1
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Bannon R, Morrison G, Smyth M, Moody TS, Wharry S, Roth PMC, Gauron G, Baumann M. Continuous Flow Approach for Benzylic Photo-oxidations Using Compressed Air. Org Process Res Dev 2024; 28:3307-3312. [PMID: 39171129 PMCID: PMC11334174 DOI: 10.1021/acs.oprd.4c00213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/03/2024] [Accepted: 07/11/2024] [Indexed: 08/23/2024]
Abstract
A continuous flow approach for the aerobic photo-oxidation of benzylic substrates to ketone and aldehyde products is presented. The resulting process exploits UV-A LEDs (375 nm) in combination with a Corning AFR reactor that ensures effective gas-liquid mixing and leads to short residence times of 1 min. A variety of benzylic substrates are converted to their corresponding carbonyl products, and scalability is demonstrated to produce multigram quantities of products within a few hours. Overall, this continuous flow approach offers several improvements over alternative oxidation methods due to the combined use of air as an oxidant and SAS (sodium anthraquinone-2 sulfonate) as a water-soluble photocatalyst. The use of greener and safer conditions together with process intensification principles renders this flow approach attractive for further industrial applications.
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Affiliation(s)
- Ruairi Bannon
- School
of Chemistry, Science Centre South, University
College Dublin, Dublin D04 N2E5, Ireland
| | - Gary Morrison
- Technology
Department, Almac Sciences, Craigavon BT63 5QD, U.K.
| | - Megan Smyth
- Technology
Department, Almac Sciences, Craigavon BT63 5QD, U.K.
| | - Thomas S. Moody
- Technology
Department, Almac Sciences, Craigavon BT63 5QD, U.K.
- Arran
Chemical Company, Monksland Industrial
Estate, Roscommon N37 DN24, Ireland
| | - Scott Wharry
- Technology
Department, Almac Sciences, Craigavon BT63 5QD, U.K.
| | - Philippe M. C. Roth
- Corning
Reactor Technologies, Corning SAS, 7 bis Avenue de Valvins, CS 70156
Samois sur Seine, 77215 Avon Cedex, France
| | - Guillaume Gauron
- Corning
Reactor Technologies, Corning SAS, 7 bis Avenue de Valvins, CS 70156
Samois sur Seine, 77215 Avon Cedex, France
| | - Marcus Baumann
- School
of Chemistry, Science Centre South, University
College Dublin, Dublin D04 N2E5, Ireland
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2
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Pijper B, Saavedra LM, Lanzi M, Alonso M, Fontana A, Serrano M, Gómez JE, Kleij AW, Alcázar J, Cañellas S. Addressing Reproducibility Challenges in High-Throughput Photochemistry. JACS AU 2024; 4:2585-2595. [PMID: 39055158 PMCID: PMC11267557 DOI: 10.1021/jacsau.4c00312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 05/21/2024] [Accepted: 06/13/2024] [Indexed: 07/27/2024]
Abstract
Light-mediated reactions have emerged as an indispensable tool in organic synthesis and drug discovery, enabling novel transformations and providing access to previously unexplored chemical space. Despite their widespread application in both academic and industrial research, the utilization of light as an energy source still encounters challenges regarding reproducibility and data robustness. Herein we present a comprehensive head-to-head comparison of commercially available batch photoreactors, alongside the introduction of the use of batch and flow photoreactors in parallel synthesis. Hence, we aim to establish a reliable and consistent platform for light-mediated reactions in high-throughput mode. Herein, we showcase the identification of several platforms aligning with the rigorous demands for efficient and robust high-throughput experimentation screenings and library synthesis.
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Affiliation(s)
- Brenda Pijper
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Lucía M. Saavedra
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Matteo Lanzi
- Institute
of Chemical Research of Catalonia (ICIQ), the Barcelona Institute
of Science and Technology, Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Maialen Alonso
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Alberto Fontana
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Marta Serrano
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - José Enrique Gómez
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Arjan W. Kleij
- Institute
of Chemical Research of Catalonia (ICIQ), the Barcelona Institute
of Science and Technology, Av. Països Catalans 16, 43007 Tarragona, Spain
- Catalan
Institute of Research and Advanced Studies (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Jesús Alcázar
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
| | - Santiago Cañellas
- Chemical
Capabilities, Analytical & Purification, Global Discovery Chemistry. Janssen-Cilag, S.A., E-45007 Toledo, Spain
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3
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Crawford R, Baumann M. Telescoped Flow Synthesis of Azacyclic Scaffolds Exploiting the Chromoselective Photolysis of Vinyl Azides and Azirines. Chemistry 2024; 30:e202401491. [PMID: 38716703 DOI: 10.1002/chem.202401491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Indexed: 07/07/2024]
Abstract
An efficient chromoselective photochemical process is presented for the synthesis of 2H-azirines and 1,3-diazabicylo[3.1.0]hex-3-enes from readily available vinyl azides. The method exploits continuous flow photochemistry to enable the safe consumption of the hazardous azide group and provides uniform irradiation using high-power LEDs at 365-450 nm. Additionally, a scaled telescoped process has been developed providing access to drug-like 1,6-dihydropyrimidines and pyrimidines via integrated ring-expansion and oxidation reactions. Given the prevalence of various azacyclic targets in pharmaceutical, agrochemical and materials applications it is anticipated that this methodology will enable further exploitations of these important scaffolds.
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Affiliation(s)
- Ruairi Crawford
- University College Dublin, School of Chemistry, Science Centre South, D04 N2E5, Dublin, Ireland
| | - Marcus Baumann
- University College Dublin, School of Chemistry, Science Centre South, D04 N2E5, Dublin, Ireland
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4
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Alfano AI, Smyth M, Wharry S, Moody TS, Nuño M, Butters C, Baumann M. Multiphase photochemistry in flow mode via an integrated continuous stirred tank reactor (CSTR) approach. Chem Commun (Camb) 2024; 60:7037-7040. [PMID: 38895750 DOI: 10.1039/d4cc02477j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
A new photochemical CSTR system capable of handling solids in scaled continuous processes is presented. High-power UV-LEDs are integrated in these CSTRs containing an insoluble base that aids in generating pyrazolines via cycloaddition between alkenes and in situ generated diazo species. Contrary to reported batch methods product degradation via ring contraction is suppressed whilst generating gram quantities of spirocyclic pyrazolines.
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Affiliation(s)
| | - Megan Smyth
- Almac Sciences, Technology Department, Craigavon BT63 5QD, UK
| | - Scott Wharry
- Almac Sciences, Technology Department, Craigavon BT63 5QD, UK
| | - Thomas S Moody
- Almac Sciences, Technology Department, Craigavon BT63 5QD, UK
- Arran Chemical Company, Monksland Industrial Estate, Roscommon N37 DN24, Ireland
| | - Manuel Nuño
- Vapourtec, Fornham St Genevieve, Bury St Edmunds, Suffolk, IP28 6TS, UK
| | - Chris Butters
- Vapourtec, Fornham St Genevieve, Bury St Edmunds, Suffolk, IP28 6TS, UK
| | - Marcus Baumann
- School of Chemistry, University College Dublin, Science Centre South, Dublin 4, Ireland.
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5
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Weiser M, Pálvölgyi Á, Weil M, Bica-Schröder K. Continuous Enantioselective α-Alkylation of Ketones via Direct Photoexcitation. J Org Chem 2024; 89:8906-8914. [PMID: 38856707 PMCID: PMC11197082 DOI: 10.1021/acs.joc.4c00759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/24/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024]
Abstract
Motivated by the scarcity of enantioselective direct intermolecular α-alkylation reactions of ketones with simple alkyl halides, we report a photo-organocatalytic process to access diethyl 2-(2-oxocyclohexyl)malonate and derivatives in good yield and enantioselectivity. The reaction design is based on highly abundant and nature-derived 9-amino-9-deoxy-epi-cinchona alkaloids to activate ketones as transient secondary enamines, which exist unfavorably in equilibrium with imines. These condensed species can serve as powerful photoinitiators via direct photoexcitation. This concept provides access to both enantiomeric antipodes. In addition to introducing an uncomplicated batch-optimized procedure, we investigated the feasibility and limitations of implementing the reaction in continuous flow, thus enabling to obtain diethyl 2-(2-oxocyclohexyl)malonate with a productivity of 47 μmol/h and 84% enantioselectivity.
