1
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Svestka D, Bobal P, Waser M, Otevrel J. Asymmetric Organocatalyzed Transfer Hydroxymethylation of Isoindolinones Using Formaldehyde Surrogates. Org Lett 2024; 26:2505-2510. [PMID: 38502794 PMCID: PMC10985653 DOI: 10.1021/acs.orglett.4c00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/12/2024] [Accepted: 03/15/2024] [Indexed: 03/21/2024]
Abstract
The piperidine-based Takemoto catalyst has been successfully employed in a novel asymmetric transfer hydroxymethylation of activated isoindolinones, allowing us to prepare the enantioenriched hydroxymethylated adducts in good to excellent yields (48-96%) and enantiopurities (81:19-97:3 e.r.). To increase the reaction rate without compromising the selectivity, carefully optimized formaldehyde surrogates were employed, providing a convenient source of anhydrous formaldehyde with a base-triggered release. The substrate scope, including 34 entries, showed the considerable generality of the asymmetric transformation, and most entries exhibited complete conversions in 24-48 h. A scale-up experiment and multiple enantioselective downstream transformations were also carried out, suggesting the prospective synthetic utility of the products.
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Affiliation(s)
- David Svestka
- Department
of Chemical Drugs, Faculty of Pharmacy, Masaryk University, Palackeho 1, 612 00 Brno, Czechia
| | - Pavel Bobal
- Department
of Chemical Drugs, Faculty of Pharmacy, Masaryk University, Palackeho 1, 612 00 Brno, Czechia
| | - Mario Waser
- Institute
of Organic Chemistry, Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Jan Otevrel
- Department
of Chemical Drugs, Faculty of Pharmacy, Masaryk University, Palackeho 1, 612 00 Brno, Czechia
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2
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Vogl LS, Mayer P, Robiette R, Waser M. Chiral Isochalcogenourea-Catalysed Enantioselective (4+2) Cycloadditions of Allenoates. Angew Chem Int Ed Engl 2024; 63:e202315345. [PMID: 38010747 PMCID: PMC10952905 DOI: 10.1002/anie.202315345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/13/2023] [Accepted: 11/27/2023] [Indexed: 11/29/2023]
Abstract
Allenoates are versatile building blocks which are primarily activated and controlled using chiral tert. phosphine and tert. amine Lewis bases. We herein report the first example of allenoate activation by using chiral isochalcogenoureas (IChU) for formal (4+2) cycloaddition reactions. Compared to established phosphine and amine catalysis, the use of these easily available Lewis bases enables new stereoselective reaction pathways proceeding with high enantioselectivities, diastereoselectivities, and in good yields. In addition, the factors governing enantioselectivity and the origin of the observed differences compared to other commonly used Lewis bases are explained.
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Affiliation(s)
- Lukas S. Vogl
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Peter Mayer
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
| | - Raphaël Robiette
- Institute of Condensed Matter and NanosciencesUniversité catholique de LouvainPlace Louis Pasteur 1 box L4.01.021348Louvain-la-NeuveBelgium
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
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3
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Zebrowski P, Monkowius U, Waser M. Cooperative Chiral Lewis Base/Palladium-Catalyzed Asymmetric Syntheses of Methylene-Containing δ-Lactams. European J Org Chem 2023; 26:e202300982. [PMID: 38601429 PMCID: PMC11005102 DOI: 10.1002/ejoc.202300982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/19/2023] [Indexed: 04/12/2024]
Abstract
We herein report a two-step approach for the enantioselective synthesis of novel chiral δ-lactams. By using a cooperative chiral ITU/achiral Pd-catalyst system, this protocol proceeds via an asymmetric α-allylation of activated aryl esters first, followed by an acid-mediated lactam formation. A variety of differently substituted products could be obtained with usually high levels of enantioselectivities and in reasonable yields (16 examples, up to 98 : 2 er and 73 % yield over two steps). In addition, further utilizations of the products via transformations of the exocyclic double bond were successfully carried out as well.
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Affiliation(s)
- Paul Zebrowski
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Uwe Monkowius
- School of EducationChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
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4
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Stockhammer L, Radetzky M, Khatoon SS, Bechmann M, Waser M. Chiral Lewis Base-Catalysed Asymmetric Syntheses of Benzo-fused ϵ-Lactones. European J Org Chem 2023; 26:e202300704. [PMID: 38601860 PMCID: PMC11005097 DOI: 10.1002/ejoc.202300704] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/24/2023] [Indexed: 04/12/2024]
Abstract
We herein report a two-step protocol for the asymmetric synthesis of novel chiral benzofused ϵ-lactones starting from O-protected hydroxymethyl-para-quinone methides and activated aryl esters. By using chiral isothiourea Lewis base catalysts a broad variety of differently substituted products could be obtained in yields of around 50 % over both steps with high levels of enantioselectivities, albeit low diastereoselectivities only.
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Affiliation(s)
- Lotte Stockhammer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Maximilian Radetzky
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Syeda Sadia Khatoon
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Matthias Bechmann
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstrasse 694040LinzAustria
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5
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Mairhofer C, Waser M. Dibenzoylperoxide as a Versatile Oxidant for Oxidative Azidations of Phenols Using Quaternary Ammonium Iodides or Bromides. Adv Synth Catal 2023; 365:2757-2762. [DOI: 10.1002/adsc.202300405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Indexed: 09/02/2023]
Abstract
AbstractDibenzoylperoxide emerged as a versatile oxidant for quaternary ammonium iodide or bromide‐catalyzed reactions of phenol derivatives with NaN3. While the use of iodides allowed for efficient benzylic azidations under these oxidative conditions, the use of bromides allowed for dearomative azidations instead. Both approaches have been successfully applied to different phenol derivatives and a first proof‐of‐concept for an enantioselective variant using chiral quat. ammonium bromides has been obtained as well.
