1
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Xiong Y, Zhang H, Huang F, Xi Y, Wu Y, Dong H, Guan J, Yu W, Wang M, Zhang B. Modular Synthesis of Arylpyridylmethylamines via Visible-Light-Driven Reductive Coupling of Amines, Aldehydes, and Pyridines. Chemistry 2025; 31:e202500622. [PMID: 40197777 DOI: 10.1002/chem.202500622] [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: 02/17/2025] [Revised: 04/08/2025] [Accepted: 04/08/2025] [Indexed: 04/10/2025]
Abstract
The arylpyridylmethylamine motif is a privileged scaffold in drug discovery. However, rapidly creating these valuable molecules with structural diversity by directly leveraging readily available, yet simple chemical feedstocks remains a challenge. Herein, we describe a versatile and modular photochemical method for the straightforward construction of arylpyridylmethylamine skeleton utilizing widely accessible starting materials, including amines, aldehydes, and pyridines. This multicomponent coupling proceeds under very mild conditions without the need for any transition-metal catalysts, photocatalysts, and acid additives and displays a broad substrate scope and excellent functional-group tolerance. The potential utility of this methodology in pharmaceutical development is demonstrated through late-stage modification of pharmaceutically relevant compounds, concise synthesis of bioactive compounds, and rapid construction of pyridyl analogue of drug molecules. Combined experimental and computational studies unveiled that this reaction proceeds through radical-radical cross-coupling between persistent pyridylphosphonium radicals and α-amino radicals.
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Affiliation(s)
- Yuyan Xiong
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Haoxiang Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Fengqing Huang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Yuan Xi
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
| | - Ye Wu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Huimin Dong
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Jie Guan
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Wenying Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Minyan Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
| | - Bo Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
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2
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Ju T, Wang ZH, Lu AL, Sun J, Huang K, Xiong W, Han Y, Yan CG. Photoredox/Palladium-Catalyzed Reduction Alkylation of Imines and Ammonium Salts via Dual C-N Bond Cleavage. J Org Chem 2025; 90:5487-5498. [PMID: 40237216 DOI: 10.1021/acs.joc.5c00098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2025]
Abstract
Here, we report a photoredox/palladium-catalyzed reduction alkylation of imines and ammonium salts via dual C-N cleavage. This reaction proceeds under mild, green, and operationally simple conditions, offering a broad scope of secondary amine compounds with alpha quaternary carbon. Mechanistic studies indicate that the α-amino carbanion, generated by a successive single-electron transfer process, is a key intermediate in photoredox/palladium catalysis.
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Affiliation(s)
- Tao Ju
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
| | - Zhi-Hao Wang
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
| | - Ai-Ling Lu
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
| | - Jing Sun
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
| | - Kun Huang
- Jiangsu Lianhuan Pharmaceutical Co., Ltd., Yangzhou 250002, P. R. China
| | - Wen Xiong
- Yangzhou Center for Disease Control and Prevention, Yangzhou 250002, P. R. China
| | - Ying Han
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
| | - Chao-Guo Yan
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 250002, P. R. China
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3
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Burke EK, Robertson KN, Speed AWH. Convenient lanthanum-mediated synthesis of bulky tert-alkyl amines from nitriles. Chem Commun (Camb) 2025; 61:1172-1175. [PMID: 39692701 DOI: 10.1039/d4cc05831c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2024]
Abstract
Tert-alkyl amines can be conveniently prepared in one step from nitriles by a double addition of ethyl or propyl Grignard reagent mediated by a commercially available lanthanum chloride-lithium chloride complex solution. The reaction operates on a variety of benzonitriles, with several heterocyclic nitriles and an alkyl nitrile also being suitable substrates.
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Affiliation(s)
- Emily K Burke
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Katherine N Robertson
- Department of Chemistry, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3, Canada
| | - Alexander W H Speed
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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4
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Su L, Dong J, Shen Y, Xie S, Wu S, Pan N, Liu F, Shang Q, Cai F, Ren TB, Yuan L, Yin SF, Han LB, Zhou Y. General (hetero)polyaryl amine synthesis via multicomponent cycloaromatization of amines. Nat Commun 2025; 16:169. [PMID: 39746930 PMCID: PMC11696898 DOI: 10.1038/s41467-024-54190-5] [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: 03/07/2024] [Accepted: 11/05/2024] [Indexed: 01/04/2025] Open
Abstract
(Hetero)polyaryl amines are extensively prevalent in pharmaceuticals, fine chemicals, and materials but the intricate and varied nature of their structures severely restricts their synthesis. Here, we present a selective multicomponent cycloaromatization of structurally and functionally diverse amine substrates for the general and modular synthesis of (hetero)polyaryl amines through copper(I)-catalysis. This strategy directly constructs a remarkable range of amino group-functionalized (hetero)polyaryl frameworks (194 examples), including naphthalene, binaphthalene, phenanthren, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, quinoline, isoquinoline, quinazoline, and others, which are challenging or impossible to obtain using alternative methods. Copper(III)-acetylide species are involved in driving the exclusive 7-endo-dig cyclization, suppressing many side-reactions that are susceptible to occur. Due to the easy introduction of various functional units into heteropolyarylamines, multiple functionalized fluorescent dyes can be arbitrarily synthesized, which can serve as effective fluorescent probes for monitoring the pathological processes (e.g. chemotherapy-induced cell apoptosis) and studying the related disease mechanisms.
