201
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Zou YQ, Chen JR, Liu XP, Lu LQ, Davis RL, Jørgensen KA, Xiao WJ. Highly efficient aerobic oxidative hydroxylation of arylboronic acids: photoredox catalysis using visible light. Angew Chem Int Ed Engl 2011; 51:784-8. [PMID: 22161996 DOI: 10.1002/anie.201107028] [Citation(s) in RCA: 360] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Indexed: 11/08/2022]
Affiliation(s)
- You-Quan Zou
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, China
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202
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Zou YQ, Chen JR, Liu XP, Lu LQ, Davis RL, Jørgensen KA, Xiao WJ. Highly Efficient Aerobic Oxidative Hydroxylation of Arylboronic Acids: Photoredox Catalysis Using Visible Light. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201107028] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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203
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Maity S, Zhu M, Shinabery RS, Zheng N. Intermolecular [3+2] Cycloaddition of Cyclopropylamines with Olefins by Visible-Light Photocatalysis. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201106162] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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204
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Lin S, Ischay MA, Fry CG, Yoon TP. Radical cation Diels-Alder cycloadditions by visible light photocatalysis. J Am Chem Soc 2011; 133:19350-3. [PMID: 22032252 DOI: 10.1021/ja2093579] [Citation(s) in RCA: 297] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ruthenium(II) polypyridyl complexes promote the efficient radical cation Diels-Alder cycloaddition of electron-rich dienophiles upon irradiation with visible light. These reactions enable facile [4 + 2] cycloadditions that would be electronically mismatched under thermal conditions. Key to the success of this methodology is the availability of ligand-modified ruthenium complexes that enable rational tuning of the electrochemical properties of the catalyst without significantly perturbing the overall photophysical properties of the system.
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Affiliation(s)
- Shishi Lin
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
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205
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Zlotorzynska M, Sammis GM. Photoinduced electron-transfer-promoted redox fragmentation of N-alkoxyphthalimides. Org Lett 2011; 13:6264-7. [PMID: 22060120 DOI: 10.1021/ol202740w] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new photoinduced electron-transfer-promoted redox fragmentation of N-alkoxyphthalimides has been developed. Mechanistic experiments have established that this reaction proceeds through a unique concerted intramolecular fragmentation process. This distinctive mechanism imparts many synthetic advantages, which are highlighted in the redox fragmentation of various heterocyclic substrates.
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Affiliation(s)
- Maria Zlotorzynska
- Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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206
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Rueping M, Zhu S, Koenigs RM. Visible-light photoredox catalyzed oxidative Strecker reaction. Chem Commun (Camb) 2011; 47:12709-11. [PMID: 22041859 DOI: 10.1039/c1cc15643h] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An aerobic photocatalytic oxidative cyanation of tertiary amines providing valuable α-aminonitriles in good to excellent yields was developed. Mild reaction conditions and low catalyst loading are attractive features of the protocol.
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Affiliation(s)
- Magnus Rueping
- RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany.
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207
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Furst L, Narayanam JMR, Stephenson CRJ. Total synthesis of (+)-gliocladin C enabled by visible-light photoredox catalysis. Angew Chem Int Ed Engl 2011; 50:9655-9. [PMID: 21751318 PMCID: PMC3496252 DOI: 10.1002/anie.201103145] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Laura Furst
- Department of Chemistry, Boston University, Boston, MA 02215 (USA)
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208
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Tucker JW, Stephenson CRJ. Tandem Visible Light-Mediated Radical Cyclization–Divinylcyclopropane Rearrangement to Tricyclic Pyrrolidinones. Org Lett 2011; 13:5468-71. [DOI: 10.1021/ol202178t] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph W. Tucker
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
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209
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Rueping M, Leonori D, Poisson T. Visible light mediated azomethine ylide formation-photoredox catalyzed [3+2] cycloadditions. Chem Commun (Camb) 2011; 47:9615-7. [PMID: 21792444 DOI: 10.1039/c1cc13660g] [Citation(s) in RCA: 169] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of highly functionalised N-heterocycles has been achieved by the visible light mediated photoredox conversion of tertiary amines to azomethine ylides and their further reaction with maleimide derivatives as dipolarophiles.
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Affiliation(s)
- Magnus Rueping
- RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany.