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Affiliation(s)
- Christopher Mairhofer
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Mario Waser
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
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6
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Monaco G, Tiffner M, Di Mola A, Herrebout W, Waser M, Massa A. Correction: Monaco et al. Chiral Phase Transfer Catalysis in the Asymmetric Synthesis of a 3,3-Disubstituted Isoindolinone and Determination of Its Absolute Configuration by VCD Spectroscopy. Molecules 2020, 25, 2272. Molecules 2023; 28:molecules28114272. [PMID: 37299043 DOI: 10.3390/molecules28114272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/19/2022] [Accepted: 09/07/2022] [Indexed: 06/12/2023] Open
Abstract
In this note, we report a correction to the published article, Molecules2020, 25, 2272 [...].
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Affiliation(s)
- Guglielmo Monaco
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Maximilian Tiffner
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Antonia Di Mola
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Wouter Herrebout
- Department of Chemistry, University of Antwerp, B-2020 Antwerp, Belgium
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Antonio Massa
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
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7
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Weinzierl D, Piringer M, Zebrowski P, Stockhammer L, Waser M. Photochemical Wolff Rearrangement Initiated Generation and Subsequent α-Chlorination of C1 Ammonium Enolates. Org Lett 2023; 25:3126-3130. [PMID: 37098273 PMCID: PMC10167681 DOI: 10.1021/acs.orglett.3c00986] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The enantioselective synthesis of α-chlorinated carboxylic acid esters with er up to 99:1 and yields up to 82% was achieved via a one-pot multistep protocol starting from α-diazoketones. This process proceeds via a photochemical Wolff rearrangement, trapping of the generated ketene with a chiral Lewis base catalyst, subsequent enantioselective α-chlorination, and a final nucleophilic displacement of the bound catalyst. The obtained products were successfully utilized for stereospecific nucleophilic displacement reactions with N- and S-nucleophiles.
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Affiliation(s)
- David Weinzierl
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Magdalena Piringer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Paul Zebrowski
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Lotte Stockhammer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
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8
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Serusi L, Zebrowski P, Schörgenhumer J, Massa A, Waser M. Stereoselective Syntheses of Masked β-Amino Acid Containing Phthalides. Helv Chim Acta 2022; 105:e202200110. [PMID: 36845268 PMCID: PMC7614226 DOI: 10.1002/hlca.202200110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We herein report a protocol for the asymmetric aldol-initiated cascade addition of isoxazolidin-5-ones to ortho-cyanobenzaldehydes by using Takemoto's bifunctional organocatalyst. This approach allows for the synthesis of various novel β2,2-amino acid-phthalide conjugates with good enantio- and diastereoselectivities in reasonable yields and the further ring-opening of these compounds to acyclic carboxylic acid derivatives was demonstrated too.
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Affiliation(s)
- Lorenzo Serusi
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, AT-4040 Linz, Austria,Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, IT-84084-Fisciano (SA), Italy
| | - Paul Zebrowski
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, AT-4040 Linz, Austria
| | - Johannes Schörgenhumer
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Antonio Massa
- Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, IT-84084-Fisciano (SA), Italy
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, AT-4040 Linz, Austria,
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9
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García Mancheño O, Waser M. Recent Developments and Trends in Asymmetric Organocatalysis. European J Org Chem 2022; 26:e202200950. [PMID: 37065706 PMCID: PMC10091998 DOI: 10.1002/ejoc.202200950] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/13/2022] [Indexed: 11/11/2022]
Abstract
Asymmetric organocatalysis has experienced a long and spectacular way since the early reports over a century ago by von Liebig, Knoevenagel and Bredig, showing that small (chiral) organic molecules can catalyze (asymmetric) reactions. This was followed by impressive first highly enantioselective reports in the second half of the last century, until the hype initiated in 2000 by the milestone publications of MacMillan and List, which finally culminated in the 2021 Nobel Prize in Chemistry. This short Perspective aims at providing a brief introduction to the field by first looking on the historical development and the more classical methods and concepts, followed by discussing selected advanced recent examples that opened new directions and diversity within this still growing field.
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Affiliation(s)
- Olga García Mancheño
- Organic Chemistry Institute University of Münster Corrensstrasse 36 48149 Münster Germany
| | - Mario Waser
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstrasse 69 4040 Linz Austria
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10
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Waser M, Winter M, Mairhofer C. (Thio)urea containing chiral ammonium salt catalysts. CHEM REC 2022:e202200198. [PMID: 36175162 DOI: 10.1002/tcr.202200198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/25/2022] [Indexed: 11/08/2022]
Abstract
(Thio)-urea-containing bifunctional quaternary ammonium salts emerged as powerful non-covalently interacting organocatalysts over the course of the last decade. The most commonly employed catalysts in this field are either based on Cinchona alkaloids, α-amino acids, or trans-cyclohexane-1,2-diamine. Our group has been heavily engaged in the design and use of such catalysts, i. e. trans-cyclohexane-1,2-diamine-based ones for around 10 years now, and it is therefore the intention of this short personal account to provide an overview of the, at least in our opinion, most significant and pioneering achievements in this field by looking on catalyst design and asymmetric method development, with a special focus on our own contributions.