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Affiliation(s)
- Lebin Su
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
- School of Physics and Chemistry, Hunan First Normal University, Changsha, China
| | - Jianyu Dong
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
- School of Physics and Chemistry, Hunan First Normal University, Changsha, China.
| | - Yang Shen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Shimin Xie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
- School of Physics and Chemistry, Hunan First Normal University, Changsha, China
| | - Shaofeng Wu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Neng Pan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Feng Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Qian Shang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Fangfang Cai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Tian-Bing Ren
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
| | - Lin Yuan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Shuang-Feng Yin
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China.
| | - Li-Biao Han
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Yongbo Zhou
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
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5
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Rafaniello AA, Kumar R, Phillips RC, Gaunt MJ. Modular Synthesis of Heterobenzylic Amines via Carbonyl Azinylative Amination. Angew Chem Int Ed Engl 2024; 63:e202408287. [PMID: 38994685 DOI: 10.1002/anie.202408287] [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: 05/01/2024] [Revised: 07/01/2024] [Accepted: 07/10/2024] [Indexed: 07/13/2024]
Abstract
Transformations enabling the synthesis of α-alkyl, α'-2-azinyl amines by addition of 2-heteroaryl-based nucleophiles to in situ-generated and non-activated alkyl-substituted iminium ions are extremely rare. Approaches involving classical 2-azinyl organometallics, such as the corresponding Grignard reagents, often fail to produce the desired products. Here, we report an operationally straightforward solution to this problem through the development of a multicomponent coupling process wherein a soft 2-azinyl indium nucleophile, generated in situ from the corresponding 2-iodo heteroarene and indium powder, adds to an iminium ion that is also formed directly in the reaction. This modular carbonyl azinylative amination (CAzA) displays a broad scope and only a metal reductant is needed to generate a reactive 2-azinyl nucleophile. Beyond the addition to iminium ions, the 2-azinyl addition to polyfluoromethyl ketones forms the corresponding tertiary alcohols. Together, the products of these reactions possess a high degree of functionality, are typically challenging to synthesize by other methods, and contain motifs recognized as privileged in the context of pharmaceuticals and agrochemicals.
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Affiliation(s)
- Alex A Rafaniello
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, CB2 1EW, United Kingdom
| | - Roopender Kumar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, CB2 1EW, United Kingdom
| | - Rachel C Phillips
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, CB2 1EW, United Kingdom
| | - Matthew J Gaunt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, CB2 1EW, United Kingdom
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6
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Waller H, Gaunt MJ. Silyl Radicals as Single-Electron Reductants: α-Aminoalkyl Radical Formation via a Photocatalytic Oxidatively Initiated Radical Chain Process. J Am Chem Soc 2024; 146:25894-25901. [PMID: 39283265 PMCID: PMC11440502 DOI: 10.1021/jacs.4c08230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 09/10/2024] [Accepted: 09/11/2024] [Indexed: 09/26/2024]
Abstract
The α-amino-radical constitutes a versatile reactive intermediate that has been used to great effect in the synthesis of complex amine-containing products. Here, we report the development of a multicomponent photocatalytic platform enabling access to all-alkyl α-amino-radicals, exploiting the oxidative formation of silyl-radicals from commercially available tris(trimethylsilyl)silane. A key design element of the new process involves the role of silyl-radicals in generating α-amino-radicals from iminium ions as part of an oxidatively initiated photocatalytic radical chain process. This distinct activation mode is showcased by engaging the ensuing radicals in cross-radical coupling with persistent arene radical anions, enabling the arylation of in situ-generated all-alkyl iminium ions to furnish alkyl-substituted benzylamines.
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Affiliation(s)
- Harry
C. Waller
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United
Kingdom
| | - Matthew J. Gaunt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United
Kingdom
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7
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He J, Gong X, Li Y, Zhao Q, Zhu C. Synthesis and Photocatalytic sp 3 C-H Bond Functionalization of Salen-Ligand-Supported Uranyl(VI) Complexes. Molecules 2024; 29:4077. [PMID: 39274925 PMCID: PMC11397425 DOI: 10.3390/molecules29174077] [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: 07/23/2024] [Revised: 08/06/2024] [Accepted: 08/27/2024] [Indexed: 09/16/2024] Open
Abstract
Recent years have seen increasing interest in uranyl(VI) photocatalysis. In this study, uranyl complexes were successfully synthesized from ligands L1-L6 and UO2(NO3)2·6H2O under reflux conditions, yielding products 1-6 with yields ranging from 30% to 50%. The complexes were thoroughly characterized using NMR spectroscopy, single-crystal X-ray diffraction, and elemental analysis. The results indicate that complexes 1-5 possess a pentagonal bipyramidal geometry, whereas complex 6 exhibits an octahedral structure. The photocatalytic properties of these novel complexes for sp3 C-H bond functionalization were explored. The results demonstrate that complex 4 functions as an efficient photocatalyst for converting C-H bonds to C-C bonds via hydrogen atom transfer under blue light irradiation.
