1
|
Lemmerer M, Zhang H, Fernandes AJ, Fischer T, Mießkes M, Xiao Y, Maulide N. Synthese von α-Arylacrylamiden via Lewis Base vermitteltem Aryl/Wasserstoff-Austausch. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202207475. [PMID: 38505003 PMCID: PMC10947125 DOI: 10.1002/ange.202207475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 11/12/2022]
Abstract
AbstractHierin stellen wir eine neue Methode für die Synthese von α‐Arylacrylamiden vor. Die Reaktion basiert auf der Nutzung polarer S‐zu‐C Arylwanderungen, induziert durch einen Lewis‐basischen Organokatalysator. Im Unterschied zu zuvor publizierten radikalischen Arylwanderungen von Sulfonylacrylamiden, ermöglicht dieser polare Prozess eine darauffolgende Eliminierung, wodurch in Summe ein formaler Aryl/Wasserstoff‐Austausch unter Ausscheidung von SO2 stattfindet. Die vorgestellte Reaktion ist selektiv für elektronenarme aromatische Gruppen, während eine Vielfalt von Substituenten am Stickstoff und an der β‐Position toleriert werden, und erzeugt nützliche Bausteine für Folgereaktionen wie Zykloadditionen und Zyklisierungen. Der Reaktionsmechanismus wurde mithilfe quantenchemischer Berechnungen erforscht, die die unerwartete Rolle der Lewis Base in mehreren Schlüsselschritten darlegten.
Collapse
Affiliation(s)
- Miran Lemmerer
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
| | - Haoqi Zhang
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz1090WienÖsterreich
| | - Anthony J. Fernandes
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz1090WienÖsterreich
| | | | - Marianne Mießkes
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
| | - Yi Xiao
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesLazarettgasse 14, AKH BT 25.31090WienÖsterreich
| | - Nuno Maulide
- Fakultät Chemie, Institut für Organische ChemieUniversität WienWähringer Str. 381090WienÖsterreich
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz1090WienÖsterreich
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesLazarettgasse 14, AKH BT 25.31090WienÖsterreich
| |
Collapse
|
2
|
Lemmerer M, Zhang H, Fernandes AJ, Fischer T, Mießkes M, Xiao Y, Maulide N. Synthesis of α-Aryl Acrylamides via Lewis-Base-Mediated Aryl/Hydrogen Exchange. Angew Chem Int Ed Engl 2022; 61:e202207475. [PMID: 35881564 PMCID: PMC9804524 DOI: 10.1002/anie.202207475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Indexed: 01/05/2023]
Abstract
Herein we report a method for the synthesis of α-aryl acrylamides leveraging polar S-to-C aryl migrations induced by a Lewis basic organocatalyst. In contrast to previously reported radical aryl migrations of sulfonyl acrylimides, this polar process enables subsequent elimination, ultimately leading to a formal aryl/hydrogen exchange including SO2 extrusion. This reaction is selective for electron-deficient aromatic groups, while tolerating a variety of substituents on nitrogen and in the β-position, and it delivers useful building blocks for further transformations, including cycloaddition and cyclisation reactions. The mechanism was investigated in detail using quantum chemical calculations, which unexpectedly revealed the Lewis base to be involved in several decisive steps.
Collapse
Affiliation(s)
- Miran Lemmerer
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
| | - Haoqi Zhang
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz 21090ViennaAustria
| | - Anthony J. Fernandes
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz 21090ViennaAustria
| | | | - Marianne Mießkes
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
| | - Yi Xiao
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesLazarettgasse 14, AKH BT 25.31090ViennaAustria
| | - Nuno Maulide
- Faculty of ChemistryInstitute of Organic ChemistryUniversity of ViennaWähringer Str. 381090ViennaAustria
- Christian-Doppler Laboratory for Entropy-Oriented Drug DesignJosef-Holaubek-Platz 21090ViennaAustria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesLazarettgasse 14, AKH BT 25.31090ViennaAustria
| |
Collapse
|
3
|
Zhao B, Xu B. Visible-light promoted oxidative cyclization of cinnamic acid derivatives using xanthone as the photocatalyst. Org Biomol Chem 2021; 19:568-573. [DOI: 10.1039/d0ob02417a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have developed an efficient photocatalytic synthesis of coumarin derivatives via a tandem double bond isomerization/oxidative cyclization of cinnamic acids.