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Affiliation(s)
- Michael Weiser
- Institute
of Applied Synthetic Chemistry, TU Wien, 1060 Vienna, Austria
| | | | - Matthias Weil
- Institute
of Chemical Technologies and Analytics, TU Wien, 1060 Vienna, Austria
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6
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Edwards M, Pratley MT, Gordon CM, Teixeira RI, Ali H, Mahmood I, Lester R, Love A, Hermens JGH, Freese T, Feringa BL, Poliakoff M, George MW. Process Intensification of the Continuous Synthesis of Bio-Derived Monomers for Sustainable Coatings Using a Taylor Vortex Flow Reactor. Org Process Res Dev 2024; 28:1917-1928. [PMID: 38783853 PMCID: PMC11110062 DOI: 10.1021/acs.oprd.3c00462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/02/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
We describe the optimization and scale-up of two consecutive reaction steps in the synthesis of bio-derived alkoxybutenolide monomers that have been reported as potential replacements for acrylate-based coatings (Sci. Adv.2020, 6, eabe0026). These monomers are synthesized by (i) oxidation of furfural with photogenerated singlet oxygen followed by (ii) thermal condensation of the desired 5-hydroxyfuranone intermediate product with an alcohol, a step which until now has involved a lengthy batch reaction. The two steps have been successfully telescoped into a single kilogram-scale process without any need to isolate the 5-hydroxyfuranone between the steps. Our process development involved FTIR reaction monitoring, FTIR data analysis via 2D visualization, and two different photoreactors: (i) a semicontinuous photoreactor based on a modified rotary evaporator, where FTIR and 2D correlation spectroscopy (2D-COS) revealed the loss of the methyl formate coproduct, and (ii) our fully continuous Taylor Vortex photoreactor, which enhanced the mass transfer and permitted the use of near-stoichiometric equivalents of O2. The use of in-line FTIR monitoring and modeling greatly accelerated process optimization in the Vortex reactor. This led to scale-up of the photo-oxidation in 85% yield with a projected productivity of 1.3 kg day-1 and a space-time yield of 0.06 mol day-1 mL-1. Higher productivities could be achieved while sacrificing yield (e.g., 4 kg day-1 at 40% yield). The use of superheated methanol at 200 °C in a pressurized thermal flow reactor accelerated the second step, the thermal condensation of 5-hydroxyfuranone, from a 20 h batch reflux reaction (0.5 L, 85 g) to a space time of <1 min in a reactor only 3 mL in volume operating with projected productivities of >700 g day-1. Proof of concept for telescoping the two steps was established with an overall two-step yield of 67%, producing a process with a projected productivity of 1.1 kg day-1 for the methoxybutenolide monomer without any purification of the 5-hydroxyfuranone intermediate.
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Affiliation(s)
- Matthew
D. Edwards
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Matthew T. Pratley
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Charles M. Gordon
- Scale-up
Systems Ltd., 23 Shelbourne
Road, Dublin 4, D04 PY68, Ireland
| | - Rodolfo I. Teixeira
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Hamza Ali
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Irfhan Mahmood
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Reece Lester
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Ashley Love
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Johannes G. H. Hermens
- Advanced
Research Centre CBBC, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thomas Freese
- Advanced
Research Centre CBBC, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ben L. Feringa
- Advanced
Research Centre CBBC, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Martyn Poliakoff
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Michael W. George
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
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7
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Xu Z, Sun D, Xu J, Yang R, Russell JD, Liu G. Progress and Challenges in Polystyrene Recycling and Upcycling. CHEMSUSCHEM 2024:e202400474. [PMID: 38757556 DOI: 10.1002/cssc.202400474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 05/18/2024]
Abstract
Polystyrene is a staple plastic in the packaging and insulation market. Despite its good recyclability, the willingness of PS recycling remains low, largely due to the high recycling cost and limited profitability. This review examines the research progresses, gaps, and challenges in areas that affect the recycling costs, including but not limited to logistics, packaging design, and policymaking. We critically evaluate the recent developments in upcycling strategies, and we particularly focus on tandem and hydrogen-atom transfer (HAT) upcycling strategies. We conclude that future upcycling studies should focus on not only reaction chemistry and mechanisms but also economic viability of the processes. The goal of this review is to stimulate the development of innovative recycling strategies with low recycling costs and high economic output values. We hope to stimulate the economic and technological momentum of PS recycling towards a sustainable and circular economy.
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Affiliation(s)
- Zhen Xu
- School of Chemistry and Chemical Engineering, Northwest Polytechnology University, Xi'an, 710000, China
- Department of Chemistry, Virginia Tech, Blacksburg, VA-24061, US
| | - Dongshi Sun
- School of Information and Business Management, Dalian Neusoft University of Information, Dalian, 116023, China
| | - Jianjun Xu
- Institute of Supply Chain Analytics, Dongbei University of Finance and Economics, Dalian, 116025, China
| | - Rong Yang
- School of Chemistry and Chemical Engineering, Northwest Polytechnology University, Xi'an, 710000, China
| | - Jennifer D Russell
- Department of Chemistry, Virginia Tech, Blacksburg, VA-24061, US
- Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA-24061, US
| | - Guoliang Liu
- Department of Chemistry, Virginia Tech, Blacksburg, VA-24061, US
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA-24061, US
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8
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García-Lacuna J, Baumann M. Continuous Flow Synthesis of Benzotriazin-4(3 H)-ones via Visible Light Mediated Nitrogen-Centered Norrish Reaction. Org Lett 2024; 26:2371-2375. [PMID: 38466090 PMCID: PMC10985655 DOI: 10.1021/acs.orglett.4c00248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/12/2024]
Abstract
We report a new protocol for the synthesis of substituted benzotriazin-4(3H)-ones which are underrepresented heterocyclic scaffolds with important pharmacological properties. Our method exploits acyclic aryl triazine precursors that undergo a photocyclization reaction upon exposure to violet light (420 nm). Continuous flow reactor technology is exploited to afford excellent yields in only 10 min residence time with no additives or photocatalysts needed. The underlying reaction mechanism appears to be based on an unprecedented variation of the classical Norrish type II reaction with concomitant fragmentation and formation of N-N bonds. Scalability, process robustness, and green credentials of this intriguing transformation are highlighted.
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Affiliation(s)
- Jorge García-Lacuna
- University College Dublin, School of Chemistry, Science Centre South, Dublin 4, Ireland
| | - Marcus Baumann
- University College Dublin, School of Chemistry, Science Centre South, Dublin 4, Ireland
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9
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Benny A, Di Simo L, Guazzelli L, Scanlan EM. Radical Mediated Decarboxylation of Amino Acids via Photochemical Carbonyl Sulfide (COS) Elimination. Molecules 2024; 29:1465. [PMID: 38611745 PMCID: PMC11013372 DOI: 10.3390/molecules29071465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/19/2024] [Accepted: 03/24/2024] [Indexed: 04/14/2024] Open
Abstract
Herein, we present the first examples of amino acid decarboxylation via photochemically activated carbonyl sulfide (COS) elimination of the corresponding thioacids. This method offers a mild approach for the decarboxylation of amino acids, furnishing N-alkyl amino derivatives. The methodology was compatible with amino acids displaying both polar and hydrophobic sidechains and was tolerant towards widely used amino acid-protecting groups. The compatibility of the reaction with continuous-flow conditions demonstrates the scalability of the process.
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Affiliation(s)
- Alby Benny
- Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, D02 R590 Dublin, Ireland; (A.B.); (L.D.S.)
| | - Lorenzo Di Simo
- Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, D02 R590 Dublin, Ireland; (A.B.); (L.D.S.)
- Department of Pharmacy, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Lorenzo Guazzelli
- Department of Pharmacy, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy
| | - Eoin M. Scanlan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, D02 R590 Dublin, Ireland; (A.B.); (L.D.S.)
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10
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García-Lacuna J, Baumann M. Continuous Flow Synthesis of Nitrosoarenes via Photochemical Rearrangement of Aryl Imines. J Org Chem 2024; 89:617-623. [PMID: 38131303 PMCID: PMC10777388 DOI: 10.1021/acs.joc.3c02362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/20/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023]
Abstract
Nitrosoarenes are versatile organic building blocks; however, their intrinsic instability and limited synthetic accessibility have so far restricted their widespread use. Herein, we present a new continuous flow route toward these entities that is based on a direct photochemical rearrangement process using o-nitrophenylimines as starting materials. Due to the underlying redox mechanism, a new amide group accompanies the formation of the nitroso group. Crucial to the success of this approach is the use of trifluoroethanol as a solvent and high-power light-emitting diodes (365 nm) as light sources that provide uniform irradiation and high efficiency of the resulting continuous flow method. The process is fast and robust, with high functional group tolerance and high throughput. The formation of the nitroso moiety is supported by full spectroscopic analysis, including X-ray crystallography. The scalability of this flow approach allows access to gram quantities of nitroso species for which we highlight a small set of derivatization reactions underlining their synthetic utility.
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Affiliation(s)
- Jorge García-Lacuna
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland
| | - Marcus Baumann
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland
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11
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Lee TC, Tong Y, Fu WC. Advances in Continuous Flow Fluorination Reactions. Chem Asian J 2023; 18:e202300723. [PMID: 37707985 DOI: 10.1002/asia.202300723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/12/2023] [Accepted: 09/14/2023] [Indexed: 09/16/2023]
Abstract
Fluorination reactions are important in constructing organofluorine motifs, which contribute to favorable biological properties in pharmaceuticals and agrochemicals. However, fluorination reagents and reactions are associated with various problems, such as their hazardous nature, high exothermicity, and poor selectivity and scalability. Continuous flow has emerged as a transformative technology to provide many advantages relative to batch syntheses. This review article summarizes recent continuous flow techniques that address the limitations and challenges of fluorination reactions. Approaches based on different flow techniques are discussed, including gas-liquid reactions, packed-bed reactors, in-line purifications, streamlined multistep synthesis, large-scale reactions well as flow photoredox- and electrocatalysis.
