201
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Zheng X, Liu J, Ye CX, Wang A, Wang AE, Huang PQ. SmI2-Mediated Radical Coupling Strategy to Securinega Alkaloids: Total Synthesis of (−)-14,15-Dihydrosecurinine and Formal Total Synthesis of (−)-Securinine. J Org Chem 2014; 80:1034-41. [DOI: 10.1021/jo502522x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiao Zheng
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
- Key
Laboratory of Synthetic Chemistry of Natural Substances, Shanghai
Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Juan Liu
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Chen-Xi Ye
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Ao Wang
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Ai-E Wang
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Pei-Qiang Huang
- Department
of Chemistry and The Key Laboratory for Chemical Biology of Fujian
Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
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202
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Suizu H, Shigeoka D, Aoyama H, Yoshimitsu T. Total Synthesis of Clavilactone B: A Radical Cyclization–Fragmentation Strategy. Org Lett 2014; 17:126-9. [DOI: 10.1021/ol503356m] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Hiroshi Suizu
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6
Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Daisuke Shigeoka
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6
Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroshi Aoyama
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6
Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takehiko Yoshimitsu
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6
Yamadaoka, Suita, Osaka 565-0871, Japan
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203
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Yalavac I, Lyons SE, Webb MR, Procter DJ. SmI2-H2O-mediated 5-exo/6-exo lactone radical cyclisation cascades. Chem Commun (Camb) 2014; 50:12863-6. [PMID: 25211167 DOI: 10.1039/c4cc05404k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The SmI2-H2O reagent system mediates challenging 5-exo/6-exo lactone radical cascade cyclisations that deliver carbo[5.4.0]bicyclic motifs in a diastereoselective, one-pot process that establish two new carbocyclic rings and four stereocentres.
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Affiliation(s)
- Irem Yalavac
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
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204
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Szostak M, Spain M, Eberhart AJ, Procter DJ. Mechanism of SmI2/Amine/H2O-Promoted Chemoselective Reductions of Carboxylic Acid Derivatives (Esters, Acids, and Amides) to Alcohols. J Org Chem 2014; 79:11988-2003. [DOI: 10.1021/jo5018525] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Michal Szostak
- Department
of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Malcolm Spain
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Andrew J. Eberhart
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - David J. Procter
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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205
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Chciuk TV, Hilmersson G, Flowers RA. Solvent-Dependent Substrate Reduction by {Sm[N(SiMe3)2]2(THF)2}. An Alternative Approach for Accelerating the Rate of Substrate Reduction by Sm(II). J Org Chem 2014; 79:9441-3. [DOI: 10.1021/jo501819z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Tesia V. Chciuk
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Göran Hilmersson
- Department
of Chemistry, University of Gothenburg, Kemivägen 10, SE-412 96 Göteborg, Sweden
| | - Robert A. Flowers
- Department
of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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206
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Streuff J. Reductive umpolung reactions with low-valent titanium catalysts. CHEM REC 2014; 14:1100-13. [PMID: 25234255 DOI: 10.1002/tcr.201402058] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Indexed: 12/24/2022]
Abstract
The coupling of similarly polarized carbon fragments can be achieved by a reductive umpolung strategy. This gives access to compounds with functional groups in even bond distances, which are difficult to synthesize by other means. Low-valent titanium catalysts enable such couplings under mild conditions. This account covers the recent progress on this topic with a focus on the development of cross-selective coupling reactions and stereoselective examples.
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Affiliation(s)
- Jan Streuff
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, D-79104, Freiburg, Germany.
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207
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Abstract
The concise total synthesis of aplykurodinone-1 with an unusual cis-fused hydrindane moiety has been accomplished without the need for any protecting group chemistry using a unique SmI2 mediated reductive cascade cyclization reaction and a direct cuprate mediated 1,4-addition. This work represents the first example of the use of a SmI2-mediated intramolecular cascade cyclization reaction between "halide, alkene and aldehyde" groups.
