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Sugisawa N, Nakabayashi K, Sugisawa H, Fuse S. One-Flow Syntheses of Unsymmetrical Sulfamides and N-Substituted Sulfamate Esters. Org Lett 2024; 26:2739-2744. [PMID: 37306668 DOI: 10.1021/acs.orglett.3c01546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We developed one-flow syntheses of unsymmetrical sulfamides and N-substituted sulfamate esters by changing a nucleophile and a tertiary amine from inexpensive and commercially available chlorosulfonic acid. In the synthesis of N-substituted sulfamate esters, unexpected symmetrical sulfite formation was suppressed by changing the tertiary amine. The effect of tertiary amines was proposed using linear regression. Our approach rapidly (≤90 s) provides desired products containing acidic and/or basic labile groups without tedious purification under mild (20 °C) conditions.
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Affiliation(s)
- Naoto Sugisawa
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan
| | - Kohei Nakabayashi
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan
| | - Hiroki Sugisawa
- Science & Innovation Center, Mitsubishi Chemical Corporation, Yokohama, 227-8502, Japan
| | - Shinichiro Fuse
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan
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Fuse S, Kanda S, Masui H. One-Flow Synthesis of Substituted Indoles via Sequential 1,2-Addition/Nucleophilic Substitution of Indolyl-3-Carbaldehydes. Chem Asian J 2024; 19:e202300909. [PMID: 37962410 DOI: 10.1002/asia.202300909] [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: 10/13/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/15/2023]
Abstract
Substituted indoles are important as drugs. A number of valuable indoles have been synthesized via nucleophilic substitution at the 3'-position of indoles. However, the preparation of an indolylmethyl electrophile containing a tertiary carbon at the 3'-position and its subsequent nucleophilic substitution are challenging owing to the instability of the electrophile. Herein, we demonstrated the rapid one-flow synthesis of indoles via sequential 1,2-addition/nucleophilic substitution of indolyl-3-carbaldehydes. The use of a microflow technology helped in suppressing the undesired reactions caused by the unstable intermediates, resulting in significantly higher yields and reproducibility compared to those under batch conditions. A crown ether was effective when 1-alkylindole-3-carboxaldehyde was used as a substrate. However, the crown ether exerted a detrimental effect when 1H-indole-3-carboxaldehyde was used. A total of 15 structurally diverse indole derivatives were obtained in generally acceptable to good yields.
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Affiliation(s)
- Shinichiro Fuse
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Sena Kanda
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hisashi Masui
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
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Sugisawa N, Ando A, Fuse S. Rapid and column-chromatography-free peptide chain elongation via a one-flow, three-component coupling approach. Chem Sci 2023; 14:6986-6991. [PMID: 37389269 PMCID: PMC10306071 DOI: 10.1039/d3sc01333b] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/04/2023] [Indexed: 07/01/2023] Open
Abstract
Short peptides are extremely important as drugs and building blocks for the syntheses of longer peptides. Both solid- and liquid-phase peptide syntheses suffer from a large number of synthetic steps, high cost, and/or tedious purification. Here, we developed a rapid, mild, inexpensive, and column-chromatography-free peptide chain elongation via a one-flow, three-component coupling (3CC) approach that is the first to use α-amino acid N-carboxy anhydrides (α-NCAs) both as electrophiles and nucleophiles. We demonstrated the high-yielding and column-chromatography-free syntheses of 17 tripeptides, as well as a gram-scale synthesis of a tripeptide. The total synthesis of beefy meaty peptide was achieved by repeating the 3CC approach with the addition of only one column chromatographic purification. We also demonstrated a one-flow tripeptide synthesis via in situ preparation of α-NCA starting from three readily available protected amino acids. With this study, we achieved dramatic reductions in both time and cost compared with typical solid-phase synthesis.
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Affiliation(s)
- Naoto Sugisawa
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Nagoya 464-8601 Japan
| | - Akira Ando
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Nagoya 464-8601 Japan
| | - Shinichiro Fuse
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Nagoya 464-8601 Japan
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Masui H, Fuse S. Micro-Flow <i>N</i>-Acylation Using Highly Electrophilic Acyl Ammonium Cations for Peptide and Urethane-Protected <i>N</i>-Carboxyanhydride Syntheses. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.986] [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]
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Ashikari Y, Guan K, Nagaki A. Flash functional group-tolerant biaryl-synthesis based on integration of lithiation, zincation and negishi coupling in flow. FRONTIERS IN CHEMICAL ENGINEERING 2022. [DOI: 10.3389/fceng.2022.964767] [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
We achieved an integration of a lithiation of aryl bromides, a zincation of thus-generated aryllithiums, and a Negishi coupling of the arylzinc with an aryl halide in one flow. Taking advantages of flow microreactors, biaryls bearing a wide range of functional groups, especially biaryls bearing multiple electrophilic-functionalities were synthesized.
