1
|
Malakhova EV, Kostromitin VS, Cheboksarov DY, Levin VV, Dilman AD. Sodium Hypophosphite as a Halogen Atom Transfer (XAT) Agent under Photocatalytic Conditions. J Org Chem 2024. [PMID: 39120448 DOI: 10.1021/acs.joc.4c01412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
The ability of sodium hypophosphite to generate the phosphorus-centered radical, which can activate the carbon-halogen bond via the halogen atom transfer (XAT) is described. The hydroalkylation of nonactivated alkenes with methyl bromoacetate was performed using sodium hypophosphite as reducing agent under photocatalytic conditions. The key phosphorus centered radical is formed from the hypophosphite anion by hydrogen atom abstraction.
Collapse
Affiliation(s)
- Ekaterina V Malakhova
- N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian Federation
- Higher Chemical College, D. Mendeleev University of Chemical Technology of Russia, 125047 Moscow, Miusskaya sq. 9, Russian Federation
| | - Vladislav S Kostromitin
- N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian Federation
- Lomonosov Moscow State University, Department of Chemistry, 119991 Moscow, Leninskie Gory 1-3, Russian Federation
| | - Demian Y Cheboksarov
- N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian Federation
- Lomonosov Moscow State University, Department of Chemistry, 119991 Moscow, Leninskie Gory 1-3, Russian Federation
| | - Vitalij V Levin
- N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian Federation
| | - Alexander D Dilman
- N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian Federation
| |
Collapse
|
2
|
Wan T, Ciszewski ŁW, Ravelli D, Capaldo L. Photoinduced Intermolecular Radical Hydroalkylation of Olefins via Ligated Boryl Radicals-Mediated Halogen Atom Transfer. Org Lett 2024; 26:5839-5843. [PMID: 38950385 PMCID: PMC11250028 DOI: 10.1021/acs.orglett.4c02034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/21/2024] [Accepted: 06/26/2024] [Indexed: 07/03/2024]
Abstract
Light-mediated Halogen-Atom Transfer (XAT) has become a significant methodology in contemporary synthesis. Unlike α-aminoalkyl and silyl radicals, ligated boryl radicals (LBRs) have not been extensively explored as halogen atom abstractors. In this study, we introduce NHC-ligated boranes as optimal radical chain carriers for the intermolecular reductive radical hydroalkylation and hydroarylation of electron-deficient olefins by using direct UV-A light irradiation. DFT analysis allowed us to rationalize the critical role of the NHC ligand in facilitating efficient chain propagation.
Collapse
Affiliation(s)
- Ting Wan
- Flow
Chemistry Group, van’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
- The
Research Center of Chiral Drugs, Innovation Research Institute of
Traditional Chinese Medicine, Shanghai University
of Traditional Chinese Medicine, Shanghai 201203, China
| | - Łukasz W. Ciszewski
- Flow
Chemistry Group, van’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Davide Ravelli
- PhotoGreen
Lab, Department of Chemistry, University
of Pavia, 27100 Pavia, Italy
| | - Luca Capaldo
- Flow
Chemistry Group, van’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, 1098 XH Amsterdam, The Netherlands
- SynCat
Lab, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| |
Collapse
|
3
|
Ma YQ, Zhang M, Tian SK. Silyl Radical as an Isocyanide Transfer Agent for Giese-Type Reactions Involving Aliphatic Amines. Org Lett 2024; 26:5172-5176. [PMID: 38864545 DOI: 10.1021/acs.orglett.4c01706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Herein we report silyl radicals serve as isocyanide transfer agents for Giese-type reaction from aliphatic amines and electron-deficient olefins. α-Primary, α-secondary, and sterically encumbered α-tertiary primary amines could be easily converted into isocyanides for coupling with electron-deficient olefins by employing latent silyl radicals under visible light irradiation. Notably, the abstraction of silane-mediated isocyanide not only enables voltage-independent activation of strong C-N bonds but also represents a mechanistic alternative Giese-type reaction in which single electron reduction and protonation processes are replaced by direct hydrogen atom transfer. This transformation occurs under photoinduced catalyst-free conditions and exhibits excellent functional group compatibility and mild reaction conditions.