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Affiliation(s)
- Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
| | - Michael Winter
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
| | - Christopher Mairhofer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
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11
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Di Mola A, Nicastro G, Serusi L, Filosa R, Waser M, Massa A. Scalable (Enantioselective) Syntheses of Novel 3-Methylated Analogs of Pazinaclone, (S)-PD172938 and Related Biologically Relevant Isoindolinones. Molecules 2022; 27:molecules27175647. [PMID: 36080411 PMCID: PMC9458024 DOI: 10.3390/molecules27175647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Herein, we report the application of an efficient and practical K2CO3 promoted cascade reaction of 2-acetylbenzonitrile in the synthesis of novel 3-methylated analogs of Pazinaclone and PD172938, belonging to isoindolinones heterocyclic class bearing a tetrasubstituted stereocenter. Organocatalytic asymmetric synthesis of the key intermediate and its transformation into highly enantioenriched 3-methylated analog of (S)-PD172938 was also developed. These achievements can be of particular interest also for medicinal chemistry, since the methyl group is a very useful structural modification in the rational design of new and more effective bioactive compounds.
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Affiliation(s)
- Antonia Di Mola
- Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy
- Correspondence: (A.D.M.); (A.M.)
| | - Giorgia Nicastro
- Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy
| | - Lorenzo Serusi
- Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy
| | - Rosanna Filosa
- Dipartimento di Scienze e Tecnologia, Università degli Studi del Sannio, Via De Sanctis, 82100 Benevento, Italy
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Antonio Massa
- Dipartimento di Chimica e Biologia “A. Zambelli”, Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, Italy
- Correspondence: (A.D.M.); (A.M.)
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12
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Röser K, Scheucher A, Mairhofer C, Bechmann M, Waser M. Oxidative decarboxylative ammonium hypoiodite-catalysed dihydrobenzofuran synthesis. Org Biomol Chem 2022; 20:3273-3276. [PMID: 35363244 DOI: 10.1039/d2ob00463a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The catalytic use of quaternary ammonium iodides under oxidative conditions allows for the direct conversion of readily available β-ketolactones into dihydrobenzofurans via a decarboxylative oxidative cycloetherification sequence facilitated by an in situ formed ammonium hypoiodite species.
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Affiliation(s)
- Katharina Röser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, Linz 4040, Austria.
| | - Anna Scheucher
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, Linz 4040, Austria.
| | - Christopher Mairhofer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, Linz 4040, Austria.
| | - Matthias Bechmann
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, Linz 4040, Austria.
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, Linz 4040, Austria.
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13
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Chowdhury R, Dubey MK, Waser M. Catalytic Enantioselective Decarboxylative Aldol reactions of Malonic acid half thio(oxy)ester and β‐ketoacids. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Raghunath Chowdhury
- Bhabha Atomic Research Centre Bio-Organic Division Tombay 400085 Mumbai INDIA
| | | | - Mario Waser
- Johannes Kepler Universität Linz: Johannes Kepler Universitat Linz Institute of Organic Chemistry AUSTRIA
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14
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Haider V, Zebrowski P, Michalke J, Monkowius U, Waser M. Enantioselective organocatalytic syntheses of α-selenated α- and β-amino acid derivatives. Org Biomol Chem 2022; 20:824-830. [PMID: 35015015 PMCID: PMC8790592 DOI: 10.1039/d1ob02235k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 12/22/2022]
Abstract
Selenium-containing amino acids are valuable targets but methods for the stereoselective α-selenation of simple amino acid precursors are rare. We herein report the enantioselective electrophilic α-selenation of azlactones (masked α-amino acid derivatives) and isoxazolidin-5-ones (masked β-amino acids) using Cinchona alkaloids as easily accessible organocatalysts. A variety of differently substituted derivatives was accessed with reasonable levels of enantioselectivities and further studies concerning the stability and suitability of these compounds for further manipulations have been carried out as well.
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Affiliation(s)
- Victoria Haider
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
| | - Paul Zebrowski
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
| | - Jessica Michalke
- Institute of Catalysis, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Uwe Monkowius
- School of Education, Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
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15
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Mairhofer C, Stockhammer L, Waser M. Organocatalytic asymmetric α-functionalizations of β-ketoesters with hypervalent iodine-based reagents and catalysts. ARKIVOC 2021. [DOI: 10.24820/ark.5550190.p011.612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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16
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Zebrowski P, Eder I, Eitzinger A, Mallojjala SC, Waser M. Enantioselective Catalytic Synthesis of α-Halogenated α-Aryl-β 2,2-amino Acid Derivatives. ACS Org Inorg Au 2021; 2:34-43. [PMID: 35141714 PMCID: PMC8815071 DOI: 10.1021/acsorginorgau.1c00025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 01/22/2023]
Abstract
The enantioselective synthesis of a broad variety of novel differently functionalized α-halogenated α-aryl-β2,2-amino acid derivatives by means of an ammonium-salt-catalyzed asymmetric α-halogenation of isoxazolidin-5-ones was accomplished. Key to success to obtain high levels of enantioselectivities was the use of Maruoka's spirocyclic binaphthyl-based ammonium salts, and detailed accompanying mechanistic studies using density functional theory methods revealed the key features for the catalyst-substrate interactions.
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Affiliation(s)
- Paul Zebrowski
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Isabella Eder
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Andreas Eitzinger
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Sharath Chandra Mallojjala
- Department
of Chemistry, State University of New York
at Binghamton, Binghamton, New York 13902, United States,
| | - Mario Waser
- Institute
of Organic Chemistry, Johannes Kepler University
Linz, Altenbergerstrasse 69, 4040 Linz, Austria,Phone: +4373224685411.
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17
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Stockhammer L, Weinzierl D, Bögl T, Waser M. Enantioselective α-Chlorination Reactions of in Situ Generated C1 Ammonium Enolates under Base-Free Conditions. Org Lett 2021; 23:6143-6147. [PMID: 34319102 PMCID: PMC8353620 DOI: 10.1021/acs.orglett.1c02256] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
The asymmetric α-chlorination
of activated aryl acetic acid
esters can be carried out with high levels of enantioselectivities
utilizing commercially available isothiourea catalysts under base-free
conditions. The reaction, which proceeds via the in situ formation
of chiral C1 ammonium enolates, is best carried out under cryogenic
conditions combined with a direct trapping of the activated α-chlorinated
ester derivative to prevent epimerization, thus allowing for enantioselectivities
of up to e.r. 99:1.
