known procedure. The critical tricyclic framework bearing the challenging C7 bridgehead all-carbon quaternary center is strategically constructed through a Ti-mediated reductive cyclization and semipinacol rearrangement sequence. This study provides a general approach to the syntheses of (ent-)longipinane-type molecules.
Collapse
Affiliation(s)
- Jiuzhou Yi
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 Gansu, P. R. China
| | - Min He
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 Gansu, P. R. China
| | - Yan Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 Gansu, P. R. China
| | - Pengfei Yu
- 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
| | - Xuegong She
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 Gansu, P. R. China
| |
Collapse
|
3
|
Wiesler S, Sennari G, Popescu MV, Gardner KE, Aida K, Paton RS, Sarpong R. Late-stage benzenoid-to-troponoid skeletal modification of the cephalotanes exemplified by the total synthesis of harringtonolide. Nat Commun 2024; 15:4125. [PMID: 38750061 PMCID: PMC11096412 DOI: 10.1038/s41467-024-48586-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Accepted: 05/07/2024] [Indexed: 05/18/2024] Open
Abstract
Skeletal modifications enable elegant and rapid access to various derivatives of a compound that would otherwise be difficult to prepare. They are therefore a powerful tool, especially in the synthesis of natural products or drug discovery, to explore different natural products or to improve the properties of a drug candidate starting from a common intermediate. Inspired by the biosynthesis of the cephalotane natural products, we report here a single-atom insertion into the framework of the benzenoid subfamily, providing access to the troponoid congeners - representing the reverse of the proposed biosynthesis (i.e., a contra-biosynthesis approach). Computational evaluation of our designed transformation prompted us to investigate a Büchner-Curtius-Schlotterbeck reaction of a p-quinol methylether, which ultimately results in the synthesis of harringtonolide in two steps from cephanolide A, which we had previously prepared. Additional computational studies reveal that unconventional selectivity outcomes are driven by the choice of a Lewis acid and the nucleophile, which should inform further developments of these types of reactions.
Collapse
Affiliation(s)
- Stefan Wiesler
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Goh Sennari
- Department of Chemistry, University of California, Berkeley, California, USA
- Ōmura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, Japan
| | - Mihai V Popescu
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado, USA
| | - Kristen E Gardner
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Kazuhiro Aida
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Robert S Paton
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado, USA.
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, California, USA.
| |
Collapse
|
4
|
Sennari G, Yamagishi H, Sarpong R. Remote C-H Amination and Alkylation of Camphor at C8 through Hydrogen-Atom Abstraction. J Am Chem Soc 2024; 146:7850-7857. [PMID: 38447162 DOI: 10.1021/jacs.4c01351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Camphor continues to serve as a versatile chiral building block for chemical synthesis. We have developed a novel method to functionalize the camphor skeleton at C8 using an intramolecular hydrogen atom abstraction. The key advance involves the use of a camphor-derived aminonitrile, which is converted to the corresponding nitrogen-centered radical under photoredox conditions to effect the 1,5-hydrogen atom transfer at C8. The resulting carbon-centered radical at C8 was utilized in a C-H amination to access topologically complex proline derivatives. Furthermore, the total synthesis of several sesquiterpenoids was accomplished by engaging the radical generated at C8 in alkylation reactions.
Collapse
Affiliation(s)
- Goh Sennari
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- O̅mura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hiroki Yamagishi
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| |
Collapse
|
5
|
Fay N, Kouklovsky C, de la Torre A. Natural Product Synthesis: The Endless Quest for Unreachable Perfection. ACS ORGANIC & INORGANIC AU 2023; 3:350-363. [PMID: 38075446 PMCID: PMC10704578 DOI: 10.1021/acsorginorgau.3c00040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/24/2023] [Accepted: 09/25/2023] [Indexed: 06/13/2024]
Abstract
Total synthesis is a field in constant progress. Its practitioners aim to develop ideal synthetic strategies to build complex molecules. As such, they are both a driving force and a showcase of the progress of organic synthesis. In this Perspective, we discuss recent notable total syntheses. The syntheses selected herein are classified according to the key strategic considerations for each approach.