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Affiliation(s)
- Gang Liu
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School , Shenzhen 518055, China
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208
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Yella R, Hoz S. Channeling the SmI2 Reactions to the Radical Path: Radicals Resisting Reduction by SmI2. Org Lett 2014; 16:3876-9. [PMID: 25030208 DOI: 10.1021/ol501490f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ramesh Yella
- Department
of Chemistry, Bar-Illan University, Ramat-Gan 52900, Israel
| | - Shmaryahu Hoz
- Department
of Chemistry, Bar-Illan University, Ramat-Gan 52900, Israel
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209
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Abstract
As a potent neurotrophic agent, the sesquiterpenoid jiadifenolide represents a valuable small-molecule lead for the potential therapeutic treatment of neurodegenerative diseases. A stereocontrolled total synthesis of this densely functionalized natural product is reported, central to which is an adventurous samarium-mediated cyclization reaction to establish the tricyclic core and the adjacent C5 and C6 quaternary stereocenters.
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Affiliation(s)
- Ian Paterson
- University Chemical Laboratory, University of CambridgeLensfield Road, Cambridge, CB2 1EW (UK)Homepage: http://www.paterson.ch.cam.ac.uk/
| | - Mengyang Xuan
- University Chemical Laboratory, University of CambridgeLensfield Road, Cambridge, CB2 1EW (UK)Homepage: http://www.paterson.ch.cam.ac.uk/
| | - Stephen M Dalby
- Department of Process Chemistry, Merck & CoPO Box 2000, Rahway, NJ 07065 (USA)
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210
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Yoshimura A, Tomisaka Y, Li Z, Nomoto A, Ogawa A. Photoinduced Reductive Coupling of Organochlorosilanes with SmI2/Sm. HETEROATOM CHEMISTRY 2014. [DOI: 10.1002/hc.21186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Aya Yoshimura
- Department of Applied Chemistry; Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Yuri Tomisaka
- Department of Applied Chemistry; Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Zhifang Li
- Key Laboratory of Organosilicon Chemistry; Hangzhou Normal University; Hangzhou 310012 People's Republic of China
| | - Akihiro Nomoto
- Department of Applied Chemistry; Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
| | - Akiya Ogawa
- Department of Applied Chemistry; Graduate School of Engineering; Osaka Prefecture University; Sakai Osaka 599-8531 Japan
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211
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A unified strategy for the synthesis of (−)-maoecrystal Z, (−)-trichorabdal A, and (−)-longikaurin E. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.03.071] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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212
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Sun L, Mellah M. Efficient Electrosynthesis of SmCl2, SmBr2, and Sm(OTf)2 from a “Sacrificial” Samarium Anode: Effect of nBu4NPF6 on the Reactivity. Organometallics 2014. [DOI: 10.1021/om500222a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Linhao Sun
- Equipe
de Catalyse Moléculaire, University Paris-Sud, ICMMO, UMR 8182, Orsay, F-91405 France
| | - Mohamed Mellah
- Equipe
de Catalyse Moléculaire, University Paris-Sud, ICMMO, UMR 8182, Orsay, F-91405 France
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213
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Affiliation(s)
- Ian Paterson
- University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK) http://www.paterson.ch.cam.ac.uk/
| | - Mengyang Xuan
- University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK) http://www.paterson.ch.cam.ac.uk/
| | - Stephen M. Dalby
- Department of Process Chemistry, Merck & Co, PO Box 2000, Rahway, NJ 07065 (USA)
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214
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Ghosh T, Maity S, Prasad E. Rate and Mechanistic Investigation of Eu(OTf)2-Mediated Reduction of Graphene Oxide at Room Temperature. J Phys Chem B 2014; 118:5524-31. [DOI: 10.1021/jp501994k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tufan Ghosh
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Sandeepan Maity
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Edamana Prasad
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
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215
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Le TX, Papin C, Doisneau G, Beau JM. Direct Umpolung of Glycals and Related 2,3-UnsaturatedN-Acetylneuraminic Acid Derivatives Using Samarium Diiodide. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402891] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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216
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Le TX, Papin C, Doisneau G, Beau JM. Direct Umpolung of Glycals and Related 2,3-UnsaturatedN-Acetylneuraminic Acid Derivatives Using Samarium Diiodide. Angew Chem Int Ed Engl 2014; 53:6184-7. [DOI: 10.1002/anie.201402891] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 03/27/2014] [Indexed: 11/10/2022]
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217
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Szostak M, Fazakerley NJ, Parmar D, Procter DJ. Cross-Coupling Reactions Using Samarium(II) Iodide. Chem Rev 2014; 114:5959-6039. [DOI: 10.1021/cr400685r] [Citation(s) in RCA: 290] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Michal Szostak
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Neal J. Fazakerley
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Dixit Parmar
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - David J. Procter
- School
of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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218
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Zhang N, Samanta SR, Rosen BM, Percec V. Single Electron Transfer in Radical Ion and Radical-Mediated Organic, Materials and Polymer Synthesis. Chem Rev 2014; 114:5848-958. [DOI: 10.1021/cr400689s] [Citation(s) in RCA: 320] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Na Zhang
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Shampa R. Samanta
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Brad M. Rosen
- DuPont Titanium Technologies, Chestnut Run Plaza, Wilmington, Delaware 19805, United States
| | - Virgil Percec
- Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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219
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Abstract
Chemists have long aspired to synthesize molecules the way that plants do-using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light-absorbing transition metal complexes to catalyze a broad range of synthetically valuable reactions. In this review, we highlight how an understanding of the mechanisms of photocatalytic activation available to these transition metal complexes, and of the general reactivity patterns of the intermediates accessible via visible light photocatalysis, has accelerated the development of this diverse suite of reactions.