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Affiliation(s)
- Tsz Chun Lee
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Yi Tong
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Wai Chung Fu
- Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong SAR, China
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12
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Oelgemöller M, Zhang L, Zhao F, Su Y. Editorial: Novel technologies for sustainable and energy-efficient flow photochemistry. Front Chem 2023; 11:1322556. [PMID: 37965212 PMCID: PMC10642221 DOI: 10.3389/fchem.2023.1322556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 11/16/2023] Open
Affiliation(s)
- Michael Oelgemöller
- Faculty of Chemistry and Biology, Fresenius University of Applied Sciences, Idstein, Germany
| | - Lijing Zhang
- School of Chemistry, Dalian University of Technology, Dalian, China
| | - Fang Zhao
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai, China
| | - Yuanhai Su
- Department of Chemical Engineering, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
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13
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Bracken C, Baumann M. Synthesis of Highly Reactive Ketenimines via Photochemical Rearrangement of Isoxazoles. Org Lett 2023; 25:6593-6597. [PMID: 37616597 PMCID: PMC10496124 DOI: 10.1021/acs.orglett.3c02556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Indexed: 08/26/2023]
Abstract
Ketenimines are highly electrophilic species with multiple applications as building blocks in organic synthesis; however, the effective preparation of these versatile entities remains a synthetic challenge. Here we report a continuous photochemical process that generates ketenimines via skeletal rearrangement of trisubstituted isoxazoles. The resulting flow process is noteworthy, as it provides for the first time a straightforward entry into these ketenimines that were previously only observed spectroscopically. The value of this methodology toward heterocyclic transposition reactions is demonstrated by converting isoxazoles via isolable ketenimines into pharmaceutically relevant pyrazoles.
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Affiliation(s)
- Cormac Bracken
- School of Chemistry, University
College Dublin, Science Centre South, Dublin 4, Ireland
| | - Marcus Baumann
- School of Chemistry, University
College Dublin, Science Centre South, Dublin 4, Ireland
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14
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Raymenants F, Masson TM, Sanjosé-Orduna J, Noël T. Efficient C(sp 3 )-H Carbonylation of Light and Heavy Hydrocarbons with Carbon Monoxide via Hydrogen Atom Transfer Photocatalysis in Flow. Angew Chem Int Ed Engl 2023; 62:e202308563. [PMID: 37459232 DOI: 10.1002/anie.202308563] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023]
Abstract
Despite their abundance in organic molecules, considerable limitations still exist in synthetic methods that target the direct C-H functionalization at sp3 -hybridized carbon atoms. This is even more the case for light alkanes, which bear some of the strongest C-H bonds known in Nature, requiring extreme activation conditions that are not tolerant to most organic molecules. To bypass these issues, synthetic chemists rely on prefunctionalized alkyl halides or organometallic coupling partners. However, new synthetic methods that target regioselectively C-H bonds in a variety of different organic scaffolds would be of great added value, not only for the late-stage functionalization of biologically active molecules but also for the catalytic upgrading of cheap and abundant hydrocarbon feedstocks. Here, we describe a general, mild and scalable protocol which enables the direct C(sp3 )-H carbonylation of saturated hydrocarbons, including natural products and light alkanes, using photocatalytic hydrogen atom transfer (HAT) and gaseous carbon monoxide (CO). Flow technology was deemed crucial to enable high gas-liquid mass transfer rates and fast reaction kinetics, needed to outpace deleterious reaction pathways, but also to leverage a scalable and safe process.
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Affiliation(s)
- Fabian Raymenants
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Tom M Masson
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Jesús Sanjosé-Orduna
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Timothy Noël
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
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15
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Chen W, Abedin MJ, Barua T, Mirshekarloo MS, El Meragawi S, Majumder M. Customized Production of Holey Graphene Oxides via a Continuous Flow Process. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2304227. [PMID: 37649176 DOI: 10.1002/smll.202304227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 08/04/2023] [Indexed: 09/01/2023]
Abstract
Continuous flow manufacturing is an innovative technology mainly applied in the chemical and pharmaceutical industries that is progressively being adapted to the manufacturing of nanomaterials to overcome the challenge of reproducing a product with consistent characteristics at a large scale. Here, a flow photochemical system is designed and prototyped for the synthesis of holey graphene oxides (hGOs). Compared to existing methods for the synthesis of hGO, the process is fast, highly scalable, and controllable. Through a combination of rigorous data analysis using machine learning algorithms on transmission electron microscope images and systematic studies of process parameters, it is demonstrated that characteristics of the produced hGO (i.e., porosity and pore size) are remarkably reproducible to the extent that it can be predicted by empirical models of processing-property correlations. Depending on the tailored nanopore structures, the synthesized hGOs out-performed GO in a range of applications that can benefit from the nanoporous two-dimensional (2D) sheets such as in supercapacitors, gas adsorption, and nanofiltration membranes. These results are significant in offering new perspectives on the low-cost industrialization of 2D nanomaterials.
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Affiliation(s)
- Wanqing Chen
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Graphene Enabled Industry Transformation, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Advanced Manufacturing with Two-dimensional Materials (AM2D), Monash University, Clayton, VIC, 3800, Australia
| | - Md Joynul Abedin
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Graphene Enabled Industry Transformation, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Advanced Manufacturing with Two-dimensional Materials (AM2D), Monash University, Clayton, VIC, 3800, Australia
| | - Titon Barua
- AFRL Laboratory, Department of Computer Science and Engineering, University of South Carolina, Columbia, SC, 29208, USA
| | - Meysam Sharifzadeh Mirshekarloo
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Graphene Enabled Industry Transformation, Monash University, Clayton, VIC, 3800, Australia
| | - Sally El Meragawi
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Graphene Enabled Industry Transformation, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Advanced Manufacturing with Two-dimensional Materials (AM2D), Monash University, Clayton, VIC, 3800, Australia
| | - Mainak Majumder
- Nanoscale Science and Engineering Laboratory (NSEL), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Graphene Enabled Industry Transformation, Monash University, Clayton, VIC, 3800, Australia
- ARC Research Hub for Advanced Manufacturing with Two-dimensional Materials (AM2D), Monash University, Clayton, VIC, 3800, Australia
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16
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Subjalearndee N, Panith P, Narkbuakaew T, Thongkam P, Intasanta V. Supported TiO 2-ZnWO 4 Photocatalytic Nanofibrous Membranes for Flow-Through and Fixed-Bed Reactors. ACS OMEGA 2023; 8:30389-30401. [PMID: 37636910 PMCID: PMC10448639 DOI: 10.1021/acsomega.3c03527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 07/31/2023] [Indexed: 08/29/2023]
Abstract
We developed utilization models of supported electrospun TiO2-ZnWO4 photocatalytic nanofibrous membranes for air and water purifications using a noncomplex system with facile adaptation for large-scale processes. For this uniquely designed and multimode catalyst, ZnWO4 is selected for a visible light activity, while TiO2 is incorporated to enhance physical stability. Morphological structures of the TiO2-ZnWO4 membrane are characterized by scanning electron microscopy and scanning electron microscopy-energy-dispersive X-ray spectroscopy. The distinguished growth of ZnWO4 nanorods at the surface of the TiO2-ZnWO4 membrane is revealed by transmission electron microscopy (TEM). The relaxation process and charge transfer mechanism are proposed following the examination of interface and band gap (2.76 eV) between TiO2 and ZnWO4 particles via HR-TEM and UV-vis spectrophotometry. For the gas-phase reaction, a transparent photocatalytic converter is designed to support the pleated TiO2-ZnWO4 membrane for toluene decomposition under visible light. To obtain a crack-free and homogeneous fiber structure of the pleated TiO2-ZnWO4 membrane, 1 h of nanofibrous membrane fabrication via a Nanospider machine is required. On the other hand, a fiberglass-supported TiO2-ZnWO4 membrane is fabricated as a fixed-bed photocatalyst membrane for methylene blue decomposition under natural sunlight. It is observed that using the calcination temperature at 800 °C results in the formation of metal complexes between fiber glass and the TiO2-ZnWO4 membrane. The TiO2-ZnWO4 membrane successfully decomposes toluene vapor up to 40% under a continuous-flow circumstance in a borosilicate photocatalytic converter and 70% for methylene blue in solution within 3 h. Finally, the mechanically robust and supported TiO2-ZnWO4 nanofibrous membranes are proven for an alternate potential in environmental remediation.