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Affiliation(s)
- Jialu He
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xingxing Gong
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yafei Li
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Qianyi Zhao
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
| | - Congqing Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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8
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Dai L, Fu Y, Wei M, Wang F, Tian B, Wang G, Li S, Ding M. Harnessing Electro-Descriptors for Mechanistic and Machine Learning Analysis of Photocatalytic Organic Reactions. J Am Chem Soc 2024; 146:19019-19029. [PMID: 38963153 DOI: 10.1021/jacs.4c03085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Photocatalysis has emerged as an effective tool for addressing the contemporary challenges in organic synthesis. However, the trial-and-error-based screening of feasible substrates and optimal reaction conditions remains time-consuming and potentially expensive in industrial practice. Here, we demonstrate an electrochemical-based data-acquisition approach that derives a simple set of redox-relevant electro-descriptors for effective mechanistic analysis and performance evaluation through machine learning (ML) in photocatalytic synthesis. These electro-descriptors correlate to the quantification of shifted charge transfer processes in response to the photoirradiation and enabled construction of reactivity diagram where high-yield reactive "hot zones" can reflect subtle changes of the reaction system. For the model reaction of photocatalytic deoxygenation reaction, the influence of varying carboxylic acids (substrate A, oxidation-intended) and alkenes (substrate B, reduction-intended) and varying reaction conditions on the reaction yield can be visualized, while mathematical analysis of the electro-descriptor patterns further revealed distinct mechanistic/kinetic impacts from different substrates and conditions. Additionally, in the application of ML algorithms, the experimentally derived electro-descriptors reflect an overall redox kinetic outcome contributed from vast reaction parameters, serving as a capable means to reduce the dimensionality in the case of complex multiparameter chemical space. As a result, utilization of electro-descriptors enabled efficient and robust quantitative evaluation of chemical reactivity, demonstrating promising potential of introducing operando-relevant experimental insights in the data-driven chemistry.
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Affiliation(s)
- Luhan Dai
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yulong Fu
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Mengran Wei
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Fangyuan Wang
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Bailin Tian
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Guoqiang Wang
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Shuhua Li
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Mengning Ding
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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9
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Liu WQ, Lee BC, Song N, He Z, Shen ZA, Lu Y, Koh MJ. Electrochemical Synthesis of C(sp 3)-Rich Amines by Aminative Carbofunctionalization of Carbonyl Compounds. Angew Chem Int Ed Engl 2024; 63:e202402140. [PMID: 38650440 DOI: 10.1002/anie.202402140] [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: 01/30/2024] [Revised: 04/16/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Alkylamines form the backbone of countless nitrogen-containing small molecules possessing desirable biological properties. Despite advances in amine synthesis through transition metal catalysis and photoredox chemistry, multicomponent reactions that leverage inexpensive materials to transform abundant chemical feedstocks into three-dimensional α-substituted alkylamines bearing complex substitution patterns remain scarce. Here, we report the design of a catalyst-free electroreductive manifold that merges amines, carbonyl compounds and carbon-based radical acceptors under ambient conditions without rigorous exclusion of air and moisture. Key to this aminative carbofunctionalization process is the chemoselective generation of nucleophilic α-amino radical intermediates that readily couple with electrophilic partners, providing straightforward access to architecturally intricate alkylamines and drug-like scaffolds which are inaccessible by conventional means.
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Affiliation(s)
- Wen-Qiang Liu
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - NingXi Song
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Zhenghao He
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Zi-An Shen
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Yixin Lu
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
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10
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Phelps J, Kumar R, Robinson JD, Chu JCK, Flodén NJ, Beaton S, Gaunt MJ. Multicomponent Synthesis of α-Branched Amines via a Zinc-Mediated Carbonyl Alkylative Amination Reaction. J Am Chem Soc 2024; 146:9045-9062. [PMID: 38488310 PMCID: PMC10996026 DOI: 10.1021/jacs.3c14037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 03/21/2024]
Abstract
Methods for the synthesis of α-branched alkylamines are important due to their ubiquity in biologically active molecules. Despite the development of many methods for amine preparation, C(sp3)-rich nitrogen-containing compounds continue to pose challenges for synthesis. While carbonyl reductive amination (CRA) between ketones and alkylamines is the cornerstone method for α-branched alkylamine synthesis, it is sometimes limited by the sterically demanding condensation step between dialkyl ketones and amines and the more restricted availability of ketones compared to aldehydes. We recently reported a "higher-order" variant of this transformation, carbonyl alkylative amination (CAA), which utilized a halogen atom transfer (XAT)-mediated radical mechanism, enabling the streamlined synthesis of complex α-branched alkylamines. Despite the efficacy of this visible-light-driven approach, it displayed scalability issues, and competitive reductive amination was a problem for certain substrate classes, limiting applicability. Here, we report a change in the reaction regime that expands the CAA platform through the realization of an extremely broad zinc-mediated CAA reaction. This new strategy enabled elimination of competitive CRA, simplified purification, and improved reaction scope. Furthermore, this new reaction harnessed carboxylic acid derivatives as alkyl donors and facilitated the synthesis of α-trialkyl tertiary amines, which cannot be accessed via CRA. This Zn-mediated CAA reaction can be carried out at a variety of scales, from a 10 μmol setup in microtiter plates enabling high-throughput experimentation, to the gram-scale synthesis of medicinally-relevant compounds. We believe that this transformation enables robust, efficient, and economical access to α-branched alkylamines and provides a viable alternative to the current benchmark methods.
