1
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Palani V, Wendlandt AE. Strain-Inducing Positional Alkene Isomerization. J Am Chem Soc 2023; 145:20053-20061. [PMID: 37647593 DOI: 10.1021/jacs.3c06935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Small, strained ring systems are important pharmacophores in medicinal chemistry and versatile intermediates in organic synthesis. However, the kinetic and thermodynamic instability of many strained organic molecules renders them challenging to prepare. Here, we report a strain-inducing positional alkene isomerization reaction that provides mild and selective access to cyclobutene building blocks from readily obtained cyclobutylidene precursors. This endergonic isomerization relies on the sequential and synergistic action of a decatungstate polyanion photocatalyst and cobaloxime co-catalyst to store potential energy in the form of ring strain. The versatility of the cyclobutene products is demonstrated through diverse subsequent strain-releasing transformations. Mechanistic studies reveal a steric basis for strain-selective product formation.
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Affiliation(s)
- Vignesh Palani
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alison E Wendlandt
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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2
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Shigeno M, Kajima A, Toyama E, Korenaga T, Yamakoshi H, Nozawa-Kumada K, Kondo Y. LiHMDS-Mediated Deprotonative Coupling of Toluenes with Ketones. Chemistry 2023; 29:e202203549. [PMID: 36479733 DOI: 10.1002/chem.202203549] [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: 11/15/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
We demonstrate that lithium hexamethyldisilazide (LiHMDS) acts as an effective base for deprotonative coupling reactions of toluenes with ketones to afford stilbenes. Various functionalities (halogen, OCF3 , amide, Me, aryl, alkenyl, alkynyl, SMe, and SPh) are allowed on the toluenes. Notably, this system proved successful with low-reactive toluenes bearing a large pKa value compared to that of the conjugate acid of LiHMDS (hexamethyldisilazane, 25.8, THF), as demonstrated by 4-phenyltoluene (38.57, THF) and toluene itself (∼43, DMSO).
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Affiliation(s)
- Masanori Shigeno
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan.,JST, PRESTO, Kawaguchi, Saitama, 332-0012, Japan
| | - Akihisa Kajima
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Eito Toyama
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Toshinobu Korenaga
- Department of Chemistry and Biological Sciences Faculty of Science and Engineering, Iwate University Ueda, Morioka, 020-8551, Japan.,Soft-Path Science and Engineering Research Center (SPERC), Iwate University, Ueda, Morioka, 020-8551, Japan
| | - Hiroyuki Yamakoshi
- Central Analytical Center, Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Kanako Nozawa-Kumada
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Yoshinori Kondo
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
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3
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Zeng J, Torigoe T, Kuninobu Y. Control of Site-Selectivity in Hydrogen Atom Transfer by Electrostatic Interaction: Proximal-Selective C(sp3)–H Alkylation of 2-Methylanilinium Salts Using a Decatungstate Photocatalyst. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00278] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Jialin Zeng
- Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
| | - Takeru Torigoe
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
- Department of Interdisciplinary Engineering Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
| | - Yoichiro Kuninobu
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
- Department of Interdisciplinary Engineering Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
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4
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Abstract
The fields of C-H functionalization and photoredox catalysis have garnered enormous interest and utility in the past several decades. Many different scientific disciplines have relied on C-H functionalization and photoredox strategies including natural product synthesis, drug discovery, radiolabeling, bioconjugation, materials, and fine chemical synthesis. In this Review, we highlight the use of photoredox catalysis in C-H functionalization reactions. We separate the review into inorganic/organometallic photoredox catalysts and organic-based photoredox catalytic systems. Further subdivision by reaction class─either sp2 or sp3 C-H functionalization─lends perspective and tactical strategies for use of these methods in synthetic applications.
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Affiliation(s)
- Natalie Holmberg-Douglas
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - David A Nicewicz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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5
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Abstract
In recent years, visible light-induced transition metal catalysis has emerged as a new paradigm in organic photocatalysis, which has led to the discovery of unprecedented transformations as well as the improvement of known reactions. In this subfield of photocatalysis, a transition metal complex serves a double duty by harvesting photon energy and then enabling bond forming/breaking events mostly via a single catalytic cycle, thus contrasting the established dual photocatalysis in which an exogenous photosensitizer is employed. In addition, this approach often synergistically combines catalyst-substrate interaction with photoinduced process, a feature that is uncommon in conventional photoredox chemistry. This Review describes the early development and recent advances of this emerging field.
