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Becerril-Jiménez F, Lussier T, Leblanc L, Eymard C, Dostie S, Prévost M, Guindon Y. Photoredox-Catalyzed Stereoselective Radical Reactions to Synthesize Nucleoside Analogues with a C2'-Stereogenic All-Carbon Quaternary Center. J Org Chem 2019; 84:14795-14804. [PMID: 31638391 DOI: 10.1021/acs.joc.9b02374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The design of novel nucleoside analogues bearing a C2' all-carbon quaternary center is described. The construction of this all-carbon stereogenic center involves the use of photoredox catalysis to initiate an intramolecular attack of a silyl-tethered vinyl functionality on a tertiary radical. Density functional theory calculations were performed to explore the origin of the high syn diastereoselectivity obtained through the preferred 5-exo-trig cyclization mode. The intramolecular vinyl addition also enables the preparation of the complementary configuration of the C2' all-carbon stereocenter when performed after lactonization.
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Affiliation(s)
- Fabiola Becerril-Jiménez
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada.,Department of Chemistry , Université de Montréal , Montréal , Québec H3C 3J7 , Canada
| | - Tommy Lussier
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada.,Department of Chemistry , Université de Montréal , Montréal , Québec H3C 3J7 , Canada
| | - Louis Leblanc
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada.,Department of Chemistry , Université de Montréal , Montréal , Québec H3C 3J7 , Canada
| | - Carla Eymard
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada.,Department of Chemistry , Université de Montréal , Montréal , Québec H3C 3J7 , Canada
| | - Starr Dostie
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada
| | - Michel Prévost
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada
| | - Yvan Guindon
- Bio-Organic Chemistry Laboratory , Institut de Recherches Cliniques de Montréal , Montréal , Québec H2W 1R7 , Canada.,Department of Chemistry , Université de Montréal , Montréal , Québec H3C 3J7 , Canada.,Department of Biochemistry, Microbiology and Immunology , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
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2
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Matsubara H, Kawamoto T, Fukuyama T, Ryu I. Applications of Radical Carbonylation and Amine Addition Chemistry: 1,4-Hydrogen Transfer of 1-Hydroxylallyl Radicals. Acc Chem Res 2018; 51:2023-2035. [PMID: 30137961 DOI: 10.1021/acs.accounts.8b00278] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
1,4-Hydrogen transfer from the 1-hydroxyallyl radical to give the enoxyl (α-keto) radical is an exothermic process with a high activation energy based on DFT calculations. The lack of experimental examples of such 1,4-H shift reactions lies in the difficulty of generating the 1-hydroxyallyl radical. We have shown that radical carbonylation of alkenyl radicals with CO followed by nucleophilic trapping of the carbonyl portion of the resulting radical by amines gives rise to 1-amino-substituted 1-hydroxyallyl radicals in situ. At the outset of this chemistry, we examined intramolecular trapping reactions via radical carbonylation of alkynylamines mediated by tributyltin hydride. Consequently, α-methylene lactams were obtained, for which the initially formed 1-amino-substituted 1-hydroxyallyl radical underwent a 1,4-H shift followed by subsequent β-scission, which led to the expulsion of a tributyltin radical. A competing pathway of the 1,4-H shift of 1-amino-substituted 1-hydroxyallyl radicals involving hydrogen abstraction was observed, which led to the formation of α-stannylmethylene lactams as a major byproduct. However, in contrast, when intermolecular trapping of α-ketenyl radicals by amines was carried out, the 1,4-H shift from the 1-amino-substituted 1-hydroxyallyl radical became the major pathway, which gave good yields of α,β-unsaturated amides. Thus, we were able to develop three-component reactions comprising terminal alkynes, CO, and amines that led to α,β-unsaturated amides via the 1,4-H shift reaction. DFT calculations support the observation that the 1,4-H shift is more facile when 1-hydroxyallyl radicals have both 1-amino and 3-tin substituents. The choice of substituents on the amine nitrogen is also important, since N-C bond cleavage via an SH2-type reaction can become a competing pathway. Such an unusual SH2-type reaction at the amine nitrogen is favored when the leaving alkyl radicals are stable, such as PhC(•)H(CH3) and t-Bu•. Interestingly, even nucleophilic attack of tertiary amines onto α-ketenyl radicals causes cleavage of the C-N bond. For this reaction, DFT calculations predict an indirect homolytic substitution mechanism involving expulsion of alkyl radicals through the zwitterionic radical intermediate arising from nucleophilic amine addition onto the α-ketenyl radical. In contrast, the carbonylation of aryl radicals, generated from aryl iodides, in the presence of amines gave aromatic carboxylic amides in good yields. It is proposed that radical anions originating from acyl radicals and amines undergo electron transfer to aryl iodides to give aminocarbonylation products.
