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Takashima K, Asai A, Ashidate M, Suzuki R, Marumoto S, Ishikawa F, Morikawa T, Tanabe G. Total Synthesis of Calanthoside, a Potential Hair Growth Stimulant: A Facile Synthetic Approach via One-Pot S- and O-Glucosidic Bond Formation. JOURNAL OF NATURAL PRODUCTS 2023; 86:2672-2684. [PMID: 37964561 DOI: 10.1021/acs.jnatprod.3c00815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
The first total synthesis of calanthoside (1), which exhibits potent proliferative activity against human hair follicle dermal papilla cells, has been achieved in seven steps with an overall yield of 43% on a gram scale starting from anthranilic acid (11). The synthetic strategy features a one-pot process involving thioglucoside bond formation via nucleophilic substitution reaction and enol-glucosylation for building the S-,O-bisdesmoside structure of 1. Moreover, the one-pot reaction showed broad substrate adaptability to several sugar donors other than d-glucose, thus affording S,O-bisglycoside intermediates in ∼84% yield.
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2
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Schneider Y, Jadhav AP, Legault CY. Synthesis of Indoles Using the Electrophilic Potential of Diazirines. J Org Chem 2023; 88:14809-14819. [PMID: 37779242 DOI: 10.1021/acs.joc.3c01673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The electrophilic potential of diazirines has been utilized to obtain N-substituted diaziridines that are directly hydrolyzed to produce monosubstituted hydrazines. The hydrazines can undergo the Fisher process with enolizable carbonyls to yield multiple indole derivatives in moderate to high yields. The N-metalated diaziridine intermediates can undergo isomerization prior to electrophilic substitution, to form N,N-disubstituted hydrazones. The latter react with enolizable carbonyls to produce N-protected indole derivatives in a single step. This protocol was used to efficiently synthesize indomethacin, an anti-inflammatory drug.
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Affiliation(s)
- Yoann Schneider
- University of Sherbrooke, Department of Chemistry, 2500 boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Amol P Jadhav
- University of Sherbrooke, Department of Chemistry, 2500 boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Claude Y Legault
- University of Sherbrooke, Department of Chemistry, 2500 boul. de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
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3
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Banda S, Villinger A, Brasholz M. Synthesis of azepane-fused pyrano[3,2- b]indoles by Lewis acid-catalysed oxa Diels-Alder reactions. Org Biomol Chem 2023; 21:4379-4381. [PMID: 36883361 DOI: 10.1039/d3ob00234a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
The dihydroazepino[1,2-a]indole diones 3 are tricyclic oxindole-type enones which are readily accessible by catalytic photooxygenation of cyclohepta[b]indoles 1 followed by dehydration. Lewis acid-catalysed oxa Diels-Alder reactions of enones 3 with enol ethers 4 were developed that lead to novel tetracyclic azepane-fused pyrano[3,2-b]indoles 5, with high stereoselectivity and under mild reaction conditions.
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Affiliation(s)
- Saikumar Banda
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.
| | - Alexander Villinger
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.
| | - Malte Brasholz
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany. .,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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4
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Dasi R, Villinger A, Brasholz M. Photocatalytic Azetidine Synthesis by Aerobic Dehydrogenative [2 + 2] Cycloadditions of Amines with Alkenes. Org Lett 2022; 24:8041-8046. [PMID: 36264267 DOI: 10.1021/acs.orglett.2c03291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photocatalytic dehydrogenative [2 + 2] cycloadditions between amines and alkenes were developed that allow for the stereoselective and high-yielding synthesis of functionalized azetidines. The oxidative formal Aza Paternò-Büchi reactions are induced by photoredox-catalyzed aerobic oxidation of dihydroquinoxalinones 1 as the amines, and in the presence of structurally diverse alkenes 3 intermolecular [2 + 2] cyclization to dihydro-1H-azeto[1,2-a]quinoxalin-3(4H)-ones 4 occurs. The utility of the method is illustrated by the selective conversion of amino acid derived dihydroquinoxalinones 1, including oxidation-prone lysine and tryptophan derivatives.
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Affiliation(s)
- Rajesh Dasi
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Alexander Villinger
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Malte Brasholz
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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5
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Pareek A, Singh G, Yaragorla S. Synthetic Applications of Ambiphilic C‐Acylimines in Organic Synthesis. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | - Garima Singh
- University of Hyderabad School of Chemistry Chemistry INDIA
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6
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Xiao J, Zhou G, Ji C. Syntheses of Mersicarpine, a Monoterpenoid Indole Alkaloid with an Atypical Tetracyclic Structure. ChemistrySelect 2022. [DOI: 10.1002/slct.202201373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jie Xiao
- School of Chemistry and Environmental Sciences Shangrao Normal University No. 401 Zhimin Road Shangrao Jiangxi 334001 People's Republic of China
| | - Guang‐Hua Zhou
- School of Chemistry and Food Science Nanchang Normal University No. 889 Ruixiang Road Nanchang Jiangxi 330032 People's Republic of China
| | - Cong‐Bin Ji
- School of Chemistry and Environmental Sciences Shangrao Normal University No. 401 Zhimin Road Shangrao Jiangxi 334001 People's Republic of China
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7
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Frahm M, Voss A, Brasholz M. A short total synthesis of (±)-mersicarpine via visible light-induced cascade photooxygenation. Chem Commun (Camb) 2022; 58:5467-5469. [PMID: 35416221 DOI: 10.1039/d2cc01316a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A short total synthesis of the Kopsia alkaloid (±)-mersicarpine is presented. As the key step, a visible light-induced catalytic cascade photooxygenation was utilized, to convert a 3,3-disubstituted tetrahydrocarbazole intermediate, in one step, into a perhydropyrido[1,2-a]indole dione as the immediate precursor to the natural product. The synthesis of mersicarpine was achieved with an overall yield of 12% over 13 steps.