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Affiliation(s)
- Kelvin Pak Shing Cheung
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Sumon Sarkar
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Vladimir Gevorgyan
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
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6
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Gant Kanegusuku AL, Roizen JL. Recent Advances in Photoredox-Mediated Radical Conjugate Addition Reactions: An Expanding Toolkit for the Giese Reaction. Angew Chem Int Ed Engl 2021; 60:21116-21149. [PMID: 33629454 PMCID: PMC8382814 DOI: 10.1002/anie.202016666] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Indexed: 12/18/2022]
Abstract
Photomediated Giese reactions are at the forefront of radical chemistry, much like the classical tin-mediated Giese reactions were nearly forty years ago. With the global recognition of organometallic photocatalysts for the mild and tunable generation of carbon-centered radicals, chemists have developed a torrent of strategies to form previously inaccessible radical intermediates that are capable of engaging in intermolecular conjugate addition reactions. This Review summarizes advances in photoredox-mediated Giese reactions since 2013, with a focus on the breadth of methods that provide access to crucial carbon-centered radical intermediates that can engage in radical conjugate addition processes.
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Affiliation(s)
| | - Jennifer L Roizen
- Department of Chemistry, Duke University, Box 90346, Durham, NC, 27708-0354, USA
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7
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Capaldo L, Ravelli D, Fagnoni M. Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C-H Bonds Elaboration. Chem Rev 2021; 122:1875-1924. [PMID: 34355884 PMCID: PMC8796199 DOI: 10.1021/acs.chemrev.1c00263] [Citation(s) in RCA: 338] [Impact Index Per Article: 112.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Direct photocatalyzed
hydrogen atom transfer (d-HAT) can be considered
a method of choice for the elaboration of
aliphatic C–H bonds. In this manifold, a photocatalyst (PCHAT) exploits the energy of a photon to trigger the homolytic
cleavage of such bonds in organic compounds. Selective C–H
bond elaboration may be achieved by a judicious choice of the hydrogen
abstractor (key parameters are the electronic character and the molecular
structure), as well as reaction additives. Different are the classes
of PCsHAT available, including aromatic ketones, xanthene
dyes (Eosin Y), polyoxometalates, uranyl salts, a metal-oxo porphyrin
and a tris(amino)cyclopropenium radical dication. The processes (mainly
C–C bond formation) are in most cases carried out under mild
conditions with the help of visible light. The aim of this review
is to offer a comprehensive survey of the synthetic applications of
photocatalyzed d-HAT.
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Affiliation(s)
- Luca Capaldo
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Davide Ravelli
- 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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8
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Gant Kanegusuku AL, Roizen JL. Recent Advances in Photoredox‐Mediated Radical Conjugate Addition Reactions: An Expanding Toolkit for the Giese Reaction. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016666] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Jennifer L. Roizen
- Department of Chemistry Duke University Box 90346 Durham NC 27708-0354 USA
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9
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Kim K, Lee S, Hong SH. Direct C(sp 3)-H Cyanation Enabled by a Highly Active Decatungstate Photocatalyst. Org Lett 2021; 23:5501-5505. [PMID: 34228456 DOI: 10.1021/acs.orglett.1c01846] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A highly efficient, direct C(sp3)-H cyanation was developed under mild photocatalytic conditions. The method enabled the direct cyanation of various C(sp3)-H substrates with excellent functional group tolerance. Notably, complex natural products and bioactive compounds were efficiently cyanated.
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Affiliation(s)
- Kunsoon Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.,Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Seulchan Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Soon Hyeok Hong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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10
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Treacy SM, Rovis T. Copper Catalyzed C(sp 3)-H Bond Alkylation via Photoinduced Ligand-to-Metal Charge Transfer. J Am Chem Soc 2021; 143:2729-2735. [PMID: 33576606 DOI: 10.1021/jacs.1c00687] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Utilizing catalytic CuCl2 we report the functionalization of numerous feedstock chemicals via the coupling of unactivated C(sp3)-H bonds with electron-deficient olefins. The active cuprate catalyst undergoes Ligand-to-Metal Charge Transfer (LMCT) to enable the generation of a chlorine radical which acts as a powerful hydrogen atom transfer reagent capable of abstracting strong electron-rich C(sp3)-H bonds. Of note is that the chlorocuprate catalyst is an exceedingly mild oxidant (0.5 V vs SCE) and that a proposed protodemetalation mechanism offers a broad scope of electron-deficient olefins, offering high diastereoselectivity in the case of endocyclic alkenes. The coupling of chlorine radical generation with Cu reduction through LMCT enables the generation of a highly active HAT reagent in an operationally simple and atom economical protocol.