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Affiliation(s)
- Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takuji Kawamoto
- 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
| | - 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 300, ROC
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3
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Meesin J, Pohmakotr M, Reutrakul V, Soorukram D, Leowanawat P, Saithong S, Kuhakarn C. TBAI/TBHP-Mediated Cascade Cyclization toward Sulfonylated Indeno[1,2-c]quinolines. Org Lett 2017; 19:6546-6549. [DOI: 10.1021/acs.orglett.7b03246] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jatuporn Meesin
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Manat Pohmakotr
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Vichai Reutrakul
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Darunee Soorukram
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Pawaret Leowanawat
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Saowanit Saithong
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry
(PERCH−CIC), Faculty of Science, Prince of Songkla University, Hat Yai, Songkla 90112, Thailand
| | - Chutima Kuhakarn
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH−CIC), Faculty of
Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
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4
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Mäsing F, Mardyukov A, Doerenkamp C, Eckert H, Malkus U, Nüsse H, Klingauf J, Studer A. Kontrollierte lichtvermittelte Synthese von Gold-Nanopartikeln über Norrish-Typ-I-Reaktion in photoaktiven Polymeren. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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5
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Mäsing F, Mardyukov A, Doerenkamp C, Eckert H, Malkus U, Nüsse H, Klingauf J, Studer A. Controlled Light-Mediated Preparation of Gold Nanoparticles by a Norrish Type I Reaction of Photoactive Polymers. Angew Chem Int Ed Engl 2015; 54:12612-7. [DOI: 10.1002/anie.201505133] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/20/2015] [Indexed: 12/22/2022]
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6
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Liu D, Liu C, Lei A. Carbon-Centered Radical Addition to C=X Bonds for C−X Bond Formation. Chem Asian J 2015; 10:2040-54. [DOI: 10.1002/asia.201500326] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Dong Liu
- College of Chemistry and Molecular Sciences; the Institute for Advanced Studies (IAS); Wuhan University; Wuhan, Hubei 430072 P.R. China
| | - Chao Liu
- College of Chemistry and Molecular Sciences; the Institute for Advanced Studies (IAS); Wuhan University; Wuhan, Hubei 430072 P.R. China
| | - Aiwen Lei
- College of Chemistry and Molecular Sciences; the Institute for Advanced Studies (IAS); Wuhan University; Wuhan, Hubei 430072 P.R. China
- National Research Center for Carbohydrate Synthesis; Jiangxi Normal University; Nanchang, Jiangxi 330022 P.R. China
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7
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Studer A, Curran DP. The electron is a catalyst. Nat Chem 2015; 6:765-73. [PMID: 25143210 DOI: 10.1038/nchem.2031] [Citation(s) in RCA: 506] [Impact Index Per Article: 56.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 07/03/2014] [Indexed: 12/23/2022]
Abstract
The electron is an efficient catalyst for conducting various types of radical cascade reaction that proceed by way of radical and radical ion intermediates. But because electrons are omnipresent, catalysis by electrons often passes unnoticed. In this Review, a simple analogy between acid/base catalysis and redox catalysis is presented. Conceptually, the electron is a catalyst in much the same way that a proton is a catalyst. The 'electron is a catalyst' paradigm unifies mechanistically an assortment of synthetic transformations that otherwise have little or no apparent relationship. Diverse radical cascades, including unimolecular radical substitution reactions (SRN1-type chemistry), base-promoted homolytic aromatic substitutions (BHAS), radical Heck-type reactions, radical cross-dehydrogenative couplings (CDC), direct arene trifluoromethylations and radical alkoxycarbonylations, can all be viewed as electron-catalysed reactions.