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Affiliation(s)
- Lotte Stockhammer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - David Weinzierl
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Thomas Bögl
- Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
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18
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Röser K, Berger B, Widhalm M, Waser M. Enantioselective Synthesis of Acyclic Orthogonally Functionalized Compounds Bearing a Quaternary Stereocenter Using Chiral Ammonium Salt Catalysis. ChemistryOpen 2021; 10:756-759. [PMID: 34351087 PMCID: PMC8340069 DOI: 10.1002/open.202100162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/09/2021] [Indexed: 11/29/2022] Open
Abstract
We herein report an asymmetric protocol to access a series of orthogonally functionalized acyclic chiral target molecules containing a quaternary stereogenic center by carrying out the enantioselective α-alkylation of novel orthogonally functionalized dioxolane-containing cyanoacetates under chiral ammonium salt catalysis. By using just 1 mol % of Maruoka's spirocyclic ammonium salt catalysts enantioselectivities up to e.r.=97.5 : 2.5 could be achieved and further functional group manipulations of the products were carried out as well.
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Affiliation(s)
- Katharina Röser
- Johannes Kepler University LinzInstitute of Organic ChemistryAltenbergerstraße 694040LinzAustria
| | - Bettina Berger
- University of ViennaInstitute of Chemical CatalysisWähringer Strasse 381090ViennaAustria
| | - Michael Widhalm
- University of ViennaInstitute of Chemical CatalysisWähringer Strasse 381090ViennaAustria
| | - Mario Waser
- Johannes Kepler University LinzInstitute of Organic ChemistryAltenbergerstraße 694040LinzAustria
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19
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Weinzierl D, Waser M. Synthesis of [2.2]Paracyclophane‐Based Glycidic Amides Using Chiral Ammonium Ylides. Helv Chim Acta 2021. [DOI: 10.1002/hlca.202100073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- David Weinzierl
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 AT-4040 Linz Austria
| | - Mario Waser
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 AT-4040 Linz Austria
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20
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Bencivenni G, Salazar Illera D, Moccia M, Houk KN, Izzo JA, Novacek J, Grieco P, Vetticatt MJ, Waser M, Adamo MFA. Study of Ground State Interactions of Enantiopure Chiral Quaternary Ammonium Salts and Amides, Nitroalkanes, Nitroalkenes, Esters, Heterocycles, Ketones and Fluoroamides. Chemistry 2021; 27:11352-11366. [PMID: 33963788 PMCID: PMC8453964 DOI: 10.1002/chem.202100908] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Indexed: 11/21/2022]
Abstract
Chiral phase‐transfer catalysis provides high level of enantiocontrol, however no experimental data showed the interaction of catalysts and substrates. 1H NMR titration was carried out on Cinchona and Maruoka ammonium bromides vs. nitro, carbonyl, heterocycles, and N−F containing compounds. It was found that neutral organic species and quaternary ammonium salts interacted via an ensemble of catalyst +N−C−H and (sp2)C−H, specific for each substrate studied. The correspondent BArF salts interacted with carbonyls via a diverse set of +N−C−H and (sp2)C−H compared to bromides. This data suggests that BArF ammonium salts may display a different enantioselectivity profile. Although not providing quantitative data for the affinity constants, the data reported proofs that chiral ammonium salts coordinate with substrates, prior to transition state, through specific C−H positions in their structures, providing a new rational to rationalize the origin of enantioselectivity in their catalyses.
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Affiliation(s)
- Grazia Bencivenni
- Department of Chemistry, RCSI, University of Medicine and Health Science, 123 St Stephen's Green, Dublin 2, Dublin, Republic of Ireland
| | - Diana Salazar Illera
- Department of Chemistry, RCSI, University of Medicine and Health Science, 123 St Stephen's Green, Dublin 2, Dublin, Republic of Ireland
| | - Maria Moccia
- CNR-ICC, Institute of Crystallography, Via G. Amendola 122/O, 70126, Bari, Italy
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, USA
| | - Joseph A Izzo
- Department of Chemistry, State University of NY Binghamton, Binghamton, NY, USA
| | - Johanna Novacek
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
| | - Paolo Grieco
- Faculty of Pharmacy, University of Naples Federico II, Corso Umberto I, 40, 80138, Napoli, NA, Italy
| | - Mathew J Vetticatt
- Department of Chemistry, State University of NY Binghamton, Binghamton, NY, USA
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040, Linz, Austria
| | - Mauro F A Adamo
- Department of Chemistry, RCSI, University of Medicine and Health Science, 123 St Stephen's Green, Dublin 2, Dublin, Republic of Ireland
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21
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Weinzierl D, Waser M. Chiral isothiourea-catalyzed kinetic resolution of 4-hydroxy[2.2]paracyclophane. Beilstein J Org Chem 2021; 17:800-804. [PMID: 33889220 PMCID: PMC8042488 DOI: 10.3762/bjoc.17.68] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/01/2021] [Indexed: 01/07/2023] Open
Abstract
We herein report a method for the kinetic resolution of racemic 4-hydroxy[2.2]paracyclophane by means of a chiral isothiourea-catalyzed acylation with isobutyric anhydride. This protocol allows for a reasonable synthetically useful s-factor of 20 and provides a novel entry to obtain this interesting planar chiral motive in an enantioenriched manner.
