1
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Gao X, He H, Miao K, Zhang L, Ni SF, Li M, Guo W. Electrochemical Allylic C(sp 3)-H Isothiocyanation via [3,3]-Sigmatropic Rearrangement. Org Lett 2024; 26:4554-4559. [PMID: 38767297 DOI: 10.1021/acs.orglett.4c01463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The direct allylic C(sp3)-H functionalization provides a straightforward protocol for the synthesis of valuable molecules. We report herein the first chemo- and site-selective method for allylic C(sp3)-H isothiocyanation of various internal alkenes under mild electrochemical conditions. This method exhibits broad functional group tolerance and excellent selectivity and can be applied for late-stage isothiocyanation of bioactive molecules. Combined experimental and computational studies indicate that the reaction proceeds via an unexpected [3,3]-sigmatropic rearrangement.
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Affiliation(s)
- Xuezhuang Gao
- College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, 53 Zhengzhou Road, 266042 Qingdao, P. R. China
| | - Hui He
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong, Shantou University, Shantou, 515063 Guangdong, P. R. China
| | - Kaili Miao
- College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, 53 Zhengzhou Road, 266042 Qingdao, P. R. China
| | - Linbao Zhang
- College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, 53 Zhengzhou Road, 266042 Qingdao, P. R. China
| | - Shao-Fei Ni
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong, Shantou University, Shantou, 515063 Guangdong, P. R. China
| | - Ming Li
- College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, 53 Zhengzhou Road, 266042 Qingdao, P. R. China
| | - Weisi Guo
- College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, 53 Zhengzhou Road, 266042 Qingdao, P. R. China
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2
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Das B, Dahiya A, Patel BK. Isothiocyanates: happy-go-lucky reagents in organic synthesis. Org Biomol Chem 2024; 22:3772-3798. [PMID: 38656266 DOI: 10.1039/d4ob00281d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Owing to their unique structural features, isothiocyanates (ITCs) are a class of highly useful and inimitable reagents as the -NCS group serves both as electrophile and nucleophile in organic synthesis. ITCs share a rich legacy in organic, medicinal, and combinatorial chemistry. Compared to their oxygen equivalents, isocyanates, ITCs are easily available, less unpleasant, and somewhat less harmful to work with (mild conditions) which makes them happy-go-lucky reagents. Functionalized ITCs can finely tune the reactivity of the -NCS group and thus can be exploited in the late-stage functionalization processes. This review's primary aim is to outline ITC chemistry in the construction and derivatization of heterocycles through the lens of sustainability. For ease and brevity, the sections are divided based on reactive centers present in functionalized ITCs and modes of cyclisation. Scrutinizing their probable unexplored directions for future research studies is also addressed.
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Affiliation(s)
- Bubul Das
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India.
- Department of Chemistry, Bagadhar Brahma Kishan College, Jalah, Assam 781327, India
| | - Anjali Dahiya
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India.
| | - Bhisma K Patel
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India.
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3
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Liu J, Du J, Zhang LB, Li M, Guo W. Electrochemical Benzylic C-H Amination via N-Aminopyridinium. J Org Chem 2024; 89:6465-6473. [PMID: 38644574 DOI: 10.1021/acs.joc.4c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
An electrochemical protocol for benzylic C(sp3)-H aminopyridylation via direct C-H/N-H cross-coupling of alkylarenes with N-aminopyridinium triflate has been developed. This method features excellent site-selectivity, broad substrate scope, redox reagent-free and facile scalability. The generated benzylaminopyridiniums can be readily converted to benzylamines via electroreductive N-N bond cleavage.
