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Požgan F, Grošelj U, Svete J, Štefane B, Al Mamari HH. Recent Advances in the Nickel-Catalyzed Alkylation of C-H Bonds. Molecules 2024; 29:1917. [PMID: 38731408 PMCID: PMC11085484 DOI: 10.3390/molecules29091917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
Functionalization of C-H bonds has emerged as a powerful strategy for converting inert, nonfunctional C-H bonds into their reactive counterparts. A wide range of C-H bond functionalization reactions has become possible by the catalysis of metals, typically from the second row of transition metals. First-row transition metals can also catalyze C-H functionalization, and they have the merits of greater earth-abundance, lower cost and better environmental friendliness in comparison to their second-row counterparts. C-H bond alkylation is a particularly important C-H functionalization reaction due to its chemical significance and its applications in natural product synthesis. This review covers Ni-catalyzed C-H bond alkylation reactions using alkyl halides and olefins as alkyl sources.
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Affiliation(s)
- Franc Požgan
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia; (F.P.); (U.G.); (J.S.); (B.Š.)
| | - Uroš Grošelj
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia; (F.P.); (U.G.); (J.S.); (B.Š.)
| | - Jurij Svete
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia; (F.P.); (U.G.); (J.S.); (B.Š.)
| | - Bogdan Štefane
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia; (F.P.); (U.G.); (J.S.); (B.Š.)
| | - Hamad H. Al Mamari
- Department of Chemistry, College of Science, Sultan Qaboos University, Muscat 123, Oman
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2
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Al Mamari HH, Borel J, Hickey A, Courtney E, Merz J, Zhang X, Friedrich A, Marder TB, McGlacken GP. Regioselective Iridium-Catalyzed C8-H Borylation of 4-Quinolones via Transient O-Borylated Quinolines. Chemistry 2023; 29:e202301734. [PMID: 37280155 DOI: 10.1002/chem.202301734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 06/08/2023]
Abstract
The quinolone-quinoline tautomerization is harnessed to effect the regioselective C8-borylation of biologically important 4-quinolones by using [Ir(OMe)(cod)]2 as the catalyst precursor, the silica-supported monodentate phosphine Si-SMAP as the ligand, and B2 pin2 as the boron source. Initially, O-borylation of the quinoline tautomer takes place. Critically, the newly formed 4-(pinBO)-quinolines then undergo N-directed selective Ir-catalyzed borylation at C8. Hydrolysis of the OBpin moiety on workup returns the system to the quinolone tautomer. The C8-borylated quinolines were converted to their corresponding potassium trifluoroborate (BF3 K) salts and to their C8-chlorinated quinolone derivatives. The two-step C-H borylation-chlorination reaction sequence resulted in various C8-Cl quinolones in good yields. Conversion to C8-OH-, C8-NH2 -, and C8-Ar-substituted quinolones was also feasible by using this methodology.
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Affiliation(s)
- Hamad H Al Mamari
- Department of Chemistry, College of Science, Sultan Qaboos University, PO Box 36, Al Khoudh 123, Muscat, Sultanate of Oman
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julie Borel
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Aobha Hickey
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
| | - Eimear Courtney
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
| | - Julia Merz
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Xiaolei Zhang
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institut für Anorganische Chemie and, Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Gerard P McGlacken
- School of Chemistry & Analytical and, Biological Chemistry Research Facility, University College Cork, T12 YN60, Ireland
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3
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Li Y, Huang Y, Li Z, Sun J. Recent Advances in Regioselective C-H Bond Functionalization of Free Phenols. Molecules 2023; 28:molecules28083397. [PMID: 37110630 PMCID: PMC10143084 DOI: 10.3390/molecules28083397] [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: 03/17/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Phenols are important readily available synthetic building blocks and starting materials for organic synthetic transformations, which are widely found in agrochemicals, pharmaceuticals, and functional materials. The C-H functionalization of free phenols has proven to be an extremely useful tool in organic synthesis, which provides efficient increases in phenol molecular complexity. Therefore, approaches to functionalizing existing C-H bonds of free phenols have continuously attracted the attention of organic chemists. In this review, we summarize the current knowledge and recent advances in ortho-, meta-, and para-selective C-H functionalization of free phenols in the last five years.
