1
|
Rahman MA, Cellnik T, Ahuja BB, Li L, Healy AR. A catalytic enantioselective stereodivergent aldol reaction. SCIENCE ADVANCES 2023; 9:eadg8776. [PMID: 36921040 PMCID: PMC10017038 DOI: 10.1126/sciadv.adg8776] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The aldol reaction is among the most powerful and strategically important carbon-carbon bond-forming transformations in organic chemistry. The importance of the aldol reaction in constructing chiral building blocks for complex small-molecule synthesis has spurred continuous efforts toward the development of direct catalytic variants. The realization of a general catalytic aldol reaction with control over both the relative and absolute configurations of the newly formed stereogenic centers has been a longstanding goal in the field. Here, we report a decarboxylative aldol reaction that provides access to all four possible stereoisomers of the aldol product in one step from identical reactants. The mild reaction can be carried out on a large scale in an open flask, and generates CO2 as the only by-product. The method tolerates a broad substrate scope and generates chiral β-hydroxy thioester products with substantial downstream utility.
Collapse
Affiliation(s)
- Md. Ataur Rahman
- Chemistry Program, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates (UAE)
| | - Torsten Cellnik
- Chemistry Program, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates (UAE)
| | - Brij Bhushan Ahuja
- Chemistry Program, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates (UAE)
| | - Liang Li
- Chemistry Program, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates (UAE)
- Department of Sciences and Engineering, Sorbonne University Abu Dhabi, Abu Dhabi, United Arab Emirates (UAE)
| | - Alan R. Healy
- Chemistry Program, New York University Abu Dhabi (NYUAD), Saadiyat Island, Abu Dhabi, United Arab Emirates (UAE)
| |
Collapse
|
2
|
Khademi Z, Heravi MM. Applications of Claisen condensations in total synthesis of natural products. An old reaction, a new perspective. Tetrahedron 2022. [DOI: 10.1016/j.tet.2021.132573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
3
|
Boateng A, Harada T, Ashikari Y, Nakajima M, Sugiura M. Synthesis of conjugated multiunsaturated thioesters via one-pot TiCl4-promoted aldol condensation. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
Qiu ZB, Chen LY, Ji J, Ren X, Li Y. Highly diastereoselective aldol reactions of 3-Fluorooxindoles promoted by MgBr2•OEt2/iPr2NEt. J Fluor Chem 2020. [DOI: 10.1016/j.jfluchem.2020.109594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
5
|
Qiu ZB, Ren XF, Chen XY, Chen LY, Ji J, Li Y. MgBr2OEt2-promoted direct Aldol reactions of S-aryl 2-fluoroethanethioate. J Fluor Chem 2019. [DOI: 10.1016/j.jfluchem.2019.109368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
6
|
Wu S, Gu B, Xu H, Zheng X, Luo X, Deng W. Organocatalytic Asymmetric Inverse‐Electron‐Demand Diels‐Alder Reaction of Pyrrolidone‐Dienes with Enals. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900664] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Shu‐Xiao Wu
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| | - Bo‐Qi Gu
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| | - Hui Xu
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| | - Xing Zheng
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| | - Xiaoyan Luo
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| | - Wei‐Ping Deng
- Shanghai Key Laboratory of New Drug Design and School of PharmacyEast China University of Science and Technology 130 Meilong Road Shanghai 200237 People's Republic of China
| |
Collapse
|
7
|
Gu BQ, Yang WL, Wu SX, Wang YB, Deng WP. Organocatalytic asymmetric synthesis of tetrahydrocarbazoles via an inverse-electron-demand Diels–Alder reaction of 2,3-indole-dienes with enals. Org Chem Front 2018. [DOI: 10.1039/c8qo01042k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A novel 2,3-indole-diene synthon was designed and first applied to an inverse-electron-demand Diels–Alder reaction to construct tetrahydrocarbazoles with excellent stereoselectivities.
Collapse
Affiliation(s)
- Bo-Qi Gu
- School of Pharmacy and Shanghai Key Laboratory of New Drug Design
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Wu-Lin Yang
- School of Pharmacy and Shanghai Key Laboratory of New Drug Design
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Shu-Xiao Wu
- School of Pharmacy and Shanghai Key Laboratory of New Drug Design
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Yan-Bing Wang
- School of Pharmacy and Shanghai Key Laboratory of New Drug Design
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Wei-Ping Deng
- School of Pharmacy and Shanghai Key Laboratory of New Drug Design
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| |
Collapse
|
8
|
Nakatsuji H, Kamada R, Kitaguchi H, Tanabe Y. Dehydration-type Ti-Claisen Condensation (Carbonhomologation) of α-Heteroatom-substituted Acetates with Alkyl Formates: Utilization as (Z
)-Stereodefined Cross-coupling Partners and Application to Concise Synthesis of Strobilurin A. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hidefumi Nakatsuji
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Risa Kamada
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Hideya Kitaguchi
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| | - Yoo Tanabe
- Department of Chemistry, School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen Sanda, Hyogo 669-1337 Japan
| |
Collapse
|
9
|
Zhu L, Yan P, Zhang L, Chen Z, Zeng X, Zhong G. TiCl4/DMAP mediated Z-selective knovenagel condensation of isatins with nitroacetates and related compounds. RSC Adv 2017. [DOI: 10.1039/c7ra09951g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A Z-selective Knovenagel condensation reaction of isatins with nitroacetates and related compounds mediated by TiCl4 and DMAP was described.