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Affiliation(s)
- David Weinzierl
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
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22
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Eitzinger A, Otevrel J, Haider V, Macchia A, Massa A, Faust K, Spingler B, Berkessel A, Waser M. Enantioselective Bifunctional Ammonium Salt-Catalyzed Syntheses of 3-CF 3S-, 3-RS-, and 3-F-Substituted Isoindolinones. Adv Synth Catal 2021; 363:1955-1962. [PMID: 33897314 PMCID: PMC8050839 DOI: 10.1002/adsc.202100029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/09/2021] [Indexed: 01/12/2023]
Abstract
We herein report the ammonium salt-catalyzed synthesis of chiral 3,3-disubstituted isoindolinones bearing a heteroatom functionality in the 3-position. A broad variety of differently substituted CF3S- and RS-derivatives were obtained with often high enantioselectivities when using Maruoka's bifunctional chiral ammonium salt catalyst. In addition, a first proof-of-concept for the racemic synthesis of the analogous F-containing products was obtained as well, giving access to one of the rare examples of a fairly stable α-F-α-amino acid derivative.
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Affiliation(s)
- Andreas Eitzinger
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Jan Otevrel
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
- Department of Chemical DrugsFaculty of PharmacyMasaryk UniversityPalackeho 1946/1612 00BrnoCzechia
| | - Victoria Haider
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Antonio Macchia
- Dipartimento di Chimica e BiologiaUniversità di SalernoVia Giovanni Paolo II, 13284084FiscianoSAItaly
| | - Antonio Massa
- Dipartimento di Chimica e BiologiaUniversità di SalernoVia Giovanni Paolo II, 13284084FiscianoSAItaly
| | - Kirill Faust
- Institute of CatalysisJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Bernhard Spingler
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
| | - Albrecht Berkessel
- Department of ChemistryCologne UniversityGreinstrasse 450939CologneGermany
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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23
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Stockhammer L, Schörgenhumer J, Mairhofer C, Waser M. Asymmetric α-Chlorination of β-Keto Esters Using Hypervalent Iodine-Based Cl-Transfer Reagents in Combination with Cinchona Alkaloid Catalysts. European J Org Chem 2021; 2021:82-86. [PMID: 33519300 PMCID: PMC7821243 DOI: 10.1002/ejoc.202001217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Indexed: 01/29/2023]
Abstract
We herein report an unprecedented strategy for the asymmetric α-chlorination of β-keto esters with hypervalent iodine-based Cl-transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an α-chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl-transfer reagent in situ. Using at least 20 mol-% of the alkaloid catalyst allows for good yields and enantioselectivities for a variety of different β-keto esters under operationally simple conditions.
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Affiliation(s)
- Lotte Stockhammer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Johannes Schörgenhumer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Christopher Mairhofer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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24
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Abstract
We herein report the deoxyfluorination of cyclic α-hydroxy-β-ketoesters using diethylaminosulfur trifluoride (DAST). The reaction proceeds with excellent levels of stereospecificity, giving the configurationally inverted α-fluoro-β-ketoesters in high yields under operationally simple conditions.
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Affiliation(s)
- Christopher Mairhofer
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria.
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25
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Abstract
AbstractIsoxazol-5-ones and isoxazolidin-5-ones represent two important classes of heterocycles, with several applications as bioactive compounds and as versatile building blocks for further transformations. Unlike the parent aromatic isoxazoles, the presence of one or two stereocenters in the ring renders their asymmetric construction particularly important. In this review, starting from the description of general features and differences between these two related compound families, we present an overview on the most important enantioselective synthesis strategies to access these heterocycles. Both chiral metal catalysts and organocatalysts have recently been successfully employed for this task and some of the most promising approaches will be discussed.1 Introduction2 Isoxazol-5-ones as Nucleophiles2.1 Isoxazol-5-ones as C-Nucleophiles2.2 Isoxazol-5-ones as N-Nucleophiles2.3 Isoxazol-5-ones as C-Nucleophiles in Cyclization Processes3 Asymmetric Construction of Isoxazolidin-5-ones3.1 Enantioselective α-Functionalizations of Isoxazolidin-5-ones4 Arylideneisoxazol-5-ones in Conjugated Addition5 Conclusions
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Affiliation(s)
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz
| | - Antonio Massa
- Department of Chemistry and Biology ‘A. Zambelli’, University of Salerno
| | - Antonio Macchia
- Department of Chemistry and Biology ‘A. Zambelli’, University of Salerno
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26
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Eder I, Haider V, Zebrowski P, Waser M. Recent Progress in the Asymmetric Syntheses of α‐Heterofunctionalized (Masked) α‐ and β‐Amino Acid Derivatives. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Isabella Eder
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Victoria Haider
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Paul Zebrowski
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
| | - Mario Waser
- Institute of Organic Chemistry Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz Austria
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27
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Haider V, Kreuzer V, Tiffner M, Spingler B, Waser M. Ammonium Salt-Catalyzed Ring-Opening of Aryl-Aziridines with β-Keto Esters. European J Org Chem 2020; 2020:5173-5177. [PMID: 32982577 PMCID: PMC7508174 DOI: 10.1002/ejoc.202000916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Indexed: 02/03/2023]
Abstract
We herein report an ammonium salt-catalyzed protocol for the regioselective ring opening of aryl-aziridines with β-keto esters. The reaction gives access to a variety of highly functionalized target molecules with two consecutive stereo-genic centers and can be rendered enantioselective (up to e.r. = 91:9) by using bifunctional chiral ammonium salt catalysts.