Collapse
Affiliation(s)
- Bin Zhao
- Key Laboratory of Science and Technology of Eco-Textiles
- Ministry of Education
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
| | - Bo Xu
- Key Laboratory of Science and Technology of Eco-Textiles
- Ministry of Education
- College of Chemistry
- Chemical Engineering and Biotechnology
- Donghua University
| |
Collapse
|
4
|
Laudadio G, Fusini G, Casotti G, Evangelisti C, Angelici G, Carpita A. Synthesis of Pterostilbene through supported-catalyst promoted Mizoroki-Heck reaction, and its transposition in continuous flow reactor. J Flow Chem 2019. [DOI: 10.1007/s41981-019-00033-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
5
|
Kolli MK, Palani E, Govindasamy C, Katta VR. Highly efficient one-pot synthesis of α-aminophosphonates using nanoporous AlSBA-15 catalyst in a three-component system. RESEARCH ON CHEMICAL INTERMEDIATES 2018. [DOI: 10.1007/s11164-018-3458-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
6
|
García CS, Uberman PM, Martín SE. An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki-Heck coupling reaction under microwave irradiation. Beilstein J Org Chem 2017; 13:1717-1727. [PMID: 28904615 PMCID: PMC5564268 DOI: 10.3762/bjoc.13.166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/04/2017] [Indexed: 01/13/2023] Open
Abstract
Aqueous Mizoroki–Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The reaction was carried out in a short reaction time and with low catalyst loading, leading to high turnover frequency (TOFs of the order of 100 h−1). The advantages like operational simplicity, high robustness, efficiency and turnover frequency, the utilization of aqueous media and simple product work-up make this protocol a great option for stilbene syntheses by Mizoroki–Heck reaction.
Collapse
Affiliation(s)
- Carolina S García
- INFIQC-CONICET- Universidad Nacional de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Paula M Uberman
- INFIQC-CONICET- Universidad Nacional de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| | - Sandra E Martín
- INFIQC-CONICET- Universidad Nacional de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
| |
Collapse
|
7
|
Ceyhan S, Cetinkaya Y, Akdag A, Balci M. Regioselectivity observed in manganese(III) acetate mediated addition of acetylacetone to various alkenes: mechanistic and theoretical studies. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
8
|
Tang Y, Zeng Y, Hu Q, Huang F, Jin L, Mo W, Sun N, Hu B, Shen Z, Hu X, Sun WH. Efficient Catalyst for Both Suzuki and Heck Cross-Coupling Reactions: Synthesis and Catalytic Behaviour of Geometry- Constrained Iminopyridylpalladium Chlorides. Adv Synth Catal 2016. [DOI: 10.1002/adsc.201600294] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yujie Tang
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Yanning Zeng
- Key laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science; Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 People's Republic of China
| | - Qingxia Hu
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Fang Huang
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
- Key laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science; Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 People's Republic of China
| | - Liqun Jin
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Weimin Mo
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Nan Sun
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Baoxiang Hu
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Zhenlu Shen
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
| | - Xinquan Hu
- College of Chemical Engineering; Zhejiang University of Technology; Hangzhou 310032 People's Republic of China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences; Lanzhou 730000 People's Republic of China
| | - Wen-Hua Sun
- Key laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science; Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 People's Republic of China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences; Lanzhou 730000 People's Republic of China
| |
Collapse
|
9
|
Fu W, Feng Y, Fang Z, Chen Q, Tang T, Yu Q, Tang T. Zeolite Y nanosheet assembled palladium catalysts with high catalytic activity and selectivity in the vinylation of thiophenes. Chem Commun (Camb) 2016; 52:3115-8. [PMID: 26794615 DOI: 10.1039/c5cc08366d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Zeolite Y nanosheets with a micro-meso-macroporous structure were synthesized, and applied in the assembly of a Pd catalyst (Pd/NS-Y) for direct vinylation of thiophenes with high activity and selectivity, as compared to Pd(OAc)2, Pd(NO3)2, and Pd(PPh3)4 catalysts. This feature should be assigned to the highly dispersed Pd(δ+) (δ < 2) species in Pd/NS-Y, which are more active than Pd(2+).