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Affiliation(s)
- Danielle M Schultz
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
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220
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Szostak M, Spain M, Procter DJ. On the role of pre- and post-electron-transfer steps in the SmI2 /amine/H(2)O-mediated reduction of esters: new mechanistic insights and kinetic studies. Chemistry 2014; 20:4222-6. [PMID: 24615806 PMCID: PMC4497321 DOI: 10.1002/chem.201400295] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Indexed: 02/02/2023]
Abstract
The mechanism of the SmI2 -mediated reduction of unactivated esters has been studied using a combination of kinetic, radical clocks and reactivity experiments. The kinetic data indicate that all reaction components (SmI2 , amine, H2 O) are involved in the rate equation and that electron transfer is facilitated by Brønsted base assisted deprotonation of water in the transition state. The use of validated cyclopropyl-containing radical clocks demonstrates that the reaction occurs via fast, reversible first electron transfer, and that the electron transfer from simple Sm(II) complexes to aliphatic esters is rapid. Notably, the mechanistic details presented herein indicate that complexation between SmI2 , H2 O and amines affords a new class of structurally diverse, thermodynamically powerful reductants for efficient electron transfer to carboxylic acid derivatives as an attractive alternative to the classical hydride-mediated reductions and as a source of acyl-radical equivalents for CC bond forming processes.
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Affiliation(s)
- Michal Szostak
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK), Fax: (+44) 161-275-4939
| | - Malcolm Spain
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK), Fax: (+44) 161-275-4939
| | - David J Procter
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK), Fax: (+44) 161-275-4939
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221
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Cheng H, Zeng FH, Ma D, Jiang ML, Xu L, Wang FP. Expedient construction of the ABEF azatetracyclic ring systems of lycoctonine-type and 7,17-seco-type C₁₉-diterpenoid alkaloids. Org Lett 2014; 16:2299-301. [PMID: 24701960 DOI: 10.1021/ol500726x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A synthetic strategy for the modeling construction of the highly bridged azatetracyclic ABEF ring system of numerous lycoctonine-type C19-diterpenoid alkaloids bearing a characteristic oxygenated quaternary center at C-7 has been successfully developed. The tetracyclic core was constructed rapidly from a readily prepared 6,7-bicyclic AB ring precursor through a 13-step sequence via an advanced tetracyclic N,O-acetal intermediate, which belong to another core structure of natural 7,17-seco-type alkaloids. The key step involves an SmI2-promoted intramolecular radical coupling reaction of an N,O-acetal with a carbonyl group, mimicking a plausible biogenetic transformation.
