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Hu C, Mena J, Alabugin IV. Design principles of the use of alkynes in radical cascades. Nat Rev Chem 2023:10.1038/s41570-023-00479-w. [PMID: 37117812 DOI: 10.1038/s41570-023-00479-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2023] [Indexed: 03/30/2023]
Abstract
One of the simplest organic functional groups, the alkyne, offers a broad canvas for the design of cascade transformations in which up to three new bonds can be added to each of the two sterically unencumbered, energy-rich carbon atoms. However, kinetic protection provided by strong π-orbital overlap makes the design of new alkyne transformations a stereoelectronic puzzle, especially on multifunctional substrates. This Review describes the electronic properties contributing to the unique utility of alkynes in radical cascades. We describe how to control the selectivity of alkyne activation by various methods, from dynamic covalent chemistry with kinetic self-sorting to disappearing directing groups. Additionally, we demonstrate how the selection of reactive intermediates directly influences the propagation and termination of the cascade. Diverging from a common departure point, a carefully planned reaction route can allow access to a variety of products.
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2
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Watson HA, Fielding AJ, Hale KJ. EPR evidence for α-triphenylstannylvinyl radicals in the O-directed hydrostannation of dialkylacetylenes with Ph 3SnH/cat. Et 3B/O 2. Chem Commun (Camb) 2021; 57:7449-7452. [PMID: 34235526 DOI: 10.1039/d1cc01702k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we provide definitive EPR evidence for the existence of α-triphenylstannylvinyl radicals in the low temperature O-directed free radical hydrostannation of dialkyl propargylic alcohols with Ph3SnH/cat. Et3B and O2 in PhMe. Isotropic hyperfine splitting patterns and spectral simulations confirm the assignments made. In the case of the α-triphenylstannylvinyl radical (Z)-2, an isotopic 119/117Sn hyperfine coupling constant of 9.5 mT (95 G) was measured along with a 1Hβ hyperfine coupling constant of 1.1 mT.
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Affiliation(s)
- Hamish A Watson
- The School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK.
| | - Alistair J Fielding
- The School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
| | - Karl J Hale
- The School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK.
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3
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The stannylvinyl cation that never was! New concentration- and temperature-dependent probe studies confirm an entirely free radical mechanism and O–Sn coordinative control of the hydrostannation of propargylically-oxygenated dialkyl acetylenes with stannanes and cat. Et3B. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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4
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Gonzalez-Rodriguez E, Abdo MA, Dos Passos Gomes G, Ayad S, White FD, Tsvetkov NP, Hanson K, Alabugin IV. Twofold π-Extension of Polyarenes via Double and Triple Radical Alkyne peri-Annulations: Radical Cascades Converging on the Same Aromatic Core. J Am Chem Soc 2020; 142:8352-8366. [PMID: 32249571 DOI: 10.1021/jacs.0c01856] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A versatile synthetic route to distannyl-substituted polyarenes was developed via double radical peri-annulations. The cyclization precursors were equipped with propargylic OMe traceless directing groups (TDGs) for regioselective Sn-radical attack at the triple bonds. The two peri-annulations converge at a variety of polycyclic cores to yield expanded difunctionalized polycyclic aromatic hydrocarbons (PAHs). This approach can be extended to triple peri-annulations, where annulations are coupled with a radical cascade that connects two preexisting aromatic cores via a formal C-H activation step. The installed Bu3Sn groups serve as chemical handles for further functionalization via direct cross-coupling, iodination, or protodestannylation and increase solubility of the products in organic solvents. Photophysical studies reveal that the Bu3Sn-substituted PAHs are moderately fluorescent, and their protodestannylation results in an up to 10-fold fluorescence quantum yield enhancement. DFT calculations identified the most likely possible mechanism of this complex chemical transformation involving two independent peri-cyclizations at the central core.