Collapse
Affiliation(s)
- Wenqian Fu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Yu Feng
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Zhongxue Fang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Qun Chen
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Ting Tang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Quanyong Yu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China.
| | - Tiandi Tang
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, Jiangsu 213164, P. R. China. and College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| |
Collapse
|
10
|
Tyson GE, Tokmic K, Oian CS, Rabinovich D, Valle HU, Hollis TK, Kelly JT, Cuellar KA, McNamara LE, Hammer NI, Webster CE, Oliver AG, Zhang M. Synthesis, characterization, photophysical properties, and catalytic activity of an SCS bis(N-heterocyclic thione) (SCS-NHT) Pd pincer complex. Dalton Trans 2015. [PMID: 26205732 DOI: 10.1039/c4dt03324h] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Treatment of 1,3-bis(3'-butylimidazolyl-1'-yl)benzene diiodide with elemental sulfur in the presence of a base produced a bis(N-heterocyclic thione) (NHT) pincer ligand precursor. Its reaction with PdCl2(CH3CN)2 produced chloro[1,3-bis(3'-butylimidazole-2'-thione-κ-S)benzene-κ-C]palladium(ii), a 6,6-fused ring SCS-NHT palladium pincer complex. This air stable compound is, to our knowledge, the first SCS pincer complex that utilizes N-heterocyclic thione (NHT) donor groups. The molecular structures of the ligand precursor and the palladium complex were determined by X-ray crystallography and computational studies provided insight into the interconversion between its rac and meso conformations. The photophysical properties of the complex were established, and its catalytic activity in Suzuki, Heck, and Sonogashira cross-coupling reactions was evaluated.
Collapse
Affiliation(s)
- Ginger E Tyson
- Department of Chemistry, Mississippi State University, Mississippi State. and MS 39762 and Department of Chemistry and Biochemistry, The University of Mississippi, University, MS 38677, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Ortega-Jiménez F, Domínguez-Villa FX, Rosas-Sánchez A, Penieres-Carrillo G, López-Cortés JG, Ortega-Alfaro MC. An expedient approach to enhance Mizoroki-Heck coupling reaction by infrared irradiation using palladacycle compounds. Appl Organomet Chem 2015. [DOI: 10.1002/aoc.3331] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Fernando Ortega-Jiménez
- Departamento de Ciencias Químicas; Facultad de Estudios Superiores Cuautitlán-UNAM; Campo 1, Avenida 1 de Mayo s/n Cuautitlán Izcalli CP 54740 Estado de México México
| | | | - Alfredo Rosas-Sánchez
- Instituto de Ciencias Nucleares, UNAM; Circuito Exterior, Cd. Universitaria México 04360 DF México
| | - Guillermo Penieres-Carrillo
- Departamento de Ciencias Químicas; Facultad de Estudios Superiores Cuautitlán-UNAM; Campo 1, Avenida 1 de Mayo s/n Cuautitlán Izcalli CP 54740 Estado de México México
| | - José G. López-Cortés
- Instituto de Química UNAM; Circuito Exterior, Ciudad Universitaria México 04360 DF México
| | - M. Carmen Ortega-Alfaro
- Instituto de Ciencias Nucleares, UNAM; Circuito Exterior, Cd. Universitaria México 04360 DF México
| |
Collapse
|
12
|
Muddala NP, Nammalwar B, Selvaraju S, Bourne CR, Henry M, Bunce RA, Berlin KD, Barrow EW, Barrow WW. Evaluation of New Dihydrophthalazine-Appended 2,4-Diaminopyrimidines against Bacillus anthracis: Improved Syntheses Using a New Pincer Complex. Molecules 2015; 20:7222-44. [PMID: 25905602 PMCID: PMC4445145 DOI: 10.3390/molecules20047222] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/14/2015] [Accepted: 04/15/2015] [Indexed: 02/05/2023] Open
Abstract
The synthesis and evaluation of ten new dihydrophthalazine-appended 2,4-diaminopyrimidines as potential drugs to treat Bacillus anthracis is reported. An improved synthesis utilizing a new pincer catalyst, dichlorobis[1-(dicyclohexylphosphanyl)-piperidine]palladium(II), allows the final Heck coupling to be performed at 90 °C using triethylamine as the base. These milder conditions have been used to achieve improved yields for new and previously reported substrates with functional groups that degrade or react at the normal 140 °C reaction temperature. An analytical protocol for separating the S and R enantiomers of two of the most active compounds is also disclosed. Finally, the X-ray structure for the most active enantiomer of the lead compound, (S)-RAB1, is given.