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Affiliation(s)
| | | | | | | | - Nils J. Flodén
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Sarah Beaton
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Matthew J. Gaunt
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
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11
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Wang LC, Yuan Y, Zhang Y, Wu XF. Cobalt-catalyzed aminoalkylative carbonylation of alkenes toward direct synthesis of γ-amino acid derivatives and peptides. Nat Commun 2023; 14:7439. [PMID: 37978196 PMCID: PMC10656502 DOI: 10.1038/s41467-023-43306-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
γ-Amino acids and peptides analogues are common constituents of building blocks for numerous biologically active molecules, pharmaceuticals, and natural products. In particular, γ-amino acids are providing with better metabolic stability than α-amino acids. Herein we report a multicomponent carbonylation technology that combines readily available amides, alkenes, and the feedstock gas carbon monoxide to build architecturally complex and functionally diverse γ-amino acid derivatives in a single step by the implementation of radical relay catalysis. This transformation can also be used as a late-stage functionalization strategy to deliver complex, advanced γ-amino acid products for pharmaceutical and other areas.
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Affiliation(s)
- Le-Cheng Wang
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
- Leibniz-Institut für Katalyse e.V., Rostock, Germany
| | - Yang Yuan
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
| | - Youcan Zhang
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
| | - Xiao-Feng Wu
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China.
- Leibniz-Institut für Katalyse e.V., Rostock, Germany.
- University of Chinese Academy of Sciences, Beijing, China.
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12
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Wang A, Yin YY, Rukhsana, Wang LQ, Jin JH, Shen YM. Visible-Light-Mediated Three-Component Decarboxylative Coupling Reactions to Synthesize 1,4-Diol Monoethers. J Org Chem 2023; 88:13871-13882. [PMID: 37683099 DOI: 10.1021/acs.joc.3c01483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
An efficient approach for 1,2-difunctionalization of aromatic olefins and the synthesis of functionalized 1,4-diols monoethers has been established via a photoinduced three-component reaction of an α-alkoxycarboxylic acid, an aromatic olefin, and an aldehyde. The reaction proceeds by photoinduced oxidative decarboxylation of the carboxylic acid followed by the addition of the α-alkoxyalkyl radical to the olefin, one-electron reduction of the addition radical, and the nucleophilic attack of the resulting carbanion to the aldehyde. Besides the convenient one-pot protocol of the three-component reaction, this method offers several other advantages, including good functional group tolerance for the three substrates, gentle reaction conditions, and ease of scaling up. The reaction mechanism has been investigated through free radical trapping experiment and isotope labeling experiments.
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Affiliation(s)
- Ai Wang
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
| | - Yu-Yun Yin
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
- Zhejiang Sci-Tech University Shengzhou Innovation Research Institute, Shengzhou 312400, P.R. China
| | - Rukhsana
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
| | - Le-Quan Wang
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
| | - Jia-Hui Jin
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
| | - Yong-Miao Shen
- School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, P.R. China
- Zhejiang Sci-Tech University Shengzhou Innovation Research Institute, Shengzhou 312400, P.R. China
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13
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Cao Q, Tibbetts JD, Wrigley GL, Smalley AP, Cresswell AJ. Modular, automated synthesis of spirocyclic tetrahydronaphthyridines from primary alkylamines. Commun Chem 2023; 6:215. [PMID: 37794068 PMCID: PMC10550966 DOI: 10.1038/s42004-023-01012-2] [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: 07/13/2023] [Accepted: 09/22/2023] [Indexed: 10/06/2023] Open
Abstract
Spirocyclic tetrahydronaphthyridines (THNs) are valuable scaffolds for drug discovery campaigns, but access to this 3D chemical space is hampered by a lack of modular and scalable synthetic methods. We hereby report an automated, continuous flow synthesis of α-alkylated and spirocyclic 1,2,3,4-tetrahydro-1,8-naphthyridines ("1,8-THNs"), in addition to their regioisomeric 1,6-THN analogues, from abundant primary amine feedstocks. An annulative disconnection approach based on photoredox-catalysed hydroaminoalkylation (HAA) of halogenated vinylpyridines is sequenced in combination with intramolecular SNAr N-arylation. To access the remaining 1,7- and 1,5-THN isomers, a photoredox-catalysed HAA step is telescoped with a palladium-catalysed C-N bond formation. Altogether, this provides a highly modular access to four isomeric THN cores from a common set of unprotected primary amine starting materials, using the same bond disconnections. The simplifying power of the methodology is illustrated by a concise synthesis of the spirocyclic THN core of Pfizer's MC4R antagonist PF-07258669.