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Affiliation(s)
- Edgar Gonzalez-Rodriguez
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Miguel A Abdo
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Gabriel Dos Passos Gomes
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Suliman Ayad
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Frankie D White
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Nikolay P Tsvetkov
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Kenneth Hanson
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
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5
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Kamimura A, Itaya T, Yoshinaga T, Nozawa R, Kawamoto T, Sumimoto M, Uno H. Highly Cumulated Radical Cascade Reaction of aza-1,6-Enyenes: Stereoselective Synthesis of exo
-Methylene Piperidines. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Akio Kamimura
- Department Applied Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Tomoyuki Itaya
- Department Applied Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Tatsuro Yoshinaga
- Department Applied Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Ryo Nozawa
- Department Applied Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Takuji Kawamoto
- Department Applied Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Michinori Sumimoto
- Department Environmental Chemistry; Yamaguchi University; 755-8611 Ube Japan
| | - Hidemitsu Uno
- Department of Chemistry; Ehime University; 790-8577 Matsuyama Japan
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6
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Diaz-Muñoz G, Miranda IL, Sartori SK, de Rezende DC, Alves Nogueira Diaz M. Use of chiral auxiliaries in the asymmetric synthesis of biologically active compounds: A review. Chirality 2019; 31:776-812. [PMID: 31418934 DOI: 10.1002/chir.23103] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/13/2019] [Accepted: 05/22/2019] [Indexed: 01/16/2023]
Abstract
This review article describes the use of some of the most popular chiral auxiliaries in the asymmetric synthesis of biologically active compounds. Chiral auxiliaries derived from naturally occurring compounds, such as amino acids, carbohydrates, and terpenes, are considered essential tools for the construction of highly complex molecules. We highlight the auxiliaries of Evans, Corey, Yamada, Enders, Oppolzer, and Kunz, which led to remarkable progress in asymmetric synthesis in the last decades and continue to bring advances until the present day.
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Affiliation(s)
- Gaspar Diaz-Muñoz
- Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Izabel Luzia Miranda
- Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Suélen Karine Sartori
- Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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7
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Watson HA, Manaviazar S, Steeds HG, Hale KJ. Fast ring-opening of an intermediary α-stannyl-β-cyclopropylvinyl radical does not support formation of an α-stannylvinyl cation in the O-directed free radical hydrostannation of dialkyl acetylenes. Chem Commun (Camb) 2019; 55:14454-14457. [DOI: 10.1039/c9cc05492h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
O-directed hydrostannation of β-cyclopropyl propargyl alcohol 22 with stannanes and cat. Et3B in THF/H2O or PhMe/MeOH fails to deliver any detectable products of α-stannylvinyl cation capture.
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Affiliation(s)
- Hamish A. Watson
- The School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Soraya Manaviazar
- The School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Hannah G. Steeds
- The School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
| | - Karl J. Hale
- The School of Chemistry and Chemical Engineering
- Queen's University Belfast
- Belfast BT9 5AG
- UK
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8
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Hale KJ, Manaviazar S, Watson HA. The O‐Directed Free Radical Hydrostannation of Propargyloxy Dialkyl Acetylenes with Ph3SnH/cat. Et3B. A Refutal of the Stannylvinyl Cation Mechanism. CHEM REC 2018; 19:238-319. [DOI: 10.1002/tcr.201700104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 09/04/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Karl J. Hale
- School of Chemistry and Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB)Queen's University Belfast Stranmillis Road Belfast BT9 5AG, Northern Ireland United Kingdom
| | - Soraya Manaviazar
- School of Chemistry and Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB)Queen's University Belfast Stranmillis Road Belfast BT9 5AG, Northern Ireland United Kingdom
| | - Hamish A. Watson
- School of Chemistry and Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB)Queen's University Belfast Stranmillis Road Belfast BT9 5AG, Northern Ireland United Kingdom
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9
