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Rao CN, Reissig HU. Samarium(II)‐Promoted Cyclizations of Non‐activated Indolyl Sulfinyl Imines to Polycyclic Tertiary Carbinamines. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chintada Nageswara Rao
- Freie Universität Berlin: Freie Universitat Berlin Institut für Chemie und Biochemie 14195 Berlin GERMANY
| | - Hans-Ulrich Reissig
- Freie Universität Berlin Institut für Chemie und Biochemie Takustr. 3 14195 Berlin GERMANY
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2
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Rao CN, Reissig H. Synthesis and Evaluation of Enantiopure HMPA Analogs in Samarium‐Diiodide‐Promoted Dearomatizations of N‐Acylated Indole Derivatives. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Chintada Nageswara Rao
- Institut für Chemie und Biochemie Freie Universität Berlin Takustrasse 3 14195 Berlin Germany
| | - Hans‐Ulrich Reissig
- Institut für Chemie und Biochemie Freie Universität Berlin Takustrasse 3 14195 Berlin Germany
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3
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McDonald CE, Bendorf HD, Mauck JR, McAtee CC, Green AI, Ciccarelli DJ, Bendyk CA, Conrad BJ, Delgado AT. The SmI 2/TEU --Mediated Cyclization of Unsaturated Halides. Org Lett 2020; 22:5685-5689. [PMID: 32603130 DOI: 10.1021/acs.orglett.0c02074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The combination of SmI2 and the conjugate base of triethylurea (TEU-) has been shown to favor the cyclization of unsaturated halides over direct reduction to a much greater extent than other SmI2-based reductants. Aryl, heteroaryl, and alkyl halides (X = Br, Cl, F) readily undergo heterocyclization and carbocyclization in the presence of SmI2/TEU-.
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Affiliation(s)
- Chriss E McDonald
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Holly D Bendorf
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Joseph R Mauck
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Christopher C McAtee
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Ahren I Green
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - David J Ciccarelli
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Cassandra A Bendyk
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Brandon J Conrad
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
| | - Angelique T Delgado
- Department of Chemistry, Lycoming College, One College Place, Williamsport, Pennsylvania 17701, United States
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4
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Beemelmanns C, Nitsch D, Bentz C, Reissig HU. Stereoselective Cascade Cyclizations with Samarium Diiodide to Tetracyclic Indolines: Precursors of Fluorostrychnines and Brucine. Chemistry 2019; 25:8780-8789. [PMID: 31033048 DOI: 10.1002/chem.201900087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/25/2019] [Indexed: 12/16/2022]
Abstract
A series of γ-indolylketones with fluorine, cyano or alkoxy substituents at the benzene moiety was prepared and subjected to samarium diiodide-promoted cyclization reactions. The desired dearomatizing ketyl cascade reaction forming two new rings proceeded in all cases with high diastereoselectivity, but with differing product distribution. In most cases, the desired annulated tetracyclic compounds were obtained in moderate to good yields, but as second product tetracyclic spirolactones were isolated in up to 29 % yield. The reaction rate was influenced by the substituents at the benzene moiety of the substrate as expected, with electron-accepting groups accelerating and electron-donating groups decelerating the cyclization process. In case of a difluoro-substituted γ-indolylketone a partial defluorination was observed. The intermediate samarium enolate of the tetracyclic products could be trapped by adding reactive alkylating agents as electrophiles delivering products with quarternary carbons. In the case of a dimethoxy-substituted tetracyclic cyclization product a subsequent reductive amination stereoselectively provided a pentacyclic compound that was subsequently N-protected and subjected to a regioselective elimination. The obtained functionalized pentacyclic product should be convertible into the alkaloid brucine by four well-established steps. Overall, the presented report shows that functionalized tetracyclic compounds with different substituents are rapidly available with the samarium diiodide cascade cyclization as crucial step. Hence, analogues of the landmark alkaloid strychnine, for example, with specific fluorine substitutions, should be easily accessible.
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Affiliation(s)
- Christine Beemelmanns
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.,Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie, Beutenbergstraße 11a, 07745, Jena, Germany
| | - Dominik Nitsch
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Christoph Bentz
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Hans-Ulrich Reissig
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
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5
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McDonald CE, Ramsey JD, McAtee CC, Mauck JR, Hale EM, Cumens JA. The Use of Ureates as Activators for Samarium Diiodide. J Org Chem 2016; 81:5903-14. [DOI: 10.1021/acs.joc.6b00733] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chriss E. McDonald
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
| | - Jeremy D. Ramsey
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
| | - Christopher C. McAtee
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
| | - Joseph R. Mauck
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
| | - Erin M. Hale
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
| | - Justin A. Cumens
- Department
of Chemistry, Lycoming College, 700 College Place, Williamsport, Pennsylvania 17701, United States
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6
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Rao CN, Bentz C, Reissig H. Lithium Bromide/Water as Additives in Dearomatizing Samarium‐Ketyl (Hetero)Arene Cyclizations. Chemistry 2015; 21:15951-4. [DOI: 10.1002/chem.201502912] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Indexed: 12/11/2022]
Affiliation(s)
- Chintada Nageswara Rao
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany)
| | - Christoph Bentz
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany)
| | - Hans‐Ulrich Reissig
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany)
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7
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Liu C, Sun L, Li C. Aqueous Reduction of Iodosteroids to Deoxysteroids. JOURNAL OF CHEMICAL RESEARCH 2014. [DOI: 10.3184/174751914x13968892307636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A new method for the reduction of iodosteroids to deoxysteroids has been developed using Zn, HCOOH and a catalytic amount of Aliquat 336 in water. In total, 13 iodosteroids were reduced in good to excellent yields. The higher solubilities of the substrates lead to the faster reactions, and the aqueous reaction was efficiently accelerated by granular polytetrafluoroethylene. The advantage of the aqueous system over eight organic solvents has also been demonstrated.
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Affiliation(s)
- Changsheng Liu
- Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P.R. China
| | - Lili Sun
- Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P.R. China
| | - Chunbao Li
- Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, P.R. China
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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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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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10
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Szostak M, Spain M, Procter DJ. Recent advances in the chemoselective reduction of functional groups mediated by samarium(ii) iodide: a single electron transfer approach. Chem Soc Rev 2013; 42:9155-83. [DOI: 10.1039/c3cs60223k] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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