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Affiliation(s)
- Yanan Li
- School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Yekai Huang
- School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Zhi Li
- School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China
| | - Jianan Sun
- School of Biomedical Engineering, Anhui Medical University, Hefei 230032, China
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4
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Yang Y, Lu B, Xu G, Wang X. Overcoming O-H Insertion to Para-Selective C-H Functionalization of Free Phenols: Rh(II)/Xantphos Catalyzed Geminal Difunctionalization of Diazo Compounds. ACS CENTRAL SCIENCE 2022; 8:581-589. [PMID: 35647279 PMCID: PMC9136979 DOI: 10.1021/acscentsci.2c00004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Indexed: 05/04/2023]
Abstract
Para-selective C-H functionalization of free phenols by metal carbenoids is rather challenging due to the generally more favorable competing O-H insertion. Herein, with the use of the combination of Rh(II) and a Xantphos ligand as the catalyst, a novel multicomponent reaction of free phenols, diazoesters, and allylic carbonates was successfully developed, affording a wide variety of phenol derivatives, bearing an all-carbon quaternary center and a synthetically useful allylic unit. This reaction is likely to occur through a tandem process of carbene-induced para-selective C-H functionalization, followed by Rh(II)/Xantphos-catalyzed allylation. The distinctive reactivity of para-selective C-H rather than O-H insertion for the carbenoid intermediate, combined with features of excellent functional group compatibility, high atom and step economy, and ease in further diversification of the products, might render this protocol highly attractive in facile functionalization of unprotected phenols.
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Affiliation(s)
- Yang Yang
- Henan
Engineering Research Center of Chiral Hydroxyl Pharmaceutical, Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
- State
Key Laboratory of Organometallic Chemistry, Center for Excellence
in Molecular Synthesis, Shanghai Institute
of Organic Chemistry, University of Chinese Academy of Sciences, Chinese
Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Bin Lu
- State
Key Laboratory of Organometallic Chemistry, Center for Excellence
in Molecular Synthesis, Shanghai Institute
of Organic Chemistry, University of Chinese Academy of Sciences, Chinese
Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Guiqing Xu
- Henan
Engineering Research Center of Chiral Hydroxyl Pharmaceutical, Collaborative
Innovation Center of Henan Province for Green Manufacturing of Fine
Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry
of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
- (G.X.)
| | - Xiaoming Wang
- State
Key Laboratory of Organometallic Chemistry, Center for Excellence
in Molecular Synthesis, Shanghai Institute
of Organic Chemistry, University of Chinese Academy of Sciences, Chinese
Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
- School
of Chemistry and Materials Science, Hangzhou Institute for Advanced
Study, University of Chinese Academy of
Sciences, 1 Sub-lane
Xiangshan, Hangzhou 310024, China
- (X.W.)
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5
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Zhu DL, Jiang S, Young DJ, Wu Q, Li HY, Li HX. Visible-light-driven C(sp 2)-H arylation of phenols with arylbromides enabled by electron donor-acceptor excitation. Chem Commun (Camb) 2022; 58:3637-3640. [PMID: 35212323 DOI: 10.1039/d1cc07127k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have developed a catalyst-free visible-light-driven C(sp2)-H arylation of unprotected phenols with arylbromides to give 2-arylated phenols. This reaction proceeds through the excitation of an electron donor-acceptor complex between a phenolate and an arylbromide, electron transfer, and debrominative C(sp2)-C(sp2) coupling.