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Affiliation(s)
- Hang Cheng
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, Department of Chemistry of Medicinal Natural Products, West China School of Pharmacy, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University , Chengdu 610041, China
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222
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223
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Szostak M, Spain M, Procter DJ. Determination of the Effective Redox Potentials of SmI2, SmBr2, SmCl2, and their Complexes with Water by Reduction of Aromatic Hydrocarbons. Reduction of Anthracene and Stilbene by Samarium(II) Iodide–Water Complex. J Org Chem 2014; 79:2522-37. [DOI: 10.1021/jo4028243] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Michal Szostak
- School of Chemistry, University of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
| | - Malcolm Spain
- School of Chemistry, University of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
| | - David J. Procter
- School of Chemistry, University of Manchester, Oxford
Road, Manchester M13 9PL, United Kingdom
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224
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Halder S, Hoz S. Hydroxylated HMPA Enhances both Reduction Potential and Proton Donation in SmI2 Reactions. J Org Chem 2014; 79:2682-7. [DOI: 10.1021/jo500161s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sandipan Halder
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Shmaryahu Hoz
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel
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225
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Endoma-Arias MAA, Hudlicky JR, Simionescu R, Hudlicky T. Chemoenzymatic Formal Total Synthesis ofent-Codeine and Other MorphinansviaNitrone Cycloadditions and/or Radical Cyclizations. Comparison of Strategies for Control of C-9/C-14 Stereogenic Centers. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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226
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Szostak M, Sautier B, Spain M, Procter DJ. Electron transfer reduction of nitriles using SmI2-Et3N-H2O: synthetic utility and mechanism. Org Lett 2014; 16:1092-5. [PMID: 24494855 DOI: 10.1021/ol403668e] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The first general reduction of nitriles to primary amines under single electron transfer conditions is demonstrated using SmI2 (Kagan's reagent) activated with Lewis bases. The reaction features excellent functional group tolerance and represents an attractive alternative to the use of pyrophoric alkali metal hydrides. Notably, the electron transfer from Sm(II) to CN functional groups generates imidoyl-type radicals from bench stable nitrile precursors.
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Affiliation(s)
- Michal Szostak
- School of Chemistry, University of Manchester , Oxford Road, Manchester, M13 9PL, U.K
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227
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Xu J, Lacoske MH, Theodorakis EA. Neurotrophic natural products: chemistry and biology. Angew Chem Int Ed Engl 2014; 53:956-87. [PMID: 24353244 PMCID: PMC3945720 DOI: 10.1002/anie.201302268] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases and spinal cord injury affect approximately 50 million people worldwide, bringing the total healthcare cost to over 600 billion dollars per year. Nervous system growth factors, that is, neurotrophins, are a potential solution to these disorders, since they could promote nerve regeneration. An average of 500 publications per year attests to the significance of neurotrophins in biomedical sciences and underlines their potential for therapeutic applications. Nonetheless, the poor pharmacokinetic profile of neurotrophins severely restricts their clinical use. On the other hand, small molecules that modulate neurotrophic activity offer a promising therapeutic approach against neurological disorders. Nature has provided an impressive array of natural products that have potent neurotrophic activities. This Review highlights the current synthetic strategies toward these compounds and summarizes their ability to induce neuronal growth and rehabilitation. It is anticipated that neurotrophic natural products could be used not only as starting points in drug design but also as tools to study the next frontier in biomedical sciences: the brain activity map project.
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Affiliation(s)
- Jing Xu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0358 (USA), Homepage: http://theodorakisgroup.ucsd.edu
| | - Michelle H. Lacoske
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0358 (USA), Homepage: http://theodorakisgroup.ucsd.edu
| | - Emmanuel A. Theodorakis
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0358 (USA), Homepage: http://theodorakisgroup.ucsd.edu
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228
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Abstract
![]()
A redox-economic
method for the direct coupling of olefins that
uses an inexpensive iron catalyst and a silane reducing agent is reported.
Thus, unactivated olefins can be joined directly to electron-deficient
olefins in both intra- and intermolecular settings to generate hindered
bicyclic systems, vicinal quaternary centers, and even cyclopropanes
in good yield. The reaction is not sensitive to oxygen or moisture
and has been performed on gram-scale. Most importantly, it allows
access to many compounds that would be difficult or perhaps impossible
to access using other methods.