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Huwyler N, Radkowski K, Rummelt SM, Fürstner A. Two Enabling Strategies for the Stereoselective Conversion of Internal Alkynes into Trisubstituted Alkenes. Chemistry 2017; 23:12412-12419. [DOI: 10.1002/chem.201702470] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Nikolas Huwyler
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
| | - Karin Radkowski
- 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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Guchhait S, Chatterjee S, Ampapathi RS, Goswami RK. Total Synthesis of Reported Structure of Baulamycin A and Its Congeners. J Org Chem 2017; 82:2414-2435. [DOI: 10.1021/acs.joc.6b02838] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Sandip Guchhait
- Department
of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Shamba Chatterjee
- Department
of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | | | - Rajib Kumar Goswami
- Department
of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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11
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Doherty W, Adler N, Knox A, Nolan D, McGouran J, Nikalje AP, Lokwani D, Sarkate A, Evans P. Synthesis and Evaluation of 1,2,3-Triazole-Containing Vinyl and Allyl Sulfones as Anti-Trypanosomal Agents. European J Org Chem 2017. [DOI: 10.1002/ejoc.201601221] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- William Doherty
- Centre for Synthesis and Chemical Biology; School of Chemistry; University College Dublin; 4 Dublin Ireland
| | - Nikoletta Adler
- School of Biochemistry and Immunology; Trinity Biomedical Sciences Institute; Trinity College Dublin; Pearse Street 2 Dublin Ireland
| | - Andrew Knox
- School of Biochemistry and Immunology; Trinity Biomedical Sciences Institute; Trinity College Dublin; Pearse Street 2 Dublin Ireland
- School of Biological Sciences; Dublin Institute of Technology; Kevin Street 8 Dublin Ireland
| | - Derek Nolan
- School of Biochemistry and Immunology; Trinity Biomedical Sciences Institute; Trinity College Dublin; Pearse Street 2 Dublin Ireland
| | - Joanna McGouran
- School of Chemistry; Trinity Biomedical Sciences Institute; Trinity College Dublin; Pearse Street 2 Dublin Ireland
| | - Anna Pratima Nikalje
- Y. B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus 431001 Aurangabad Maharashtra India
| | - Deepak Lokwani
- Y. B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus 431001 Aurangabad Maharashtra India
| | - Aniket Sarkate
- Department of Chemical Technology; Dr. Babasaheb Ambedkar Marathwada University; 431004 Aurangabad Maharashtra India
| | - Paul Evans
- Centre for Synthesis and Chemical Biology; School of Chemistry; University College Dublin; 4 Dublin Ireland
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12
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Frihed TG, Fürstner A. Progress in the trans-Reduction and trans-Hydrometalation of Internal Alkynes. Applications to Natural Product Synthesis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2016. [DOI: 10.1246/bcsj.20150317] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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13
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Abstract
This review of simple indolizidine and quinolizidine alkaloids (i.e., those in which the parent bicyclic systems are in general not embedded in polycyclic arrays) is an update of the previous coverage in Volume 55 of this series (2001). The present survey covers the literature from mid-1999 to the end of 2013; and in addition to aspects of the isolation, characterization, and biological activity of the alkaloids, much emphasis is placed on their total synthesis. A brief introduction to the topic is followed by an overview of relevant alkaloids from fungal and microbial sources, among them slaframine, cyclizidine, Steptomyces metabolites, and the pantocins. The important iminosugar alkaloids lentiginosine, steviamine, swainsonine, castanospermine, and related hydroxyindolizidines are dealt with in the subsequent section. The fourth and fifth sections cover metabolites from terrestrial plants. Pertinent plant alkaloids bearing alkyl, functionalized alkyl or alkenyl substituents include dendroprimine, anibamine, simple alkaloids belonging to the genera Prosopis, Elaeocarpus, Lycopodium, and Poranthera, and bicyclic alkaloids of the lupin family. Plant alkaloids bearing aryl or heteroaryl substituents include ipalbidine and analogs, secophenanthroindolizidine and secophenanthroquinolizidine alkaloids (among them septicine, julandine, and analogs), ficuseptine, lasubines, and other simple quinolizidines of the Lythraceae, the simple furyl-substituted Nuphar alkaloids, and a mixed quinolizidine-quinazoline alkaloid. The penultimate section of the review deals with the sizable group of simple indolizidine and quinolizidine alkaloids isolated from, or detected in, ants, mites, and terrestrial amphibians, and includes an overview of the "dietary hypothesis" for the origin of the amphibian metabolites. The final section surveys relevant alkaloids from marine sources, and includes clathryimines and analogs, stellettamides, the clavepictines and pictamine, and bis(quinolizidine) alkaloids.