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Affiliation(s)
- Mario Frahm
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.
| | - Alice Voss
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.
| | - Malte Brasholz
- Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany. .,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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8
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Eichhorst A, Gallhof M, Voss A, Sekora A, Eggers L, Le Thi H, Junghanss C, Murua Escobar H, Brasholz M. Spirooxindol‐1,3‐oxazine alkaloids: highly potent and selective antitumor agents evolved from iterative structure optimization. ChemMedChem 2022; 17:e202200162. [PMID: 35491398 PMCID: PMC9400852 DOI: 10.1002/cmdc.202200162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/26/2022] [Indexed: 11/10/2022]
Abstract
Spirooxindole‐1,3‐oxazines are a small and structurally unique class of spirooxindole alkaloids. To date, only four of these compounds have been isolated from natural sources, and their biological properties remained unknown thus far. Dioxyreserpine is a synthetic spirooxindole‐1,3‐oxazine, that can readily be prepared from the Rauvolfia alkaloid (–)‐reserpine by catalytic photooxygenation. While dioxyreserpine itself was now identified as a moderately effective antitumoral agent, structurally modified analogs of it emerged as a new class of highly potent and selective growth inhibitors of various human cancers, including pancreatic cancers. Systematic structural optimization ultimately led to an inhibitor displaying low‐micromolar IC50‐values against six cancer cell lines as well as selective apoptosis induction in vitro.
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Affiliation(s)
- Annika Eichhorst
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Malte Gallhof
- Universität Rostock Mathematisch-Naturwissenschaftliche Fakultät: Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institut für Chemie GERMANY
| | - Alice Voss
- Universität Rostock Mathematisch-Naturwissenschaftliche Fakultät: Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institut für Chemie GERMANY
| | - Anett Sekora
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Leon Eggers
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Huyen Le Thi
- Hanoi University of Science: Vietnam National University University of Science Institute of Chemistry GERMANY
| | - Christian Junghanss
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Hugo Murua Escobar
- Universitätsklinikum Rostock: Universitatsmedizin Rostock Department of Internal Medicine, Medical Clinic III GERMANY
| | - Malte Brasholz
- Universitat Rostock Mathematisch-Naturwissenschaftliche Fakultat Institute of Chemistry Albert-Einstein-Str. 3a 18059 Rostock GERMANY
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9
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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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10
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Gronbach LM, Voss A, Frahm M, Villinger A, Bresien J, Michalik D, Brasholz M. Lewis Acid-Catalyzed Carbofunctionalization of Uncommon C, N-Diacyliminium Ions: Controlling Regio- and Enantioselectivity. Org Lett 2021; 23:7834-7838. [PMID: 34596417 DOI: 10.1021/acs.orglett.1c02857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The tricyclic azepino[1,2-a]indole acetates 7, readily accessible by visible-light-driven catalytic photooxygenation of cyclohepta[b]indoles 1, are convenient precursors to novel and uncommon cyclic C,N-diacyliminium ions 3. We report here the first Lewis acid-catalyzed C-C bond forming reactions of these species with TMSCN and silyl enol ethers as nucleophiles and utilizing TIPSOTf as well as Sc(OTf)3 as catalysts. Employing Sc(OTf)3/pybox complexes as a chiral catalyst system, regio- and enantioselective asymmetric alkylations with silyl enol ethers were achieved.
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Affiliation(s)
- Lisa Marie Gronbach
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Alice Voss
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Mario Frahm
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Alexander Villinger
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Jonas Bresien
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Dirk Michalik
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Malte Brasholz
- University of Rostock, Institute of Chemistry, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.,Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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11
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Smajlagic I, Kazim M, Lectka T, Dudding T. DFT Case Study of the Mechanism of a Metal-Free Oxygen Atom Insertion into a p-Quinone Methide C(sp 3)-C(sp 2) Bond. J Org Chem 2020; 85:10110-10117. [PMID: 32633515 DOI: 10.1021/acs.joc.0c01371] [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 site-selective introduction of an oxygen atom into an organic molecule, without the assistance of metals, is a useful transformation, though understanding the mechanistic underpinning of such a process is oftentimes a challenging task. In exploring this chemical space and in building upon experimental precedents, we have utilized computational tools to delineate the mechanistic details of site-selective oxygen atom insertion into a p-quinone methide C(sp3)-C(sp2) bond. To this end, several different reaction pathways for oxygen atom insertion were explored-each encompassing a unique element qualifying the respective pathway as being more or less feasible. The findings of these investigations revealed several features that were vital to this reactivity, including the formation of a dimeric intermediate, interconversion between ground- and excited-state species, and strain. Notably, the latter finding adds to the portfolio of strain-release-driven reactions that have emerged as popular methods to achieve otherwise difficult chemical transformations.
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Affiliation(s)
- Ivor Smajlagic
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Muhammad Kazim
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Thomas Lectka
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Travis Dudding
- Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
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