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Iwata T, Hatae K, Shindo M. Practical Synthesis of α,α-Dibromo Esters from Aldehydes. J Org Chem 2024; 89:10384-10387. [PMID: 38980823 DOI: 10.1021/acs.joc.4c01078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Herein, we report an efficient and practical method for synthesizing α,α-dibromo esters, which are the precursors of ynolates, through the dibromination of aldehydes followed by oxidative esterification using iodine. Our method was successfully employed in a large-scale synthesis to yield more than 30 g of dibromo esters. These two steps can be performed in a one-pot manner, which makes the method adaptable even for aldehydes having low boiling points.
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Affiliation(s)
- Takayuki Iwata
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasugako-en, Kasuga, Fukuoka 816-8580, Japan
| | - Kiichi Hatae
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugako-en, Kasuga, Fukuoka 816-8580, Japan
| | - Mitsuru Shindo
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasugako-en, Kasuga, Fukuoka 816-8580, Japan
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Yamaoka Y, Imahori H, Namioka M, Nishina R, Kobori Y, Ueda M, Shindo M, Takasu K. Entry into Lithium Ynolates from α,α,α-Tribromomethyl Ketones: Synthesis of Cyclobutenes via the [2 + 2] Cycloaddition with α,β-Unsaturated Carbonyls. Org Lett 2024; 26:1896-1901. [PMID: 38421178 DOI: 10.1021/acs.orglett.4c00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
This study reports the synthesis of cyclobutene derivatives in good yields via the [2 + 2] cycloaddition between lithium ynolates and α,β-unsaturated carbonyls. The ynolates are generated from α,α,α-tribromomethyl ketones and tert-butyl lithium via a simple and novel method, which does not produce any harmful byproducts, such as lithium alkoxide, which induces a polymerization reaction with α,β-unsaturated carbonyls.
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Affiliation(s)
- Yousuke Yamaoka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
- School of Pharmacy, Hyogo Medical University, Minatojima, Chuo-ku, Kobe, 770-8505, Japan
| | - Hidetaka Imahori
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Motoki Namioka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ryo Nishina
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yukiko Kobori
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Motoki Ueda
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mitsuru Shindo
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Kiyosei Takasu
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
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3
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Christopher A, Brandes D, Kelly S, Minehan TG. n-Butyllithium-Induced Tandem [3,3]-Sigmatropic Rearrangement and Carbonyl Olefination of Allyl-1,1-dichlorovinyl Ethers. J Org Chem 2021; 86:17487-17495. [PMID: 34761941 DOI: 10.1021/acs.joc.1c02178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exposure of dichlorovinyl ethers 1 to n-butyllithium and addition of saturated or unsaturated aldehydes, ketones, or esters at ambient temperature furnishes rearranged α,β-unsaturated carboxylic acids, isolated as their corresponding methyl esters 2 in 48-91% overall yields. Exposure of dichlorovinyl ethers 1 to n-butyllithium, addition of aldehydes, ketones, dialdehydes, or diketones at -78 °C, and warming to 80 °C in the presence of SiO2 provide 1,4-dienes 3 or cycloalken-1-ols (or their dehydration products) 4 in 45-72% overall yields.
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Affiliation(s)
- Aaron Christopher
- Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330, United States
| | - Dahniel Brandes
- Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330, United States
| | - Stephen Kelly
- Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330, United States
| | - Thomas G Minehan
- Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330, United States
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Shindo M, Iwata T. Cycloaddition Initiated by Ynolates: High-Energy Dianion Equivalents as a Molecular Glue. Synlett 2021. [DOI: 10.1055/s-0040-1719857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractIn this paper, ynolate-initiated cycloaddition (annulation) to form a range of carbocycles and heterocycles is described. Ynolates consist of a ketene anion equivalent, which contains both nucleophilic and electrophilic moieties, and a carbodianion equivalent that achieves double addition. Hence, in addition to the usual [n+2] cycloaddition, ynolates can perform formal [n+1]-type annulations. Their high-energy performance has been demonstrated by their triple addition to arynes to generate triptycenes, in which the C–C triple bond of ynolates is cleaved. The synthetic applications of these methods, including natural products synthesis, are also described.1 Introduction2 Preparation of Ynolates2.1 Double Lithiation2.2 Flow Synthesis2.3 Double Deprotonation3 [2+2] Cycloaddition to C=O Bond3.1 To Aldehydes and Ketones3.2 Sequential Cycloaddition4 [2+2] Cycloaddition to Imino Groups
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Sun J, Iwata T, Shindo M. Synthesis of 9-Hydroxytriptycenes Bearing a Functionalized Substituent at the C-10 Position through a Triple Cycloaddition Reaction of Ynolates Derived from 2,6-Di-tert-butylphenyl Esters. CHEM LETT 2020. [DOI: 10.1246/cl.200412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jun Sun
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Takayuki Iwata
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Mitsuru Shindo
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
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Iwata T, Hyodo M, Fukami T, Shiota Y, Yoshizawa K, Shindo M. Anthranoxides as Highly Reactive Arynophiles for the Synthesis of Triptycenes. Chemistry 2020; 26:8506-8510. [PMID: 32432370 DOI: 10.1002/chem.202002065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/19/2020] [Indexed: 12/14/2022]
Abstract
We report herein an efficient method to synthesize triptycenes by the reaction of benzynes and anthranoxides, which are electron-rich and readily prepared from the corresponding anthrones. Using this method, 1,9-syn-substituted triptycenes were regioselectively obtained employing 3-methoxybenzynes. This method was also applied to synthesize pentiptycenes. A DFT study revealed that the cycloaddition of lithium anthranoxide and benzyne proceeds stepwise.
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Affiliation(s)
- Takayuki Iwata
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
| | - Mizuki Hyodo
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
| | - Takuto Fukami
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
| | - Mitsuru Shindo
- Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga-koen, Kasuga, 816-8580, Japan
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