Collapse
Affiliation(s)
- Luyi Zhu
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Peipei Yan
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Lvye Zhang
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Zhangtao Chen
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Xiaofei Zeng
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Guofu Zhong
- College of Material, Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| |
Collapse
|
10
|
|
11
|
Sugi M, Nagase R, Misaki T, Nakatsuji H, Tanabe Y. Asymmetric Total Synthesis of (-)-Azaspirene by Utilizing Ti-Claisen Condensation and Ti-Direct Aldol Reaction. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600766] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mikiko Sugi
- Department of Chemistry; School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen 669-1337 Sanda Hyogo Japan
| | - Ryohei Nagase
- Department of Chemistry; School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen 669-1337 Sanda Hyogo Japan
| | - Tomonori Misaki
- Graduate School of Material Science; University of Hyogo; 3-2-1 Kohto 678-1297 Kamigori Hyogo Japan
| | - Hidefumi Nakatsuji
- Department of Chemistry; School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen 669-1337 Sanda Hyogo Japan
| | - Yoo Tanabe
- Department of Chemistry; School of Science and Technology; Kwansei Gakuin University; 2-1 Gakuen 669-1337 Sanda Hyogo Japan
| |
Collapse
|
12
|
Straightforward Synthesis of 2(5H)-Furanones as Promising Cross-Coupling Partners: Direct Furanone Annulation Utilizing Ti-Mediated Aldol Addition. MOLBANK 2016. [DOI: 10.3390/m908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
|
13
|
Sugiura M, Ashikari Y, Nakajima M. One-Pot Synthesis of β,β-Disubstituted α,β-Unsaturated Carbonyl Compounds. J Org Chem 2015; 80:8830-5. [DOI: 10.1021/acs.joc.5b01217] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masaharu Sugiura
- Graduate School of Pharmaceutical
Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973, Japan
| | - Yasuhiko Ashikari
- Graduate School of Pharmaceutical
Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973, Japan
| | - Makoto Nakajima
- Graduate School of Pharmaceutical
Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973, Japan
| |
Collapse
|
14
|
Nishii Y. Highly Stereoselective Construction and Chiral Transfer Ring-expansion of Highly Substituted Cyclopropanes. J SYN ORG CHEM JPN 2015. [DOI: 10.5059/yukigoseikyokaishi.73.701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
15
|
Ghorbani-Choghamarani A, Shiri L, Rostami A. Acetylation of alcohols with acetic anhydride promoted by N,N,N-trimethylanilinium tribromide. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2014. [DOI: 10.1134/s1070428013120026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
16
|
Xiao J, Li GW, Zhang WQ. Aldol reactions catalyzed by proline functionalized polyacrylonitrile fiber. Chem Res Chin Univ 2013. [DOI: 10.1007/s40242-013-2236-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
17
|
Polyvinylpolypyrrolidoniume Tribromide as an Efficient Catalyst for the Acetylation of Alcohols and Phenols. CHINESE JOURNAL OF CATALYSIS 2012. [DOI: 10.1016/s1872-2067(11)60428-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
18
|
Chen XL, Liu HL, Li J, Xin GR, Guo YW. Paracaseolide A, First α-Alkylbutenolide Dimer with an Unusual Tetraquinane Oxa-Cage Bislactone Skeleton from Chinese Mangrove Sonneratia paracaseolaris. Org Lett 2011; 13:5032-5. [PMID: 21875121 DOI: 10.1021/ol201809q] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xue-Lian Chen
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road, 555, Shanghai 201203, China, and Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China
| | - Hai-Li Liu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road, 555, Shanghai 201203, China, and Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China
| | - Jia Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road, 555, Shanghai 201203, China, and Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China
| | - Guo-Rong Xin
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road, 555, Shanghai 201203, China, and Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China
| | - Yue-Wei Guo
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zu Chong Zhi Road, 555, Shanghai 201203, China, and Institute of Biological Science, Sun Yat-Sen University, Xin Gang West Road 135, Guangzhou 510275, China
| |
Collapse
|
19
|
Pawełczyk A, Zaprutko L. Synthesis of fragrant heterocyclic thioketo analogues of jasmone under microwave conditions. FLAVOUR FRAG J 2010. [DOI: 10.1002/ffj.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
20
|
Nagase R, Osada J, Tamagaki H, Tanabe Y. Pentafluorophenylammonium Trifluoromethanesulfonimide: Mild, Powerful, and Robust Catalyst for Mukaiyama Aldol and Mannich Reactions between Ketene Silyl Acetals and Ketones or Oxime Ethers. Adv Synth Catal 2010. [DOI: 10.1002/adsc.200900869] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
21
|
Marrone A, Renzetti A, De Maria P, Gérard S, Sapi J, Fontana A, Re N. Condensation of beta-diester titanium enolates with carbonyl substrates: a combined DFT and experimental investigation. Chemistry 2010; 15:11537-50. [PMID: 19777518 DOI: 10.1002/chem.200901595] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The condensation of dialkyl beta-diesters with various aldehydes promoted by TiCl4 has been studied by DFT approaches and experimental methods, including NMR, IR and UV/Vis spectroscopy. Various possible reaction pathways have been investigated and their energy profiles evaluated to find out a plausible mechanism of the reaction. Theoretical results and experimental evidence point to a three-step mechanism: 1) Ti-induced formation of the enolate ion; 2) aldol reaction between the enolate ion and the aldehyde, both coordinated to titanium; and 3) intramolecular elimination that leads to a titanyl complex. The presented mechanistic hypothesis allows one to better understand the pivotal role of titanium(IV) in the reaction.