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Affiliation(s)
- Da-Liang Zhu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China. .,School of Chemistry and Environmental Engineering, Analysis and Testing Centre, Yancheng Teachers University, Yancheng 224007, China
| | - Shan Jiang
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - David James Young
- College of Engineering, IT and Environment, Charles Darwin University, Darwin, NT 0909, Australia
| | - Qi Wu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Hai-Yan Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Hong-Xi Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
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6
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Luan YY, Gou XY, Shi WY, Liu HC, Chen X, Liang YM. Three-Component Ruthenium-Catalyzed meta-C-H Alkylation of Phenol Derivatives. Org Lett 2022; 24:1136-1140. [PMID: 35084198 DOI: 10.1021/acs.orglett.1c04182] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we realized the multicomponent reactions of phenol derivatives via a six-membered cycloruthenated intermediate for the first time. This strategy exhibited good substrate suitability and functional group tolerance with various phenol derivatives and provided a potential synthetic drug approach. Mechanistic studies showed that a radical might be involved in this process. In addition, the meta alkylated phenol was obtained by further removal of the directing group.
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Affiliation(s)
- Yu-Yong Luan
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
| | - Xue-Ya Gou
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
| | - Wei-Yu Shi
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
| | - Hong-Chao Liu
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
| | - Xi Chen
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
| | - Yong-Min Liang
- State Key Laboratory of Applied Organic Chemistry, School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P.R. China
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7
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Shchepochkin AV, Antipin FV, Charushin VN, Chupakhin ON. Oxidative C–H Functionalization of Arenes: Main Tool of 21st Century Green Chemistry. A Review. DOKLADY CHEMISTRY 2021. [DOI: 10.1134/s0012500821070016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Bose SK, Mao L, Kuehn L, Radius U, Nekvinda J, Santos WL, Westcott SA, Steel PG, Marder TB. First-Row d-Block Element-Catalyzed Carbon-Boron Bond Formation and Related Processes. Chem Rev 2021; 121:13238-13341. [PMID: 34618418 DOI: 10.1021/acs.chemrev.1c00255] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Organoboron reagents represent a unique class of compounds because of their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation of the carbon-boron bond into a carbon-X (X = C, N, and O) bond in a stereocontrolled fashion has become invaluable in medicinal chemistry, agrochemistry, and natural products chemistry as well as materials science. Over the past decade, first-row d-block transition metals have become increasingly widely used as catalysts for the formation of a carbon-boron bond, a transformation traditionally catalyzed by expensive precious metals. This recent focus on alternative transition metals has enabled growth in fundamental methods in organoboron chemistry. This review surveys the current state-of-the-art in the use of first-row d-block element-based catalysts for the formation of carbon-boron bonds.
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Affiliation(s)
- Shubhankar Kumar Bose
- Centre for Nano and Material Sciences (CNMS), Jain University, Jain Global Campus, Bangalore-562112, India
| | - Lujia Mao
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, School of Pharmacy, Hainan Medical University, 571199 Haikou, Hainan, P. R. China
| | - Laura Kuehn
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Nekvinda
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Webster L Santos
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stephen A Westcott
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada
| | - Patrick G Steel
- Department of Chemistry, University of Durham, Science Laboratories South Road, Durham DH1 3LE, U.K
| | - Todd B Marder
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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9
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Al Mamari HH, Al Kiumi D, Al Rashdi T, Al Quraini H, Al Rashdi M, Al Sheraiqi S, Al Harmali S, Al Lamki M, Al Sheidi A, Al Zadjali A. Ru‐Catalyzed C(sp
2
)−H Bond Arylation of Benzamides Bearing a Novel 4‐Aminoantipyrine as a Directing Group. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hamad H. Al Mamari
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Diana Al Kiumi
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Tamadher Al Rashdi
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Huda Al Quraini
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Malak Al Rashdi
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Sumayya Al Sheraiqi
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Sara Al Harmali
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Mohammed Al Lamki
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Ahmed Al Sheidi
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
| | - Asma Al Zadjali
- Department of Chemistry, College of Science Sultan Qaboos University PO Box 36, Al Khoudh 123 Muscat Sultanate of Oman