Collapse
Affiliation(s)
- Nicolas Fay
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
| | - Cyrille Kouklovsky
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
| | - Aurélien de la Torre
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 17 Avenue des Sciences, 91405 Orsay, France
| |
Collapse
|
6
|
Lavernhe R, Domke P, Wang Q, Zhu J. Enantioselective Total Synthesis of (-)-Artatrovirenol A. J Am Chem Soc 2023; 145:24408-24415. [PMID: 37874878 DOI: 10.1021/jacs.3c09683] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
We report herein an enantioselective total synthesis of (-)-artatrovirenol A, a structurally unprecedented cage-like sesquiterpenoid. The synthesis features the following key steps: (a) cationic chiral oxazaborolidinium-catalyzed Diels-Alder reaction between isoprene and ethyl (E)-5-((tert-butyldimethylsilyl)oxy)-4-oxopent-2-enoate for the rapid synthesis of an enantioenriched 10-carbon bicyclic lactone; (b) union of two enantioenriched fragments by a diastereoselective Mukaiyama-Michael addition for the convergent assembly of an intermediate with all 15 carbons of the natural product; (c) intramolecular de Mayo [2 + 2] cycloaddition/retro-aldol sequence transforming a bicyclic compound to a tetracyclic one with concomitant generation of a five- and a seven-membered ring; (d) Lewis acid-triggered intramolecular ring opening of epoxide generating the norbornane substructure; and (e) Chugaev elimination converting the norbornane to the more strained norbornene.
Collapse
Affiliation(s)
- Rémi Lavernhe
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| | - Patrick Domke
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| | - Qian Wang
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| | - Jieping Zhu
- Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland
| |
Collapse
|
7
|
Bakanas I, Lusi RF, Wiesler S, Hayward Cooke J, Sarpong R. Strategic application of C-H oxidation in natural product total synthesis. Nat Rev Chem 2023; 7:783-799. [PMID: 37730908 DOI: 10.1038/s41570-023-00534-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2023] [Indexed: 09/22/2023]
Abstract
The oxidation of unactivated C-H bonds has emerged as an effective tactic in natural product synthesis and has altered how chemists approach the synthesis of complex molecules. The use of C-H oxidation methods has simplified the process of synthesis planning by expanding the choice of starting materials, limiting functional group interconversion and protecting group manipulations, and enabling late-stage diversification. In this Review, we propose classifications for C-H oxidations on the basis of their strategic purpose: type 1, which installs functionality that is used to establish the carbon skeleton of the target; type 2, which is used to construct a heterocyclic ring; and type 3, which installs peripheral functional groups. The reactions are further divided based on whether they are directed or undirected. For each classification, examples from recent literature are analysed. Finally, we provide two case studies of syntheses from our laboratory that were streamlined by the judicious use of C-H oxidation reactions.
Collapse
Affiliation(s)
- Ian Bakanas
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Robert F Lusi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Stefan Wiesler
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Jack Hayward Cooke
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
| |
Collapse
|
8
|
Ricca M, Yao S, Le T, White JM, Donnelly PS, Rizzacasa MA. A cis-β-iron(III) SALPN catalyst for hydrogen atom transfer reductions and olefin cross couplings. Org Biomol Chem 2023; 21:6789-6793. [PMID: 37566401 DOI: 10.1039/d3ob01085f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
An inexpensive Fe(III) SALPN catalyst for MHAT reactions such as reductions of α,β-unsaturated carbonyl compounds and olefin cross couplings is reported. The majority of these reactions proceeded in good yields and high stereoselectivities with low catalyst loadings at room temperature.