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Kitamura H, Otake Y, Sugisawa N, Sugisawa H, Ida T, Nakamura H, Fuse S. Sequential Nucleophilic Substitution of Phosphorus Trichloride with Alcohols in a Continuous‐Flow Reactor and Consideration of a Mechanism for Reduced Over‐reaction through the Addition of Imidazole. Chemistry 2022; 28:e202200932. [DOI: 10.1002/chem.202200932] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Indexed: 12/28/2022]
Affiliation(s)
- Hiroshi Kitamura
- School of Life Science and Technology Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
| | - Yuma Otake
- School of Life Science and Technology Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
| | - Naoto Sugisawa
- Department of Basic Medicinal Sciences Graduate School of Pharmaceutical Sciences Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8601 Japan
| | - Hiroki Sugisawa
- Division of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Kakuma-machi Kanazawa Ishikawa 920-1192 Japan
| | - Tomonori Ida
- Division of Material Chemistry Graduate School of Natural Science and Technology Kanazawa University Kakuma-machi Kanazawa Ishikawa 920-1192 Japan
| | - Hiroyuki Nakamura
- School of Life Science and Technology Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku Yokohama 226-8503 Japan
| | - Shinichiro Fuse
- Department of Basic Medicinal Sciences Graduate School of Pharmaceutical Sciences Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8601 Japan
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Okabe R, Sugisawa N, Fuse S. A micro-flow rapid dual activation approach for urethane-protected α-amino acid N-carboxyanhydride synthesis. Org Biomol Chem 2022; 20:3303-3310. [PMID: 35229099 DOI: 10.1039/d2ob00167e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study demonstrated the rapid dual activation (10 s, 20 °C) of a combination of an α-amino acid N-carboxyanhydride and alkyl chloroformate in the synthesis of a urethane-protected α-amino acid N-carboxyanhydride in a micro-flow reactor. The key to success was the combined use of two amines that activated both substrates with proper timing. Three amines, i-Pr2NEt, Me2NBn, or N-ethylmorpholine, were used with pyridine in accordance with the steric bulkiness of a side chain in the α-amino acid N-carboxyanhydride. A variety of 16 urethane-protected α-amino acid N-carboxyanhydrides were synthesized in high yields. The role of amines was investigated based on the measurement of the time-dependent (0.5 to 10 s) decrease of α-amino acid N-carboxyanhydrides and alkyl chloroformates in the presence of amines via flash mixing technology using a micro-flow reactor. It was suggested that the in situ generated acylpyridinium cation was highly active and less prone to causing undesired decomposition compared with the acylammonium cation examined in this study. Thus, even at a very low concentration, the acylpyridinium cation facilitated the desired coupling reaction.
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Affiliation(s)
- Ren Okabe
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Naoto Sugisawa
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Shinichiro Fuse
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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Fuse S, Komuro K, Otake Y, Masui H, Nakamura H. Rapid and Mild Lactamization Using Highly Electrophilic Triphosgene in a Microflow Reactor. Chemistry 2021; 27:7525-7532. [PMID: 33496974 DOI: 10.1002/chem.202100059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Indexed: 12/23/2022]
Abstract
Lactams are cyclic amides that are indispensable as drugs and as drug candidates. Conventional lactamization includes acid-mediated and coupling-agent-mediated approaches that suffer from narrow substrate scope, much waste, and/or high cost. Inexpensive, less-wasteful approaches mediated by highly electrophilic reagents are attractive, but there is an imminent risk of side reactions. Herein, a methods using highly electrophilic triphosgene in a microflow reactor that accomplishes rapid (0.5-10 s), mild, inexpensive, and less-wasteful lactamization are described. Methods A and B, which use N-methylmorpholine and N-methylimidazole, respectively, were developed. Various lactams and a cyclic peptide containing acid- and/or heat-labile functional groups were synthesized in good to high yields without the need for tedious purification. Undesired reactions were successfully suppressed, and the risk of handling triphosgene was minimized by the use of microflow technology.
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Affiliation(s)
- Shinichiro Fuse
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Keiji Komuro
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.,School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
| | - Yuma Otake
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.,School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
| | - Hisashi Masui
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hiroyuki Nakamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
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Maiti R, Xu J, Yan JL, Mondal B, Yang X, Chai H, Hao L, Jin Z, Chi YR. Carbene-catalyzed selective addition of isothioureas to enals for access to sulphur-containing 5,6-dihyropyrimidin-4-ones. Org Chem Front 2021. [DOI: 10.1039/d0qo01380c] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A carbene-catalyzed highly regioselective and enantioselective 1,4-addition reaction between isothioureas and enals has been achieved under oxidative conditions.
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Affiliation(s)
- Rakesh Maiti
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Jun Xu
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Jia-Lei Yan
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Bivas Mondal
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Xing Yang
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Huifang Chai
- Guizhou University of Traditional Chinese Medicine
- Guiyang 550025
- China
| | - Lin Hao
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
| | - Zhichao Jin
- Key Laboratory of Green Pesticide and Agriculture Bioengineering
- Ministry of Education
- Guizhou University
- Guiyang 550025
- China
| | - Yonggui Robin Chi
- Division of Chemistry & Biological Chemistry
- School of Physical & Mathematical Science
- Nanyang Technological University
- Singapore 637371
- Singapore
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Abstract
Developments that result in high-yielding, low-cost, safe, scalable, and less-wasteful processes are the most important goals in synthetic organic chemistry. Continuous-flow reactions have garnered much attention due to many advantages over conventional batch reactions that include precise control of short reaction times and temperatures, low risk in handling dangerous compounds, and ease in scaling up synthesis. Combinations of continuous-flow reactions with homogeneous, metal-free catalysts further enhances advantages that include low-cost and ready availability, low toxicity, higher stability in air and water, and increased synthetic efficiency due to the avoidance of the time-consuming removal of toxic metal traces. This review summarizes recently reported continuous-flow reactions using metal-free homogeneous catalysts and classifies them either as acidic catalysts, basic catalysts, or miscellaneous catalysts. In addition, we compare the results between continuous-flow conditions and conventional batch conditions to reveal the advantages of using flow reactions with metal-free homogeneous catalysts.
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