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Affiliation(s)
- Qiao Cao
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Joshua D Tibbetts
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Gail L Wrigley
- Medicinal Chemistry, Oncology R&D, AstraZeneca, Cambridge, CB4 0WG, UK
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14
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Dang VQ, Teets TS. Reductive photoredox transformations of carbonyl derivatives enabled by strongly reducing photosensitizers. Chem Sci 2023; 14:9526-9532. [PMID: 37712019 PMCID: PMC10498680 DOI: 10.1039/d3sc03000h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/18/2023] [Indexed: 09/16/2023] Open
Abstract
Visible-light photoredox catalysis is well-established as a powerful and versatile organic synthesis strategy. However, some substrate classes, despite being attractive precursors, are recalcitrant to single-electron redox chemistry and thus not very amenable to photoredox approaches. Among these are carbonyl derivatives, e.g. ketones, aldehydes, and imines, which in most cases require Lewis or Brønsted acidic additives to activate via photoinduced electron transfer. In this work, we unveil a range of photoredox transformations on ketones and imines, enabled by strongly reducing photosensitizers and operating under simple, general conditions with a single sacrificial reductant and no additives. Specific reactions described here are umpolung C-C bond forming reactions between aromatic ketones or imines and electron-poor alkenes, imino-pinacol homocoupling reactions of challenging alkyl-aryl imine substrates, and γ-lactonization reactions of aromatic ketones with methyl acrylate. The reactions are all initiated by photoinduced electron transfer to form a ketyl or iminyl that is subsequently trapped.
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Affiliation(s)
- Vinh Q Dang
- University of Houston, Department of Chemistry 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
| | - Thomas S Teets
- University of Houston, Department of Chemistry 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
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15
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Arachchi MK, Schaugaard RN, Schlegel HB, Nguyen HM. Scope and Mechanistic Probe into Asymmetric Synthesis of α-Trisubstituted-α-Tertiary Amines by Rhodium Catalysis. J Am Chem Soc 2023; 145:19642-19654. [PMID: 37651695 PMCID: PMC10581542 DOI: 10.1021/jacs.3c04211] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Asymmetric reactions that convert racemic mixtures into enantioenriched amines are of significant importance due to the prevalence of amines in pharmaceuticals, with about 60% of drug candidates containing tertiary amines. Although transition-metal catalyzed allylic substitution processes have been developed to provide access to enantioenriched α-disubstituted allylic amines, enantioselective synthesis of sterically demanding α-tertiary amines with a tetrasubstituted carbon stereocenter remains a major challenge. Herein, we report a chiral diene-ligated rhodium-catalyzed asymmetric substitution of racemic tertiary allylic trichloroacetimidates with aliphatic secondary amines to afford α-trisubstituted-α-tertiary amines. Mechanistic investigation is conducted using synergistic experimental and computational studies. Density functional theory calculations show that the chiral diene-ligated rhodium promotes the ionization of tertiary allylic substrates to form both anti and syn π-allyl intermediates. The anti π-allyl pathway proceeds through a higher energy than the syn π-allyl pathway. The rate of conversion of the less reactive π-allyl intermediate to the more reactive isomer via π-σ-π interconversion was faster than the rate of nucleophilic attack onto the more reactive intermediate. These data imply that the Curtin-Hammett conditions are met in the amination reaction, leading to dynamic kinetic asymmetric transformation. Computational studies also show that hydrogen bonding interactions between β-oxygen of allylic substrate and amine-NH greatly assist the delivery of amine nucleophile onto more hindered internal carbon of the π-allyl intermediate. The synthetic utility of the current methodology is showcased by efficient preparation of α-trisubstituted-α-tertiary amines featuring pharmaceutically relevant secondary amine cores with good yields and excellent selectivities (branched-linear >99:1, up to 99% enantiomeric excess).
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Affiliation(s)
- Madhawee K Arachchi
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Richard N Schaugaard
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - H Bernhard Schlegel
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Hien M Nguyen
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
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16
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Regni A, Bartoccini F, Piersanti G. Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine. Beilstein J Org Chem 2023; 19:918-927. [PMID: 37404801 PMCID: PMC10315889 DOI: 10.3762/bjoc.19.70] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 06/15/2023] [Indexed: 07/06/2023] Open
Abstract
An unusual photoredox-catalyzed radical decarboxylative cyclization cascade reaction of γ,γ-dimethylallyltryptophan (DMAT) derivatives containing unactivated alkene moieties has been developed, providing green and efficient access to various six-, seven-, and eight-membered ring 3,4-fused tricyclic indoles. This type of cyclization, which was hitherto very difficult to comprehend in ergot biosynthesis and to accomplish by more conventional procedures, enables the synthesis of ergot alkaloid precursors. In addition, this work describes a mild, environmentally friendly method to activate, reductively and oxidatively, natural carboxylic acids for decarboxylative C-C bond formation by exploiting the same photocatalyst.