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Affiliation(s)
- Nakarin Subjalearndee
- National Nanotechnology Center, National Science and Technology Development Agency, 111 Phahonyothin Road, Klong Nueng,
Klong Luang, Pathumthani 12120, Thailand
| | - Pasinee Panith
- National Nanotechnology Center, National Science and Technology Development Agency, 111 Phahonyothin Road, Klong Nueng,
Klong Luang, Pathumthani 12120, Thailand
| | - Tanaporn Narkbuakaew
- National Nanotechnology Center, National Science and Technology Development Agency, 111 Phahonyothin Road, Klong Nueng,
Klong Luang, Pathumthani 12120, Thailand
| | - Pech Thongkam
- National Nanotechnology Center, National Science and Technology Development Agency, 111 Phahonyothin Road, Klong Nueng,
Klong Luang, Pathumthani 12120, Thailand
| | - Varol Intasanta
- National Nanotechnology Center, National Science and Technology Development Agency, 111 Phahonyothin Road, Klong Nueng,
Klong Luang, Pathumthani 12120, Thailand
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17
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Dinter R, Willems S, Nissalk T, Hastürk O, Brunschweiger A, Kockmann N. Development of a microfluidic photochemical flow reactor concept by rapid prototyping. Front Chem 2023; 11:1244043. [PMID: 37608867 PMCID: PMC10441772 DOI: 10.3389/fchem.2023.1244043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 07/25/2023] [Indexed: 08/24/2023] Open
Abstract
The transfer from batch to flow chemistry is often based on commercial microfluidic equipment, such as costly complete reactor systems, which cannot be easily tailored to specific requirements of technologies such as DNA-encoded library technology (DELT), in particular for increasingly important photochemical reactions. Customized photoreactor concepts using rapid prototyping technology offer a modular, flexible, and affordable design that allows for adaptation to various applications. In order to validate the prototype reactors, a photochemical pinacol coupling reaction at 368 nm was conducted to demonstrate the transfer from batch to flow chemistry. The conversion rates were optimized by adapting the design parameters of the microfluidic flow photoreactor module. Subsequently, the photoreactor module has been extended to an application with DNA-tagged substrates by switching to LEDs with a wavelength of 454 nm. The successful recovery of DNA confirmed the feasibility of the modular-designed flow photo reactor. This collaborative approach holds enormous potential to drive the development of DELT and flow equipment design.
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Affiliation(s)
- Robin Dinter
- Laboratory of Equipment Design, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Suzanne Willems
- Medicinal Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Thilo Nissalk
- Laboratory of Equipment Design, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
| | - Oguz Hastürk
- Medicinal Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
| | - Andreas Brunschweiger
- Medicinal Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany
- Department of Chemistry and Pharmacy, Institute for Pharmacy and Food Chemistry, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Norbert Kockmann
- Laboratory of Equipment Design, Department of Biochemical and Chemical Engineering, TU Dortmund University, Dortmund, Germany
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18
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Franco M, Silva RC, Rosa GHS, Flores LM, de Oliveira KT, de Assis FF. Synthesis of the Brivaracetam Employing Asymmetric Photocatalysis and Continuous Flow Conditions. ACS OMEGA 2023; 8:23008-23016. [PMID: 37396260 PMCID: PMC10308561 DOI: 10.1021/acsomega.3c02134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/30/2023] [Indexed: 07/04/2023]
Abstract
An original total synthesis of the antiepileptic drug brivaracetam (BRV) is reported. The key step in the synthesis consists of an enantioselective photochemical Giese addition, promoted by visible-light and the chiral bifunctional photocatalyst Δ-RhS. Continuous flow conditions were employed to improve the efficiency and allow an easy scale-up of the enantioselective photochemical reaction step. The intermediate obtained from the photochemical step was converted into BRV by two different pathways, followed by one alkylation and amidation, thus giving the desired active pharmaceutical ingredients (API) in 44% overall yield, 9:1 diastereoisomeric ratio (dr) and >99:1 enantiomeric ratio (er).
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Affiliation(s)
- Marcelo
S. Franco
- Department
of Chemistry, Universidade Federal de Santa
Catarina, Campus Universitário Trindade, Florianópolis, Santa Catarina 88040-900, Brazil
| | - Rodrigo C. Silva
- Department
of Chemistry, Universidade Federal de São
Carlos, Rodovia Washington Luis km 235, São
Carlos, São Paulo 13565-905, Brazil
| | - Gabriel H. S. Rosa
- Department
of Chemistry, Universidade Federal de São
Carlos, Rodovia Washington Luis km 235, São
Carlos, São Paulo 13565-905, Brazil
| | - Lara M. Flores
- Department
of Chemistry, Universidade Federal de Santa
Catarina, Campus Universitário Trindade, Florianópolis, Santa Catarina 88040-900, Brazil
| | - Kleber T. de Oliveira
- Department
of Chemistry, Universidade Federal de São
Carlos, Rodovia Washington Luis km 235, São
Carlos, São Paulo 13565-905, Brazil
| | - Francisco F. de Assis
- Department
of Chemistry, Universidade Federal de Santa
Catarina, Campus Universitário Trindade, Florianópolis, Santa Catarina 88040-900, Brazil
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19
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Zondag SDA, Mazzarella D, Noël T. Scale-Up of Photochemical Reactions: Transitioning from Lab Scale to Industrial Production. Annu Rev Chem Biomol Eng 2023; 14:283-300. [PMID: 36913716 DOI: 10.1146/annurev-chembioeng-101121-074313] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
In the past two decades, we have witnessed a rapid emergence of new and powerful photochemical and photocatalytic synthetic methods. Although these methods have been used mostly on a small scale, there is a growing need for efficient scale-up of photochemistry in the chemical industry. This review summarizes and contextualizes the advancements made in the past decade regarding the scale-up of photo-mediated synthetic transformations. Simple scale-up concepts and important fundamental photochemical laws have been provided along with a discussion concerning suitable reactor designs that should facilitate scale-up of this challenging class of organic reactions.
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Affiliation(s)
- Stefan D A Zondag
- Flow Chemistry Group, van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Amsterdam, The Netherlands;
| | - Daniele Mazzarella
- Flow Chemistry Group, van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Amsterdam, The Netherlands;
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Timothy Noël
- Flow Chemistry Group, van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Amsterdam, The Netherlands;
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20
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Zhou F, Cai L, Ye W, Zhu K, Li J, Li Y, Xu W, Wang P, Duanmu C. Efficient and Controllable Synthesis of 1-Aminoanthraquinone via High-Temperature Ammonolysis Using Continuous-Flow Method. Molecules 2023; 28:molecules28114314. [PMID: 37298791 DOI: 10.3390/molecules28114314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
Anthraquinone dyes are the second most important type of dyes after azo dyes. In particular, 1-aminoanthraquinone has been extensively utilized in the preparation of diverse anthraquinone dyes. This study employed a continuous-flow method to synthesize 1-aminoanthraquinone safely and efficiently through the ammonolysis of 1-nitroanthraquinone at high temperatures. Various conditions (reaction temperature, residence time, molar ratio of ammonia to 1-nitroanthraquinone (M-ratio), and water content) were investigated to explore the details of the ammonolysis reaction behavior. Operation conditions for the continuous-flow ammonolysis were optimized using Box-Behnken design in the response surface methodology, and ~88% yield of 1-aminoanthraquinone could be achieved with an M-ratio of 4.5 at 213 °C and 4.3 min. The developed process's reliability was evaluated by performing a 4 h process stability test. The kinetic behavior for the preparation of 1-aminoanthraquinone was investigated under continuous-flow mode to guide the reactor design and to gain a deeper understanding of the ammonolysis process.
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Affiliation(s)
- Feng Zhou
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Lei Cai
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Wenjie Ye
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Kai Zhu
- China Construction Industrial & Energy Engineering Group Co., Ltd., 6 Wenlan Road, Qixia District, Nanjing 210023, China
| | - Jin Li
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Yanxing Li
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Weichuan Xu
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Pan Wang
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Chuansong Duanmu
- National & Local Joint Engineering Research Center for Deep Utilization Technology of Rock-Salt Resource, Faculty of Chemical Engineering, Huaiyin Institute of Technology, Huaian 223003, China
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21
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Molnár M, Kappe CO, Ötvös SB. Merger of Visible Light-Driven Chiral Organocatalysis and Continuous Flow Chemistry: An Accelerated and Scalable Access into Enantioselective α-Alkylation of Aldehydes. Adv Synth Catal 2023; 365:1660-1670. [PMID: 38515505 PMCID: PMC10952295 DOI: 10.1002/adsc.202300289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/21/2023] [Indexed: 03/23/2024]
Abstract
The electron donor-acceptor complex-enabled asymmetric photochemical alkylation strategy holds potential to attain elusive chiral α-alkylated aldehydes without an external photoredox catalyst. The photosensitizer-free conditions are beneficial concerning process costs and sustainability. However, lengthy organocatalyst preparation steps as well as limited productivity and difficult scalability render the current approaches unsuitable for synthesis on enlarged scales. Inspired by these limitations, a protocol was developed for the enantioselective α-alkylation of aldehydes based on the synergistic combination of visible light-driven asymmetric organocatalysis and a controlled continuous flow reaction environment. With the aim to reduce process costs, a commercially available chiral catalyst has been exploited to achieve photosensitizer-free enantioselective α-alkylations using phenacyl bromide derivates as alkylating agents. As a result of elaborate optimization and process development, the present flow strategy furnishes an accelerated and inherently scalable entry into enantioenriched α-alkylated aldehydes including a chiral key intermediate of the antirheumatic esonarimod.