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Affiliation(s)
- Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Dennis P Curran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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8
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9
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Godin F, Prévost M, Gorelsky SI, Mochirian P, Nguyen M, Viens F, Guindon Y. Diastereoselective hydrogen-transfer reactions: an experimental and DFT study. Chemistry 2013; 19:9308-18. [PMID: 23733260 DOI: 10.1002/chem.201300377] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Indexed: 01/14/2023]
Abstract
Radical reductions of halogenated precursors bearing a heterocycle exo (α) to the carbon-centered radical proceed with enhanced anti-selectivity, a phenomenon that we termed "exocyclic effect". New experimental data and DFT calculations at the BHandHLYP/TZVP level demonstrate that the origin of the exocyclic effect is linked to the strain energy required for a radical intermediate to reach its reactive conformation at the transition state (ΔE(≠)(strain)). Furthermore, radical reductions of constrained THP systems indicate that high 2,3-anti inductions are reached only when the radical chain occupies an equatorial orientation. Hydride deliveries to different acyclic substrates and calculations also suggest that the higher anti-selectivities obtained with borinate intermediates are not related to the formation of a complex mimicking an exocycle. From a broader standpoint, this study reveals important conformational factors for reactions taking place at a center vicinal to a heterocycle or an α-alkoxy group.
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Affiliation(s)
- François Godin
- Département de Chimie, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec, H3C 3J7, Canada
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10
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Godin F, Prévost M, Viens F, Mochirian P, Brazeau JF, Gorelsky SI, Guindon Y. A Study of Exocyclic Radical Reductions of Polysubstituted Tetrahydropyrans. J Org Chem 2013; 78:6075-103. [DOI: 10.1021/jo400721e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- François Godin
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Michel Prévost
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Frédérick Viens
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Philippe Mochirian
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Jean-François Brazeau
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
| | - Serge I. Gorelsky
- Department of Chemistry and
Center for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, Canada K1N
6N5
| | - Yvan Guindon
- Institut de recherches cliniques de Montréal (IRCM), Bio-Organic Chemistry
Laboratory, 110 avenue des Pins Ouest, Montréal, Québec,
Canada H2W 1R7
- Département
de Chimie, Université de Montréal, C.P. 6128, succursale
Centre-ville, Montréal, Québec, Canada H3C 3J7
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal,
Québec, Canada H3A 2K6
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11
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Fukuyama T, Nakashima N, Okada T, Ryu I. Free-Radical-Mediated [2 + 2 + 1] Cycloaddition of Acetylenes, Amidines, and CO Leading to Five-Membered α,β-Unsaturated Lactams. J Am Chem Soc 2013; 135:1006-8. [DOI: 10.1021/ja312654q] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
| | - Nao Nakashima
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
| | - Takuma Okada
- 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
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12
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Neves AC, Aitken HM, Kyne SH, Fensterbank L, Lacôte E, Malacria M, Ollivier C, Schiesser CH. Intramolecular homolytic substitution of seleninates – a computational study. Tetrahedron 2012. [DOI: 10.1016/j.tet.2011.10.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Ryu I, Fukuyama T, Tojino M, Uenoyama Y, Yonamine Y, Terasoma N, Matsubara H. Radical carbonylation of ω-alkynylamines leading to α-methylene lactams. Synthetic scope and the mechanistic insights. Org Biomol Chem 2011; 9:3780-6. [DOI: 10.1039/c1ob05145h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Kyne SH, Aitken HM, Schiesser CH, Lacôte E, Malacria M, Ollivier C, Fensterbank L. Intramolecular homolytic substitution of sulfinates and sulfinamides – a computational study. Org Biomol Chem 2011; 9:3331-7. [DOI: 10.1039/c1ob05043e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kyne SH, Schiesser CH, Matsubara H. An ab initio and DFT study of radical addition reactions of imidoyl and thioyl radicals to methanimine. Org Biomol Chem 2011; 9:3217-24. [DOI: 10.1039/c1ob05105a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Nakayama R, Matsubara H, Fujino D, Kobatake T, Yoshida S, Yorimitsu H, Oshima K. Intermolecular Reductive Radical Addition to 2-(2,2,2-Trifluoroethylidene)-1,3-dithiane 1-Oxide: Experimental and Theoretical Studies. Org Lett 2010; 12:5748-51. [DOI: 10.1021/ol1025926] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryota Nakayama
