1
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Higashimura I, Shele M, Akamatsu T, Ohmura R, Liang F, Okazoe T, Tsuda A. Photo-on-Demand In Situ One-Pot Synthesis of Carbonate Esters from Tetrachloroethylene. J Org Chem 2024; 89:1864-1872. [PMID: 38198222 DOI: 10.1021/acs.joc.3c02588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
The present study reports a novel one-pot synthesis of carbonate esters with photo-oxidized tetrachloroethylene (TCE). Acyclic and cyclic alkyl carbonate esters could be synthesized through base-promoted condensation reactions of alcohols with the photo-oxidized TCE that was prepared by irradiation with UV-C or visible light under O2 or O2/Cl2 (∼4%) bubbling, respectively. Cyclic carbonate esters could also be synthesized from a solution of TCE and the ethylene glycol derivative by irradiation of UV-C light under O2 bubbling. With respect to the reaction mechanism, the photochemical oxidation of TCE mainly provides the highly toxic and corrosive trichloroacetyl chloride (TCAC), which then reacts in situ with the alcohol to give the corresponding trichloroacetic acid ester (TCAE). The subsequent intermolecular or intramolecular base-catalyzed condensation reaction of TCAE with or without the addition of alcohol leads to elimination of CHCl3 in the corresponding carbonate ester. The present reactions enable the in situ one-pot synthesis of a variety of alkyl carbonate esters under mild conditions without the direct handling of TCAC. This is beneficial in terms of safety, cost, and reduced environmental impact.
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Affiliation(s)
- Ikkei Higashimura
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Muge Shele
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Toshiki Akamatsu
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Ryota Ohmura
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Fengying Liang
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Takashi Okazoe
- Materials Integration Laboratories, AGC Inc., 1-1 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Akihiko Tsuda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
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2
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Tsuda A, Ozawa N, Muranaka R, Kuwahara T, Matsune A, Liang F. Photo-on-Demand In Situ Phosgenation Reactions That Cross Three Phases of a Heterogeneous Solution of Chloroform and Aqueous NaOH. ACS OMEGA 2023; 8:27802-27810. [PMID: 37546672 PMCID: PMC10398853 DOI: 10.1021/acsomega.3c04290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 06/30/2023] [Indexed: 08/08/2023]
Abstract
Here, we report a novel photo-on-demand in situ phosgenation reaction that crosses three phases of a heterogeneous solution of chloroform (CHCl3) and aqueous NaOH containing an aryl alcohol or amine. This reaction system enables the safe, convenient, and inexpensive synthesis of carbonate esters, polycarbonates, and N-substituted ureas from aryl alcohols, aryl diols, and primary/secondary amines, respectively, on a practical scale and with good yield. The photochemical oxidation of CHCl3 to phosgene (COCl2) occurs upon irradiation with UV light from a low-pressure mercury lamp of both the gas and liquid phases of the reaction system under O2 bubbling of the vigorously stirred sample solution. The following reaction mechanisms are suggested: The aryl alcohol reacts in situ with the generated COCl2 at the interfaces of the organic/aqueous phases and aqueous/gas phases, in competition with the decomposition of COCl2 due to hydrolysis. Nucleophilicity and hydrophilicity are enhanced by the formation of aryl alkoxide ion through the reaction with NaOH, whereas the reaction of amine proceeds through neutralization of the generated HCl by the aqueous NaOH.