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Affiliation(s)
- Victoria Haider
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Viktoria Kreuzer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Maximilian Tiffner
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Bernhard Spingler
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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28
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Mairhofer C, Novacek J, Waser M. Synergistic Ammonium (Hypo)Iodite/Imine Catalysis for the Asymmetric α-Hydroxylation of β-Ketoesters. Org Lett 2020; 22:6138-6142. [PMID: 32706973 PMCID: PMC7418104 DOI: 10.1021/acs.orglett.0c02198] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Indexed: 12/14/2022]
Abstract
The synergistic use of chiral bifunctional ammonium iodide catalysts in combination with simple catalytically relevant aldimines allows for an unprecedented asymmetric α-hydroxylation reaction of β-ketoesters using H2O2. The reaction proceeds via in situ formation of a hypervalent iodine species, which then reacts with the used aldimine to generate an activated electrophilic oxygen transfer reagent.
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Affiliation(s)
- Christopher Mairhofer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | | | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
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29
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Abstract
A new family of CF3-containing para-quinone methides (CF3-QMs) was systematically investigated for its suitability in organic synthesis. Addition of different nucleophiles gives access to target molecules with a benzylic CF3-containing stereogenic center straightforwardly. The electrophilicity parameter E of the prototypical CF3-QM 2,6-di-tert-butyl-4-(2,2,2-trifluoroethylidene)cyclohexa-2,5-dien-1-one was determined to be -11.68 according to the Mayr scale, making it one of the most reactive quinone methides known so far.
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Affiliation(s)
- Michael Winter
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstraße 694040LinzAustria
| | - Roman Schütz
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstraße 694040LinzAustria
| | - Andreas Eitzinger
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstraße 694040LinzAustria
| | - Armin R. Ofial
- Department ChemieLudwig‐Maximilians‐Universität MünchenButenandtstraße 5‐1381377MünchenGermany
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstraße 694040LinzAustria
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30
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Kováč O, Zálešák F, J-Y D Bon D, Roiser L, Baar LV, Waser M, Pospíšil J. Trisubstituted Highly Activated Benzo[ d]thiazol-2-yl-sulfone-Containing Olefins as Building Blocks in Organic Synthesis. J Org Chem 2020; 85:7192-7206. [PMID: 32352285 DOI: 10.1021/acs.joc.0c00571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In this paper, we report the formation of highly electrophilic 1,1-deactivated olefins, their use as novel synthetic building blocks, and their transformation to structurally diverse molecular scaffolds. Synthesis of 1,1-deactivated olefins substituted with a BT-sulfonyl group and a carbonyl or nitrile, respectively, consists of unusual Ti(OPri)4-mediated Knoevenagel-type condensation and proceed in good to excellent yields. Generated olefins can be further transformed in a highly stereoselective manner and in good yields to various polyfunctionalized heterocycles and acyclic molecular scaffolds. Overall, the obtained structures are accessed in two to four steps starting from the (mostly) commercially available aldehydes. In addition, the presence of the BT-sulfonyl group in prepared structures allows for further chemoselective functionalization/post-synthetic transformations to provide structurally diverse final compounds.
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Affiliation(s)
- Ondřej Kováč
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic
| | - František Zálešák
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic
| | - David J-Y D Bon
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic
| | - Lukas Roiser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Lubomír V Baar
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Jiří Pospíšil
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic.,Laboratory of Growth Regulators, Palacky University & Institute of Experimental Botany AS CR, Šlechtitelů 27, CZ-783 71 Olomouc, Czech Republic
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31
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Abstract
![]()
The
electrophilic reactivity of a series of 8-arylated vinyl p-quinone methides (pVQMs) was determined by analyzing
the kinetics of their reactions with carbanions in DMSO at 20 °C
according to the linear free energy relationship log k = sN(N + E). The electrophilicity
parameters E for pVQMs were used
to successfully predict Michael-additions with structurally diverse
C-, N-, S-, and H-nucleophiles.
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Affiliation(s)
- Andreas Eitzinger
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Robert J Mayer
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Nathalie Hampel
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Peter Mayer
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Armin R Ofial
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
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32
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Abstract
We herein report a novel entry towards chiral α-SCF3-β2,2-amino acids by carrying out the ammonium salt-catalyzed α-trifluoromethylthiolation of isoxazolidin-5-ones. This approach allowed for high enantioselectivities and high yields and the obtained heterocycles proved to be versatile platforms to access other targets of potential interest.
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Affiliation(s)
- Andreas Eitzinger
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria
| | | | - Dominique Cahard
- CNRS, UMR 6014 COBRA, Normandie Univ, UNIROUEN, INSA Rouen, 76000 Rouen, France
| | - Mario Waser
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria
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33
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Eitzinger A, Winter M, Schörgenhumer J, Waser M. Quaternary β 2,2-amino acid derivatives by asymmetric addition of isoxazolidin-5-ones to para-quinone methides. Chem Commun (Camb) 2019; 56:579-582. [PMID: 31830176 DOI: 10.1039/c9cc09239k] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The highly enantioselective (>99.5% ee) synthesis of a new class of densely functionalized β2,2-amino acid derivatives by reacting isoxazolidin-5-ones with para-quinone methides in the presence of chiral ammonium salt phase-transfer catalysts was developed. The reaction proceeds with exceptionally low catalyst loadings down to 20 ppm on gram scale and the utilization of the primary addition products towards further manipulations was demonstrated for selected examples.
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Affiliation(s)
- Andreas Eitzinger
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria. mario.waser@jku
| | - Michael Winter
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria. mario.waser@jku
| | - Johannes Schörgenhumer
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria. mario.waser@jku
| | - Mario Waser
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstraße 69, 4040 Linz, Austria. mario.waser@jku
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34
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Waser M, Stefani A, Holzknecht E, Garn H, Kohn B, Hackner H, Brandauer E, Bergmann M, Taupe P, Gall M, Högl B. A new diagnostic approach to identify isolated REM sleep behavior disorder (IRBD): 3D video analysis. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.1153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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35
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Abstract
We herein report a high yielding protocol for the direct α-allylation of easily accessible trifluoropyruvate-derived imines using Pd-catalysis. The reaction gives access to a variety of different α-allylated-α-CF3-amino acids in a straightforward manner, starting from commercially available trifluoropyruvate. We also provide a proof-of-concept for an enantioselective protocol (up to er = 75:25) by using chiral phosphane ligands.