Collapse
Affiliation(s)
- Alessandro Marrone
- Dipartimento di Scienze del Farmaco, Università degli Studi G. d'Annunzio di Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy
| | | | | | | | | | | | | |
Collapse
|
22
|
Takai K, Nawate Y, Okabayashi T, Nakatsuji H, Iida A, Tanabe Y. Practical and robust method for stereoselective preparations of ketene silyl (thio)acetal derivatives and NaOH-catalyzed crossed-Claisen condensation between ketene silyl acetals and methyl esters. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.02.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
23
|
Zhang P, Iding H, Cedilote M, Brunner S, Williamson T, Cleary TP. A practical synthesis of (2R)-3,5-di-O-benzoyl-2-fluoro-2-C-methyl-d-ribono-γ-lactone. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.tetasy.2009.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
24
|
Nagano T, Motoyoshiya J, Kakehi A, Nishii Y. SmI2-Promoted Reformatsky-Type Reaction and Acylation of Alkyl 1-Chlorocyclopropanecarboxylates. Org Lett 2008; 10:5453-6. [DOI: 10.1021/ol8022038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takao Nagano
- Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
| | - Jiro Motoyoshiya
- Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
| | - Akikazu Kakehi
- Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
| | - Yoshinori Nishii
- Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
| |
Collapse
|
25
|
Boukouvalas J, Loach RP. General, regiodefined access to alpha-substituted butenolides through metal-halogen exchange of 3-bromo-2-silyloxyfurans. Efficient synthesis of an anti-inflammatory gorgonian lipid. J Org Chem 2008; 73:8109-12. [PMID: 18798671 DOI: 10.1021/jo8015924] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A variety of alpha-substituted butenolides were efficiently prepared from 3-bromo-2-triisopropylsilyloxyfuran via lithium-bromine exchange and in situ quench with carbon or heteroatom electrophiles. The inherent flexibility of this methodology is illustrated by a short and efficient synthesis of an anti-inflammatory marine natural product.
Collapse
Affiliation(s)
- John Boukouvalas
- Département de Chimie, Université Laval, Quebec City, Quebec G1K 7P4, Canada.
| | | |
Collapse
|
26
|
Nagase R, Katayama M, Mura H, Matsuo N, Tanabe Y. Synthesis of the seed germination stimulant 3-methyl-2H-furo[2,3-c]pyran-2-ones utilizing direct and regioselective Ti-crossed aldol addition. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.05.052] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
27
|
Funatomi T, Nakazawa S, Matsumoto K, Nagase R, Tanabe Y. Ti-mediated direct and highly stereoselective Mannich reactions between esters and oximeethers. Chem Commun (Camb) 2008:771-3. [DOI: 10.1039/b717318k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
28
|
Iida A, Osada J, Nagase R, Misaki T, Tanabe Y. Mild and Efficient Pentafluorophenylammonium Triflate (PFPAT)-Catalyzed C-Acylations of Enol Silyl Ethers or Ketene Silyl (Thio)Acetals with Acid Chlorides. Org Lett 2007; 9:1859-62. [PMID: 17429977 DOI: 10.1021/ol070191b] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A pentafluorophenylammonium triflate (PFPAT) catalyst (5 mol %) successfully promoted C-acylation of enol silyl ethers with acid chloride to produce various beta-diketones (12 examples; 62-92% yield). Similarly, C-acylation of ketene silyl acetals or ketene silyl thioacetals (i.e., crossed Claisen condensation) proceeded smoothly to provide not only alpha-monoalkylated beta-keto (thio)esters but also thermodynamically unfavorable (less accessible) alpha,alpha-dialkylated beta-keto (thio)esters in good to excellent yield (38 examples; 60-92% yield).
Collapse
Affiliation(s)
- Akira Iida
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, Japan
| | | | | | | | | |
Collapse
|