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Matsubara
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Daishi Fujino
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takayuki Kobatake
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Suguru Yoshida
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Hideki Yorimitsu
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Koichiro Oshima
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan, Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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Amos RI, Smith JA, Yates BF, Schiesser CH. Acyl radical addition to benzene and related systems—a computational study. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.07.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Tran TA, Schiesser CH. Reactions of Acetyl Radical with Acetylene - A Computational Study. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.03.595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Fang X, Liu K, Li C. Efficient Regio- and Stereoselective Formation of Azocan-2-ones via 8-Endo Cyclization of α-Carbamoyl Radicals. J Am Chem Soc 2010; 132:2274-83. [DOI: 10.1021/ja9082649] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xinqiang Fang
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Kun Liu
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Chaozhong Li
- Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
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Ryu I, Kobayashi S, Hirao H, Kawauchi T. Novel Radical Cyclization Method Accompanied by Elimination of Hydrazyl Radical. HETEROCYCLES 2010. [DOI: 10.3987/com-09-s(s)115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Kyne SH, Lin CY, Ryu I, Coote ML, Schiesser CH. First determination of the rate constant for ring-closure of an azahexenoyl radical: 6-aza-7-ethyl-5-hexenoyl. Chem Commun (Camb) 2010; 46:6521-3. [DOI: 10.1039/c0cc01262a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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22
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23
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Horvat SM, Schiesser CH. Ab Initio and DFT Study of Homolytic Substitution Reactions of Acyl Radicals at Silicon, Germanium, and Tin. Organometallics 2009. [DOI: 10.1021/om801016x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sonia M. Horvat
- School of Chemistry, The University of Melbourne, Victoria, Australia, 3010, and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia, 3010
| | - Carl H. Schiesser
- School of Chemistry, The University of Melbourne, Victoria, Australia, 3010, and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia, 3010
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Abstract
All in one pot! Radical, radical-ionic, and radical-organometallic MCR are highly convergent processes, representing a useful pathway to molecular and structural diversity (see scheme). This concept article highlights recent developments in the field and shows the potential of the strategy for the economical elaboration of various kinds of organic substrates.Progress in multicomponent reactions (MCRs) based on ionic and organometallic processes has recently allowed the synthesis, with high efficiency, of large collections of drug-like molecules. In contrast, MCRs based on cascade radical reactions appear to have attracted, so far, much less interest. This concept article highlights the latest progress in the field and underlines the potential of such an approach. The collected examples demonstrate that radical and radical-ionic MCRs are highly convergent processes leading to useful structural diversity.
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Affiliation(s)
- Edouard Godineau
- University Bordeaux-1, Institut des Sciences Moléculaires, ISM-UMR 5255, 351, cours de la libération 33405 Talence Cedex, France
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25
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Kyne SH, Schiesser CH. Ab Initio Studies of Carbonyl Radical Additions to Hydrazone Systems. Aust J Chem 2009. [DOI: 10.1071/ch09165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ab initio and DFT calculations reveal that intermolecular radical additions of both acyl and oxyacyl radials to hydrazones occur through SOMO → π*hydrazone, πhydrazone → SOMO and LPN → SOMO interactions between the radical and the hydrazone π-system. Both acetyl and methoxycarbonyl radicals show preference for addition to the carbon end of the carbon–nitrogen π-bond. At the highest level of theory used in this study (G2//MP2(full)/6-31G*), energy barriers of 11.2 and 22.6 kJ mol–1 are calculated for acetyl radical addition to the carbon and nitrogen-ends of N-aminomethanimine respectively. The analogous energy barriers for the methoxycarbonyl radical are 4.9 and 25.7 kJ mol–1 at the same level of theory.