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Affiliation(s)
- Julian C Lo
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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229
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Affiliation(s)
- Fabrice Dénès
- Laboratoire CEISAM UMR CNRS 6230 - UFR des Sciences et Techniques, Université de Nantes , 2 rue de la Houssinière, BP 92208 - 44322 Nantes Cedex 3, France
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230
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Szostak M, Sautier B, Procter DJ. Structural analysis and reactivity of unusual tetrahedral intermediates enabled by SmI2-mediated reduction of barbituric acids: vinylogous N-acyliminium additions to α-hydroxy-N-acyl-carbamides. Chem Commun (Camb) 2014; 50:2518-21. [DOI: 10.1039/c3cc48932a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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231
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Szostak M, Lyons SE, Spain M, Procter DJ. Mechanistic investigation of the selective reduction of Meldrum's acids to β-hydroxy acids using SmI2and H2O. Chem Commun (Camb) 2014; 50:8391-4. [DOI: 10.1039/c4cc03216k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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232
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Takemoto Y, Tsukano C. Synthetic Approaches to Spiro-oxindoles and Iminoindolines Based on Formation of C2–C3 Bond. HETEROCYCLES 2014. [DOI: 10.3987/rev-14-805] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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233
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Maity S, Prasad E. Photoinduced electron transfer from Eu(II)-complexes to organic molecules: Rate and mechanistic investigation. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2013.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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234
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Szostak M, Sautier B, Procter DJ. Stereoselective Capture of N-Acyliminium Ions Generated from α-Hydroxy-N-acylcarbamides: Direct Synthesis of Uracils from Barbituric Acids Enabled by SmI2 Reduction. Org Lett 2013; 16:452-5. [DOI: 10.1021/ol403340j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Michal Szostak
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, U.K
| | - Brice Sautier
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, U.K
| | - David J. Procter
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, U.K
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235
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Xu J, Lacoske MH, Theodorakis EA. Neurotrophe Naturstoffe - ihre Chemie und Biologie. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201302268] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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236
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Szostak M, Sautier B, Spain M, Behlendorf M, Procter DJ. Selective reduction of barbituric acids using SmI2/H2O: synthesis, reactivity, and structural analysis of tetrahedral adducts. Angew Chem Int Ed Engl 2013; 52:12559-63. [PMID: 24123558 PMCID: PMC4065343 DOI: 10.1002/anie.201306484] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Michal Szostak
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | - Brice Sautier
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | | | | | - David J Procter
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
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237
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Beemelmanns C, Gross S, Reissig HU. Towards the Core Structure ofStrychnosAlkaloids Using Samarium Diiodide-Induced Reactions of Indole Derivatives. Chemistry 2013; 19:17801-8. [DOI: 10.1002/chem.201302795] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Indexed: 01/03/2023]
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238
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Tejedor D, Álvarez-Méndez SJ, López-Soria JM, Martín VS, García-Tellado F. A Robust and General Protocol for the Lewis-Base-Catalysed Reaction of Alcohols and Alkyl Propiolates. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301303] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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239
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The Orthoester Johnson-Claisen Rearrangement in the Synthesis of Bioactive Molecules, Natural Products, and Synthetic Intermediates - Recent Advances. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301033] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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240
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Sun L, Sahloul K, Mellah M. Use of Electrochemistry to Provide Efficient SmI2 Catalytic System for Coupling Reactions. ACS Catal 2013. [DOI: 10.1021/cs400587s] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Linhao Sun
- Laboratoire
de Catalyse Moléculaire,
UMR 8182− ICMMO, Université Paris Sud, Orsay F-91405, France
| | - Kamar Sahloul
- Laboratoire
de Catalyse Moléculaire,
UMR 8182− ICMMO, Université Paris Sud, Orsay F-91405, France
| | - Mohamed Mellah
- Laboratoire
de Catalyse Moléculaire,
UMR 8182− ICMMO, Université Paris Sud, Orsay F-91405, France
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241
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Szostak M, Sautier B, Spain M, Behlendorf M, Procter DJ. Selective Reduction of Barbituric Acids Using SmI2/H2O: Synthesis, Reactivity, and Structural Analysis of Tetrahedral Adducts. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201306484] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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242
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Yella R, Hoz S. Reduction of 4-Styrylpyridine by SmI2: An Inner Sphere Electron Tranfer Case Where the Binding Site Differs from the Reaction Center. Org Lett 2013; 15:5262-5. [DOI: 10.1021/ol402484j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Ramesh Yella
- Department of Chemistry, Bar-Illan University, Ramat-Gan 52900, Israel
| | - Shmaryahu Hoz
- Department of Chemistry, Bar-Illan University, Ramat-Gan 52900, Israel
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243
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Lu P, Gu Z, Zakarian A. Total synthesis of maoecrystal V: early-stage C-H functionalization and lactone assembly by radical cyclization. J Am Chem Soc 2013; 135:14552-5. [PMID: 24047444 DOI: 10.1021/ja408231t] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A total synthesis of the unusual ent-kaurane maoecrystal V is described. The synthesis strategy features a counterintuitive early disconnection of the lactone subunit to a polycyclic enol ether intermediate in order to preserve the central tetrahydrofuran ring until the beginning stages of the synthesis. This strategy enables an application of C-H functionalization at the early phase of the synthesis during the construction of a dihydrobenzofuran intermediate.