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Affiliation(s)
- Márk Molnár
- Institute of ChemistryUniversity of GrazNAWI Graz, Heinrichstrasse 28A-8010GrazAustria
- Servier Research Institute of Medicinal ChemistryZáhony u. 71031BudapestHungary
| | - C. Oliver Kappe
- Institute of ChemistryUniversity of GrazNAWI Graz, Heinrichstrasse 28A-8010GrazAustria
- Center for Continuous Flow Synthesis and Processing (CC FLOW)Research Center Pharmaceutical Engineering GmbH (RCPE)Inffeldgasse 13A-8010GrazAustria
| | - Sándor B. Ötvös
- Institute of ChemistryUniversity of GrazNAWI Graz, Heinrichstrasse 28A-8010GrazAustria
- Center for Continuous Flow Synthesis and Processing (CC FLOW)Research Center Pharmaceutical Engineering GmbH (RCPE)Inffeldgasse 13A-8010GrazAustria
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22
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Alfano A, Pelliccia S, Rossino G, Chianese O, Summa V, Collina S, Brindisi M. Photo-Flow Technology for Chemical Rearrangements: A Powerful Tool to Generate Pharmaceutically Relevant Compounds. ACS Med Chem Lett 2023; 14:672-680. [PMID: 37197467 PMCID: PMC10184314 DOI: 10.1021/acsmedchemlett.3c00072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/31/2023] [Indexed: 05/19/2023] Open
Abstract
In recent years, photochemistry has increasingly emerged as an enabling methodology in both academia and the pharmaceutical industry. Long photolysis times and the gradual reduction of light penetration remained for many years unsolved issues for photochemical rearrangements, triggering the generation of highly reactive species in an uncontrolled fashion and causing the formation of multiple side products. The emergence of continuous-flow chemistry significantly helped to overcome these issues, thus prompting the implementation of photo-flow-based approaches for the generation of pharmaceutically relevant substructures. This Technology Note highlights the benefits of flow chemistry for photochemical rearrangements, including Wolff, Favorskii, Beckmann, Fries, and Claisen rearrangements. We showcase recent advances for photo-rearrangements in continuous flow applied to the synthesis of privileged scaffolds and active pharmaceutical ingredients.
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Affiliation(s)
- Antonella
Ilenia Alfano
- Department
of Pharmacy (DoE 2023-2027), University
of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy
| | - Sveva Pelliccia
- Department
of Pharmacy (DoE 2023-2027), University
of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy
| | - Giacomo Rossino
- Department
of Drug Sciences, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Orazio Chianese
- Genetic
S.p.A., Via Canfora,
64, 84084 Fisciano (Salerno), Italy
| | - Vincenzo Summa
- Department
of Pharmacy (DoE 2023-2027), University
of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy
| | - Simona Collina
- Department
of Drug Sciences, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Margherita Brindisi
- Department
of Pharmacy (DoE 2023-2027), University
of Naples Federico II, via D. Montesano 49, 80131 Naples, Italy
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23
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Capaldo L, Wen Z, Noël T. A field guide to flow chemistry for synthetic organic chemists. Chem Sci 2023; 14:4230-4247. [PMID: 37123197 PMCID: PMC10132167 DOI: 10.1039/d3sc00992k] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/15/2023] [Indexed: 03/17/2023] Open
Abstract
Flow chemistry has unlocked a world of possibilities for the synthetic community, but the idea that it is a mysterious "black box" needs to go. In this review, we show that several of the benefits of microreactor technology can be exploited to push the boundaries in organic synthesis and to unleash unique reactivity and selectivity. By "lifting the veil" on some of the governing principles behind the observed trends, we hope that this review will serve as a useful field guide for those interested in diving into flow chemistry.
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Affiliation(s)
- Luca Capaldo
- Flow Chemistry Group, Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam 1098 XH Amsterdam The Netherlands
| | - Zhenghui Wen
- Flow Chemistry Group, Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam 1098 XH Amsterdam The Netherlands
| | - Timothy Noël
- Flow Chemistry Group, Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam 1098 XH Amsterdam The Netherlands
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24
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Burke A, Di Filippo M, Spiccio S, Schito AM, Caviglia D, Brullo C, Baumann M. Antimicrobial Evaluation of New Pyrazoles, Indazoles and Pyrazolines Prepared in Continuous Flow Mode. Int J Mol Sci 2023; 24:ijms24065319. [PMID: 36982392 PMCID: PMC10048858 DOI: 10.3390/ijms24065319] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
Multi-drug resistant bacterial strains (MDR) have become an increasing challenge to our health system, resulting in multiple classical antibiotics being clinically inactive today. As the de-novo development of effective antibiotics is a very costly and time-consuming process, alternative strategies such as the screening of natural and synthetic compound libraries is a simple approach towards finding new lead compounds. We thus report on the antimicrobial evaluation of a small collection of fourteen drug-like compounds featuring indazoles, pyrazoles and pyrazolines as key heterocyclic moieties whose synthesis was achieved in continuous flow mode. It was found that several compounds possessed significant antibacterial potency against clinical and MDR strains of the Staphylococcus and Enterococcus genera, with the lead compound (9) reaching MIC values of 4 µg/mL on those species. In addition, time killing experiments performed on compound 9 on Staphylococcus aureus MDR strains highlight its activity as bacteriostatic. Additional evaluations regarding the physiochemical and pharmacokinetic properties of the most active compounds are reported and showcased, promising drug-likeness, which warrants further explorations of the newly identified antimicrobial lead compound.
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Affiliation(s)
- Adam Burke
- Science Centre South, School of Chemistry, University College Dublin, Dublin 4, Ireland
| | - Mara Di Filippo
- Science Centre South, School of Chemistry, University College Dublin, Dublin 4, Ireland
| | - Silvia Spiccio
- Science Centre South, School of Chemistry, University College Dublin, Dublin 4, Ireland
| | - Anna Maria Schito
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, 16132 Genoa, Italy
| | - Debora Caviglia
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, 16132 Genoa, Italy
- Section of Medicinal Chemistry, Department of Pharmacy (DIFAR), University of Genoa, 16132 Genoa, Italy
| | - Chiara Brullo
- Section of Medicinal Chemistry, Department of Pharmacy (DIFAR), University of Genoa, 16132 Genoa, Italy
| | - Marcus Baumann
- Science Centre South, School of Chemistry, University College Dublin, Dublin 4, Ireland
- Correspondence:
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25
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Flow photochemistry — from microreactors to large-scale processing. Curr Opin Chem Eng 2023. [DOI: 10.1016/j.coche.2023.100897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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26
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Di Filippo M, Baumann M. Carbene-controlled regioselectivity in photochemical cascades. Org Biomol Chem 2023; 21:2930-2934. [PMID: 36745509 DOI: 10.1039/d3ob00122a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A highly regioselective route to complex carbocyclic scaffolds through a continuous photochemical process is reported. Crucially, we uncovered that ortho substitutents on the right-hand aryl ring are placed away from a transient carbene species which induces the exclusive regioselectivity observed. By varying the non-symmetrically substituted aryl moiety, we demonstrate how the product outcome favors cyclobutenes for electron-poor and neutral substituents and cycloheptatrienes for more electron-rich systems. Additionally, a photochemically induced rearrangement was uncovered for highly electron-rich substrates that ultimately generates complex hydroperoxides. Overall, this facile one-step process is fast and high yielding and demonstrates the power of photochemistry towards the exploration of new chemical space.
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Affiliation(s)
- Mara Di Filippo
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland.
| | - Marcus Baumann
- University College Dublin, School of Chemistry, Science Centre South, Belfield, Dublin 4, Ireland.
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27
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Comito M, Monguzzi R, Tagliapietra S, Palmisano G, Cravotto G. Towards Antibiotic Synthesis in Continuous-Flow Processes. Molecules 2023; 28:molecules28031421. [PMID: 36771086 PMCID: PMC9919330 DOI: 10.3390/molecules28031421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
Continuous-flow chemistry has become a mainstream process and a notable trend among emerging technologies for drug synthesis. It is routinely used in academic and industrial laboratories to generate a wide variety of molecules and building blocks. The advantages it provides, in terms of safety, speed, cost efficiency and small-equipment footprint compared to analog batch processes, have been known for some time. What has become even more important in recent years is its compliance with the quality objectives that are required by drug-development protocols that integrate inline analysis and purification tools. There can be no doubt that worldwide government agencies have strongly encouraged the study and implementation of this innovative, sustainable and environmentally friendly technology. In this brief review, we list and evaluate the development and applications of continuous-flow processes for antibiotic synthesis. This work spans the period of 2012-2022 and highlights the main cases in which either active ingredients or their intermediates were produced under continuous flow. We hope that this manuscript will provide an overview of the field and a starting point for a deeper understanding of the impact of flow chemistry on the broad panorama of antibiotic synthesis.