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3
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Akamatsu T, Shele M, Matsune A, Kashiki Y, Liang F, Okazoe T, Tsuda A. Photo-on-Demand In Situ Synthesis of N-Substituted Trichloroacetamides with Tetrachloroethylene and Their Conversions to Ureas, Carbamates, and Polyurethanes. ACS OMEGA 2023; 8:2669-2684. [PMID: 36687089 PMCID: PMC9851034 DOI: 10.1021/acsomega.2c07233] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
N-substituted trichloroacetamides (NTCAs), which serve as blocked isocyanates, were synthesized in ∼97% yields by in situ photo-on-demand trichloroacetylation of amines with tetrachloroethylene (TCE). The reactions were performed by photo-irradiation of TCE solutions containing an amine under O2 bubbling over 70 °C with a low-pressure mercury lamp. TCE underwent photochemical oxidation to afford trichloroacetyl chloride having high toxicity and corrosivity, which then reacts in situ with the amine to afford NTCA. Compared with conventional NTCA synthesis with hexachloroacetone, the present reaction has the advantage of being widely applicable to a variety of amines, even those with low nucleophilicity such as amides, fluorinated amines, and amine HCl salts. NTCAs could be converted to the corresponding N-substituted ureas and carbamates through base-catalyzed condensation with amines and alcohols, respectively, with the elimination of CHCl3. The reaction may proceed by the initial formation of isocyanate and its subsequent addition reaction with the amine or alcohol. This photochemical reaction also enables the synthesis of fluorinated NTCAs, which accelerate the reactions, and realizes the synthesis of novel fluorinated chemicals including polyurethanes.
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Affiliation(s)
- Toshiki Akamatsu
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
| | - Muge Shele
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
| | - Ayako Matsune
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
| | - Yoshiyuki Kashiki
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
| | - Fengying Liang
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
| | - Takashi Okazoe
- Materials
Integration Laboratories, AGC Inc., 1-1 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa230-0045, Japan
| | - Akihiko Tsuda
- Department
of Chemistry, Graduate School of Science, Kobe University, 1-1
Rokkodai-cho, Nada-ku, Kobe657-8501, Japan
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4
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Hatsumura S, Hashimoto Y, Hosokawa S, Nagao A, Eda K, Harada H, Ishitsuka K, Okazoe T, Tsuda A. Reactivity and Product Selectivity of Fluoroalkyl Carbonates in Substitution Reactions with Primary Alcohols and Amines. J Org Chem 2022; 87:11572-11582. [PMID: 35981240 DOI: 10.1021/acs.joc.2c01180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study reports a systematic investigation of the substitution reactions of a series of symmetric and unsymmetric fluoroalkyl carbonates with primary alcohols or amines. The reactivity of the haloalkyl carbonate depends mainly on the electrophilicity and steric crowdedness of the carbonyl group and the leaving ability of the haloalkyl alcohols. Diethyl carbonate as a reference substrate showed no reaction with the alcohol or amine. However, bis(2,2,2-trifluoroethyl) carbonate [(F3-EtO)2CO] having electron-withdrawing trifluoroethyl groups enabled substitution reactions, with relatively higher reactivities to those for diphenyl carbonate [(PhO)2CO]. Furthermore, (F6-iPrO)2CO, bearing two sets of hexafluoroisopropyl groups, showed dramatic acceleration of the reactions, in which the observed reactivities were similar to those for bis(perfluorophenyl) carbonate [(F5-PhO)2CO]. The electrophilicity of the carbonyl group and the leaving ability of the alcohols in the series of haloalkyl carbonates were found to be correlated with the wavenumbers of their carbonyl groups in IR spectra and pKa for the eliminated alcohols, respectively. Since the eliminated fluoroalkyl alcohols exhibit weak affinity with the organic products and have lower boiling points owing to a characteristic property of the fluoroalkyl group, they could be readily removed from the product by simple evaporation below 100 °C with or without reduced pressure.