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Affiliation(s)
- Sean M Treacy
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Tomislav Rovis
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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11
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Prieto A, Taillefer M. Visible-Light Decatungstate/Disulfide Dual Catalysis for the Hydro-Functionalization of Styrenes. Org Lett 2021; 23:1484-1488. [DOI: 10.1021/acs.orglett.1c00189] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexis Prieto
- ICGM, Univ Montpellier, CNRS, ENSCM, 34000 Montpellier, France
| | - Marc Taillefer
- ICGM, Univ Montpellier, CNRS, ENSCM, 34000 Montpellier, France
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12
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Inoa J, Patel M, Dominici G, Eldabagh R, Patel A, Lee J, Xing Y. Benzylic Hydroperoxidation via Visible-Light-Induced Csp 3-H Activation. J Org Chem 2020; 85:6181-6187. [PMID: 32242417 DOI: 10.1021/acs.joc.0c00385] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A highly efficient benzylic hydroperoxidation has been realized through a visible-light-induced Csp3-H activation. We believe that this reaction undergoes a direct HAT mechanism catalyzed by eosin Y. This approach features the use of a metal-free catalyst (eosin Y), an energy-economical light source (blue LED), and a sustainable oxidant (molecular oxygen). Primary, secondary, and tertiary hydroperoxides as well as silyl, benzyl, and acyl peroxides were successfully prepared with good yields and excellent functional group compatibility.
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Affiliation(s)
- Joan Inoa
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - Mansi Patel
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - Grecia Dominici
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - Reem Eldabagh
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - Anjali Patel
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - John Lee
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
| | - Yalan Xing
- Department of Chemistry, William Paterson University of New Jersey, 300 Pompton Road, Wayne, New Jersey 07470, United States
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13
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Dai ZY, Nong ZS, Wang PS. Light-Mediated Asymmetric Aliphatic C–H Alkylation with Hydrogen Atom Transfer Catalyst and Chiral Phosphoric Acid. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00610] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Zhen-Yao Dai
- Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Zhong-Sheng Nong
- Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
| | - Pu-Sheng Wang
- Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China
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14
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Yazaki R, Ohshima T. Recent strategic advances for the activation of benzylic C–H bonds for the formation of C–C bonds. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.151225] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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15
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Liu G, Walsh PJ, Mao J. Alkaline-Metal-Catalyzed One-Pot Aminobenzylation of Aldehydes with Toluenes. Org Lett 2019; 21:8514-8518. [PMID: 31542933 DOI: 10.1021/acs.orglett.9b02737] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel and easily accessible MN(SiMe3)2 (M = Li or Na)/Cs2CO3 co-catalyzed benzylation of in situ generated N-(trimethylsilyl) aldimines with toluene derivatives has been successfully developed. The catalyst exhibits high chemoselectivity for deprotonation of toluenes at the benzylic position. The utility of this system is exemplified by the one-pot synthesis of a diverse array of bioactive 1,2-diarylethylamines with excellent efficiency and broad functional group tolerance.