Collapse
Affiliation(s)
- Nagendra Prasad Muddala
- Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, OK 74078, USA.
| | - Baskar Nammalwar
- Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, OK 74078, USA.
| | - Subhashini Selvaraju
- Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, OK 74078, USA.
| | - Christina R Bourne
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, USA.
| | - Mary Henry
- Department of Veterinary Pathobiology, Oklahoma State University, 250 McElroy Hall, Stillwater, OK 74078, USA.
| | - Richard A Bunce
- Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, OK 74078, USA.
| | - K Darrell Berlin
- Department of Chemistry, Oklahoma State University, 107 Physical Sciences, Stillwater, OK 74078, USA.
| | - Esther W Barrow
- Department of Veterinary Pathobiology, Oklahoma State University, 250 McElroy Hall, Stillwater, OK 74078, USA.
| | - William W Barrow
- Department of Veterinary Pathobiology, Oklahoma State University, 250 McElroy Hall, Stillwater, OK 74078, USA.
| |
Collapse
|
13
|
Quinteros GJ, Uberman PM, Martín SE. Bulky Monodentate Biphenylarsine Ligands: Synthesis and Evaluation of Their Structure Effects in the Palladium-Catalyzed Heck Reaction. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403658] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
14
|
Rajendra Prasad Reddy B, Vasu Govardhana Reddy P, Reddy BN. Efficient solvent free synthesis of tertiary α-aminophosphonates using H2Ti3O7 nanotubes as a reusable solid-acid catalyst. NEW J CHEM 2015. [DOI: 10.1039/c5nj01914a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Kabachnik–Fields reaction was applied for the synthesis of α-aminophosphonates from aldehydes, secondary amines and dialkyl phosphites in the presence of H2Ti3O7 nanotubes as reusable solid-acid catalysts.
Collapse
|
15
|
Hosseini-Sarvari M, Moeini F. Nano copper(i) oxide–zinc oxide catalyzed coupling of aldehydes or ketones, secondary amines, and terminal alkynes in solvent-free conditions. NEW J CHEM 2014. [DOI: 10.1039/c3nj01146a] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
16
|
|
17
|
|
18
|
Boeck F, Blazejak M, Anneser MR, Hintermann L. Cyclization of ortho-hydroxycinnamates to coumarins under mild conditions: A nucleophilic organocatalysis approach. Beilstein J Org Chem 2012; 8:1630-6. [PMID: 23209495 PMCID: PMC3510995 DOI: 10.3762/bjoc.8.186] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 08/20/2012] [Indexed: 11/23/2022] Open
Abstract
(E)-Alkyl ortho-hydroxycinnamates cyclize to coumarins at elevated temperatures of 140-250 °C. We find that the use of tri-n-butylphosphane (20 mol %) as a nucleophilic organocatalyst in MeOH solution allows cyclization to take place under much milder conditions (60-70 °C). Several coumarins were prepared, starting from ortho-hydroxyarylaldehydes, by Wittig reaction with Ph(3)P=CHCO(2)Me to (E)-methyl ortho-hydroxycinnamates, followed by the phosphane catalyzed cyclization.
Collapse
Affiliation(s)
- Florian Boeck
- Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | | | | | | |
Collapse
|
19
|
Gerber R, Frech CM. Alkyne Hydrothiolation Catalyzed by a Dichlorobis(aminophosphine) Complex of Palladium: Selective Formation of cis-Configured Vinyl Thioethers. Chemistry 2012; 18:8901-5. [DOI: 10.1002/chem.201200388] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/24/2012] [Indexed: 11/08/2022]
|