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Affiliation(s)
- Shuto Hatsumura
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Yuka Hashimoto
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Sasuga Hosokawa
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Akihiro Nagao
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Kazuo Eda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Hirofumi Harada
- Innovative Technology Laboratories, AGC Inc, 1-1 Suehiro-cho Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Kei Ishitsuka
- Innovative Technology Laboratories, AGC Inc, 1-1 Suehiro-cho Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Takashi Okazoe
- Materials Integration Laboratories, AGC Inc, 1-1 Suehiro-cho Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Akihiko Tsuda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
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5
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Suri G, Liang F, Hu M, Wang M, Bu R, Zhang X, Wang H, Dong W, Eerdun C, Tsuda A. Direct Syntheses of Diphenylmethanol Derivatives from Substituted Benzenes and CHCl 3 through Friedel-Crafts Alkylation and Post-Synthetic Hydrolysis or Alcoholysis Catalyzed by Alumina. ChemistryOpen 2022; 11:e202200042. [PMID: 35585035 PMCID: PMC9117155 DOI: 10.1002/open.202200042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/22/2022] [Indexed: 11/14/2022] Open
Abstract
The present study reports an innovative finding that alumina containing water or primary alcohol catalyzes the hydrolysis or alcoholysis, respectively, of the product formed through AlCl3 -mediated Friedel-Crafts alkylation of methyl-substituted benzenes and CHCl3 . The former and later reactions mainly provided hydroxy- and alkoxy-substituted diarylmethanes, respectively, while the reference reactions without alumina provided bisarylchloromethane. This method enables the selective syntheses of diphenylmethanol derivatives with very simple procedures, without expensive reagents and apparatuses. Furthermore, the alumina used in the reaction could be recycled by washing with water and subsequent drying. From the viewpoint of material recycling, this function is very important for the development of sustainable chemical reactions.
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Affiliation(s)
- Guga Suri
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Fengying Liang
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Mixia Hu
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Meiling Wang
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Ren Bu
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Xiaoying Zhang
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Hui Wang
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Wenyan Dong
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Chaolu Eerdun
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
| | - Akihiko Tsuda
- Department of Pharmaceutical SciencesInner Mongolia Medical UniversityJinshan Economic & Technology Development DistrictHohhot, InnerMongolia010110P. R. China
- Department of ChemistryGraduate School of ScienceKobe University1-1 Rokkodai-cho, Nada-kuKobe657-8501Japan
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6
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Hashimoto Y, Hosokawa S, Liang F, Suzuki Y, Dai N, Tana G, Eda K, Kakiuchi T, Okazoe T, Harada H, Tsuda A. Photo-on-Demand Base-Catalyzed Phosgenation Reactions with Chloroform: Synthesis of Arylcarbonate and Halocarbonate Esters. J Org Chem 2021; 86:9811-9819. [PMID: 34182754 DOI: 10.1021/acs.joc.1c01210] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carbonate esters are utilized as solvents and reagents for C1 building blocks in organic synthesis. This study reports a novel photo-on-demand in situ synthesis of carbonate esters with CHCl3 solutions containing a mixture of an aromatic or haloalkyl alcohol having relatively high acidity, and an organic base. We found that the acid-base interaction of the alcohol and base in the CHCl3 solution plays a key role in enabling the photochemical reaction. This reaction allows practical syntheses of diphenyl carbonate derivatives, haloalkyl carbonates, and polycarbonates, which are important chemicals and materials in industry.