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Affiliation(s)
- Guoqing Liu
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials , Nanjing Tech University , 30 South Puzhu Road , Nanjing 211816 , P.R. China
| | - Patrick J Walsh
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Jianyou Mao
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials , Nanjing Tech University , 30 South Puzhu Road , Nanjing 211816 , P.R. China
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16
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Yuan Z, Yang H, Malik N, Čolović M, Weber DS, Wilson D, Bénard F, Martin RE, Warren JJ, Schaffer P, Britton R. Electrostatic Effects Accelerate Decatungstate-Catalyzed C–H Fluorination Using [18F]- and [19F]NFSI in Small Molecules and Peptide Mimics. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02220] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Zheliang Yuan
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S2, Canada
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Noeen Malik
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Milena Čolović
- Department of Molecular Oncology, BC Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - David S. Weber
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S2, Canada
| | - Darryl Wilson
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S2, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer Agency, Vancouver, British Columbia V5Z 1L3, Canada
| | - Rainer E. Martin
- Medicinal Chemistry, Roche Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | - Jeffrey J. Warren
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S2, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Robert Britton
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S2, Canada
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17
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Chiral acid-catalysed enantioselective C-H functionalization of toluene and its derivatives driven by visible light. Nat Commun 2019; 10:1774. [PMID: 30992448 PMCID: PMC6467922 DOI: 10.1038/s41467-019-09857-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/02/2019] [Indexed: 11/30/2022] Open
Abstract
Toluene and its derivatives are petroleum-derived raw materials produced from gasoline by catalytic reformation. These abundant chemical feedstocks are commonly used as solvents in organic synthesis. The C(sp3)−H functionalization of these unactivated substrates has been widely used to directly introduce benzylic motifs into diverse molecules to furnish important compounds. Despite these advances, progress in asymmetric catalysis remains underdeveloped. Here, we report photoinduced radical-based enantioselective C(sp3)−C(sp3) coupling reactions of activated ketones with toluene and its derivatives by means of chiral acid catalysis. With a La(OTf)3/pybox complex catalyst, a variety of chiral 3-hydroxy-3-benzyl-substituted 2-oxindoles, including many conventionally difficult-to-access variants, are obtained directly from isatins in high yields with good to excellent enantioselectivities. Acenaphthoquinone is also compatible with the use of a chiral phosphoric acid (CPA) catalyst, leading to another series of important enantioenriched tertiary alcohols. Asymmetric transformations involving abundant chemical feedstocks such as toluene and its derivatives are rather rare. Here, the authors report the radical enantioselective C(sp3) −C(sp3) coupling of activated ketones with toluenes by means of chiral acid catalysis to afford enantioenriched tertiary alcohols.
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18
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Suzuki K, Mizuno N, Yamaguchi K. Polyoxometalate Photocatalysis for Liquid-Phase Selective Organic Functional Group Transformations. ACS Catal 2018. [DOI: 10.1021/acscatal.8b03498] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kosuke Suzuki
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Precursory Research
for Embryonic Science and Technology (PRESTO), Japan Science and Technology
Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Noritaka Mizuno
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kazuya Yamaguchi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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19
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Mazzarella D, Crisenza GEM, Melchiorre P. Asymmetric Photocatalytic C–H Functionalization of Toluene and Derivatives. J Am Chem Soc 2018; 140:8439-8443. [DOI: 10.1021/jacs.8b05240] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Daniele Mazzarella
- ICIQ − Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007 Tarragona, Spain
| | - Giacomo E. M. Crisenza
- ICIQ − Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007 Tarragona, Spain
| | - Paolo Melchiorre
- ICIQ − Institute of Chemical Research of Catalonia, the Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007 Tarragona, Spain
- ICREA − Passeig Lluís Companys 23, 08010 Barcelona, Spain
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20
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Liu H, Ma L, Zhou R, Chen X, Fang W, Wu J. One-Pot Photomediated Giese Reaction/Friedel–Crafts Hydroxyalkylation/Oxidative Aromatization To Access Naphthalene Derivatives from Toluenes and Enones. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00481] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Haiwang Liu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Republic of Singapore
| | - Lishuang Ma
- College of Chemistry, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Rong Zhou
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Republic of Singapore
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, People’s Republic of China
| | - Xuebo Chen
- College of Chemistry, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Weihai Fang
- College of Chemistry, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Jie Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Republic of Singapore
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21
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Quattrini MC, Fujii S, Yamada K, Fukuyama T, Ravelli D, Fagnoni M, Ryu I. Versatile cross-dehydrogenative coupling of heteroaromatics and hydrogen donors via decatungstate photocatalysis. Chem Commun (Camb) 2018; 53:2335-2338. [PMID: 28164184 DOI: 10.1039/c6cc09725a] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A facile sunlight-induced derivatization of heteroaromatics via photocatalyzed C-H functionalization in amides, ethers, alkanes and aldehydes is described. Tetrabutylammonium decatungstate (TBADT) was used as the photocatalyst and allowed to carry out the process under mild conditions.
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Affiliation(s)
- Matteo C Quattrini
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy.
| | - Saki Fujii
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
| | - Keiichi Yamada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
| | - Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
| | - Davide Ravelli
- 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.