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Affiliation(s)
- Michael Winter
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Hyunwoo Kim
- Department of ChemistryKorea Advanced Institute of Science and Technology291 Daehak‐ro34141DaejeonYuseong‐guRepublic of Korea
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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36
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Winter M, Faust K, Himmelsbach M, Waser M. Synthesis of α-CF 3-proline derivatives by means of a formal (3 + 2)-cyclisation between trifluoropyruvate imines and Michael acceptors. Org Biomol Chem 2019; 17:5731-5735. [PMID: 31149695 PMCID: PMC6625964 DOI: 10.1039/c9ob01134j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We herein report the first formal (3 + 2)-cyclisation between 3,3,3-trifluoropyruvate-derived imines and indandione-based Michael acceptors. This reaction gives access to a novel class of spirocyclic α-CF3-α-proline derivatives with complete control of the diastereoselectivity under phase transfer-catalysed reaction conditions.
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Affiliation(s)
- Michael Winter
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
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37
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Zielke K, Kováč O, Winter M, Pospíšil J, Waser M. Enantioselective Catalytic [4+1]-Cyclization of ortho-Hydroxy-para-Quinone Methides with Allenoates. Chemistry 2019; 25:8163-8168. [PMID: 31020717 PMCID: PMC6618147 DOI: 10.1002/chem.201901784] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 12/25/2022]
Abstract
The first highly asymmetric catalytic synthesis of densely functionalized dihydrobenzofurans is reported, which starts from ortho‐hydroxy‐containing para‐quinone methides. The reaction relies on an unprecedented formal [4+1]‐annulation of these quinone methides with allenoates in the presence of a commercially available chiral phosphine catalyst. The chiral dihydrobenzofurans were obtained as single diastereomers in yields up to 90 % and with enantiomeric ratios up to 95:5.
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Affiliation(s)
- Katharina Zielke
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria
| | - Ondřej Kováč
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic
| | - Michael Winter
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria
| | - Jiří Pospíšil
- Department of Organic Chemistry, Faculty of Science, Palacky University, tř. 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic.,Laboratory of Growth Regulators, The Czech Academy of Sciences, Institute of Experimental Botany & Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria
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Gärtner P, Waser M. Happy birthday Heinz Falk. Monatsh Chem 2019. [DOI: 10.1007/s00706-019-02439-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Schörgenhumer J, Waser M. Transition metal-free coupling of terminal alkynes and hypervalent iodine-based alkyne-transfer reagents to access unsymmetrical 1,3-diynes. Org Biomol Chem 2018; 16:7561-7563. [PMID: 30288537 DOI: 10.1039/c8ob02375a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A variety of unsymmetrical 1,3-diynes can easily be accessed in good yields under catalyst- and transition metal-free conditions by reacting terminal alkynes with hypervalent iodine-based electrophilic alkyne-transfer reagents.
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Affiliation(s)
- J Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
| | - M Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria.
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40
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Capaccio V, Zielke K, Eitzinger A, Massa A, Palombi L, Faust K, Waser M. Asymmetric phase-transfer catalysed β-addition of isoxazolidin-5-ones to MBH carbonates. Org Chem Front 2018; 5:3336-3340. [PMID: 30505454 PMCID: PMC6261335 DOI: 10.1039/c8qo01057a] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel high yielding, enantio- and diastereoselective protocol for the synthesis of α-allylated highly functionalised β-amino acid derivatives by adding isoxazolidin-5-ones to MBH carbonates under asymmetric phase-transfer catalysis has been developed.
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Affiliation(s)
- Vito Capaccio
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Katharina Zielke
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Andreas Eitzinger
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Antonio Massa
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Laura Palombi
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Kirill Faust
- Institute of Catalysis, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
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Abstract
The formal (4+1)-cyclization between in situ generated achiral carbonyl-stabilized ammonium ylides and vinylogous p-quinone methides can be carried out under operationally simple conditions, leading to two different double bond regioisomers depending on the used conditions. Besides these racemic approaches, also a first proof-of-concept for enantioselective versions of these reactions has been obtained.
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Affiliation(s)
- Lukas Roiser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Katharina Zielke
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
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Eitzinger A, Zielke K, Widhalm M, Robiette R, Waser M. Syntheses of Highly Functionalized Spirocyclohexenes by Formal [4+2] Annulation of Arylidene Azlactones with Allenoates. ASIAN J ORG CHEM 2018; 7:1620-1625. [PMID: 30175031 PMCID: PMC6114148 DOI: 10.1002/ajoc.201800275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A straightforward phosphine-catalyzed formal [4+2] annulation between α-branched allenoates and arylidene azlactones has been developed to access highly functionalized spirocyclohexenes. This cyclization favors the γ-addition of the phosphine-activated allenoates over a β'-addition pathway. Detailed computational studies support the proposed mechanism and provide a reasonable explanation for the observed regioselectivity and the noted effect of the catalyst.
