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Tu JL, Huang B. Direct C(sp 3)-H functionalization with aryl and alkyl radicals as intermolecular hydrogen atom transfer (HAT) agents. Chem Commun (Camb) 2024; 60:11450-11465. [PMID: 39268687 DOI: 10.1039/d4cc03383c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2024]
Abstract
Recent years have witnessed the emergence of direct intermolecular C(sp3)-H bond functionalization using in situ generated aryl/alkyl radicals as a unique class of hydrogen atom transfer (HAT) agents. A variety of precursors have been exploited to produce these radical HAT agents under photocatalytic, electrochemical or thermal conditions. To date, viable aryl radical precursors have included aryl diazonium salts or aryl azosulfones, diaryliodonium salts, O-benzoyl oximes, aryl sulfonium salts, aryl thioesters, and aryl halides; and applicable alkyl radical sources have included tetrahalogenated methanes (e.g., CCl3Br, CBr4 and CF3I), N-hydroxyphthalimide esters, alkyl bromides, and acetic acid. This review summarizes the current advances in direct intermolecular C(sp3)-H functionalization through key HAT events with in situ generated aryl/alkyl radicals and categorizes the procedures by the specific radical precursors applied. With an emphasis on the reaction conditions, mechanisms and representative substrate scopes of these protocols, this review aims to demonstrate the current trends and future challenges of this emerging field.
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Affiliation(s)
- Jia-Lin Tu
- Faculty of Arts and Sciences, Beijing Normal University, Zhuhai 519085, China.
- School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Binbin Huang
- Faculty of Arts and Sciences, Beijing Normal University, Zhuhai 519085, China.
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Russo C, Volpe C, Santoro F, Brancaccio D, Di Porzio A, Carotenuto A, Randazzo A, Grimaud L, Vitale MR, Protti S, Giustiniano M. Visible Light-promoted C(sp 3)-H α-Carbamoylation of Cyclic Ethers with Isocyanides. Chemistry 2024; 30:e202401997. [PMID: 38873846 DOI: 10.1002/chem.202401997] [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: 05/22/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/15/2024]
Abstract
A protocol exploiting isocyanides as carbamoylating agents for the α-C(sp3)-H functionalization of cyclic ethers has been optimized via a combined visible light-driven hydrogen atom transfer/Lewis acid-catalyzed approach. The isocyanide substrate scope revealed an exquisite functional group compatibility (18 examples, with yields up to 99 %). Both radical and polar trapping, kinetic isotopic effect and real-time NMR studies support the mechanistic hypothesis and provide insightful details for the design of new chemical processes involving the generation of oxocarbenium ions.
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Affiliation(s)
- Camilla Russo
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Carmine Volpe
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Federica Santoro
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Diego Brancaccio
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Anna Di Porzio
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Alfonso Carotenuto
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
| | - Laurence Grimaud
- Laboratoire des Biomolécules (LBM), Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Maxime R Vitale
- Laboratoire des Biomolécules (LBM), Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Stefano Protti
- PhotoGreenLab, Department of Chemistry, University of Pavia, viale Taramelli 12, 27100, Pavia, Italy
| | - Mariateresa Giustiniano
- Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Napoli, Italy
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Di Terlizzi L, Nicchio L, Protti S, Fagnoni M. Visible photons as ideal reagents for the activation of coloured organic compounds. Chem Soc Rev 2024; 53:4926-4975. [PMID: 38596901 DOI: 10.1039/d3cs01129a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
In recent decades, the traceless nature of visible photons has been exploited for the development of efficient synthetic strategies for the photoconversion of colourless compounds, namely, photocatalysis, chromophore activation, and the formation of an electron donor/acceptor (EDA) complex. However, the use of photoreactive coloured organic compounds is the optimal strategy to boost visible photons as ideal reagents in synthetic protocols. In view of such premises, the present review aims to provide its readership with a collection of recent photochemical strategies facilitated via direct light absorption by coloured molecules. The protocols have been classified and presented according to the nature of the intermediate/excited state achieved during the transformation.
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Affiliation(s)
- Lorenzo Di Terlizzi
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
| | - Luca Nicchio
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
| | - Stefano Protti
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
| | - Maurizio Fagnoni
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
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Chawla R, Singh AK, Dutta PK. Arylazo sulfones: multifaceted photochemical reagents and beyond. Org Biomol Chem 2024; 22:869-893. [PMID: 38196324 DOI: 10.1039/d3ob01599h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The photochemical action of arylazo sulfones under visible light irradiation has recently gained considerable attention for the construction of carbon-carbon and carbon-heteroatom bonds in organic synthesis. The inherent dyedauxiliary group (-N2SO2R) embedded in the reagent is responsible for the absorption of visible light even in the absence of a photocatalyst, additive or oxidant, leading to the generation of three different radicals, viz. aryl (carbon-centred), sulfonyl (sulphur-centred) and diazenyl (nitrogen-centred) radicals, under different reaction conditions. Encountering a reagent with such a versatile behaviour is quite rare, which makes arylazo sulfones a highly interesting class of compounds. The mild reaction conditions under which these reagents can operate are an added advantage. Recently, they are also being used as non-ionic photoacid generators (PAGs), electron acceptors, and hydrogen atom transfer (HAT) and imination reagents in a number of synthetic transformations. They have displayed substantial damaging effect on the structure of DNA in the presence of light which can lead to their use as phototoxic pharmaceuticals for cancer treatment. Moreover, their photochemistry is also being exploited in polymerization reactions (as photoinitiators) and in materials chemistry (surface modification).
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Affiliation(s)
- Ruchi Chawla
- Polymer Research Laboratory, Department of Chemistry, Motilal Nehru National Institute of Technology Allahabad, Prayagraj 211004, India.
| | - Atul K Singh
- Department of Chemistry, University of Allahabad, Prayagraj 211002, India
| | - Pradip K Dutta
- Polymer Research Laboratory, Department of Chemistry, Motilal Nehru National Institute of Technology Allahabad, Prayagraj 211004, India.
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