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210
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Furst L, Narayanam JMR, Stephenson CRJ. Total Synthesis of (+)-Gliocladin C Enabled by Visible-Light Photoredox Catalysis. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201103145] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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211
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Rueping M, Zhu S, Koenigs RM. Photoredox catalyzed C-P bond forming reactions-visible light mediated oxidative phosphonylations of amines. Chem Commun (Camb) 2011; 47:8679-81. [PMID: 21720622 DOI: 10.1039/c1cc12907d] [Citation(s) in RCA: 247] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A visible light mediated, carbon-phosphorus bond forming reaction has been developed. With the use of a readily available photoredox catalyst, α-amino phosphonates were obtained in good yields under mild reaction conditions.
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Affiliation(s)
- Magnus Rueping
- RWTH Aachen University, Institute of Organic Chemistry, Landoltweg 1, D-52074 Aachen, Germany.
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212
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Teplý F. Photoredox catalysis by [Ru(bpy)3]2+ to trigger transformations of organic molecules. Organic synthesis using visible-light photocatalysis and its 20th century roots. ACTA ACUST UNITED AC 2011. [DOI: 10.1135/cccc2011078] [Citation(s) in RCA: 435] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Reactions triggered by light constitute a treasure trove of unique synthetic methods that are available to chemists. Photoinduced redox processes using visible light in conjunction with sensitizing dyes offer a great variety of catalytic transformations useful in the realm of organic synthesis. The recent literature amply shows that this preparative toolbox is expanding substantially. This review discusses historical and contemporary work in the area of photoredox catalysis with [Ru(bpy)3]2+. Elegant examples from the most recent literature document the importance of this fast developing area of research. The photoredox chemistry has also emerged as a promising bond-making and bond-breaking tool for chemical biology and materials chemistry. A review with 96 references.
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213
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Pham PV, Nagib DA, MacMillan DWC. Photoredox catalysis: a mild, operationally simple approach to the synthesis of α-trifluoromethyl carbonyl compounds. ANGEWANDTE CHEMIE (INTERNATIONAL ED. IN ENGLISH) 2011. [PMID: 21604347 DOI: 10.1002/anie.201101861.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Phong V Pham
- Merck Center for Catalysis at Princeton University, Princeton, NJ 08544-1009, USA
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214
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Zou YQ, Lu LQ, Fu L, Chang NJ, Rong J, Chen JR, Xiao WJ. Visible-light-induced oxidation/[3+2] cycloaddition/oxidative aromatization sequence: a photocatalytic strategy to construct pyrrolo[2,1-a]isoquinolines. Angew Chem Int Ed Engl 2011; 50:7171-5. [PMID: 21698733 DOI: 10.1002/anie.201102306] [Citation(s) in RCA: 366] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2011] [Indexed: 11/10/2022]
Affiliation(s)
- You-Quan Zou
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei, China
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215
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Zou YQ, Lu LQ, Fu L, Chang NJ, Rong J, Chen JR, Xiao WJ. Visible-Light-Induced Oxidation/[3+2] Cycloaddition/Oxidative Aromatization Sequence: A Photocatalytic Strategy To Construct Pyrrolo[2,1-a]isoquinolines. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201102306] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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216
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Abstract
We have discovered a photocatalytic intramolecular hetero-Diels-Alder reaction of tethered bis(enones). This transformation involves the intermediacy of an enone radical anion and constitutes the formal coupling of an electron-deficient heterodiene with an electronically mismatched enone dienophile. The diastereoselectivity and regioselectivity of the process are high, and the dihydropyran products are amenable to a variety of synthetically useful transformations.