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Affiliation(s)
- Marziale Comito
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy
- Research and Development, ACS Dobfar SpA, Via Paullo 9, 20067 Tribiano, Italy
| | - Riccardo Monguzzi
- Research and Development, ACS Dobfar SpA, Via Paullo 9, 20067 Tribiano, Italy
| | - Silvia Tagliapietra
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy
| | - Giovanni Palmisano
- Dipartimento di Scienza e Alta Tecnologia, University of Insubria, Via Valleggio 9, 22100 Como, Italy
| | - Giancarlo Cravotto
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Via Pietro Giuria 9, 10125 Turin, Italy
- Correspondence: ; Tel.: +39-011-670-7183
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Bazzoni M, Lhoste C, Bonnet J, Konan KE, Bernard A, Giraudeau P, Felpin FX, Dumez JN. In-line Multidimensional NMR Monitoring of Photochemical Flow Reactions. Chemistry 2023; 29:e202203240. [PMID: 36651473 DOI: 10.1002/chem.202203240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/19/2023]
Abstract
This work demonstrates the in-line monitoring of a flow photochemical reaction using 1D and ultrafast 2D NMR methods at high magnetic field. The reaction mixture exiting the flow reactor is flown through the NMR spectrometer and directly analyzed. In the case of simple substrates, suitable information can be obtained through 1D 1 H spectra, but for molecules of higher complexity the use of 2D experiments is key to address signal overlaps and assignment issues. Here we show the usefulness of ultrafast 2D COSY experiments acquired in 70 s or less, for the in-line monitoring of photochemical reactions, and the possibility to obtain reliable quantitative information. This is a powerful framework to, for example, efficiently screen reaction conditions.
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Affiliation(s)
| | - Célia Lhoste
- Nantes Université, CNRS, CEISAM UMR6230, F-4400, Nantes, France
| | - Justine Bonnet
- Nantes Université, CNRS, CEISAM UMR6230, F-4400, Nantes, France
| | | | - Aurélie Bernard
- Nantes Université, CNRS, CEISAM UMR6230, F-4400, Nantes, France
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29
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Simon K, Znidar D, Boutet J, Guillamot G, Lenoir JY, Dallinger D, Kappe CO. Generation of 1,2-Difluorobenzene via a Photochemical Fluorodediazoniation Step in a Continuous Flow Mode. Org Process Res Dev 2023. [DOI: 10.1021/acs.oprd.2c00348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Kevin Simon
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, Graz 8010, Austria
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, Graz 8010, Austria
| | - Desiree Znidar
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, Graz 8010, Austria
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, Graz 8010, Austria
| | - Julien Boutet
- Seqens SAS, 21 Chemin de la Sauvegarde, 21 Ecully Parc, Ecully 69130, France
| | - Gérard Guillamot
- Seqens SAS, 21 Chemin de la Sauvegarde, 21 Ecully Parc, Ecully 69130, France
| | - Jean-Yves Lenoir
- Seqens SAS, 21 Chemin de la Sauvegarde, 21 Ecully Parc, Ecully 69130, France
| | - Doris Dallinger
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, Graz 8010, Austria
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, Graz 8010, Austria
| | - C. Oliver Kappe
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, Graz 8010, Austria
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, Graz 8010, Austria
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30
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Braga FC, Ramos TO, Brocksom TJ, de Oliveira KT. Synthesis of Fentanyl under Continuous Photoflow Conditions. Org Lett 2022; 24:8331-8336. [DOI: 10.1021/acs.orglett.2c03338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Felipe C. Braga
- Department of Chemistry, Federal University of São Carlos, São Carlos, São Paulo 13565-905, Brazil
| | - Tiago O. Ramos
- Department of Chemistry, Federal University of São Carlos, São Carlos, São Paulo 13565-905, Brazil
| | - Timothy J. Brocksom
- Department of Chemistry, Federal University of São Carlos, São Carlos, São Paulo 13565-905, Brazil
| | - Kleber T. de Oliveira
- Department of Chemistry, Federal University of São Carlos, São Carlos, São Paulo 13565-905, Brazil
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31
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Grillo G, Cintas P, Colia M, Calcio Gaudino E, Cravotto G. Process intensification in continuous flow organic synthesis with enabling and hybrid technologies. FRONTIERS IN CHEMICAL ENGINEERING 2022. [DOI: 10.3389/fceng.2022.966451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Industrial organic synthesis is time and energy consuming, and generates substantial waste. Traditional conductive heating and mixing in batch reactors is no longer competitive with continuous-flow synthetic methods and enabling technologies that can strongly promote reaction kinetics. These advances lead to faster and simplified downstream processes with easier workup, purification and process scale-up. In the current Industry 4.0 revolution, new advances that are based on cyber-physical systems and artificial intelligence will be able to optimize and invigorate synthetic processes by connecting cascade reactors with continuous in-line monitoring and even predict solutions in case of unforeseen events. Alternative energy sources, such as dielectric and ohmic heating, ultrasound, hydrodynamic cavitation, reactive extruders and plasma have revolutionized standard procedures. So-called hybrid or hyphenated techniques, where the combination of two different energy sources often generates synergistic effects, are also worthy of mention. Herein, we report our consolidated experience of all of these alternative techniques.
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32
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Song Q, Lei X, Yang S, Wang S, Wang J, Chen J, Xiang Y, Huang Q, Wang Z. Continuous-Flow Synthesis of Nitro- o-xylenes: Process Optimization, Impurity Study and Extension to Analogues. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27165139. [PMID: 36014379 PMCID: PMC9416712 DOI: 10.3390/molecules27165139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/04/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022]
Abstract
An efficient continuous-flow nitration process of o-xylene at pilot scale was demonstrated. The effects of parameters such as temperature, ratio of H2SO4 to HNO3, H2SO4 concentration, flow rate, and residence time on the reaction were studied. Under the optimal conditions, the yield of products reached 94.1%, with a product throughput of 800 g/h. The main impurities of this continuous-flow nitration process were also studied in detail. Compared with batch process, phenolic impurity decreased from 2% to 0.1%, which enabled the omission of the alkaline solution washing step and thus reduced the wastewater emission. The method was also successfully applied to the nitrification of p-xylene, toluene, and chlorobenzene with good yields.
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Affiliation(s)
- Qiao Song
- Department of Chemistry, Xihua University, Chengdu 610039, China
- Asymmetric Synthesis and Chiral Technology Key Laboratory of Sichuan Province, Yibin 644000, China
- Correspondence: (Q.S.); (Z.W.)
| | - Xiangui Lei
- Department of Chemistry, Xihua University, Chengdu 610039, China
- Asymmetric Synthesis and Chiral Technology Key Laboratory of Sichuan Province, Yibin 644000, China
| | - Sheng Yang
- Department of Chemistry, Xihua University, Chengdu 610039, China
- Asymmetric Synthesis and Chiral Technology Key Laboratory of Sichuan Province, Yibin 644000, China
| | - Sheng Wang
- Department of Chemistry, Xihua University, Chengdu 610039, China
| | - Jianhui Wang
- Yinguang Group Sichuan North Hongguang Special Chemical Co., Ltd., Yibin 644000, China
| | - Jiujun Chen
- Yinguang Group Sichuan North Hongguang Special Chemical Co., Ltd., Yibin 644000, China
| | - Yong Xiang
- Yinguang Group Sichuan North Hongguang Special Chemical Co., Ltd., Yibin 644000, China
| | - Qingwu Huang
- Yinguang Group Sichuan North Hongguang Special Chemical Co., Ltd., Yibin 644000, China
| | - Zhouyu Wang
- Department of Chemistry, Xihua University, Chengdu 610039, China
- Yinguang Group Sichuan North Hongguang Special Chemical Co., Ltd., Yibin 644000, China
- Correspondence: (Q.S.); (Z.W.)
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33
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Steiner A, Nelson RC, Dallinger D, Kappe CO. Synthesis of Thiomorpholine via a Telescoped Photochemical Thiol–Ene/Cyclization Sequence in Continuous Flow. Org Process Res Dev 2022; 26:2532-2539. [PMID: 36032361 PMCID: PMC9396661 DOI: 10.1021/acs.oprd.2c00214] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander Steiner
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, 8010 Graz, Austria
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
| | - Ryan C. Nelson
- Medicines for All Institute, Virginia Commonwealth University, 737 North Fifth Street, P.O. Box 980100, Richmond, Virginia 23298, United States
| | - Doris Dallinger
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, 8010 Graz, Austria
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
| | - C. Oliver Kappe
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, 8010 Graz, Austria
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
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34
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Ziegenbalg D, Pannwitz A, Rau S, Dietzek‐Ivanšić B, Streb C. Comparative Evaluation of Light‐Driven Catalysis: A Framework for Standardized Reporting of Data**. Angew Chem Int Ed Engl 2022; 61:e202114106. [PMID: 35698245 PMCID: PMC9401044 DOI: 10.1002/anie.202114106] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Indexed: 01/05/2023]
Affiliation(s)
- Dirk Ziegenbalg
- Institute of Chemical Engineering Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Andrea Pannwitz
- Institute of Inorganic Chemistry I Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Sven Rau
- Institute of Inorganic Chemistry I Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Benjamin Dietzek‐Ivanšić
- Institute of Physical Chemistry and Center of Energy and Environmental Chemistry Jena (CEEC Jena) Friedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
- Department Functional Interfaces Leibniz Institute of Photonic Technology Jena (IPHT) Albert-Einstein-Straße 9 07745 Jena Germany
| | - Carsten Streb
- Institute of Inorganic Chemistry I Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
- Department of Chemistry Johannes Gutenberg University Mainz Duesbergweg 10-14 55128 Mainz Germany
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35
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Donnelly K, Baumann M. Continuous Flow Technology as an Enabler for Innovative Transformations Exploiting Carbenes, Nitrenes, and Benzynes. J Org Chem 2022; 87:8279-8288. [PMID: 35700424 PMCID: PMC9251729 DOI: 10.1021/acs.joc.2c00963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Miniaturization offered
by microreactors provides for superb reaction
control as well as excellent heat and mass transfer. By performing
chemical reactions in microreactors or tubular systems under continuous
flow conditions, increased safety can be harnessed which allows exploitation
of these technologies for the generation and immediate consumption
of high-energy intermediates. This Synopsis demonstrates the use of
flow technology to effectively exploit benzynes, carbenes, and nitrenes
in synthetic chemistry programs.