Collapse
Affiliation(s)
- Yu-Qing Ma
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Muliang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Shi-Kai Tian
- Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
4
|
Xia XR, Du J, Zhang YX, Jiang H, Cheng WM. Catalyst-Free Visible Light-Driven Hydrosulfonylation of Alkenes and Alkynes with Sulfonyl Chlorides in Water. CHEMSUSCHEM 2024:e202400650. [PMID: 38850152 DOI: 10.1002/cssc.202400650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/17/2024] [Accepted: 06/07/2024] [Indexed: 06/10/2024]
Abstract
A convenient and sustainable method for synthesizing sulfonyl-containing compounds through a catalyst-free aqueous-phase hydrosulfonylation of alkenes and alkynes with sulfonyl chlorides under visible light irradiation is presented. Unactivated alkenes, electron-deficient alkenes, alkyl and aryl alkynes can be hydrosulfonylated with various sulfonyl chlorides at room temperature with excellent yields and geometric selectivities by using tris(trimethylsilyl)silane as a hydrogen atom donor and silyl radical precursor to activate sulfonyl chlorides. Mechanistic studies revealed that the photolysis of tris(trimethylsilyl)silane in aqueous solution to produce silyl radical is crucial for the success of this reaction.
Collapse
Affiliation(s)
- Xi-Rui Xia
- College of Chemistry, Huazhong Agricultural University, Wuhan, 430070, China
| | - Juan Du
- College of Chemistry, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yu-Xing Zhang
- College of Chemistry, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong Jiang
- College of Chemistry, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wan-Min Cheng
- College of Chemistry, Huazhong Agricultural University, Wuhan, 430070, China
| |
Collapse
|
5
|
Ma YQ, Tian SK. Catalyst-free visible light-promoted defunctionalization of alkyl isocyanides with a hydrosilane through C-N bond cleavage. Org Biomol Chem 2024; 22:2562-2565. [PMID: 38451158 DOI: 10.1039/d4ob00173g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
A radical initiator-free defunctionalization reaction of alkyl isocyanides with a hydrosilane has been established through C-N bond cleavage under catalyst-free visible light irradiation. Various alkyl isocyanides participated in the defunctionalization with tris(trimethylsilyl)silane under blue light irradiation at room temperature, delivering the reduced products in good yields with high chemoselectivity.
Collapse
Affiliation(s)
- Yu-Qing Ma
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Precision and Intelligent Chemistry, and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Shi-Kai Tian
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Precision and Intelligent Chemistry, and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| |
Collapse
|
6
|
Quirós I, Martín M, Gomez-Mendoza M, Cabrera-Afonso MJ, Liras M, Fernández I, Nóvoa L, Tortosa M. Isonitriles as Alkyl Radical Precursors in Visible Light Mediated Hydro- and Deuterodeamination Reactions. Angew Chem Int Ed Engl 2024; 63:e202317683. [PMID: 38150265 DOI: 10.1002/anie.202317683] [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: 11/20/2023] [Revised: 12/20/2023] [Accepted: 12/27/2023] [Indexed: 12/28/2023]
Abstract
Herein, we report the use of isonitriles as alkyl radical precursors in light-mediated hydro- and deuterodeamination reactions. The reaction is scalable, shows broad functional group compatibility and potential to be used in late-stage functionalization. Importantly, the method is general for Cα -primary, Cα -secondary and Cα -tertiary alkyl isonitriles. For most examples, high yields were obtained through direct visible-light irradiation of the isonitrile in the presence of a silyl radical precursor. Interestingly, in the presence of an organic photocatalyst (4CzIPN) a dramatic acceleration was observed. In-depth mechanistic studies using UV/Vis absorption, steady-state and time-resolved photoluminescence, and transient absorption spectroscopy suggest that the excited state of 4CzIPN can engage in a single-electron transfer with the isonitrile.
Collapse
Affiliation(s)
- Irene Quirós
- Organic Chemistry Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
| | - María Martín
- Organic Chemistry Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
| | - Miguel Gomez-Mendoza
- Photoactivated Processes Unit, IMDEA Energy, Av. Ramón de la Sagra 3, Móstoles, 28935, Madrid, Spain
| | - María Jesús Cabrera-Afonso
- Organic Chemistry Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
| | - Marta Liras
- Photoactivated Processes Unit, IMDEA Energy, Av. Ramón de la Sagra 3, Móstoles, 28935, Madrid, Spain
| | - Israel Fernández
- Department of Organic Chemistry, Faculty of Chemistry, Complutense University of Madrid, 28040, Madrid, Spain
- Center of Innovation in Advanced Chemistry (ORFEO-CINQA), Spain
| | - Luis Nóvoa
- Organic Chemistry Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
| | - Mariola Tortosa
- Organic Chemistry Department, Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid (UAM), Avda. Francisco Tomás y Valiente 7, Cantoblanco, 28049, Madrid, Spain
- Center of Innovation in Advanced Chemistry (ORFEO-CINQA), Spain
| |
Collapse
|
7
|
Xu J, Lan Y, Liu B. Activation of Aryl and Alkyl Halides Enabled by Strong Photoreduction Potentials of a Hantzsch Ester/Cs 2CO 3 System. J Org Chem 2024; 89:599-604. [PMID: 38113916 DOI: 10.1021/acs.joc.3c02320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
We disclose herein a light-induced Hantzsch ester-initiated aryl and alkyl radical generation protocol from aryl halides (Br and Cl) and alkyl iodides. This method provides access to a wide range of benzo-fused heterocycles and C(sp3)-C(sp3) coupling products. The reductive detosylation reaction has also been demonstrated using the same reaction conditions. Initial mechanism studies provide evidence of the formation of an alkyl radical.