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Affiliation(s)
- Alessio Regni
- Department of Biomolecular Sciences, University of Urbino, Carlo Bo Piazza Rinascimento 6, 61029 Urbino, PU, Italy
| | - Francesca Bartoccini
- Department of Biomolecular Sciences, University of Urbino, Carlo Bo Piazza Rinascimento 6, 61029 Urbino, PU, Italy
| | - Giovanni Piersanti
- Department of Biomolecular Sciences, University of Urbino, Carlo Bo Piazza Rinascimento 6, 61029 Urbino, PU, Italy
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17
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Rezazadeh S, Martin MI, Kim RS, Yap GPA, Rosenthal J, Watson DA. Photoredox-Nickel Dual-Catalyzed C-Alkylation of Secondary Nitroalkanes: Access to Sterically Hindered α-Tertiary Amines. J Am Chem Soc 2023; 145:4707-4715. [PMID: 36795911 PMCID: PMC9992296 DOI: 10.1021/jacs.2c13174] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The preparation of tertiary nitroalkanes via the nickel-catalyzed alkylation of secondary nitroalkanes using aliphatic iodides is reported. Previously, catalytic access to this important class of nitroalkanes via alkylation has not been possible due to the inability of catalysts to overcome the steric demands of the products. However, we have now found that the use of a nickel catalyst in combination with a photoredox catalyst and light leads to much more active alkylation catalysts. These can now access tertiary nitroalkanes. The conditions are scalable as well as air and moisture tolerant. Importantly, reduction of the tertiary nitroalkane products allows rapid access to α-tertiary amines.
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Affiliation(s)
- Sina Rezazadeh
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Maxwell I Martin
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Raphael S Kim
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Glenn P A Yap
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Joel Rosenthal
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Donald A Watson
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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18
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Harris G, Trowbridge AD, Gaunt MJ. A Chiral Amine Transfer Approach to the Photocatalytic Asymmetric Synthesis of α-Trialkyl-α-tertiary Amines. Org Lett 2023; 25:861-866. [PMID: 36724345 PMCID: PMC9926512 DOI: 10.1021/acs.orglett.2c04308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A long-standing challenge within radical chemistry is that of controlling the absolute stereochemistry of the products. Here, we report the stereocontrolled addition of α-amino radicals reductively generated from imines via visible-light-mediated photoredox-catalysis to alkenes, giving rise to enantioenriched α-trialkyl-α-tertiary amines. This process exploits a commercially available phenylglycinol derivative as a source of both nitrogen and chiral information. DFT studies support a stereochemical model whereby an intramolecular H-bond rigidifies the transition state of the enantiodetermining step.
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19
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Sherborne GJ, Kemmitt P, Prentice C, Zysman-Colman E, Smith AD, Fallan C. Visible Light-Mediated Cyclisation Reaction for the Synthesis of Highly-Substituted Tetrahydroquinolines and Quinolines. Angew Chem Int Ed Engl 2023; 62:e202207829. [PMID: 36342443 DOI: 10.1002/anie.202207829] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Indexed: 11/09/2022]
Abstract
Condensation of 2-vinylanilines and conjugated aldehydes followed by an efficient light-mediated cyclisation selectively yields either substituted tetrahydroquinolines with typically high dr, or in the presence of an iridium photocatalyst the synthesis of quinoline derivatives is demonstrated. These atom economical processes require mild conditions, with the substrate scope demonstrating excellent site selectivity and functional group tolerance, including azaarene-bearing substrates. A thorough experimental mechanistic investigation explores multiple pathways and the key role that imine and iminium intermediates play in the absorption of visible light to generate reactive excited states. The synthetic utility of the reactions is demonstrated on gram scale quantities in both batch and flow, alongside further manipulation of the medicinally relevant products.
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Affiliation(s)
- Grant J Sherborne
- Medicinal Chemistry Oncology R&D, Research and Early Development, AstraZeneca, Cambridge Science Park, Unit 310, Darwin Building, Cambridge, CB4 0WG, UK
| | - Paul Kemmitt
- Medicinal Chemistry Oncology R&D, Research and Early Development, AstraZeneca, Cambridge Science Park, Unit 310, Darwin Building, Cambridge, CB4 0WG, UK
| | - Callum Prentice
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK.,EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Andrew D Smith
- EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Charlene Fallan
- Medicinal Chemistry Oncology R&D, Research and Early Development, AstraZeneca, Cambridge Science Park, Unit 310, Darwin Building, Cambridge, CB4 0WG, UK
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20
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Tian J, Zhao L, Yang C, Yang C, Guo L, Xia W. Four-Component Synthesis of Spiro-Imidazolidines Enabled by Carbon Nitride Photocatalysis. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Jian Tian
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Lulu Zhao
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Chuan Yang
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Chao Yang
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Lin Guo
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wujiong Xia
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
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21
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Murray PD, Leibler INM, Hell SM, Villalona E, Doyle AG, Knowles RR. Radical Redox Annulations: A General Light-Driven Method for the Synthesis of Saturated Heterocycles. ACS Catal 2022; 12:13732-13740. [PMID: 36366762 PMCID: PMC9638994 DOI: 10.1021/acscatal.2c04316] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/14/2022] [Indexed: 11/29/2022]
Abstract
We introduce here a two-component annulation strategy that provides access to a diverse collection of five- and six-membered saturated heterocycles from aryl alkenes and a family of redox-active radical precursors bearing tethered nucleophiles. This transformation is mediated by a combination of an Ir(III) photocatalyst and a Brønsted acid under visible-light irradiation. A reductive proton-coupled electron transfer generates a reactive radical which undergoes addition to an alkene. Then, an oxidative radical-polar crossover step leading to carbocation formation is followed by ring closure through cyclization of the tethered nucleophile. A wide range of heterocycles are easily accessible, including pyrrolidines, piperidines, tetrahydrofurans, morpholines, δ-valerolactones, and dioxanones. We demonstrate the scope of this approach through broad structural variation of both reaction components. This method is amenable to gram-scale preparation and to complex fragment coupling.