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Alonso R, Campos PJ, Rodríguez MA, Sampedro D. Photocyclization of Iminyl Radicals: Theoretical Study and Photochemical Aspects. J Org Chem 2008; 73:2234-9. [DOI: 10.1021/jo7025542] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rafael Alonso
- Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, Unidad Asociada al C.S.I.C., Madre de Dios, 51, 26006 Logroño, Spain
| | - Pedro J. Campos
- Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, Unidad Asociada al C.S.I.C., Madre de Dios, 51, 26006 Logroño, Spain
| | - Miguel A. Rodríguez
- Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, Unidad Asociada al C.S.I.C., Madre de Dios, 51, 26006 Logroño, Spain
| | - Diego Sampedro
- Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, Unidad Asociada al C.S.I.C., Madre de Dios, 51, 26006 Logroño, Spain
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Krenske EH, Schiesser CH. A comparison of orbital interactions in the additions of phosphonyl and acyl radicals to double bonds. Org Biomol Chem 2008; 6:854-9. [PMID: 18292876 DOI: 10.1039/b714597g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Calculation of the barriers for addition of the H2P(=O) and HC(=O) radicals to alkenes, at the CCSD(T)/aug-cc-pVDZ//BHandHLYP/6-311G** level, indicates that both radicals display ambiphilic behaviour. For the HC(=O) radical this behaviour occurs because a secondary orbital interaction of the type pi*(C=O)<--HOMO acts in conjunction with the primary SOMO<--HOMO interaction to balance the SOMO-->LUMO interaction. For the H2P(=O) radical, on the other hand, the much higher-lying LUMO (the sigma*P-O orbital) allows for only minimal secondary interaction, and this radical's ambiphilic behaviour is therefore reflective of a balance between SOMO-->LUMO and SOMO<--HOMO interactions.
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Affiliation(s)
- Elizabeth H Krenske
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, Australia.
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Kyne SH, Schiesser CH, Matsubara H. Multiorbital Interactions during Acyl Radical Addition Reactions Involving Imines and Electron-Rich Olefins. J Org Chem 2007; 73:427-34. [DOI: 10.1021/jo701825y] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sara H. Kyne
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Carl H. Schiesser
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Matsubara
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia, and Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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Yu YY, Fu Y, Xie M, Liu L, Guo QX. Controlling regioselectivity in cyclization of unsaturated amidyl radicals: 5-exo versus 6-endo. J Org Chem 2007; 72:8025-32. [PMID: 17887697 DOI: 10.1021/jo070146h] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intramolecular cyclization of an amidyl radical onto an olefin provides an appealing method for the synthesis of lactams and other nitrogen-containing heterocycles. Here we conducted the first, systematic theoretical study on the regioselectivity in the cyclization of various types of pent-4-enamidyl radicals that carried synthetically relevant substituents. It was found that the cyclization of most of the substituted pent-4-enamidyl radicals produced the 5-exo products (gamma-lactams) almost exclusively. Marcus theory analysis showed the involvement of both the thermodynamic (stabilization of the starting double bond or the resulting radical center) and intrinsic (mainly steric effects) contributions in determining the 5-exo selectivity. Nonetheless, in two types of systems we found that the delta-lactams became the favored products through the 6-endo cyclization. In one of the systems an aromatic substituent was placed at the C4-position, whereas in the other system an electron-rich aromatic ring was incorporated into the pent-4-enamidyl radical backbone at the C2- and C3-positions. This unprecedented 6-endo mode of amidyl radical cyclization provided an interesting route for the preparation of mono- and bicyclic delta-lactams (pyridinones).
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Affiliation(s)
- Yi-Yun Yu
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
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Schiesser CH, Wille U, Matsubara H, Ryu I. Radicals masquerading as electrophiles: dual orbital effects in nitrogen-philic acyl radical cyclization and related addition reactions. Acc Chem Res 2007; 40:303-13. [PMID: 17444607 DOI: 10.1021/ar600015v] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Free-radical chemistry has come a long way in a relatively short period of time. The synthetic practitioner takes for granted the wealth of mechanistic and rate constant data now available and can apply free-radical techniques to the synthesis of many different classes of target molecule with confidence. Despite this, there are still mechanistic anomalies that need to be addressed. This Account highlights recent work involving nucleophilic radicals with low-lying unoccupied orbitals, such as acyl, oxyacyl, silyl, stannyl, and germyl radicals. Through interesting singly occupied molecular orbital (SOMO)-pi* and highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) interactions during these reactions, the radicals involved are able to mask as electrophiles, providing high levels of regiocontrol and efficient methods for the synthesis of important heterocycles.