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Affiliation(s)
- Yuka Hashimoto
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Sasuga Hosokawa
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Fengying Liang
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Yuto Suzuki
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Namin Dai
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Gegen Tana
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Kazuo Eda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Toshifumi Kakiuchi
- Innovative Technology Laboratories, AGC Inc., Suehiro 1-1 Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Takashi Okazoe
- Materials Integration Laboratories, AGC Inc., Suehiro 1-1 Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Hidefumi Harada
- Tokyo Research Laboratory, Mitsubishi Gas Chemical Company, Inc., Nijyuku 6-1-1 Katsushika-ku, Tokyo 125-8601, Japan
| | - Akihiko Tsuda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
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7
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Liang F, Yanai M, Suzuki Y, Tsuda A. Photo-on-Demand Synthesis of Chloroformates with a Chloroform Solution Containing an Alcohol and Its One-Pot Conversion to Carbonates and Carbamates. Org Lett 2020; 22:3566-3569. [DOI: 10.1021/acs.orglett.0c01013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Fengying Liang
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
- Department of Pharmaceutical Sciences, Inner Mongolia Medical University, Jinshan Economic & Technology Development District, Hohhot, Inner Mongolia 010110, China
| | - Masaki Yanai
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Yuto Suzuki
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Akihiko Tsuda
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
- Department of Pharmaceutical Sciences, Inner Mongolia Medical University, Jinshan Economic & Technology Development District, Hohhot, Inner Mongolia 010110, China
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8
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Poshala S, Thunga S, Golla S, Satheesh V, Kokatla HP. A Facile One‐Pot Synthesis of 2,2,2‐Trichloroacetates Through Acid‐Catalyzed Deimination and Its Applications. ChemistrySelect 2019. [DOI: 10.1002/slct.201902189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Soumya Poshala
- Department of Chemistry, National Institute of Technology Warangal Telangana 506004 India
| | - Sanjeeva Thunga
- Department of Chemistry, National Institute of Technology Warangal Telangana 506004 India
| | - Sivaparwathi Golla
- Department of Chemistry, National Institute of Technology Warangal Telangana 506004 India
| | - Vanaparthi Satheesh
- Department of Chemistry, National Institute of Technology Warangal Telangana 506004 India
| | - Hari Prasad Kokatla
- Department of Chemistry, National Institute of Technology Warangal Telangana 506004 India
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9
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Toda Y, Matsuda R, Gomyou S, Suga H. Use of trichloroacetonitrile as a hydrogen chloride generator for ring-opening reactions of aziridines. Org Biomol Chem 2019; 17:3825-3829. [PMID: 30920569 DOI: 10.1039/c9ob00602h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regioselective ring-opening reactions of 2-aryl-N-tosylaziridines are described, in which hydrogen chloride is generated by photodegradation of trichloroacetonitrile. HCl adducts are obtained in high yields in 1,4-dioxane, whereas methanol adducts are predominantly obtained in methanol. Trichloroacetonitrile can serve as a photoresponsive molecular storage generator for hydrogen chloride.
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Affiliation(s)
- Yasunori Toda
- Department of Materials Chemistry, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
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10
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Sribalan R, Sangili A, Banuppriya G, Padmini V. An efficient synthesis of nitrile, tetrazole and urea from carbonyl compounds. NEW J CHEM 2017. [DOI: 10.1039/c6nj03860c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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11
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Lebel H, Piras H, Borduy M. Iron-Catalyzed Amination of Sulfides and Sulfoxides with Azides in Photochemical Continuous Flow Synthesis. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02495] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Hélène Lebel
- Département
de Chimie,
Center for Green Chemistry and Catalysis, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
| | - Henri Piras
- Département
de Chimie,
Center for Green Chemistry and Catalysis, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
| | - Marie Borduy
- Département
de Chimie,
Center for Green Chemistry and Catalysis, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
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12
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Singh AS, Kumar D, Mishra N, Tiwari VK. An efficient one-pot synthesis of N,N′-disubstituted ureas and carbamates from N-acylbenzotriazoles. RSC Adv 2016. [DOI: 10.1039/c6ra14131e] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A facile one-pot synthesis of carbamates and N,Nʹ-disubstituted symmetrical ureas from N-acylbenzotriazoles has been devised. It is believed that, the intermediate acyl-azide undergo Curtius rearrangement.
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Affiliation(s)
- Anoop S. Singh
- Department of Chemistry
- Centre of Advanced Study
- Institute of Science
- Banaras Hindu University
- Varanasi-221005
| | | | - Nidhi Mishra
- Department of Chemistry
- Centre of Advanced Study
- Institute of Science
- Banaras Hindu University
- Varanasi-221005
| | - Vinod K. Tiwari
- Department of Chemistry
- Centre of Advanced Study
- Institute of Science
- Banaras Hindu University
- Varanasi-221005
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