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Affiliation(s)
- Philip
R. D. Murray
- Department
of Chemistry, Princeton University, Princeton, New Jersey08544, United States
| | | | - Sandrine M. Hell
- Department
of Chemistry, Princeton University, Princeton, New Jersey08544, United States
| | - Eris Villalona
- Department
of Chemistry, Princeton University, Princeton, New Jersey08544, United States
| | - Abigail G. Doyle
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California90095, United States
| | - Robert R. Knowles
- Department
of Chemistry, Princeton University, Princeton, New Jersey08544, United States
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22
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Marotta A, Adams CE, Molloy JJ. The Impact of Boron Hybridisation on Photocatalytic Processes. Angew Chem Int Ed Engl 2022; 61:e202207067. [PMID: 35748797 PMCID: PMC9544826 DOI: 10.1002/anie.202207067] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Indexed: 12/16/2022]
Abstract
Recently the fruitful merger of organoboron chemistry and photocatalysis has come to the forefront of organic synthesis, resulting in the development of new technologies to access complex (non)borylated frameworks. Central to the success of this combination is control of boron hybridisation. Contingent on the photoactivation mode, boron as its neutral planar form or tetrahedral boronate can be used to regulate reactivity. This Minireview highlights the current state of the art in photocatalytic processes utilising organoboron compounds, paying particular attention to the role of boron hybridisation for the target transformation.
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Affiliation(s)
- Alessandro Marotta
- Department of Biomolecular SystemsMax-Planck-Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
| | - Callum E. Adams
- Department of Biomolecular SystemsMax-Planck-Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
| | - John J. Molloy
- Department of Biomolecular SystemsMax-Planck-Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
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23
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West MS, Pia JE, Rousseaux SAL. Synthesis of 1- and 1,2-Substituted Cyclopropylamines from Ketone Homoenolates. Org Lett 2022; 24:5869-5873. [DOI: 10.1021/acs.orglett.2c01634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael S. West
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Julia E. Pia
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Sophie A. L. Rousseaux
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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24
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Marotta A, Adams CE, Molloy J. The Impact of Boron Hybridisation on Photocatalytic Processes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207067] [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)
- Alessandro Marotta
- Max Planck Institute of Colloids and Interfaces: Max-Planck-Institut fur Kolloid und Grenzflachenforschung biomolecular systems GERMANY
| | - Callum E. Adams
- Max Planck Institute of Colloids and Interfaces: Max-Planck-Institut fur Kolloid und Grenzflachenforschung biomolecular systems department GERMANY
| | - John Molloy
- Max Planck Institute of Colloids and Interfaces: Max-Planck-Institut fur Kolloid und Grenzflachenforschung Biomolecular Sytems Am Mühlenberg 1 14476 Potsdam GERMANY
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25
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Gan X, Wu S, Geng F, Dong J, Zhou Y. Photocatalytic C–H alkylation of coumarins mediated by triphenylphosphine and sodium iodide. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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26
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Mandigma MJP, Žurauskas J, MacGregor CI, Edwards LJ, Shahin A, d'Heureuse L, Yip P, Birch DJS, Gruber T, Heilmann J, John MP, Barham JP. An organophotocatalytic late-stage N-CH 3 oxidation of trialkylamines to N-formamides with O 2 in continuous flow. Chem Sci 2022; 13:1912-1924. [PMID: 35308839 PMCID: PMC8849051 DOI: 10.1039/d1sc05840a] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/26/2021] [Indexed: 12/25/2022] Open
Abstract
We report an organophotocatalytic, N-CH3-selective oxidation of trialkylamines in continuous flow. Based on the 9,10-dicyanoanthracene (DCA) core, a new catalyst (DCAS) was designed with solubilizing groups for flow processing. This allowed O2 to be harnessed as a sustainable oxidant for late-stage photocatalytic N-CH3 oxidations of complex natural products and active pharmaceutical ingredients bearing functional groups not tolerated by previous methods. The organophotocatalytic gas-liquid flow process affords cleaner reactions than in batch mode, in short residence times of 13.5 min and productivities of up to 0.65 g per day. Spectroscopic and computational mechanistic studies showed that catalyst derivatization not only enhanced solubility of the new catalyst compared to poorly-soluble DCA, but profoundly diverted the photocatalytic mechanism from singlet electron transfer (SET) reductive quenching with amines toward energy transfer (EnT) with O2.