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Affiliation(s)
- Jingwei Liu
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Jinyao Du
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Lin-Bao Zhang
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Ming Li
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Weisi Guo
- College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
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4
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Maeda B, Murakami K. Recent advancement in the synthesis of isothiocyanates. Chem Commun (Camb) 2024; 60:2839-2864. [PMID: 38380440 DOI: 10.1039/d3cc06118c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Isothiocyanates exhibit various biological characteristics, including antimicrobial, anti-inflammatory, and anticancer properties. Their significance extends to synthetic chemistry, where they serve as valuable platforms for versatile transformations. Consequently, they have attracted the attention of biologists and chemists. This review summarizes recent advancements in the synthesis of isothiocyanates. Access to a variety of starting materials is important to prepare isothiocyanates with diverse structures. This review categorizes synthetic methods into three types based on the starting materials and functional groups: (i) type A, derived from primary amines; (ii) type B, derived from other nitrogen functional groups; and (iii) type C, derived from non-nitrogen groups. Recent trends in synthetic methods have revealed the prevalence of type-A reactions derived from primary amines. However, type B reactions have rarely been reported. Notably, over the past four years, there has been a notable increase in type C reactions, indicating a growing interest in non-nitrogen-derived isothiocyanates. Overall, this review not only outlines the advancements in the synthesis of isothiocyanates but also highlights trends in the methodology.
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Affiliation(s)
- Bumpei Maeda
- Department of Chemistry, School of Science, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan.
| | - Kei Murakami
- Department of Chemistry, School of Science, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan.
- Japanese Science and Technology Agency (JST)-PRESTO, Chiyoda, Tokyo 102-0076, Japan
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5
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Rani S, Aslam S, Lal K, Noreen S, Alsader KAM, Hussain R, Shirinfar B, Ahmed N. Electrochemical C-H/C-C Bond Oxygenation: A Potential Technology for Plastic Depolymerization. CHEM REC 2024; 24:e202300331. [PMID: 38063812 DOI: 10.1002/tcr.202300331] [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: 10/27/2023] [Revised: 11/23/2023] [Indexed: 03/10/2024]
Abstract
Herein, we provide eco-friendly and safely operated electrocatalytic methods for the selective oxidation directly or with water, air, light, metal catalyst or other mediators serving as the only oxygen supply. Heavy metals, stoichiometric chemical oxidants, or harsh conditions were drawbacks of earlier oxidative cleavage techniques. It has recently come to light that a crucial stage in the deconstruction of plastic waste and the utilization of biomass is the selective activation of inert C(sp3 )-C/H(sp3 ) bonds, which continues to be a significant obstacle in the chemical upcycling of resistant polyolefin waste. An appealing alternative to chemical oxidations using oxygen and catalysts is direct or indirect electrochemical conversion. An essential transition in the chemical and pharmaceutical industries is the electrochemical oxidation of C-H/C-C bonds. In this review, we discuss cutting-edge approaches to chemically recycle commercial plastics and feasible C-C/C-H bonds oxygenation routes for industrial scale-up.
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Affiliation(s)
- Sadia Rani
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Samina Aslam
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Kiran Lal
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Sobia Noreen
- Institute of Chemistry, University of Sargodha, Sargodha, 40100, Pakistan
| | | | - Riaz Hussain
- Department of Chemistry, University of Education Lahore, D.G. Khan Campus, 32200, Pakistan
| | - Bahareh Shirinfar
- West Herts College - University of Hertfordshire, Watford, WD17 3EZ, London, United Kingdom
| | - Nisar Ahmed
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, United Kingdom
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6
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Qin H, Chen F, Du J, Yang X, Huang Y, Zhu K, Yue C, Fang Z, Guo K. Thiocyanate promoted difunctionalization and cyclization of unsaturated C-C bonds to construct 1-sulfur-2-nitrogen-functionalized alkenes and 2-thiocyanate indolines. Org Biomol Chem 2024; 22:1213-1218. [PMID: 38226967 DOI: 10.1039/d3ob01864d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
An unprecedented one-pot route to achieve highly regioselective 1-sulfur-functionalized 2-nitrogen-functionalized alkenes and 2-thiocyanate indolines from unsymmetrical ynamides (readily and generally available amides) using the commercially available inexpensive iodobenzene diacetate (PIDA) as the oxidant and potassium thiocyanate (KSCN) as the thiocyanate (SCN) source has been developed. The interconversion of thiocyanate (SCN) and isothiocyanate (NCS) groups simultaneously forms C-N and C-S bonds in this metal-free approach, while introducing important functional groups into homemade alkynes. A radical-chain mechanism, involving competing kinetically controlled chain transfer at the S atom and sterically-controlled chain transfer at the N atom of the thiocyanogen molecule in this mild approach, is proposed.