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Affiliation(s)
- Kian Donnelly
- School of Chemistry, Science Centre South, University College Dublin, D04 N2E2 Dublin, Ireland
| | - Marcus Baumann
- School of Chemistry, Science Centre South, University College Dublin, D04 N2E2 Dublin, Ireland
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36
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Khan MEI, Di Terlizzi L, Protti S, Palmieri A. Visible‐Light‐Driven Photocatalyst‐Free Preparation of (Z) β‐Nitroacrylate Isomers. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Muhammad Ehtisham Ibraheem Khan
- University of Camerino School of Science and Technology: Universita degli Studi di Camerino Scuola di Scienze e Tecnologie Chemistry Division Via Madonna delle Carceri, Centro di ricerca CHIP 62032 Camerino ITALY
| | - Lorenzo Di Terlizzi
- University of Pavia: Universita degli Studi di Pavia Department of Chemistry ITALY
| | - Stefano Protti
- University of Pavia: Universita degli Studi di Pavia Department of Chemistry ITALY
| | - Alessandro Palmieri
- Universita degli Studi di Camerino School of Science and Technology, Chemistry Division Via S. Agostino n. 1 62032 Camerino ITALY
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37
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Minnaard AJ, Mouthaan MLMC, Pouwer K, Borst MLG, Witte MD. α-C–H Photoalkylation of a Glucose Derivative in Continuous Flow. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1840-5483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractSite-selective photoalkylation is a powerful strategy to extend the carbon framework of carbohydrates, otherwise often attainable only through laborious syntheses. This work describes the adaptation and upscaling of the photoalkylation of a glucose derivative as a continuous flow process. The reported iridium catalyst is replaced by an organic sensitizer and the reaction has been carried out on 40-gram scale.
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Affiliation(s)
- Adriaan J. Minnaard
- Department of Chemical Biology, Stratingh Institute for Chemistry, University of Groningen
| | - Marc L. M. C. Mouthaan
- Department of Chemical Biology, Stratingh Institute for Chemistry, University of Groningen
| | | | | | - Martin D. Witte
- Department of Chemical Biology, Stratingh Institute for Chemistry, University of Groningen
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38
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Ziegenbalg D, Pannwitz A, Rau S, Dietzek‐Ivanšić B, Streb C. Vergleichende Evaluierung lichtgetriebener Katalyse: Ein Rahmenkonzept für das standardisierte Berichten von Daten**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Dirk Ziegenbalg
- Institut für Chemieingenieurwesen Universität Ulm Albert-Einstein-Allee 11 89081 Ulm Deutschland
| | - Andrea Pannwitz
- Institut für Anorganische Chemie I Universität Ulm Albert-Einstein-Allee 11 89081 Ulm Deutschland
| | - Sven Rau
- Institut für Anorganische Chemie I Universität Ulm Albert-Einstein-Allee 11 89081 Ulm Deutschland
| | - Benjamin Dietzek‐Ivanšić
- Institut für Physikalische Chemie und Center of Energy and Environmental Chemistry Jena (CEEC Jena) Friedrich-Schiller-Universität Jena Helmholtzweg 4 07743 Jena Deutschland
- Department Funktionale Grenzflächen Leibniz-Institut für Photonische Technologien Jena (IPHT) Albert-Einstein-Straße 9 07745 Jena Deutschland
| | - Carsten Streb
- Institut für Anorganische Chemie I Universität Ulm Albert-Einstein-Allee 11 89081 Ulm Deutschland
- Department of Chemistry Johannes Gutenberg University Mainz Duesbergweg 10-14 55128 Mainz Germany
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39
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Herbrik F, Sanz M, Puglisi A, Rossi S, Benaglia M. Enantioselective Organophotocatalytic Telescoped Synthesis of a Chiral Privileged Active Pharmaceutical Ingredient. Chemistry 2022; 28:e202200164. [PMID: 35239197 PMCID: PMC9325444 DOI: 10.1002/chem.202200164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Indexed: 12/24/2022]
Abstract
The continuous flow, enantioselective, organophotoredox catalytic asymmetric alkylation of aldehydes was studied, by using a homemade, custom‐designed photoreactor for reactions under cryogenic conditions. Going from microfluidic conditions up to a 10 mL mesofluidic reactor, an increase of productivity by almost 18000 % compared to the batch reaction was demonstrated. Finally, for the first time, a stereoselective photoredox organocatalytic continuous flow reaction in a fully telescoped process for an active pharmaceutical ingredient (API)synthesis was successfully achieved. The final process consists of four units of operation: visible light‐driven asymmetric catalytic benzylation under continuous flow, inline continuous work‐up, neutralisation and a final oxidative amidation step afforded the pharmaceutically active molecule in 95 % e.e.
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Affiliation(s)
- Fabian Herbrik
- Dipartimento di Chimica, Università degli Studi di Milano, Via Camillo Golgi 19, 20133, Milano, Italy
| | - Miguel Sanz
- Taros Chemicals GmbH & Co. KG, Emil-Figge-Strasse 76 A, 44227, Dortmund, Germany
| | - Alessandra Puglisi
- Dipartimento di Chimica, Università degli Studi di Milano, Via Camillo Golgi 19, 20133, Milano, Italy
| | - Sergio Rossi
- Dipartimento di Chimica, Università degli Studi di Milano, Via Camillo Golgi 19, 20133, Milano, Italy
| | - Maurizio Benaglia
- Dipartimento di Chimica, Università degli Studi di Milano, Via Camillo Golgi 19, 20133, Milano, Italy
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40
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Application of multi-wall carbon nanotubes supported L-proline in continuous flow catalysis. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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42
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Oh S, Stache EE. Chemical Upcycling of Commercial Polystyrene via Catalyst-Controlled Photooxidation. J Am Chem Soc 2022; 144:5745-5749. [PMID: 35319868 DOI: 10.1021/jacs.2c01411] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemical upcycling of polystyrene into targeted small molecules is desirable to reduce plastic pollution. Herein, we report the upcycling of polystyrene to benzoyl products, primarily benzoic acid, using a catalyst-controlled photooxidative degradation method. FeCl3 undergoes a homolytic cleavage upon irradiation with white light to generate a chlorine radical, abstracting an electron-rich hydrogen atom on the polymer backbone. Under the oxygen-rich environment, high MW polystyrene (>90 kg/mol) degrades down to <1 kg/mol and produces up to 23 mol % benzoyl products. A series of mechanistic studies showed that chlorine radicals promoted the degradation via hydrogen-atom abstraction. Commercial polystyrene degrades efficiently in our method, showing the compatibility of our system with polymer fillers. Finally, we demonstrated the potential of scaling up our approach in a photoflow process to convert gram quantities of PS to benzoic acid.
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Affiliation(s)
- Sewon Oh
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Erin E Stache
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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43
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Donnelly K, Baumann M. Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography. Beilstein J Org Chem 2022; 18:232-239. [PMID: 35280956 PMCID: PMC8895036 DOI: 10.3762/bjoc.18.27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/18/2022] [Indexed: 11/23/2022] Open
Abstract
An efficient continuous flow process is reported for the synthesis of various 1,3,4-oxadiazoles via an iodine-mediated oxidative cyclisation approach. This entails the use of a heated packed-bed reactor filled with solid K2CO3 as a base. Using DMSO as solvent, this flow method generates the target heterocycles within short residence times of 10 minutes and in yields up to 93%. Scale-up of this flow process was achieved (34 mmol/h) and featured an integrated quenching and extraction step. Lastly, the use of an automated in-line chromatography system was exploited to realise a powerful flow platform for the generation of the heterocyclic targets.