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Affiliation(s)
- Andreas Eitzinger
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstrasse 69, 4040 Linz (Austria)
| | - Katharina Zielke
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstrasse 69, 4040 Linz (Austria)
| | - Michael Widhalm
- University of Vienna, Institute of Chemical Catalysis, Wäringer Strasse 38, 1090 Vienna (Austria)
| | - Raphaël Robiette
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Place Louis Pasteur 1 box L4.01.02, 1348 Louvain-la-Neuve (Belgium)
| | - Mario Waser
- Johannes Kepler University Linz, Institute of Organic Chemistry, Altenbergerstrasse 69, 4040 Linz (Austria)
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Fan Y, Tiffner M, Schörgenhumer J, Robiette R, Waser M, Kass SR. Synthesis of Cyclic Organic Carbonates Using Atmospheric Pressure CO2 and Charge-Containing Thiourea Catalysts. J Org Chem 2018; 83:9991-10000. [PMID: 30020780 DOI: 10.1021/acs.joc.8b01374] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yang Fan
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - Maximilian Tiffner
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Johannes Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Raphaël Robiette
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Louis Pasteur 1, 1348 Louvain-la-Neuve, Belgium
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Steven R. Kass
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
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Affiliation(s)
- Johannes Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
| | - Axel Zimmermann
- Patheon Austria, part of Thermo Fisher Scientific, St. Peterstr. 25, 4020 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria
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Tiffner M, Stockhammer L, Schörgenhumer J, Röser K, Waser M. Towards an Asymmetric Organocatalytic α-Azidation of β-Ketoesters. Molecules 2018; 23:molecules23051142. [PMID: 29751597 PMCID: PMC6100502 DOI: 10.3390/molecules23051142] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/04/2018] [Accepted: 05/10/2018] [Indexed: 12/11/2022] Open
Abstract
Detailed investigations concerning the organocatalytic (asymmetric) α-azidation of prochiral β-ketoesters were carried out. It was shown that the racemic version of such a reaction can either be carried out under oxidative conditions using TMSN3 as the azide-source with quaternary ammonium iodides as the catalysts, or by using hypervalent iodine-based electrophilic azide-transfer reagents with different organocatalysts. In addition, the latter strategy could also be carried out with modest enantioselectivities when using simple cinchona alkaloid catalysts, albeit with relatively low yields.
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Affiliation(s)
- Maximilian Tiffner
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
| | - Lotte Stockhammer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
| | - Johannes Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
| | - Katharina Röser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.
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Abstract
Abstract Sultones, the cyclic esters of hydroxyl sulfonic acids, are a fascinating class of heterocycles and the recent years have witnessed an increasing interest in these molecules, especially in six-ring δ-sultones. The importance of these compounds is either because of their biological properties themselves or due to their versatility as intermediates in more complex target syntheses. Accordingly, the development of new synthesis methods to access δ-sultones is an important and rewarding task which we wish to highlight in this review. Graphical abstract ![]()
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Affiliation(s)
- Christina Gaunersdorfer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstraße 69, 4040 Linz, Austria
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47
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Abstract
The use of readily accessible ammonium ylides for (asymmetric) transformations, especially cyclization reactions, has received considerable attention over the past two decades. A variety of highly enantioselective protocols to facilitate annulation reactions have recently been introduced as an alternative to other common methods including S-ylide-mediated strategies. It is the intention of this short review to provide an introduction to this field by highlighting the potential of ammonium ylides for (asymmetric) cyclization reactions as well as to present the limitations and challenges of these methods.
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Affiliation(s)
- Lukas Roiser
- Institute of Organic Chemistry, Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz (Austria)
| | - Katharina Zielke
- Institute of Organic Chemistry, Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz (Austria)
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz Altenbergerstr. 69 4040 Linz (Austria)
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Winter M, Gaunersdorfer C, Roiser L, Zielke K, Monkowius U, Waser M. Synthesis of Trifluoroacetyl-Substituted Cyclopropanes Using Onium Ylides. European J Org Chem 2018; 2018:418-421. [PMID: 29491744 PMCID: PMC5817241 DOI: 10.1002/ejoc.201701699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Indexed: 01/27/2023]
Abstract
The use of carbonyl-stabilized ammonium- and sulfonium ylides allows for the synthesis of highly-functionalized trifluoroacetyl-substituted cyclopropanes. It turned out that the diastereoselectivities strongly depend on the nature of the chosen ylide and the employed base. The products could be obtained in good yields under operationally simple conditions.
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Affiliation(s)
- Michael Winter
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Christina Gaunersdorfer
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Lukas Roiser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Katharina Zielke
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Uwe Monkowius
- School of EducationJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
| | - Mario Waser
- Institute of Organic ChemistryJohannes Kepler University LinzAltenbergerstr. 694040LinzAustria
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Abstract
![]()
The
first (4 + 1)-annulation of o-quinone methides
with α-branched allenoates as C1 synthons has been developed.
This operationally simple protocol gives access to highly functionalized
dihydrobenzofurans in an unprecedented fashion with excellent diastereoselectivities
and high yields.
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Affiliation(s)
- Katharina Zielke
- Institute of Organic Chemistry, Johannes Kepler University Linz , Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz , Altenbergerstrasse 69, 4040 Linz, Austria
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Schörgenhumer J, Tiffner M, Waser M. Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles. Beilstein J Org Chem 2017; 13:1753-1769. [PMID: 28904619 PMCID: PMC5588627 DOI: 10.3762/bjoc.13.170] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/10/2017] [Indexed: 01/10/2023] Open
Abstract
Chiral phase-transfer catalysis is one of the major catalytic principles in asymmetric catalysis. A broad variety of different catalysts and their use for challenging applications have been reported over the last decades. Besides asymmetric C–C bond forming reactions the use of chiral phase-transfer catalysts for enantioselective α-heterofunctionalization reactions of prochiral nucleophiles became one of the most important field of application of this catalytic principle. Based on several highly spectacular recent reports, we thus wish to discuss some of the most important achievements in this field within the context of this review.
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Affiliation(s)
- Johannes Schörgenhumer
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Maximilian Tiffner
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
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