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Affiliation(s)
- Hong Qin
- Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
| | - Feng Chen
- Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
| | - Jinze Du
- Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
| | - Xiaobing Yang
- Institute of Nanjing Advanced Biomaterials & Processing Equipment, Nanjing, 210031, P. R. China
| | - Yiping Huang
- China Construction Industrial & Energy Engineering Group, Nanjing 210023, China
| | - Kai Zhu
- China Construction Industrial & Energy Engineering Group, Nanjing 210023, China
| | - Changhai Yue
- China Construction Industrial & Energy Engineering Group, Nanjing 210023, China
| | - Zheng Fang
- Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
| | - Kai Guo
- Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, 30 Puzhu Rd S., Nanjing, 211816, China
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7
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Atkins AP, Chaturvedi AK, Tate JA, Lennox AJJ. Pulsed electrolysis: enhancing primary benzylic C(sp 3)-H nucleophilic fluorination. Org Chem Front 2024; 11:802-808. [PMID: 38298566 PMCID: PMC10825853 DOI: 10.1039/d3qo01865b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/09/2023] [Indexed: 02/02/2024]
Abstract
Electrosynthesis is an efficient and powerful tool for the generation of elusive reactive intermediates. The application of alternative electrolysis waveforms provides a new level of control for dynamic redox environments. Herein, we demonstrate that pulsed electrolysis provides a favourable environment for the generation and fluorination of highly unstable primary benzylic cations from C(sp3)-H bonds. By introduction of a toff period, we propose this waveform modulates the electrical double layer to improve mass transport and limit over-oxidation.
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Affiliation(s)
- Alexander P Atkins
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
| | - Atul K Chaturvedi
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
| | - Joseph A Tate
- Jealott's Hill International Research Centre, Syngenta Jealott's Hill Bracknell RG426EY UK
| | - Alastair J J Lennox
- School of Chemistry, University of Bristol Cantock's Close BS8 1TS Bristol UK
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8
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Li Y, Castañeda-Bagatella DM, Kakkad D, Ai Y, Chen H, Champagne PA. Synthetic and mechanistic study on the conjugate isothiocyanation of enones with trimethylsilyl isothiocyanate. Org Biomol Chem 2023. [PMID: 38009326 DOI: 10.1039/d3ob01710a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
Alkyl isothiocyanates (R-NCS) have pharmacological applications and provide a synthetic handle to various functional groups including thioureas. There are however few methods to access alkyl isothiocyanates through the creation of the C-N bond. We have developed a simple approach for the conjugate isothiocyanation of enones by trimethylsilyl isothiocyanate (TMSNCS), which proceeds through the 1,4-addition of the weak isothiocyanate nucleophile to activated enones in the absence of external promoters. This method avoids the direct use of highly toxic acids and bases, produces β-isothiocyanato carbonyl products in yields of 87-98% under mild conditions (less than 6 hours at 0 °C), and displays wide functional group tolerance. Density functional theory calculations highlighted competing cationic and anionic mechanisms, where the enone activation by the TMSNCS reagent is accelerated in protic solvents. The selective formation of the isothiocyanate vs. thiocyanate isomers is explained by the thermodynamically-controlled nature of the reaction in which only the conjugate isothiocyanation is exergonic.
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Affiliation(s)
- Yanmei Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Diana M Castañeda-Bagatella
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Dhyeyi Kakkad
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Yongling Ai
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Hao Chen
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Pier Alexandre Champagne
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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9
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Wang Y, Dana S, Long H, Xu Y, Li Y, Kaplaneris N, Ackermann L. Electrochemical Late-Stage Functionalization. Chem Rev 2023; 123:11269-11335. [PMID: 37751573 PMCID: PMC10571048 DOI: 10.1021/acs.chemrev.3c00158] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Indexed: 09/28/2023]
Abstract
Late-stage functionalization (LSF) constitutes a powerful strategy for the assembly or diversification of novel molecular entities with improved physicochemical or biological activities. LSF can thus greatly accelerate the development of medicinally relevant compounds, crop protecting agents, and functional materials. Electrochemical molecular synthesis has emerged as an environmentally friendly platform for the transformation of organic compounds. Over the past decade, electrochemical late-stage functionalization (eLSF) has gained major momentum, which is summarized herein up to February 2023.
