1
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Harada S. [Catalytic Synthesis of Optically Active Polycyclic Heterocyclic Compounds]. YAKUGAKU ZASSHI 2020; 140:1213-1224. [PMID: 32999200 DOI: 10.1248/yakushi.20-00137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In basic pharmaceutical sciences to achieve drug development, research on the efficient chemical synthesis of small molecules having cyclic skeletons is important. We have been engaged in the development of artificial catalysts for asymmetric ring formation reactions that exclusively synthesize right-handed or left-handed cyclic compounds and have achieved the construction of optically active cyclic skeletons using our original catalysts. The synthesis of biologically active compounds was facilitated through six-membered ring construction by Diels-Alder reaction of Danishefsky diene; however, no asymmetric variant of the reaction has been achieved. We approached this unresolved issue using multi-coordinated lanthanide metals. A new chiral lanthanide catalyst was developed, and the catalytic asymmetric Diels-Alder reaction of Danishefsky diene was realized for the first time. By modifying the chemical structure of Danishefsky diene, we applied the lanthanide catalyst to the syntheses of polycyclic compounds and biologically active compounds. We achieved the asymmetric synthesis of natural products, antibacterial and antimalarial compounds, and an anti-obesity drug lead compound. Moreover, the novel catalyst exhibited higher performance than the previously reported ones. The latest generation of the catalyst can be handled stably in air at room temperature. Furthermore, we succeeded in the development of new catalysts by focusing on the properties of its metal precursors, such as nickel and indium, and achieved the construction of polycyclic skeletons by using these catalysts.
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Affiliation(s)
- Shinji Harada
- Graduate School of Pharmaceutical Sciences, Chiba University.,Molecular Chirality Research Center, Chiba University
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2
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Kawafuchi H, Ma L, Hossain MI, Inokuchi T. O-AcylTEMPOs, a Modified and Fundamental, but Unexplored Carboxylic Derivative: Recent Progress in Synthetic Applications. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666191019102511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
O-Acylated 2,2,6,6-tetramethylpiperidine-N-oxyls (abbr. O-AcylTEMPOs) are
easily available and stable carboxylic derivatives, but their utility in organic synthesis is
unexplored in contrast to analogues, such as the N-methoxy-N-methylamides, known as
Weinreb amides. Especially, the O–N unit of the O-acylTEMPOs dictates a fairly electronwithdrawing
character for the carbonyl function. This enhances the reactivity and stability
of the resulting enolate ions. Accordingly, O-acylTEMPOs allow various transformations
and this review encompasses seven topics: (1) Reactivity of O-acylTEMPOs towards nucleophiles
and chemoselective transformations, (2) Reactivity of anionic species derived
from O-acylTEMPOs, (3) E-Selective Knoevenagel condensation of acetoacetylTEMPOs
and synthesis of furans, (4) Electrocyclization of 2,4-dienones derived from acetoacetic
derivatives and 2-substituted enals, (5) Diastereoselective addition of amide anion to O-(2-alkenoyl)TEMPOs
and β-amino acid synthesis, (6) Thermolysis of O-acylTEMPOs, and (7) Applications for Umpolung reactions
using O-benzoylTEMPOs, useful for the electrophilic amination of alkenes and alkynes.