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217
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Pham PV, Nagib DA, MacMillan DWC. Photoredox catalysis: a mild, operationally simple approach to the synthesis of α-trifluoromethyl carbonyl compounds. Angew Chem Int Ed Engl 2011; 50:6119-22. [PMID: 21604347 DOI: 10.1002/anie.201101861] [Citation(s) in RCA: 387] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Phong V Pham
- Merck Center for Catalysis at Princeton University, Princeton, NJ 08544-1009, USA
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218
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Pham PV, Nagib DA, MacMillan DWC. Photoredox Catalysis: A Mild, Operationally Simple Approach to the Synthesis of α-Trifluoromethyl Carbonyl Compounds. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101861] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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219
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Munro-Leighton C, Adduci LL, Becker JJ, Gagné MR. Oxidative Addition of Secondary C–X Bonds to Palladium(0): A Beneficial Anomeric Acceleration. Organometallics 2011. [DOI: 10.1021/om200221r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Colleen Munro-Leighton
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Laura L. Adduci
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Jennifer J. Becker
- U.S. Army Research Office, P.O. Box 12211, Research Triangle Park, North Carolina 27709, United States
| | - Michel R. Gagné
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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220
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Larraufie MH, Pellet R, Fensterbank L, Goddard JP, Lacôte E, Malacria M, Ollivier C. Visible-Light-Induced Photoreductive Generation of Radicals from Epoxides and Aziridines. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007571] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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221
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Larraufie MH, Pellet R, Fensterbank L, Goddard JP, Lacôte E, Malacria M, Ollivier C. Visible-light-induced photoreductive generation of radicals from epoxides and aziridines. Angew Chem Int Ed Engl 2011; 50:4463-6. [PMID: 21488137 DOI: 10.1002/anie.201007571] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/15/2011] [Indexed: 10/18/2022]
Affiliation(s)
- Marie-Hélène Larraufie
- UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 7201)-FR 2769, 4 place Jussieu, C. 229, 75005 Paris, France
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222
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Andrews RS, Becker JJ, Gagné MR. Investigating the Rate of Photoreductive Glucosyl Radical Generation. Org Lett 2011; 13:2406-9. [DOI: 10.1021/ol200644w] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Stephen Andrews
- University of North Carolina at Chapel Hill, Department of Chemistry, Chapel Hill, North Carolina 27599, United States, and U.S. Army Research Office, P.O. Box 12211, Research Triangle Park, North Carolina 27709, United States
| | - Jennifer J. Becker
- University of North Carolina at Chapel Hill, Department of Chemistry, Chapel Hill, North Carolina 27599, United States, and U.S. Army Research Office, P.O. Box 12211, Research Triangle Park, North Carolina 27709, United States
| | - Michel R. Gagné
- University of North Carolina at Chapel Hill, Department of Chemistry, Chapel Hill, North Carolina 27599, United States, and U.S. Army Research Office, P.O. Box 12211, Research Triangle Park, North Carolina 27709, United States
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223
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Nguyen JD, Tucker JW, Konieczynska MD, Stephenson CRJ. Intermolecular atom transfer radical addition to olefins mediated by oxidative quenching of photoredox catalysts. J Am Chem Soc 2011; 133:4160-3. [PMID: 21381734 PMCID: PMC3086499 DOI: 10.1021/ja108560e] [Citation(s) in RCA: 631] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Atom transfer radical addition of haloalkanes and α-halocarbonyls to olefins is efficiently performed with the photocatalyst Ir[(dF(CF(3))ppy)(2)(dtbbpy)]PF(6). This protocol is characterized by excellent yields, mild conditions, low catalyst loading, and broad scope. In addition, the atom transfer protocol can be used to quickly and efficiently introduce vinyl trifluoromethyl groups to olefins and access 1,1-cyclopropane diesters.
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Affiliation(s)
- John D. Nguyen
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
| | - Joseph W. Tucker
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
| | - Marlena D. Konieczynska
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
| | - Corey R. J. Stephenson
- Department of Chemistry and Center for Chemical Methodology and Library Development (CMLD-BU), Boston University, Boston, Massachusetts 02215
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224
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Tucker JW, Narayanam JMR, Shah PS, Stephenson CRJ. Oxidative photoredox catalysis: mild and selective deprotection of PMB ethers mediated by visible light. Chem Commun (Camb) 2011; 47:5040-2. [PMID: 21431223 DOI: 10.1039/c1cc10827a] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report an advancement in the application of visible light photoredox catalysts in the oxidation of electron-rich arenes resulting in the selective deprotection of para-methoxybenzyl (PMB) ethers. This method is highlighted by excellent functional group tolerance, protecting group orthogonality, mild reaction conditions and avoidance of stoichiometric redox byproducts.