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Affiliation(s)
| | | | | | - Yang Xu
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Yanjun Li
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Nikolaos Kaplaneris
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
| | - Lutz Ackermann
- Institut für Organische
und Biomolekulare Chemie and Wöhler Research Institute for
Sustainable Chemistry (WISCh), Georg-August-Universität, Göttingen 37077, Germany
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10
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Xu Y, Li Q, Ye R, Xu B, Zhou X. Electrochemical Oxidative C-H Amination through a Ritter-Type Reaction. J Org Chem 2023. [PMID: 37262003 DOI: 10.1021/acs.joc.3c00609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A straightforward strategy for direct benzylic C-H bond amination via an electrochemical Ritter-type reaction is developed. The reaction demonstrates simpler and milder reaction conditions over the existing methods without extra mediator. Moderate to excellent yields up to 94% of the desired amide products were obtained with a broad substrate scope. The removal of the Ac group by a simple step can afford NH-free benzylic amines, providing a suitable approach for the late-stage functionalization of bioactive molecules.
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Affiliation(s)
- Yiwen Xu
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Qiang Li
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Runyou Ye
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Buyi Xu
- National Anti-Drug Laboratory Sichuan Regional Center, 36 Yunling Road, Chengdu, Sichuan 610200, P.R. China
| | - Xiangge Zhou
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
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11
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Bai F, Wang N, Bai Y, Ma X, Gu C, Dai B, Chen J. NHPI-Mediated Electrochemical α-Oxygenation of Amides to Benzimides. J Org Chem 2023. [PMID: 36866582 DOI: 10.1021/acs.joc.2c02700] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
This report describes a mild electrochemical α-oxygenation of a wide range of linear and cyclic benzamides mediated by N-hydroxyphthalimide (NHPI) in an undivided cell using O2 as the oxygen source and 2,4,6-trimethylpyridine perchlorate as an electrolyte. The radical scavenger experiment and the 18O labeling experiment were carried out, which indicated the involvement of a radical pathway and suggested O2 as an oxygen source in the imides, respectively.
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Affiliation(s)
- Fang Bai
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Ning Wang
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Yinshan Bai
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Xiaowei Ma
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Chengzhi Gu
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Bin Dai
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Xinjiang Uygur Autonomous Region 832000, China
| | - Jianpeng Chen
- Hami Shuoyuan Chemical Co., Ltd, Xinjiang Uygur Autonomous Region 832000, China
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12
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Kiaku C, Walsh JM, Leech MC, Poole DL, Mason J, Goodall ICA, Devo P, Lam K. Electrochemical Isothiocyanation of Primary Amines. Org Lett 2023; 25:1147-1150. [PMID: 36787535 DOI: 10.1021/acs.orglett.3c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Isothiocyanates are ubiquitous building blocks used across the fields. Nevertheless, their classical syntheses very often rely on the use of toxic and expensive reagents. Herein, we report a new practical, mild, high-yielding, and supporting-electrolyte-free electrochemical method for the preparation of aliphatic and aromatic isothiocyanates from amine and carbon disulfide.
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Affiliation(s)
- Cyrille Kiaku
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Jamie M Walsh
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Matthew C Leech
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Darren L Poole
- Discovery High-Throughput Chemistry, Medicinal Chemistry, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Joseph Mason
- Discovery High-Throughput Chemistry, Medicinal Chemistry, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Iain C A Goodall
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Perry Devo
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
| | - Kevin Lam
- School of Science, Faculty of Engineering and Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB, U.K
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13
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Electrochemical oxythiocyanation of ortho-olefinic amides: access to diverse thiocyanated benzoxazines. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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14
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Maeda B, Aihara Y, Sato A, Kinoshita T, Murakami K. Photoinduced Synthesis of Thiocyanates through Hydrogen Atom Transfer and One-Pot Derivatization to Isothiocyanates. Org Lett 2022; 24:7366-7371. [PMID: 36194477 DOI: 10.1021/acs.orglett.2c02896] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced benzylic C-H thiocyanation is described. A series of alkyl thiocyanates were efficiently obtained by using Selectfluor as the oxidant. Moreover, we accomplished the one-pot isothiocyanation following the C-H thiocyanation. The thiocyanates and isothiocyanates were applied to the divergent transformation of pharmaceuticals.