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Affiliation(s)
- Hiroyuki Kawafuchi
- National Institute of Technology, Toyama College 13, Hongo-machi, Toyama, 939-8630, Japan
| | - Lijian Ma
- College of Chemistry, Sichuan University Chengdu 610064, China
| | - Md Imran Hossain
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, 419 Faser Hall, University, MS 38677, United States
| | - Tsutomu Inokuchi
- Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka, Kita- Ku, 3-1-1, Okayama, 700-8530, Japan
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3
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Harada S, Nishida A. Catalytic and Enantioselective Diels‐Alder Reaction of Siloxydienes. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900159] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shinji Harada
- Graduate School of Pharmaceutical SciencesChiba University 1-8-1 Inohana, Chuo-ku Chiba 260-8675 Japan
- Molecular Chirality Research CenterChiba University 1-33 Yayoi-cho, Inage-ku Chiba 263-8522 Japan
| | - Atsushi Nishida
- Graduate School of Pharmaceutical SciencesChiba University 1-8-1 Inohana, Chuo-ku Chiba 260-8675 Japan
- Molecular Chirality Research CenterChiba University 1-33 Yayoi-cho, Inage-ku Chiba 263-8522 Japan
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4
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Trajkovic M, Ferjancic Z, Saicic RN, Bihelovic F. Enantioselective Synthesis of the Platensimycin Core by Silver(I)‐Promoted Cyclization of Δ 6‐α‐Iodoketone. Chemistry 2019; 25:4340-4344. [DOI: 10.1002/chem.201900497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Milos Trajkovic
- Faculty of ChemistryUniversity of Belgrade Studentski trg 16, POB 51 11158 Belgrade 118 Serbia
| | - Zorana Ferjancic
- Faculty of ChemistryUniversity of Belgrade Studentski trg 16, POB 51 11158 Belgrade 118 Serbia
| | - Radomir N. Saicic
- Faculty of ChemistryUniversity of Belgrade Studentski trg 16, POB 51 11158 Belgrade 118 Serbia
- Serbian Academy of Sciences and Arts Knez Mihailova 35 11000 Belgrade Serbia
| | - Filip Bihelovic
- Faculty of ChemistryUniversity of Belgrade Studentski trg 16, POB 51 11158 Belgrade 118 Serbia
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5
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Koszelewski D, Paprocki D, Madej A, Borys F, Brodzka A, Ostaszewski R. Enzymatic Tandem Approach to Knoevenagel Condensation of Acetaldehyde with Acidic Methylene Compounds in Organic Media. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700936] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Dominik Koszelewski
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Daniel Paprocki
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Arleta Madej
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Filip Borys
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Anna Brodzka
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Ryszard Ostaszewski
- Institute of Organic Chemistry; Polish Academy of Sciences; Kasprzaka 44/52 01-224 Warsaw Poland
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6
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Jiang L, Liu X, Yuan P, Zhang Y, Chen X. Stereoselective Synthesis of (+)-Annuionone A and (-)-Annuionone B. JOURNAL OF NATURAL PRODUCTS 2017; 80:805-812. [PMID: 28338330 DOI: 10.1021/acs.jnatprod.6b00522] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A stereoselective synthetic approach was utilized to synthesize enantiopure annuionones A (1b) and B (2b), two ionone-type norsesquiterpenoids that both bear a 6-oxabicyclo[3.2.1]octane framework and possess allelopathic activity. A stereoselective Diels-Alder reaction based on chiral trisubstituted dienophile 20 was employed to obtain the optically active polysubstituted cyclohexane core of both natural products. Using this approach, (+)-annuionone A (1b) and (-)-annuionone B (2b) were synthesized from lactol (+)-15 in 10% overall yield.
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Affiliation(s)
- Lizhen Jiang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, People's Republic of China
| | - Xiaojing Liu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, People's Republic of China
| | - Po Yuan
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, People's Republic of China
| | - Yanli Zhang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, People's Republic of China
| | - Xiaochuan Chen
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, People's Republic of China
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7
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Harada S, Morikawa T, Hiraoka S, Nishida A. Development of Catalytic and Enantioselective Diels-Alder Reaction of Electron-Rich Dienes Using Chiral Rare-Earth Metal Complex. J SYN ORG CHEM JPN 2013. [DOI: 10.5059/yukigoseikyokaishi.71.818] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Magee DI, Ratshonka S, McConaghy J, Hood M. Synthesis of β- and β,β-substituted Morita–Baylis–Hillman adducts using a two-step protocol. CAN J CHEM 2012. [DOI: 10.1139/v2012-017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The synthesis of a large number of β- and β,β-substituted keto esters was successful by the use of the Knoevenagel condensation reaction. The stereoselectivity of these reactions was improved by alteration of various substituent groups. Although there were few examples of complete Z selectivity, the use of tert-butyl acetoacetate with either aromatic or aliphatic aldehydes afforded Z selectivity. The selective reductions of these substituted keto esters was successfully achieved by using a combination of NaBH4 and CeCl3·7H2O or Yb(OTf)3, which allowed a facile synthesis of a large number of stereochemically pure substituted Morita–Baylis–Hillman adducts, including β,β-substituted adducts.