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10
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Jiao LY, Ning ZH, Yin XM, Hong Q, Liu S, Ma XX. Rhodium(III)-catalyzed chelation-assisted ortho-selective carbon−hydrogen alkylation of phenols with diazocarbonyl compounds involving a carbene migratory insertion process. CATAL COMMUN 2021. [DOI: 10.1016/j.catcom.2021.106278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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11
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Intensification of Dihydroxybenzenes Degradation over Immobilized TiO2 Based Photocatalysts under Simulated Solar Light. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10217571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The work is focused on the assessment of possible methods for intensification of photocatalytic degradation of common water borne pollutants. Solar photocatalysis poses certain limitations for large scale application with several possible reactor designs which have shown an optimal performance. In the current study, a comparison between two types of pilot scale reactors was made: a flat-plate cascade reactor (FPCR) and tubular reactor with a compound parabolic collector (CPC). Apart from the reactor design, another aspect of possible intensification was a photocatalyst formulation. The efficiency of photocatalytic films that consisted of pure TiO2 nanoparticles was compared to the efficiency of films that consisted of TiO2/CNT composites. Intensification assessment was performed via detailed kinetic modelling, combining the optical properties of films, irradiation conditions and reactor mass balance. Intensification was expressed via intensification indices. Results showed the advantage of the CPC-based reactor design and an unbiased effect of sensitizing agent (CNT) in the photocatalytic film formulation.
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12
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Zhao R, Zhou Z, Liu J, Wang X, Zhang Q, Li D. Silver-Catalyzed para-Selective Amination and Aminative Dearomatization of Phenols with Azodicarboxylates in Water. Org Lett 2020; 22:8144-8149. [PMID: 32989991 DOI: 10.1021/acs.orglett.0c03147] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
An efficient silver-catalyzed para-selective amination and aminative dearomatization of phenols with azodicarboxylates was developed. It afforded the para-aminophenols or amino cyclohexadieneones from free phenols depending on whether it has a para-substituent. The reaction proceeded smoothly in water under simple and mild conditions, giving the highly selective products in good yields within a short reaction time. It also showed broad substrate scope and good functional group compatibility.
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Affiliation(s)
- Ruinan Zhao
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
| | - Zhong Zhou
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
| | - Jixiang Liu
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
| | - Xia Wang
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
| | - Qian Zhang
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
| | - Dong Li
- School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China
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13
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Ai HJ, Zhang Y, Zhao F, Wu XF. Rhodium-Catalyzed Carbonylative Synthesis of Aryl Salicylates from Unactivated Phenols. Org Lett 2020; 22:6050-6054. [PMID: 32790429 DOI: 10.1021/acs.orglett.0c02133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A rhodium-catalyzed carbonylative transformation of unactivated phenols to aryl salicylates is described. This protocol is characterized by utilizing 1,3-rhodium migration as the key step to provide direct access to synthesize o-hydroxyaryl esters. Various desired aryl o-hydroxybenzoates were produced in moderate to excellent yields with bis(dicyclohexylphosphino)ethane (DCPE) as the ligand. Interestingly, diphenyl carbonate was formed as the main product when 1,3-bis(diphenylphosphino)propane (DPPP) was used as the ligand. A plausible reaction mechanism is proposed.
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Affiliation(s)
- Han-Jun Ai
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Youcan Zhang
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Fengqian Zhao
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Xiao-Feng Wu
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany.,Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian, Liaoning,China
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14
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Conformationally Driven Ru(II)-Catalyzed Multiple ortho-C–H Bond Activation in Diphenylpyrazine Derivatives in Water: Where Is the Limit? Catalysts 2020. [DOI: 10.3390/catal10040421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Ru(II)/carboxylate/PPh3 catalyst system enabled the preparation of highly conjugated pyrazine derivatives in water under microwave irradiation. Both nitrogen atoms efficiently dictated cleavage of the ortho-C–H bonds in both benzene rings of 2,3-diphenylpyrazine substrates through chelation assistance. In conformationally more flexible diphenyldihydropyrazine 1, the arylation of four ortho-C–H bonds was possible, while in the aromatic analog 2, the triarylation was the limit.
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