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Ramos A, Griffin ED, Ho KH, Singh J, Jones SA, Walter SN, Castle SL. Synthesis of the Indolizidine Core of Virosinine A via a Microwave-Promoted Cascade Cyclization Involving Iminyl Radicals. Org Lett 2024. [PMID: 38197784 DOI: 10.1021/acs.orglett.3c03852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The indolizidine core of virosinine A was synthesized by means of a microwave-promoted cascade reaction featuring 5-exo-trig iminyl radical cyclization, thiyl radical elimination, and intramolecular imine alkylation. The resulting bicyclic iminium ion underwent stereoselective reduction by Red-Al to deliver the target compound. DFT calculations suggested that both the radical cyclization and thiyl radical elimination steps are reversible at high reaction temperatures.
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Affiliation(s)
- Alexander Ramos
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Elias D Griffin
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Kai-Hang Ho
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Jatinder Singh
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Spencer A Jones
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Steven N Walter
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Steven L Castle
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
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2
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Gregori BJ, Schmotz MWS, Jacobi von Wangelin A. Stereoselective Semi-Hydrogenations of Alkynes by First-Row (3d) Transition Metal Catalysts. ChemCatChem 2022; 14:e202200886. [PMID: 36632425 PMCID: PMC9825939 DOI: 10.1002/cctc.202200886] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/25/2022] [Indexed: 01/14/2023]
Abstract
The chemo- and stereoselective semi-hydrogenation of alkynes to alkenes is a fundamental transformation in synthetic chemistry, for which the use of precious 4d or 5d metal catalysts is well-established. In mankind's unwavering quest for sustainability, research focus has considerably veered towards the 3d metals. Given their high abundancy and availability as well as lower toxicity and noxiousness, they are undoubtedly attractive from both an economic and an environmental perspective. Herein, we wish to present noteworthy and groundbreaking examples for the use of 3d metal catalysts for diastereoselective alkyne semi-hydrogenation as we embark on a journey through the first-row transition metals.
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Affiliation(s)
- Bernhard J. Gregori
- Dept. of ChemistryUniversity of HamburgMartin Luther King Pl 620146HamburgGermany
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3
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Kang G, Park S, Han S. The Chemistry of High‐Oxidation State Securinega Alkaloids. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gyumin Kang
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu Daejeon 34141, Republic of Korea E-mail: synthesis.kaist.ac.kr
| | - Sangbin Park
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu Daejeon 34141, Republic of Korea E-mail: synthesis.kaist.ac.kr
| | - Sunkyu Han
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu Daejeon 34141, Republic of Korea E-mail: synthesis.kaist.ac.kr
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4
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Shao H, Fang K, Wang YP, Zhang XM, Ding TM, Zhang SY, Chen ZM, Tu YQ. Total Synthesis of Fawcettimine-Type Alkaloid, Lycojaponicumin A. Org Lett 2020; 22:3775-3779. [PMID: 32330061 DOI: 10.1021/acs.orglett.0c00961] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The efficient total synthesis of lycojaponicumin A (1) has been accomplished for the first time. The remarkable features of this novel strategy include the following: (1) rapid construction of tricyclic intermediate 4 through a regio- and stereoselective semipinacol ring expansion, which simplified the construction of rings A and B of 1; (2) the subsequent regio- and stereoselective formation of the highly strained rings C-E of 1 through a tandem oxa-hetero [3 + 2] cycloaddition/N-cycloalkylation.
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Affiliation(s)
- Hui Shao
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240
| | - Kun Fang
- State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China, 730000
| | - Yun-Peng Wang
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240
| | - Xiao-Ming Zhang
- State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China, 730000
| | - Tong-Mei Ding
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240
| | - Shu-Yu Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240
| | - Zhi-Min Chen
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240
| | - Yong-Qiang Tu
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, Shanghai Jiao Tong University, Shanghai, P. R. China, 200240.,State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China, 730000
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Bartolo ND, Read JA, Valentín EM, Woerpel KA. Reactions of Allylmagnesium Reagents with Carbonyl Compounds and Compounds with C═N Double Bonds: Their Diastereoselectivities Generally Cannot Be Analyzed Using the Felkin-Anh and Chelation-Control Models. Chem Rev 2020; 120:1513-1619. [PMID: 31904936 PMCID: PMC7018623 DOI: 10.1021/acs.chemrev.9b00414] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This review describes the additions of allylmagnesium reagents to carbonyl compounds and to imines, focusing on the differences in reactivity between allylmagnesium halides and other Grignard reagents. In many cases, allylmagnesium reagents either react with low stereoselectivity when other Grignard reagents react with high selectivity, or allylmagnesium reagents react with the opposite stereoselectivity. This review collects hundreds of examples, discusses the origins of stereoselectivities or the lack of stereoselectivity, and evaluates why selectivity may not occur and when it will likely occur.
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Affiliation(s)
- Nicole D. Bartolo
- Department of Chemistry, New York University, 100
Washington Square East, New York, NY 10003, USA
| | - Jacquelyne A. Read
- Department of Chemistry, New York University, 100
Washington Square East, New York, NY 10003, USA
- Department of Chemistry, University of Utah, 315 South 1400
East, Salt Lake City, UT 84112, USA
| | - Elizabeth M. Valentín
- Department of Chemistry, New York University, 100
Washington Square East, New York, NY 10003, USA
- Department of Chemistry, Susquehanna University, 514
University Avenue, Selinsgrove, PA 17870, USA
| | - K. A. Woerpel
- Department of Chemistry, New York University, 100
Washington Square East, New York, NY 10003, USA
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Alkayar ZTI, Coldham I. Cascade cyclization and intramolecular nitrone dipolar cycloaddition and formal synthesis of 19-hydroxyibogamine. Org Biomol Chem 2019; 17:66-73. [PMID: 30539955 DOI: 10.1039/c8ob02839g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A cascade or domino sequence of condensation of hydroxylamine and an aldehyde to give an oxime, cyclization to a nitrone, and intramolecular 1,3-dipolar cycloaddition has been successfully employed where there is branching at C-4 as a route to the iboga alkaloids. Cyclization occurs with displacement of chloride as a leaving group and intramolecular cycloaddition occurs with an alkene as a dipolarophile. The reaction gives an azabicyclo[2.2.2]octane product containing a fused isoxazolidine as a single stereoisomer and this was converted to an isoquinuclidine that completed a formal synthesis of the alkaloid (±)-19-hydroxyibogamine.
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Affiliation(s)
- Ziad T I Alkayar
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
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Abrams DJ, Provencher PA, Sorensen EJ. Recent applications of C-H functionalization in complex natural product synthesis. Chem Soc Rev 2018; 47:8925-8967. [PMID: 30426998 DOI: 10.1039/c8cs00716k] [Citation(s) in RCA: 375] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this review, recent examples featuring C-H functionalization in the synthesis of complex natural products are discussed. A focus is given to the way in which C-H functionalization can influence the logical process of retrosynthesis, and the review is organized by the type and method of C-H functionalization.
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Affiliation(s)
- Dylan J Abrams
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
| | | | - Erik J Sorensen
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
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Movassaghi M. Biogenetic considerations. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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