Collapse
Affiliation(s)
- Junhua Xu
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China
| | - Yingjun Lan
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China
| | - Bin Liu
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi 330031, P. R. China
| |
Collapse
|
8
|
Al Zubaydi S, Onuigbo IO, Truesdell BL, Sevov CS. Cobalt-Catalyzed Electroreductive Alkylation of Unactivated Alkyl Chlorides with Conjugated Olefins. Angew Chem Int Ed Engl 2024; 63:e202313830. [PMID: 37963333 DOI: 10.1002/anie.202313830] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 11/10/2023] [Accepted: 11/14/2023] [Indexed: 11/16/2023]
Abstract
Reactions of unactivated alkyl chlorides under mild and sustainable conditions are rare compared to those of alkyl bromides or iodides. As a result, synthetic methods capable of modifying the vast chemical space of chloroalkane reagents, wastes, and materials are limited. We report the cobalt-catalyzed reductive addition of unactivated alkyl chlorides to conjugated alkenes. Co-catalyzed activation of alkyl chlorides is performed under electroreductive conditions, and the resulting reactions constitute formal alkyl-alkyl bond formation. In addition to developing an operationally simple methodology, detailed mechanistic studies provide insights into the elementary steps of a proposed catalytic cycle. In particular, we propose a switch in the mechanism of C-Cl bond activation from nucleophilic substitution to halogen atom abstraction, which is critical for efficiently generating alkyl radicals. These mechanistic insights were leveraged in designing ligands that enable couplings of primary, secondary, and tertiary alkyl chlorides.
Collapse
Affiliation(s)
- Samir Al Zubaydi
- Department of Chemistry and Biochemistry, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA
| | - Immaculata O Onuigbo
- Department of Chemistry and Biochemistry, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA
| | - Blaise L Truesdell
- Department of Chemistry and Biochemistry, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA
| | - Christo S Sevov
- Department of Chemistry and Biochemistry, The Ohio State University, 151 West Woodruff Avenue, Columbus, OH 43210, USA
| |
Collapse
|
9
|
Sun X, Zheng K. Electrochemical halogen-atom transfer alkylation via α-aminoalkyl radical activation of alkyl iodides. Nat Commun 2023; 14:6825. [PMID: 37884528 PMCID: PMC10603137 DOI: 10.1038/s41467-023-42566-y] [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: 05/21/2023] [Accepted: 10/16/2023] [Indexed: 10/28/2023] Open
Abstract
Alkyl halides, widely recognized as important building blocks and reagents in organic synthesis, can serve as versatile alkyl radical precursors in radical-based transformations. However, generating alkyl radicals directly from unactivated alkyl halides under mild conditions remains a challenge due to their extremely low reduction potentials. To address this issue, α-aminoalkyl radicals were employed as efficient halogen-atom transfer (XAT) reagents in the photoredox activation of unactivated alkyl halides. Here, we report an effective electrooxidation strategy for generating alkyl radicals from unactivated alkyl iodides via an electrochemical halogen-atom transfer (e-XAT) process under mild conditions. The α-aminoalkyl radicals generated by anodic oxidation are demonstrated to be efficient XAT reagents in these transformations. This facile electricity-driven strategy obviates the need for sacrificial anodes and external chemical oxidants. The method successfully applies to a wide variety of alkyl iodides, including primary, secondary, and tertiary, as well as structurally diverse olefins, exhibiting excellent functional group tolerance. Moreover, we further demonstrate the utility of this strategy by rapidly functionalizing complex molecules and biomolecules.
Collapse
Affiliation(s)
- Xiang Sun
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, PR China
| | - Ke Zheng
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, PR China.
| |
Collapse
|
10
|
Bhowmick A, Chatterjee A, Pathak SS, Bhat RG. A visible light-driven direct synthesis of industrially relevant glutaric acid diesters from aldehydes. Chem Commun (Camb) 2023; 59:11875-11878. [PMID: 37724011 DOI: 10.1039/d3cc02557h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
A straightforward and practical method has been developed to access α-substituted glutaric diesters from acrylates and aldehydes using visible light, with Eosin Y facilitating hydrogen atom transfer (HAT) and subsequent Giese-type addition. Also, sunlight has been successfully used as an alternative sustainable light source. The method has also been explored to access substituted 4,5-dihydro-2H-pyridazinones, which have potential biological and industrial applications. Comprehensive mechanistic investigations have been carried out.