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Affiliation(s)
- David I. Magee
- Department of Chemistry, P.O. Box 4400, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Same Ratshonka
- Department of Chemistry, P.O. Box 4400, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Jessica McConaghy
- Department of Chemistry, P.O. Box 4400, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Maggie Hood
- Department of Chemistry, P.O. Box 4400, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
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9
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Kopp F, Stratton CF, Akella LB, Tan DS. A diversity-oriented synthesis approach to macrocycles via oxidative ring expansion. Nat Chem Biol 2012; 8:358-65. [PMID: 22406518 PMCID: PMC3359144 DOI: 10.1038/nchembio.911] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 01/17/2012] [Indexed: 02/07/2023]
Abstract
Macrocycles are key structural elements in numerous bioactive small molecules and are attractive targets in the diversity-oriented synthesis of natural product-based libraries. However, efficient and systematic access to diverse collections of macrocycles has proven difficult using classical macrocyclization reactions. To address this problem, we have developed a concise, modular approach to the diversity-oriented synthesis of macrolactones and macrolactams involving oxidative cleavage of a bridging double bond in polycyclic enol ethers and enamines. These substrates are assembled in only 4–5 synthetic steps and undergo ring expansion to afford highly functionalized macrocycles bearing handles for further diversification. In contrast to macrocyclization reactions of corresponding seco-acids, the ring expansion reactions are efficient and insensitive to ring size and stereochemistry, overcoming key limitations of conventional approaches to systematic macrocycle synthesis. Cheminformatic analysis indicates that these macrocycles access regions of chemical space that overlap with natural products, distinct from currently-targeted synthetic drugs.
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Affiliation(s)
- Felix Kopp
- Molecular Pharmacology & Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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10
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Massa A, Roscigno A, De Caprariis P, Filosa R, Di Mola A. Trimethylchlorosilane and Silicon Tetrachloride in Two Novel Methodologies for the Efficient and Mild Aldol Addition of β-Keto Esters and Malonates to Aldehydes. Adv Synth Catal 2010. [DOI: 10.1002/adsc.201000573] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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11
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Anuradha N, Thiruvalluvar A, Yuvaraj C, Pandiarajan K, Butcher RJ. Ethyl 4-(4-bromophenyl)-6- r-phenyl-2-oxocyclohex-3-ene-1- t-carboxylate. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1896. [PMID: 21588230 PMCID: PMC3007547 DOI: 10.1107/s1600536810025353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 06/28/2010] [Indexed: 11/11/2022]
Abstract
In the title compound, C21H19BrO3, the cyclohexene ring adopts an envelope conformation, with all substituents equatorial. The plane through its five coplanar atoms makes dihedral angles of 28.88 (10) and 71.94 (10)° with the bromobenzene and phenyl rings, respectively. The dihedral angle between the latter two rings is 51.49 (15)°. Intermolecular C—H⋯O hydrogen bonds are found in the crystal structure; a C—H⋯π interaction is also present.
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12
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Amancha PK, Lai YC, Chen IC, Liu HJ, Zhu JL. Diels–Alder reactions of acyclic α-cyano α,β-alkenones: a new approach to highly substituted cyclohexene system. Tetrahedron 2010. [DOI: 10.1016/j.tet.2009.11.105] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Highly enantioselective Diels–Alder reaction of Danishefsky-type diene and electron-deficient olefins catalyzed by an Yb(III)/chiral bis-urea complex. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.07.110] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Liao CC, Zhu JL. Investigation on Lewis Acid Mediated Diels−Alder Reactions of 2-Phosphono-2-alkenoates. Application to Total Synthesis of (±)-α-Alasken-8-one via Reductive Alkylation of Resulting Adduct. J Org Chem 2009; 74:7873-84. [DOI: 10.1021/jo9017292] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chuan-Cheng Liao
- Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
| | - Jia-Liang Zhu
- Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan, R.O.C
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15
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Attanasi O, Berretta S, De Crescentini L, Favi G, Giorgi G, Mantellini F. Lewis Acid-Catalyzed Synthesis of Functionalized Pyrroles. Adv Synth Catal 2009. [DOI: 10.1002/adsc.200800807] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Sudo Y, Shirasaki D, Harada S, Nishida A. Highly Enantioselective Diels−Alder Reactions of Danishefsky Type Dienes with Electron-Deficient Alkenes Catalyzed by Yb(III)-BINAMIDE Complexes. J Am Chem Soc 2008; 130:12588-9. [DOI: 10.1021/ja804430n] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yukinori Sudo
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Daisuke Shirasaki
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Shinji Harada
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Atsushi Nishida
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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17
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Attanasi OA, Favi G, Filippone P, Giorgi G, Mantellini F, Moscatelli G, Spinelli D. Flexible Protocol for the Chemo- and Regioselective Building of Pyrroles and Pyrazoles by Reactions of Danishefsky’s Dienes with 1,2-Diaza-1,3-butadienes. Org Lett 2008; 10:1983-6. [DOI: 10.1021/ol800557h] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Orazio A. Attanasi
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Gianfranco Favi
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Paolino Filippone
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Gianluca Giorgi
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Fabio Mantellini
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Giada Moscatelli
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Domenico Spinelli
- Istituto di Chimica Organica, Università degli Studi di Urbino “Carlo Bo”, Via I Maggetti 24, 61029 Urbino, Italy, Centro Interdipartimentale di Analisi e Determinazioni Strutturali, Università degli Studi di Siena, Via Aldo Moro, 53100 Siena, Italy, and Dipartimento di Chimica Organica “A. Mangini”, Università degli Studi di Bologna, Via San Giacomo 11, 40126 Bologna, Italy
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Abstract
The total synthesis of (-)-cyathin A3 is described. The key step involves an unusual enantioselective Diels-Alder reaction of 2,5-dimethyl-1,4-benzoquinone with 2,4-bis(trimethylsilyloxy)-1,3-pentadiene, using Mikami's catalyst [(R)-BINOL + Cl2Ti(OiPr)2 + 4 A mol sieves] modified by addition of Mg and SiO2. Because cyathin A3 is easily transformed into allocyathin B3, cyathin B3, cyathin C3, and neoallocyathin A4, this route also constitutes formal syntheses of these natural products.