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Affiliation(s)
- Joseph W Tucker
- Department of Chemistry and Center for Chemical Methodology and Library Development, Boston University, 590 Commonwealth Ave., Boston, MA, USA
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225
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Fries P, Halter D, Kleinschek A, Hartung J. Functionalized tetrahydrofurans from alkenols and olefins/alkynes via aerobic oxidation-radical addition cascades. J Am Chem Soc 2011; 133:3906-12. [PMID: 21348446 DOI: 10.1021/ja108403s] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aerobic oxidation of alkyl- and phenyl-substituted 4-pentenols (bishomoallyl alcohols), catalyzed by cobalt(II) complexes in solutions of γ-terpinene or cyclohexa-1,4-diene, stereoselectively gave tetrahydrofurylmethyl radicals. Cyclized radicals were trapped with monosubstituted olefins (e.g., acrylonitrile, methyl acrylate), (E)- and (Z)-1,2-diacceptor-substituted olefins (e.g., dimethyl fumarate, fumarodinitrile, N-phenyl maleic imide), and ester-substituted alkynes (e.g., ethyl propynoate). Oxidation-addition cascades thus furnished side-chain-substituted (CN, CO(2)R, COR, or SO(2)R) di- and trisubstituted tetrahydrofurans in stereoselective reactions (2,3-trans, 2,4-cis, and 2,5-trans). A diastereomerically pure bistetrahydrofuran was prepared in a cascade consisting of two aerobic oxidations, one alkyne addition, and one final H-atom transfer.
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Affiliation(s)
- Patrick Fries
- Fachbereich Chemie, Organische Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Strasse, D-67663 Kaiserslautern, Germany
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226
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Xie Z, Wang C, deKrafft KE, Lin W. Highly Stable and Porous Cross-Linked Polymers for Efficient Photocatalysis. J Am Chem Soc 2011; 133:2056-9. [DOI: 10.1021/ja109166b] [Citation(s) in RCA: 356] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhigang Xie
- Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Cheng Wang
- Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Kathryn E. deKrafft
- Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Wenbin Lin
- Department of Chemistry, CB#3290, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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227
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Lu Z, Shen M, Yoon TP. [3+2] cycloadditions of aryl cyclopropyl ketones by visible light photocatalysis. J Am Chem Soc 2011; 133:1162-4. [PMID: 21214249 DOI: 10.1021/ja107849y] [Citation(s) in RCA: 252] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a new method for the formal [3+2] reaction of aryl cyclopropyl ketones with olefins to generate highly substituted cyclopentane ring systems. The key initiation step in this process is the one-electron reduction of the ketone to the corresponding radical anion, which is accomplished using a photocatalytic system comprising Ru(bpy)(3)(2+), La(OTf)(3), and TMEDA.
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Affiliation(s)
- Zhan Lu
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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228
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Radicals in transition metal catalyzed reactions? transition metal catalyzed radical reactions? - a fruitful interplay anyway: part 2. Radical catalysis by group 8 and 9 elements. Top Curr Chem (Cham) 2011; 320:191-322. [PMID: 22143610 DOI: 10.1007/128_2011_285] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This review summarizes the current status of transition metal catalyzed reactions involving radical intermediates in organic chemistry. This part focuses on radical-based methods catalyzed by group 8 and group 9 metal complexes. Reductive and redox-neutral coupling methods catalyzed by low-valent metal complexes as well as catalytic oxidative C-C bond formations are reviewed.
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229
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Shimakoshi H, Nishi M, Tanaka A, Chikama K, Hisaeda Y. Photocatalytic function of a polymer-supported B12 complex with a ruthenium trisbipyridine photosensitizer. Chem Commun (Camb) 2011; 47:6548-50. [DOI: 10.1039/c1cc11970b] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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230
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Du J, Espelt LR, Guzei IA, Yoon TP. Photocatalytic Reductive Cyclizations of Enones: Divergent Reactivity of Photogenerated Radical and Radical Anion Intermediates. Chem Sci 2011; 2:2115-2119. [PMID: 22121471 PMCID: PMC3222952 DOI: 10.1039/c1sc00357g] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Photocatalytic reactions of enones using metal polypyridyl complexes proceed by very different reaction manifolds in the presence of either Lewis or Brønsted acid additives. Previous work from our lab demonstrated that photocatalytic [2+2] cycloadditions of enones required the presence of a Lewis acidic co-catalyst, presumably to activate the enone and stabilize the key radical anion intermediate. On the other hand, Brønsted acid activators alter this reactivity and instead promote reductive cyclization reactions of a variety of aryl and aliphatic enones via a neutral radical intermediate. These two distinct reactive intermediates give rise to transformations differing in the connectivity, stereochemistry, and oxidation state of their products. In addition, this reductive coupling method introduces a novel approach to the tin-free generation of β-ketoradicals that react with high diastereoselectivity and with the high functional group compatibility typical of radical cyclization reactions.
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Affiliation(s)
- Juana Du
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue, Madison, WI, 53706, USA
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