Collapse
Affiliation(s)
- Anindita Bhowmick
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, 411008, Maharashtra, India.
| | - Abhijit Chatterjee
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, 411008, Maharashtra, India.
| | - Sidharth S Pathak
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, 411008, Maharashtra, India.
| | - Ramakrishna G Bhat
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, 411008, Maharashtra, India.
| |
Collapse
|
11
|
Luo XL, Huang MS, Li SS, Jiang YS, Chen LN, Li SH, Xia PJ. Photocatalytic Multicomponent 1, n-Carboimination with Alkyl Iodides and O-Benzoyl Oxime through EnT and XAT Processes. Org Lett 2023; 25:6407-6412. [PMID: 37607051 DOI: 10.1021/acs.orglett.3c02440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
In this study, we developed a strategy using commercially available alkyl iodides and O-benzoyl oxime to efficiently introduce alkyl and iminyl groups via energy transfer and halogen-atom transfer processes. We performed three-component 1,2-carboimination of olefins and four-component 1,4-carboimination across olefins and alkynes, resulting in the synthesis of over 60 nitrogen-containing molecules. Moreover, this transformation enables the synthesis of molecules with sensitive groups that were previously difficult to achieve.
Collapse
Affiliation(s)
- Xue-Ling Luo
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Miao-Sha Huang
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Shan-Shan Li
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Yu-Shi Jiang
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Li-Ning Chen
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Shu-Hui Li
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| | - Peng-Ju Xia
- School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, P. R. China
| |
Collapse
|
12
|
Cao H, Bhattacharya D, Cheng Q, Studer A. C-H Functionalization of Pyridines via Oxazino Pyridine Intermediates: Switching to para-Selectivity under Acidic Conditions. J Am Chem Soc 2023. [PMID: 37428649 DOI: 10.1021/jacs.3c05242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
para-Selective C-H functionalization of pyridines holds a significant value but remains underdeveloped. Site-switchable C-H functionalization of pyridines under easily tunable conditions expedites drug development. We recently reported a redox-neutral dearomatization-rearomatization strategy for meta-C-H functionalization of pyridines via oxazino pyridine intermediates. Here, we demonstrate that these oxazino pyridine intermediates undergo highly para-selective functionalization simply by switching to acidic conditions. A broad scope of para-alkylated and arylated pyridines is prepared through radical as well as ionic pathways. These mild and catalyst-free methods are applied to the late-stage para-functionalization of drugs using pyridines as the limiting reagents. Consecutive meta,para-difunctionalization of pyridines is also achieved with complete regiocontrol relying on the pH-dependent reactivity of oxazino pyridines.
Collapse
Affiliation(s)
- Hui Cao
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| | - Debkanta Bhattacharya
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| | - Qiang Cheng
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| |
Collapse
|
13
|
Kang YW, Kim RH, Atriardi SR, Woo SK. Visible-Light Photoredox-Catalyzed Giese Reaction of α-Silyl Ethers with Various Michael Acceptors. J Org Chem 2023; 88:3555-3566. [PMID: 36853651 DOI: 10.1021/acs.joc.2c02754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
We developed a photocatalyzed Giese reaction of various weakly activated Michael acceptors with a neutral silicon-based radical precursor and applied it at large-scale using a continuous flow reactor. The developed method successfully overcomes the substrate scope limitations of previous studies, shows good functional groups tolerance, and affords good to excellent yields. On the basis of mechanistic studies, we propose a reaction mechanism that involves an in situ generated alkoxymethyl radical via single-electron oxidation of α-trimethylsilyl-substituted ethers.
Collapse
Affiliation(s)
- Young Woo Kang
- Department of Chemistry, University of Ulsan, 93 Daehak-Ro, Nam-Gu, Ulsan 44610, Korea
| | - Ran Hui Kim
- Department of Chemistry, University of Ulsan, 93 Daehak-Ro, Nam-Gu, Ulsan 44610, Korea
| | | | - Sang Kook Woo
- Department of Chemistry, University of Ulsan, 93 Daehak-Ro, Nam-Gu, Ulsan 44610, Korea
| |
Collapse
|
14
|
Fanini F, Luridiana A, Mazzarella D, Ilenia Alfano A, van der Heide P, Rincón JA, García-Losada P, Mateos C, Frederick MO, Nuño M, Noël T. Flow photochemical Giese reaction via silane-mediated activation of alkyl bromides. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|