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Affiliation(s)
- Bumpei Maeda
- Department of Chemistry, School of Science, Kwansei Gakuin University, 2-1 Gakuin, Sanda, Hyogo 669-1337, Japan
| | - Yusuke Aihara
- Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Ayato Sato
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Toshinori Kinoshita
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Kei Murakami
- Department of Chemistry, School of Science, Kwansei Gakuin University, 2-1 Gakuin, Sanda, Hyogo 669-1337, Japan.,JST-PRESTO, 7 Gobancho, Chiyoda, Tokyo 102-0076, Japan
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15
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Zeng J, Wan JP, Liu Y. Photocatalytic C–H Thiocyanation of NH 2-Enaminones and the Tunable Synthetic Routes to 2-Aminothiazoles and 2-Thiazolinones. J Org Chem 2022; 87:13195-13203. [DOI: 10.1021/acs.joc.2c01667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junlong Zeng
- National Research Center for Carbohydrate Synthesis, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P.R. China
| | - Jie-Ping Wan
- National Research Center for Carbohydrate Synthesis, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P.R. China
| | - Yunyun Liu
- National Research Center for Carbohydrate Synthesis, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P.R. China
- Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process, Shaoxing University, Zhejiang 312000, P.R. China
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16
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Abstract
The development of sustainable C(sp3)-H functionalization methods is of great interest to the pharmaceutical and agrochemical industries. Anodic oxidation is an efficient means of producing benzylic cations that can undergo subsequent in situ nucleophilic attack to afford functionalized benzylic products. Herein, we demonstrate the suitability of carboxylic acids as nucleophiles to yield benzylic esters. This method employs a series of secondary benzylic substrates and functionalized carboxylic acids and is demonstrated on a gram scale in flow.
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Affiliation(s)
- Alexander P Atkins
- University of Bristol, School of Chemistry, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Albert C Rowett
- University of Bristol, School of Chemistry, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - David M Heard
- University of Bristol, School of Chemistry, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Joseph A Tate
- Syngenta, Jealott's Hill International Research Centre, Bracknell RG42 6EY, United Kingdom
| | - Alastair J J Lennox
- University of Bristol, School of Chemistry, Cantock's Close, Bristol BS8 1TS, United Kingdom
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17
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Tang S, Guillot R, Grimaud L, Vitale MR, Vincent G. Electrochemical Benzylic C-H Functionalization with Isocyanides. Org Lett 2022; 24:2125-2130. [PMID: 35286094 DOI: 10.1021/acs.orglett.2c00364] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We report the challenging direct carbamoylation or cyanation of benzylic C(sp3)-H bonds with an isocyanide via an electrochemical process giving rise to structures that are encountered in several biologically relevant compounds and drugs. This transformation proceeds under mild conditions without the need for any external oxidant and avoids the necessity to start from a prefunctionalized benzylic substrate or the deployment of the cation pool method. The anodic oxidation of the benzylic position and the subsequent addition of the isocyanide lead to the formation of a C-C bond and to a nitrilium cation that hydrolyzes to yield α-aryl acetamide derivatives, whereas the elimination of a t-butyl cation delivers α-aryl acetonitrile derivatives.
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Affiliation(s)
- Shanyu Tang
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Laurence Grimaud
- Laboratoire des Biomolécules (LBM), Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Maxime R Vitale
- Laboratoire des Biomolécules (LBM), Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Guillaume Vincent
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Saclay, CNRS, 91405 Orsay, France
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Liu D, Zhang Z, Yu J, Chen H, Lin X, Li M, Wen LR, Guo WS. Site-selective electrochemical thiocyanation of benzylic C–H bonds. Org Chem Front 2022. [DOI: 10.1039/d2qo00201a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct benzylic C(sp3)−H thiocyanation is explored as a straightforward strategy toward the synthesis of thiocyanate derivatives. We report herein an electrochemical protocol for site-selective benzylic C(sp3)−H thiocyanation under mild reaction...
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