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Affiliation(s)
- Mark John P Mandigma
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
| | - Jonas Žurauskas
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
| | - Callum I MacGregor
- GlaxoSmithKline Medicines Research Centre Gunnels Wood Road Stevenage SG1 2NY UK
| | - Lee J Edwards
- GlaxoSmithKline Medicines Research Centre Gunnels Wood Road Stevenage SG1 2NY UK
| | - Ahmed Shahin
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
- Chemistry Department, Faculty of Science, Benha University 13518 Benha Egypt
| | - Ludwig d'Heureuse
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
| | - Philip Yip
- Department of Physics, SUPA, University of Strathclyde 107 Rottenrow East Glasgow G4 0NG UK
| | - David J S Birch
- Department of Physics, SUPA, University of Strathclyde 107 Rottenrow East Glasgow G4 0NG UK
| | - Thomas Gruber
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
| | - Jörg Heilmann
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
| | - Matthew P John
- GlaxoSmithKline Medicines Research Centre Gunnels Wood Road Stevenage SG1 2NY UK
| | - Joshua P Barham
- Fakultät für Chemie und Pharmazie, Universität Regensburg 93040 Regensburg Germany
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27
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Grayson JD, Askey HE, Turner-Dore JC, Cresswell AJ. Styrene hydroaminoalkylation with primary alkylamines. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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28
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Wang J. Transition-metal-free, visible-light-induced multicomponent synthesis of allylic amines and tetrahydroquinolines. Org Chem Front 2022. [DOI: 10.1039/d2qo00620k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A visible-light-induced, 1,2,3,5-tetrakis-(carbazolyl)-4,6-dicyanobenzene (4CzIPN) catalyzed synthesis of allylic amines andtetrahydroquinolines through ‘all-alkyl’ α-amino radicals and anilinoalkyl radicals has been developed.
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Affiliation(s)
- Jian Wang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, 610106, P. R. China
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29
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Kohara K, Trowbridge A, Smith MA, Gaunt MJ. Thiol-Mediated α-Amino Radical Formation via Visible-Light-Activated Ion-Pair Charge-Transfer Complexes. J Am Chem Soc 2021; 143:19268-19274. [PMID: 34762420 DOI: 10.1021/jacs.1c09445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Visible-light-activated electron donor-acceptor complexes offer distinct reaction pathways for the synthesis of complex molecules under mild conditions. Herein, we report a method for the reductive generation of α-amino radicals via the reaction of a visible-light-activated ion-pair charge-transfer complex formed between an in situ-generated alkyl-iminium ion and a thiophenolate. This distinct activation mode is demonstrated through the development of a multicomponent coupling reaction to form substituted aminomethyl-cyclopentanes from secondary amines, cyclopropyl aldehydes, and alkenes. The operationally straightforward transformation displays broad scope and provides a means to generate cyclic amine-containing scaffolds from readily available feedstocks.
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Affiliation(s)
- Keishi Kohara
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom, CB2 1EW
| | - Aaron Trowbridge
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom, CB2 1EW
| | - Milo A Smith
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom, CB2 1EW
| | - Matthew J Gaunt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom, CB2 1EW
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30
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Askey H, Grayson JD, Tibbetts JD, Turner-Dore JC, Holmes JM, Kociok-Kohn G, Wrigley GL, Cresswell AJ. Photocatalytic Hydroaminoalkylation of Styrenes with Unprotected Primary Alkylamines. J Am Chem Soc 2021; 143:15936-15945. [PMID: 34543004 PMCID: PMC8499025 DOI: 10.1021/jacs.1c07401] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Indexed: 12/27/2022]
Abstract
Catalytic, intermolecular hydroaminoalkylation (HAA) of styrenes provides a powerful disconnection for pharmacologically relevant γ-arylamines, but current methods cannot utilize unprotected primary alkylamines as feedstocks. Metal-catalyzed HAA protocols are also highly sensitive to α-substitution on the amine partner, and no catalytic solutions exist for α-tertiary γ-arylamine synthesis via this approach. We report a solution to these problems using organophotoredox catalysis, enabling a direct, modular, and sustainable preparation of α-(di)substituted γ-arylamines, including challenging electron-neutral and moderately electron-rich aryl groups. A broad range of functionalities are tolerated, and the reactions can be run on multigram scale in continuous flow. The method is applied to a concise, protecting-group-free synthesis of the blockbuster drug Fingolimod, as well as a phosphonate mimic of its in vivo active form (by iterative α-C-H functionalization of ethanolamine). The reaction can also be sequenced with an intramolecular N-arylation to provide a general and modular access to valuable (spirocyclic) 1,2,3,4-tetrahydroquinolines and 1,2,3,4-tetrahydronaphthyridines. Mechanistic and kinetic studies support an irreversible hydrogen atom transfer activation of the alkylamine by the azidyl radical and some contribution from a radical chain. The reaction is photon-limited and exhibits a zero-order dependence on amine, azide, and photocatalyst, with a first-order dependence on styrene.
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Affiliation(s)
- Hannah
E. Askey
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - James D. Grayson
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Joshua D. Tibbetts
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | | | - Jake M. Holmes
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Gabriele Kociok-Kohn
- Materials
and Chemical Characterisation Facility (MC), University of Bath, Claverton Down, Bath BA2 7AY, U.K.
| | - Gail L. Wrigley
- Oncology
R&D, Research & Early Development, AstraZeneca, Darwin Building, 310, Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K.
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