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14
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Pati K, dos Passos Gomes G, Harris T, Hughes A, Phan H, Banerjee T, Hanson K, Alabugin IV. Traceless Directing Groups in Radical Cascades: From Oligoalkynes to Fused Helicenes without Tethered Initiators. J Am Chem Soc 2015; 137:1165-80. [DOI: 10.1021/ja510563d] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Kamalkishore Pati
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Gabriel dos Passos Gomes
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Trevor Harris
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Audrey Hughes
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Hoa Phan
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Tanmay Banerjee
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Kenneth Hanson
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Igor V. Alabugin
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
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15
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Hale KJ, Xiong Z, Wang L, Manaviazar S, Mackle R. Carreira Alkynylations with Paraformaldehyde. A Mild and Convenient Protocol for the Hydroxymethylation of Complex Base-Sensitive Terminal Acetylenes via Alkynylzinc Triflates. Org Lett 2014; 17:198-201. [DOI: 10.1021/ol503222j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Karl J Hale
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK
| | - Ziyue Xiong
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK
| | - Liping Wang
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK
| | - Soraya Manaviazar
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK
| | - Ryan Mackle
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), The Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK
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16
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Sun X, Li J, Ni Y, Ren D, Hu Z, Yu S. Synthesis of Fused Quinoline and Quinoxaline Derivatives Enabled by Domino Radical Triple Bond Insertions. ASIAN J ORG CHEM 2014. [DOI: 10.1002/ajoc.201402222] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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17
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Hale KJ, Maczka M, Kaur A, Manaviazar S, Ostovar M, Grabski M. Synthesis of the C(7)–C(22) Sector of (+)-Acutiphycin via O-Directed Double Free Radical Alkyne Hydrostannation with Ph3SnH/Et3B, Double I–Sn Exchange, and Double Stille Coupling. Org Lett 2014; 16:1168-71. [DOI: 10.1021/ol500050p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Karl J. Hale
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
| | - Maciej Maczka
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
| | - Amarjit Kaur
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
| | - Soraya Manaviazar
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
| | - Mehrnoosh Ostovar
- The
Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Milosz Grabski
- The School of Chemistry & Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen’s University Belfast, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
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18
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Hale KJ, Grabski M, Manaviazar S, Maczka M. Asymmetric total synthesis of (+)-inthomycin C via O-directed free radical alkyne hydrostannation with Ph3SnH and catalytic Et3B: reinstatement of the Zeeck-Taylor (3R)-structure for (+)-inthomycin C. Org Lett 2014; 16:1164-7. [PMID: 24502463 DOI: 10.1021/ol5000499] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (-)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (-)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama's (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor's original (3R)-stereostructure for (+)-inthomycin C is correct.
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Affiliation(s)
- Karl J Hale
- The School of Chemistry and Chemical Engineering and the Centre for Cancer Research and Cell Biology (CCRCB), the Queen's University Belfast , Stranmillis Road, Belfast BT9 5AG, Northern Ireland, United Kingdom
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19
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Micoine K, Persich P, Llaveria J, Lam MH, Maderna A, Loganzo F, Fürstner A. Total Syntheses and Biological Reassessment of Lactimidomycin, Isomigrastatin and Congener Glutarimide Antibiotics. Chemistry 2013; 19:7370-83. [DOI: 10.1002/chem.201300393] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Indexed: 12/20/2022]
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