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Affiliation(s)
- Kian Donnelly
- School of Chemistry, University College Dublin, Science Centre South, Belfield, Dublin 4, Ireland
| | - Marcus Baumann
- School of Chemistry, University College Dublin, Science Centre South, Belfield, Dublin 4, Ireland
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44
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Harper KC, Zhang EX, Liu ZQ, Grieme T, Towne TB, Mack DJ, Griffin J, Zheng SY, Zhang NN, Gangula S, Yuan JL, Miller R, Huang PZ, Gage J, Diwan M, Ku YY. Commercial-Scale Visible Light Trifluoromethylation of 2-Chlorothiophenol Using CF3I Gas. Org Process Res Dev 2022. [DOI: 10.1021/acs.oprd.1c00436] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Kaid C. Harper
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - En-Xuan Zhang
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Zhi-Qing Liu
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Timothy Grieme
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Timothy B. Towne
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Daniel J. Mack
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Jeremy Griffin
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Song-Yuan Zheng
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Ning-Ning Zhang
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Srinivas Gangula
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Jia-Long Yuan
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Robert Miller
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Ping-Zhong Huang
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - James Gage
- Asymchem Laboratories (Tianjin) Company Limited, TEDA, Tianjin 300457, P. R. China
| | - Moiz Diwan
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
| | - Yi-Yin Ku
- Abbvie Process Research & Development, 1401 N. Sheridan Road, North Chicago, Illinois 60064, United States
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45
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Burek BO, Duong HT, Hochradel K, Sutor A, Rupp M, Heilmann EK, Lovis K, Bloh JZ. Photochemistry at Scale: Wireless Light Emitters Drive Sustainability in Process Research & Development. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Bastien O. Burek
- Chemical Technology DECHEMA-Forschungsinstitut Theodor-Heuss-Allee 25 60486 Frankfurt am Main Germany
| | - Hong Thu Duong
- Chemical Technology DECHEMA-Forschungsinstitut Theodor-Heuss-Allee 25 60486 Frankfurt am Main Germany
| | - Klaus Hochradel
- Department Institute of Measurement and Sensor Technology UMIT – University for Health Sciences, Medical Informatics and Technology GmbH Eduard-Wallnöfer-Zentrum 1 16060 Hall in Tirol Austria
| | - Alexander Sutor
- Department Institute of Measurement and Sensor Technology UMIT – University for Health Sciences, Medical Informatics and Technology GmbH Eduard-Wallnöfer-Zentrum 1 16060 Hall in Tirol Austria
| | - Matthias Rupp
- Bayer AG Engineering & Technology 51368 Leverkusen Germany
| | - Eike K. Heilmann
- Bayer AG Research & Development Crop Science 40789 Monheim Germany
| | - Kai Lovis
- Bayer AG Research & Development Pharmaceuticals 42096 Wuppertal Germany
| | - Jonathan Z. Bloh
- Chemical Technology DECHEMA-Forschungsinstitut Theodor-Heuss-Allee 25 60486 Frankfurt am Main Germany
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46
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Buglioni L, Raymenants F, Slattery A, Zondag SDA, Noël T. Technological Innovations in Photochemistry for Organic Synthesis: Flow Chemistry, High-Throughput Experimentation, Scale-up, and Photoelectrochemistry. Chem Rev 2022; 122:2752-2906. [PMID: 34375082 PMCID: PMC8796205 DOI: 10.1021/acs.chemrev.1c00332] [Citation(s) in RCA: 228] [Impact Index Per Article: 114.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Indexed: 02/08/2023]
Abstract
Photoinduced chemical transformations have received in recent years a tremendous amount of attention, providing a plethora of opportunities to synthetic organic chemists. However, performing a photochemical transformation can be quite a challenge because of various issues related to the delivery of photons. These challenges have barred the widespread adoption of photochemical steps in the chemical industry. However, in the past decade, several technological innovations have led to more reproducible, selective, and scalable photoinduced reactions. Herein, we provide a comprehensive overview of these exciting technological advances, including flow chemistry, high-throughput experimentation, reactor design and scale-up, and the combination of photo- and electro-chemistry.
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Affiliation(s)
- Laura Buglioni
- Micro
Flow Chemistry and Synthetic Methodology, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, Het Kranenveld, Bldg 14—Helix, 5600 MB, Eindhoven, The Netherlands
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Fabian Raymenants
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Aidan Slattery
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Stefan D. A. Zondag
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Timothy Noël
- Flow
Chemistry Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), Universiteit van Amsterdam (UvA), Science Park 904, 1098 XH, Amsterdam, The Netherlands
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47
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Wan T, Wen Z, Laudadio G, Capaldo L, Lammers R, Rincón JA, García-Losada P, Mateos C, Frederick MO, Broersma R, Noël T. Accelerated and Scalable C(sp 3)-H Amination via Decatungstate Photocatalysis Using a Flow Photoreactor Equipped with High-Intensity LEDs. ACS CENTRAL SCIENCE 2022; 8:51-56. [PMID: 35106372 PMCID: PMC8796300 DOI: 10.1021/acscentsci.1c01109] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Indexed: 05/10/2023]
Abstract
Carbon-nitrogen bonds are ubiquitous in biologically active compounds, prompting synthetic chemists to design various methodologies for their preparation. Arguably, the ideal synthetic approach is to be able to directly convert omnipresent C-H bonds in organic molecules, enabling even late-stage functionalization of complex organic scaffolds. While this approach has been thoroughly investigated for C(sp2)-H bonds, only few examples have been reported for the direct amination of aliphatic C(sp3)-H bonds. Herein, we report the use of a newly developed flow photoreactor equipped with high intensity chip-on-board LED technology (144 W optical power) to trigger the regioselective and scalable C(sp3)-H amination via decatungstate photocatalysis. This high-intensity reactor platform enables simultaneously fast results gathering and scalability in a single device, thus bridging the gap between academic discovery (mmol scale) and industrial production (>2 kg/day productivity). The photocatalytic transformation is amenable to the conversion of both activated and nonactivated hydrocarbons, leading to protected hydrazine products by reaction with azodicarboxylates. We further validated the robustness of our manifold by designing telescoped flow approaches for the synthesis of pyrazoles, phthalazinones and free amines.
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Affiliation(s)
- Ting Wan
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Zhenghui Wen
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Gabriele Laudadio
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Luca Capaldo
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Rob Lammers
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Juan A. Rincón
- Centro
de Investigación Lilly S.A., Avda. de la Industria 30, Alcobendas-Madrid 28108, Spain
| | - Pablo García-Losada
- Centro
de Investigación Lilly S.A., Avda. de la Industria 30, Alcobendas-Madrid 28108, Spain
| | - Carlos Mateos
- Centro
de Investigación Lilly S.A., Avda. de la Industria 30, Alcobendas-Madrid 28108, Spain
| | - Michael O. Frederick
- Small Molecule
Design and Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
| | - Rémy Broersma
- Signify
Research, High Tech Campus
7, 5656 AE Eindhoven, The Netherlands
| | - Timothy Noël
- Flow
Chemistry Group, Van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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48
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Francis D, Blacker AJ, Kapur N, Marsden SP. Readily Reconfigurable Continuous-Stirred Tank Photochemical Reactor Platform. Org Process Res Dev 2021. [DOI: 10.1021/acs.oprd.1c00428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Daniel Francis
- Institute of Process Research and Development, University of Leeds, Leeds LS2 9JT, U.K
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - A. John Blacker
- Institute of Process Research and Development, University of Leeds, Leeds LS2 9JT, U.K
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, U.K
| | - Nikil Kapur
- Institute of Process Research and Development, University of Leeds, Leeds LS2 9JT, U.K
- School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, U.K
| | - Stephen P. Marsden
- Institute of Process Research and Development, University of Leeds, Leeds LS2 9JT, U.K
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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49
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Wen Z, Wan T, Vijeta A, Casadevall C, Buglioni L, Reisner E, Noël T. Photocatalytic C-H Azolation of Arenes Using Heterogeneous Carbon Nitride in Batch and Flow. CHEMSUSCHEM 2021; 14:5265-5270. [PMID: 34529334 PMCID: PMC9298336 DOI: 10.1002/cssc.202101767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/16/2021] [Indexed: 05/08/2023]
Abstract
The functionalization of aryl C(sp2 )-H bonds is a useful strategy for the late-stage modification of biologically active molecules, especially for the regioselective introduction of azole heterocycles to prepare medicinally-relevant compounds. Herein, we describe a practical photocatalytic transformation using a mesoporous carbon nitride (mpg-CNx ) photocatalyst, which enables the efficient azolation of various arenes through direct oxidation. The method exhibits a broad substrate scope and is amenable to the late-stage functionalization of several pharmaceuticals. Due to the heterogeneous nature and high photocatalytic stability of mpg-CNx , the catalyst can be easily recovered and reused leading to greener and more sustainable routes, using either batch or flow processing, to prepare these important compounds of interest in pharmaceutical and agrochemical research.
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Affiliation(s)
- Zhenghui Wen
- Flow Chemistry GroupVan't Hoff Institute for Molecular Sciences (HIMS)Universiteit van Amsterdam (UvA)Science Park 9041098 XHAmsterdamThe Netherlands
| | - Ting Wan
- Flow Chemistry GroupVan't Hoff Institute for Molecular Sciences (HIMS)Universiteit van Amsterdam (UvA)Science Park 9041098 XHAmsterdamThe Netherlands
| | - Arjun Vijeta
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUnited Kingdom
| | - Carla Casadevall
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUnited Kingdom
| | - Laura Buglioni
- Department of Chemical Engineering and ChemistrySustainable Process EngineeringEindhoven University of TechnologyP.O. Box 5135600 MBEindhovenThe Netherlands
| | - Erwin Reisner
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUnited Kingdom
| | - Timothy Noël
- Flow Chemistry GroupVan't Hoff Institute for Molecular Sciences (HIMS)Universiteit van Amsterdam (UvA)Science Park 9041098 XHAmsterdamThe Netherlands
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50
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Duffy M, Di Filippo M, Baumann M. Synthesis of 2H-indazoles via the Cadogan reaction in batch and flow mode. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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