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Affiliation(s)
- Carl H Schiesser
- School of Chemistry, The University of Melbourne, Victoria, Australia
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Aumann KM, Scammells PJ, White JM, Schiesser CH. On the stability of 2-aminoselenophene-3-carboxylates: potential dual-acting selenium-containing allosteric enhancers of A1 adenosine receptor binding. Org Biomol Chem 2007; 5:1276-81. [PMID: 17406727 DOI: 10.1039/b700812k] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ethyl-2-amino-4,5,6,7-tetrahydro-1-benzoselenophene-3-carboxylate (4), has been prepared as a potential dual-acting selenium-containing allosteric enhancer of adenosine A(1)A receptor binding utilising a modified Gewald reaction. While preliminary testing indicated that 4 is a superior enhancer of A(1)AR binding than its thiophene counterpart, its instability under mildly acidic conditions is cause for concern. X-Ray crystallography, together with DFT calculations, provide evidence that the decomposition of 4 involves the ring-opening of selenophenium ion (12b) followed by the loss of elemental selenium through a radical chain process.
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Affiliation(s)
- Kylee M Aumann
- School of Chemistry, The University of Melbourne, Victoria, Australia
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Matsubara H, Ryu I, Schiesser CH. An ab initio and DFT study of some halogen atom transfer reactions from alkyl groups to acyl radical. Org Biomol Chem 2007; 5:3320-4. [PMID: 17912385 DOI: 10.1039/b710449a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio calculations using the 6-311G**, cc-pVDZ, and (valence) double-zeta pseudopotential (DZP) basis sets, with (MP2, QCISD, CCSD(T)) and without (HF) the inclusion of electron correlation, and density functional (BHandHLYP, B3LYP) calculations predict that the transition states for the reaction of acetyl radical with several alkyl halides adopt an almost collinear arrangement of attacking and leaving radicals at the halogen atom. Energy barriers (DeltaE(double dagger)) for these halogen transfer reactions of between 89.2 (chlorine transfer from methyl group) and 25.3 kJ mol(-1) (iodine transfer from tert-butyl group) are calculated at the BHandHLYP/DZP level of theory. While the difference in forward and reverse energy barriers for iodine transfer to acetyl radical is predicted to be 15.1 kJ mol(-1) for primary alkyl iodide, these values are calculated to be 6.7 and -4.2 kJ mol(-1) for secondary and tertiary alkyl iodide respectively. These data are in good agreement with available experimental data in that atom transfer radical carbonylation reactions are sluggish with primary alkyl iodides, but proceed smoothly with secondary and tertiary alkyl iodides. These calculations also predict that bromine transfer reactions involving acyl radical are also feasible at moderately high temperature.
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Affiliation(s)
- Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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Kyne SH, Schiesser CH, Matsubara H. Multi-component orbital interactions during oxyacyl radical addition reactions involving imines and electron-rich olefins. Org Biomol Chem 2007; 5:3938-43. [DOI: 10.1039/b714324a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ryu I, Uenoyama Y, Matsubara H. Carbonylative Approaches to α,β-Unsaturated Acyl Radicals and α-Ketenyl Radicals. Their Structure and Applications in Synthesis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2006. [DOI: 10.1246/bcsj.79.1476] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Tojino M, Otsuka N, Fukuyama T, Matsubara H, Ryu I. Selective 6-endo Cyclization of the Acyl Radicals onto the Nitrogen of Imine and Oxazoline C−N Bonds. J Am Chem Soc 2006; 128:7712-3. [PMID: 16771465 DOI: 10.1021/ja0623865] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acyl radicals generated by the addition of alkyl or vinyl radicals to carbon monoxide cyclized onto the C-N bonds of imines and oxazoline with perfect 6-endo selectivity, driven by a preference for attack at nitrogen.
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Affiliation(s)
- Mami Tojino
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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Schiesser CH. Taming the free radical shrew ? learning to control homolytic reactions at higher heteroatoms. Chem Commun (Camb) 2006:4055-65. [PMID: 17024249 DOI: 10.1039/b608150a] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Free radical chemistry has come a long way in a relatively short period of time. Armed with mechanistic and rate constant data, the synthetic practitioner can now apply free radical chemistry to the synthesis of many different classes of target molecule with confidence. This Feature Article highlights progress made in the understanding and application of free radical reactions at main group higher heteroatoms and demonstrates how this knowledge can be used to construct interesting higher heterocycles, many of which exhibit biological activity, through the use of intramolecular homolytic substitution chemistry.
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Affiliation(s)
- Carl H Schiesser
- Australian Research Council Centre for Free Radical Chemistry and Biotechnology, School of Chemistry, The University of Melbourne, Victoria, Australia.
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