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Affiliation(s)
- Ping Lu
- Department of Chemistry and Biochemistry, University of California , Santa Barbara, California 93110-9510, United States
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244
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Breitler S, Carreira EM. Total Synthesis of (+)-Crotogoudin. Angew Chem Int Ed Engl 2013; 52:11168-71. [DOI: 10.1002/anie.201305822] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Indexed: 11/08/2022]
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245
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246
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Yeoman JTS, Mak VW, Reisman SE. A Unified Strategy to ent-Kauranoid Natural Products: Total Syntheses of (−)-Trichorabdal A and (−)-Longikaurin E. J Am Chem Soc 2013; 135:11764-7. [DOI: 10.1021/ja406599a] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- John T. S. Yeoman
- The Warren and Katharine Schlinger Laboratory for Chemistry
and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
91125, United States
| | - Victor W. Mak
- The Warren and Katharine Schlinger Laboratory for Chemistry
and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
91125, United States
| | - Sarah E. Reisman
- The Warren and Katharine Schlinger Laboratory for Chemistry
and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California
91125, United States
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247
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Santana AG, Paz NR, Francisco CG, Suárez E, González CC. Synthesis of Branched Iminosugars through a Hypervalent Iodine(III)-Mediated Radical-Polar Crossover Reaction. J Org Chem 2013; 78:7527-43. [DOI: 10.1021/jo401041s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Andrés G. Santana
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico Francisco Sánchez 3, 38206 La
Laguna, Tenerife, Spain
| | - Nieves R. Paz
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico Francisco Sánchez 3, 38206 La
Laguna, Tenerife, Spain
| | - Cosme G. Francisco
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico Francisco Sánchez 3, 38206 La
Laguna, Tenerife, Spain
| | - Ernesto Suárez
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico Francisco Sánchez 3, 38206 La
Laguna, Tenerife, Spain
| | - Concepción C. González
- Instituto de Productos Naturales y Agrobiología del CSIC, Avenida Astrofísico Francisco Sánchez 3, 38206 La
Laguna, Tenerife, Spain
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248
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Sautier B, Collins KD, Procter DJ. Development of an additive-controlled, SmI2-mediated stereoselective sequence: Telescoped spirocyclisation, lactone reduction and Peterson elimination. Beilstein J Org Chem 2013; 9:1443-7. [PMID: 23946841 PMCID: PMC3740502 DOI: 10.3762/bjoc.9.163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 06/28/2013] [Indexed: 11/27/2022] Open
Abstract
Studies on SmI2-mediated spirocyclisation and lactone reduction culminate in a telescoped sequence in which additives are used to “switch on” individual steps mediated by the electron transfer reagent. The sequence involves the use of two activated SmI2 reagent systems and a silicon stereocontrol element that exerts complete diastereocontrol over the cyclisation and is removed during the final stage of the sequence by Peterson elimination. The approach allows functionalised cyclopentanols containing two vicinal quaternary stereocentres to be conveniently prepared from simple starting materials.
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Affiliation(s)
- Brice Sautier
- University of Manchester, School of Chemistry, Oxford Road, Manchester M13 9PL, United Kingdom
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249
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Szostak M, Spain M, Procter DJ. Uncovering the importance of proton donors in TmI2-promoted electron transfer: facile C-N bond cleavage in unactivated amides. Angew Chem Int Ed Engl 2013; 52:7237-41. [PMID: 23828793 PMCID: PMC4265963 DOI: 10.1002/anie.201303178] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Michal Szostak
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | - Malcolm Spain
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | - David J Procter
- School of Chemistry, University of ManchesterOxford Road, Manchester M13 9PL (UK)
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250
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Tarantino KT, Liu P, Knowles RR. Catalytic ketyl-olefin cyclizations enabled by proton-coupled electron transfer. J Am Chem Soc 2013; 135:10022-5. [PMID: 23796403 DOI: 10.1021/ja404342j] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Concerted proton-coupled electron transfer is a key mechanism of substrate activation in biological redox catalysis. However, its applications in organic synthesis remain largely unexplored. Herein, we report the development of a new catalytic protocol for ketyl-olefin coupling and present evidence to support concerted proton-coupled electron transfer being the operative mechanism of ketyl formation. Notably, reaction outcomes were correctly predicted by a simple thermodynamic formalism relating the oxidation potentials and pKa values of specific Brønsted acid/reductant combinations to their capacity to act jointly as a formal hydrogen atom donor.
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Affiliation(s)
- Kyle T Tarantino
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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