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan. and Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
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22
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Fukuyama T, Yamada K, Nishikawa T, Ravelli D, Fagnoni M, Ryu I. Site-selectivity in TBADT-photocatalyzed C(sp3)–H Functionalization of Saturated Alcohols and Alkanes. CHEM LETT 2018. [DOI: 10.1246/cl.171068] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Keiichi Yamada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Tomohiro Nishikawa
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Davide Ravelli
- Photo Green Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- Photo Green Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Illhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
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23
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Ravelli D, Fagnoni M, Fukuyama T, Nishikawa T, Ryu I. Site-Selective C–H Functionalization by Decatungstate Anion Photocatalysis: Synergistic Control by Polar and Steric Effects Expands the Reaction Scope. ACS Catal 2017. [DOI: 10.1021/acscatal.7b03354] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Davide Ravelli
- 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
| | - Takahide Fukuyama
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Tomohiro Nishikawa
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Ilhyong Ryu
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
- Department
of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
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24
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Fukuyama T, Nishikawa T, Yamada K, Ravelli D, Fagnoni M, Ryu I. Photocatalyzed Site-Selective C(sp 3)-H Functionalization of Alkylpyridines at Non-Benzylic Positions. Org Lett 2017; 19:6436-6439. [PMID: 29154551 DOI: 10.1021/acs.orglett.7b03339] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Tetrabutylammonium decatungstate (TBADT)-photocatalyzed C-H functionalization of alkylpyridines was investigated. Unlike alkylbenzene counterparts, alkylation of α-C-H bonds did not proceed for the reaction of 2- and 4-alkylpyridines and reluctantly proceeded for 3-alkylpyridines, which allow site-selective C(sp3)-H functionalization at nonbenzylic positions. The observed nonbenzylic site selectivities are rationalized by the polar inductive effects of pyridyl groups in the SH2 transition states. Consecutive γ-functionalization and α-bromofunctionalization were successfully carried out in selected cases.
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Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka, 599-8531, Japan
| | - Tomohiro Nishikawa
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka, 599-8531, Japan
| | - Keiichi Yamada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka, 599-8531, Japan
| | - Davide Ravelli
- 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
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka, 599-8531, Japan.,Department of Applied Chemistry, National Chiao Tung University , Hsinchu, Taiwan
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25
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Yamada K, Fukuyama T, Fujii S, Ravelli D, Fagnoni M, Ryu I. Cooperative Polar/Steric Strategy in Achieving Site-Selective Photocatalyzed C(sp 3 )-H Functionalization. Chemistry 2017; 23:8615-8618. [PMID: 28466481 DOI: 10.1002/chem.201701865] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Indexed: 11/10/2022]
Abstract
Synergistic control over the SH 2 transition states of hydrogen abstraction exploiting polar and steric effects provides a promising cooperative strategy for site-selective C(sp3 )-H functionalization using decatungstate anion photocatalysis. By using this photocatalytic approach, the C-H bonds of substituted lactones and cyclic ketones were functionalized selectively. In the remarkable case of 2-isoamyl 4-tert-butyl cyclohexanone (1 t) bearing five methyl, five methylene, and three methine C-H bonds, one methine C-H bond in the isoamyl tether was selectively functionalized.
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Affiliation(s)
- Keiichi Yamada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Saki Fujii
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Davide Ravelli
- PhotoGreen Laboratory, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100, Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Laboratory, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100, Pavia, Italy
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan.,Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
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26
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Zhou R, Liu H, Tao H, Yu X, Wu J. Metal-free direct alkylation of unfunctionalized allylic/benzylic sp 3 C-H bonds via photoredox induced radical cation deprotonation. Chem Sci 2017; 8:4654-4659. [PMID: 28970885 PMCID: PMC5618257 DOI: 10.1039/c7sc00953d] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 04/27/2017] [Indexed: 12/25/2022] Open
Abstract
Despite notable recent efforts, a catalytic and convenient strategy for the direct alkylation of unactivated allylic or benzylic sp3 C-H bonds remains a formidable challenge facing the synthesis community. We herein report an unprecedented allylic/benzylic alkylation using only an organo-photoredox catalyst, which enables coupling of a broad scope of alkenes/arenes and electron-deficient alkenes in an atom- and redox-economic manner. A photoredox induced alkene/arene radical cation deprotonation is proposed to smoothly generate the key allylic and benzylic radical intermediates. It represents the first C-C bond formation via radical cation deprotonation under visible light conditions. The resulting products can be easily scaled up and directly converted to γ,δ-unsaturated or α,β-diaryl-acids, -esters, -amides, -pyrazoles, -isoxazoles, as well as lactones, which enables this mild and selective sp3 C-H alkylation to rapidly access complex bioactive molecules.