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Affiliation(s)
- Dale E Ward
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Canada.
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19
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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).
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Affiliation(s)
- Akira Iida
- Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, Japan
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20
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Inokuchi T, Kawafuchi H. E- or Z-Selective Knoevenagel Condensation of Acetoacetic Derivatives: Effect of Acylated Substituent, that is, TEMPO and Amines, as an Auxiliary, and New Accesses to Trisubstituted E- and Z-2-Alkenals and Furans. J Org Chem 2006; 71:947-53. [PMID: 16438506 DOI: 10.1021/jo051952w] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Knoevenagel condensation of O-acetoacetylTEMPOs (2,2,6,6-tetramethylpiperidine-1-oxyl) with aldehydes substituted with an electron-withdrawing group such as aromatic and heteroaromatic ones leads preferentially to E-adducts, while acylacetoamides including Weinreb amides produce Z-adducts, exclusively. These E- and Z-adducts are selectively converted to the corresponding (2E)- and (2Z)-2-hyroxyalkyl-2-alkenals, respectively, by stepwise reductions of the acyl group with DIBALH and then the carboxylic functions after protection of the hydroxy group. Transformation of the Knoevenagel products by taking advantage of the E-geometry to trisubstituted furans is also developed.
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Affiliation(s)
- Tsutomu Inokuchi
- Department of Bioscience and Biotechnology, Faculty of Engineering, Okayama University, Tsushima-naka, Okayama 700-8530, Japan.
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21
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Inokuchi T. 1,2-Acyl Transfer Reaction for the Construction of Multiple Carbonyl-Functionalized Architecture by Sm(II)-Induced Tandem Formation and Breaking of Cyclopropanol. J Org Chem 2005; 70:1497-500. [PMID: 15704995 DOI: 10.1021/jo0402529] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] An efficient 1,2-acyl group migration reaction based on contiguous formation and breaking tactics of 1-oxycyclopropane-2-carboxylate as an intermediate is developed. Thus, the reduction of 2-cyclohexenones, bearing gem-acyl/alkoxycarbonyl groups at the C4 position, with Sm(II) reagent leads to 2-acyl-4-oxycyclohexanecarboxylates via cyclization followed by retro-aldol cleavage of the resulting donor/acceptor cyclopropane. Mechanistic insights and the scope of the reaction are described.
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Affiliation(s)
- Tsutomu Inokuchi
- Department of Bioscience and Biotechnology, Faculty of Engineering, Okayama University, Tsushima-Naka, Okayama, 700-8530, Japan.
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22
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Lee SI, Park JH, Chung YK, Lee SG. Rhodium-Catalyzed Carbonylative [3+2+1] Cycloaddition Reaction: Catalytic Formation of Bicyclic Cyclohexenones from Trienes and Carbon Monoxide. J Am Chem Soc 2004; 126:2714-5. [PMID: 14995184 DOI: 10.1021/ja039301+] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rhodium-catalyzed carbonylative [3+2+1] cycloaddition of trienes into bicyclohexenones has been developed. The carbonylated cycloaddition products have a high regioselectivity. This catalytic system tolerates functionalities including ether, sulfonamide, and ester.
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Affiliation(s)
- Sang Ick Lee
- School of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-747, Korea
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