Collapse
Affiliation(s)
- Michael Ricca
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| | - Shaolei Yao
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| | - Tommy Le
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| | - Jonathan M White
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| | - Paul S Donnelly
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| | - Mark A Rizzacasa
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia.
| |
Collapse
|
9
|
Abstract
Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N-O•. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R1 and R2 prevents nitroxide radical dimerization, ensuring their kinetic stability. Despite their reactivity toward various transient C radicals, some nitroxides can be easily stored under air at room temperature. Furthermore, nitroxides can be oxidized to oxoammonium salts (R1R2N═O+) or reduced to anions (R1R2N-O-), enabling them to act as valuable oxidants or reductants depending on their oxidation state. Therefore, they exhibit interesting reactivity across all three oxidation states. Due to these fascinating properties, nitroxides find extensive applications in diverse fields such as biochemistry, medicinal chemistry, materials science, and organic synthesis. This review focuses on the versatile applications of nitroxides in organic synthesis. For their use in other important fields, we will refer to several review articles. The introductory part provides a brief overview of the history of nitroxide chemistry. Subsequently, the key methods for preparing nitroxides are discussed, followed by an examination of their structural diversity and physical properties. The main portion of this review is dedicated to oxidation reactions, wherein parent nitroxides or their corresponding oxoammonium salts serve as active species. It will be demonstrated that various functional groups (such as alcohols, amines, enolates, and alkanes among others) can be efficiently oxidized. These oxidations can be carried out using nitroxides as catalysts in combination with various stoichiometric terminal oxidants. By reducing nitroxides to their corresponding anions, they become effective reducing reagents with intriguing applications in organic synthesis. Nitroxides possess the ability to selectively react with transient radicals, making them useful for terminating radical cascade reactions by forming alkoxyamines. Depending on their structure, alkoxyamines exhibit weak C-O bonds, allowing for the thermal generation of C radicals through reversible C-O bond cleavage. Such thermally generated C radicals can participate in various radical transformations, as discussed toward the end of this review. Furthermore, the application of this strategy in natural product synthesis will be presented.
Collapse
Affiliation(s)
- Dirk Leifert
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| |
Collapse
|
10
|
Call A, Cianfanelli M, Besalú-Sala P, Olivo G, Palone A, Vicens L, Ribas X, Luis JM, Bietti M, Costas M. Carboxylic Acid Directed γ-Lactonization of Unactivated Primary C-H Bonds Catalyzed by Mn Complexes: Application to Stereoselective Natural Product Diversification. J Am Chem Soc 2022; 144:19542-19558. [PMID: 36228322 DOI: 10.1021/jacs.2c08620] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions that enable selective functionalization of strong aliphatic C-H bonds open new synthetic paths to rapidly increase molecular complexity and expand chemical space. Particularly valuable are reactions where site-selectivity can be directed toward a specific C-H bond by catalyst control. Herein we describe the catalytic site- and stereoselective γ-lactonization of unactivated primary C-H bonds in carboxylic acid substrates. The system relies on a chiral Mn catalyst that activates aqueous hydrogen peroxide to promote intramolecular lactonization under mild conditions, via carboxylate binding to the metal center. The system exhibits high site-selectivity and enables the oxidation of unactivated primary γ-C-H bonds even in the presence of intrinsically weaker and a priori more reactive secondary and tertiary ones at α- and β-carbons. With substrates bearing nonequivalent γ-C-H bonds, the factors governing site-selectivity have been uncovered. Most remarkably, by manipulating the absolute chirality of the catalyst, γ-lactonization at methyl groups in gem-dimethyl structural units of rigid cyclic and bicyclic carboxylic acids can be achieved with unprecedented levels of diastereoselectivity. Such control has been successfully exploited in the late-stage lactonization of natural products such as camphoric, camphanic, ketopinic, and isoketopinic acids. DFT analysis points toward a rebound type mechanism initiated by intramolecular 1,7-HAT from a primary γ-C-H bond of the bound substrate to a highly reactive MnIV-oxyl intermediate, to deliver a carbon radical that rapidly lactonizes through carboxylate transfer. Intramolecular kinetic deuterium isotope effect and 18O labeling experiments provide strong support to this mechanistic picture.
Collapse
Affiliation(s)
- Arnau Call
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Marco Cianfanelli
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Giorgio Olivo
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Andrea Palone
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain.,Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata", Via della Ricerca Scientifica 1, I-00133 Rome, Italy
| | - Laia Vicens
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Xavi Ribas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| | - Massimo Bietti
- Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata", Via della Ricerca Scientifica 1, I-00133 Rome, Italy
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17003, Catalonia, Spain
| |
Collapse
|