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Affiliation(s)
- Rong Zhou
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , 117543 , Republic of Singapore .
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan , 030024 , China
| | - Haiwang Liu
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , 117543 , Republic of Singapore .
| | - Hairong Tao
- College of Chemistry , Beijing Normal University , Beijing , China
| | - Xingjian Yu
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , 117543 , Republic of Singapore .
| | - Jie Wu
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , 117543 , Republic of Singapore .
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27
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Lazzaroni S, Ravelli D, Protti S, Fagnoni M, Albini A. Photochemical synthesis: Using light to build C–C bonds under mild conditions. CR CHIM 2017. [DOI: 10.1016/j.crci.2015.11.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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28
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Ravelli D, Protti S, Fagnoni M. Decatungstate Anion for Photocatalyzed "Window Ledge" Reactions. Acc Chem Res 2016; 49:2232-2242. [PMID: 27648722 DOI: 10.1021/acs.accounts.6b00339] [Citation(s) in RCA: 189] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The majority of organic reactions are commonly carried out inside a lab, under a fume hood. A particular case is that of photochemical reactions, a field where the pioneering experiments by Giacomo Ciamician demonstrated more than one century ago that different processes can be carried out outdoors, for example, on the balcony of his own department, upon exposure of the reacting mixtures to sunlight. The main problem related to this chemistry of the "window ledge" is that most organic compounds are colorless and their absorption in the solar light region is in most cases negligible. Recently, the impressive development in the use of visible light absorbing photocatalysts (e.g., RuII or IrIII complexes, as well as organic dyes) made light-induced processes convenient even for non-photochemistry practitioners. It is thus possible to easily perform the reactions by simply placing the reaction vessel in a sunny place outside the lab. However, most of these processes are based on single electron transfer (SET) reactions (photoredox catalysis). Other photocatalysts able to activate substrates via alternative paths, such as hydrogen atom transfer (HAT), are emerging. In the last years, we were deeply involved in the use of the decatungstate anion ([W10O32]4-, a polyoxometalate) in synthesis. Indeed, such a versatile species is able to promote the photocatalytic C-H activation of organic compounds via either SET or HAT reactions. Interestingly, though the absorption spectrum of [W10O32]4- does not extend into the visible region, it shows an overlap with solar light emission. In this Account, we provide an overview on the application of decatungstate salts as photocatalysts in window ledge chemistry. We initially discuss the nature of the photogenerated species involved in the mechanism of action of the anion, also supported by theoretical simulations. The first-formed excited state of the decatungstate anion decays rapidly to the active species, a dark state tagged wO, featuring the presence of electron-deficient oxygen centers. Next, we describe the main applications of decatungstate chemistry. A significant part of this Account is devoted to photocatalyzed synthesis (C-X bond formation, with X = C, N, O, and oxidations) carried out by adopting sunlight (or simulated solar light). This synthetic approach is versatile, and most of the reactions involved C-H activation in cycloalkanes, alkylaromatics, amides, ethers (1,4-dioxane, oxetane, benzodioxole, and THF), aldehydes, nitriles, and cyclopentanones, and the ensuing addition of the resulting radicals onto electron-deficient olefins. Finally, the increasing role of the decatungstate anion in water depollution and polymerization is briefly discussed.
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Affiliation(s)
- Davide Ravelli
- 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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29
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Capaldo L, Buzzetti L, Merli D, Fagnoni M, Ravelli D. Smooth Photocatalyzed Benzylation of Electrophilic Olefins via Decarboxylation of Arylacetic Acids. J Org Chem 2016; 81:7102-9. [DOI: 10.1021/acs.joc.6b00984] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Luca Capaldo
- PhotoGreen Lab, Department
of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Luca Buzzetti
- PhotoGreen Lab, Department
of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Daniele Merli
- 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
| | - Davide Ravelli
- PhotoGreen Lab, Department
of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
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30
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Ravelli D, Protti S, Fagnoni M. Carbon–Carbon Bond Forming Reactions via Photogenerated Intermediates. Chem Rev 2016; 116:9850-913. [DOI: 10.1021/acs.chemrev.5b00662] [Citation(s) in RCA: 724] [Impact Index Per Article: 90.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Davide Ravelli
- Department
of Chemistry, Photogreen Lab, University of Pavia, Viale Taramelli
12, 27100 Pavia, Italy
| | - Stefano Protti
- Department
of Chemistry, Photogreen Lab, University of Pavia, Viale Taramelli
12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- Department
of Chemistry, Photogreen Lab, University of Pavia, Viale Taramelli
12, 27100 Pavia, Italy
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31
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Xie R, Fan G, Yang L, Li F. Highly Efficient Hybrid Cobalt-Copper-Aluminum Layered Double Hydroxide/Graphene Nanocomposites as Catalysts for the Oxidation of Alkylaromatics. ChemCatChem 2015. [DOI: 10.1002/cctc.201500890] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Renfeng Xie
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; P. O. BOX 98 Beijing 100029 P.R. China
| | - Guoli Fan
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; P. O. BOX 98 Beijing 100029 P.R. China
| | - Lan Yang
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; P. O. BOX 98 Beijing 100029 P.R. China
| | - Feng Li
- State Key Laboratory of Chemical Resource Engineering; Beijing University of Chemical Technology; P. O. BOX 98 Beijing 100029 P.R. China
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32
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Bonassi F, Ravelli D, Protti S, Fagnoni M. Decatungstate Photocatalyzed Acylations and Alkylations in Flow viaHydrogen Atom Transfer. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500483] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Okada M, Yamada K, Fukuyama T, Ravelli D, Fagnoni M, Ryu I. Photocatalytic One-Pot Synthesis of Homoallyl Ketones via a Norrish Type I Reaction of Cyclopentanones. J Org Chem 2015; 80:9365-9. [DOI: 10.1021/acs.joc.5b01850] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Megumi Okada
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Keiichi Yamada
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takahide Fukuyama
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Davide Ravelli
- 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
| | - Ilhyong Ryu
- Department
of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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34
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Qrareya H, Dondi D, Ravelli D, Fagnoni M. Decatungstate-Photocatalyzed Si−H/C−H Activation in Silyl Hydrides: Hydrosilylation of Electron-Poor Alkenes. ChemCatChem 2015. [DOI: 10.1002/cctc.201500562] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hisham Qrareya
- PhotoGreen Lab; Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Daniele Dondi
- Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Davide Ravelli
- 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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35
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Protti S, Fagnoni M, Ravelli D. Photocatalytic CH Activation by Hydrogen-Atom Transfer in Synthesis. ChemCatChem 2015. [DOI: 10.1002/cctc.201500125] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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36
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Yamada K, Okada M, Fukuyama T, Ravelli D, Fagnoni M, Ryu I. Photocatalyzed site-selective C-H to C-C conversion of aliphatic nitriles. Org Lett 2015; 17:1292-5. [PMID: 25692554 DOI: 10.1021/acs.orglett.5b00282] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
β- or γ-Site-selective C-H alkylation of aliphatic nitriles has been achieved using a decatungstate salt as the photocatalyst. The observed site selectivity was justified by a radical polar effect in transition states for hydrogen abstraction.
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Affiliation(s)
- Keiichi Yamada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University , Sakai, Osaka 599-8531, Japan
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37
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Okada M, Fukuyama T, Yamada K, Ryu I, Ravelli D, Fagnoni M. Sunlight photocatalyzed regioselective β-alkylation and acylation of cyclopentanones. Chem Sci 2014. [DOI: 10.1039/c4sc01072h] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Visible light induced direct β-C–H/C–C conversion of cyclopentanones was accomplished by using tetrabutylammonium decatungstate, TBADT, as the photocatalyst.
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Affiliation(s)
- Megumi Okada
- Department of Chemistry
- Graduate School of Science Osaka Prefecture University
- Sakai, Japan
| | - Takahide Fukuyama
- Department of Chemistry
- Graduate School of Science Osaka Prefecture University
- Sakai, Japan
| | - Keiichi Yamada
- Department of Chemistry
- Graduate School of Science Osaka Prefecture University
- Sakai, Japan
| | - Ilhyong Ryu
- Department of Chemistry
- Graduate School of Science Osaka Prefecture University
- Sakai, Japan
| | - Davide Ravelli
- PhotoGreen Lab
- Department of Chemistry
- University of Pavia
- 27100 Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab
- Department of Chemistry
- University of Pavia
- 27100 Pavia, Italy
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