1
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Ponomarev AV, Danilkina NA, Okuneva JS, Vidyakina AA, Khmelevskaya EA, Bunev AS, Rumyantsev AM, Govdi AI, Suarez T, Alabugin IV, Balova IA. Facile synthesis of diiodoheteroindenes and understanding their Sonogashira cross-coupling selectivity for the construction of unsymmetrical enediynes. Org Biomol Chem 2024; 22:4096-4107. [PMID: 38695707 DOI: 10.1039/d4ob00530a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Electrophile-promoted cyclizations of functionalized alkynes offer a useful tool for constructing halogen-substituted heterocycles primed for further derivatization. Preinstallation of an iodo-substituent at the alkyne prior to iodo-cyclization opens access to ortho di-iodinated heterocyclic precursors for the preparation of unsymmetrical heterocycle-fused enediynes. This general approach was used to prepare 2,3-diiodobenzothiophene, 2,3-diiodoindole, and 2,3-diiodobenzofuran, a useful family of substrates for systematic studies of the role of heteroatoms on the regioselectivity of cross-coupling reactions. Diiodobenzothiophene showed much higher regioselectivity for Sonogashira cross-coupling at C2 than diiodoindole and diiodobenzofuran. As a result, benzothiophene can be conveniently involved in a one-pot sequential coupling with two different alkynes, yielding unsymmetrical benzothiophene-fused enediynes. On the other hand, the Sonogashira reaction of diiodoindole and diiodobenzofuran formed considerable amounts of di-substituted enediynes in addition to the monoalkyne product by coupling at C2. Interestingly, no C3-monocoupling products were observed for all of the diiodides, suggesting that the incorporation of the 1st alkyne at C2 activates the C3 position for the 2nd coupling. Additional factors affecting regioselectivity were detected, discussed and connected, through computational analysis, to transmetalation being the rate-determining step for the Sonogashira reaction. Several enediynes synthesized showed cytotoxic activity, which is not associated with DNA strand breaks typical of natural enediyne antibiotics.
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Affiliation(s)
- Alexander V Ponomarev
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Natalia A Danilkina
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Julia S Okuneva
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Aleksandra A Vidyakina
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Ekaterina A Khmelevskaya
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Alexander S Bunev
- Medicinal Chemistry Center, Tolyatti State University, 445020 Tolyatti, Russia
| | - Andrey M Rumyantsev
- Department of Genetics and Biotechnology, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia
| | - Anastasia I Govdi
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
| | - Thomas Suarez
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Irina A Balova
- Institute of Chemistry, Saint Petersburg State University (SPbU), Saint Petersburg, 199034, Russia.
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2
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Vo DV, Su S, Karmakar R, Lee D. Reactivity of Enyne-Allenes Generated via an Alder-Ene Reaction. Org Lett 2024; 26:1299-1303. [PMID: 38330294 DOI: 10.1021/acs.orglett.3c03696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Tandem transformations of 1,3-diynyl propiolate derivatives are described. The Alder-ene reaction generates an enyne-allene, which undergoes a formal 1,7-H shift or a Diels-Alder reaction, depending on the substituent on the alkyne. A terminal or aryl-substituted alkyne promotes a 1,7-H shift to generate a new enyne-allene, which undergoes a Myers-Saito cycloaromatization followed by a 1,5-H transfer-mediated cyclization to form highly functionalized benzo-fused 6-membered cycles. The reactivity of the preformed enyne-allene shows comparable reactivity profiles.
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Affiliation(s)
- Duy-Viet Vo
- Department of Chemistry, University of Illinois─Chicago, 845 West Taylor Street, Chicago, Illinois 60607, United States
| | - Siyuan Su
- Department of Chemistry, University of Illinois─Chicago, 845 West Taylor Street, Chicago, Illinois 60607, United States
| | - Rajdip Karmakar
- Department of Chemistry, University of Illinois─Chicago, 845 West Taylor Street, Chicago, Illinois 60607, United States
| | - Daesung Lee
- Department of Chemistry, University of Illinois─Chicago, 845 West Taylor Street, Chicago, Illinois 60607, United States
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3
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Latrache M, Lefebvre C, Abe M, Hoffmann N. Photochemically Induced Hydrogen Atom Transfer and Intramolecular Radical Cyclization Reactions with Oxazolones. J Org Chem 2023; 88:16435-16455. [PMID: 37983612 DOI: 10.1021/acs.joc.3c01951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Photochemically induced intramolecular hydrogen atom transfer in oxazolones is reported. An acetal or thioacetal function at the side chain acts as a hydrogen donor while the photochemical exited oxazolone is the acceptor. A one-step process─the electron and the proton are simultaneously transferred─is productive, while electron transfer followed by proton transfer is inefficient. Radical combination then takes place, leading to the formation of a C-C or C-N bond. The regioselectivity of the reaction is explained by the diradical/zwitterion dichotomy of radical intermediates at the singlet state. In the present case, the zwitterion structure plays a central role, and intramolecular electron transfer favors spin-orbit coupling and thus the intersystem crossing to the singlet state. The reaction of corresponding thioacetal derivatives is less efficient. In this case, photochemical electron transfer is competitive. The photoproducts resulting from C-C bond formation easily undergo stepwise thermal decarboxylation in which zwitterionic and polar transition states are involved. A computational study of this step has also been performed.
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Affiliation(s)
- Mohammed Latrache
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Corentin Lefebvre
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
| | - Manabu Abe
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Hiroshima Research Center for Photo-Drug-Delivery Systems (Hi-P-DDS), 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Norbert Hoffmann
- ICMR, Equipe de Photochimie, CNRS, Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, Reims 51687 France
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4
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Lindner MM, Alachraf MW, Mitschke B, Schulze P, Leutzsch M, List B. Toward a Formyl-to-Phenyl Conversion: An Unexpected Photochemical Fulvene Rearrangement. Angew Chem Int Ed Engl 2023; 62:e202303119. [PMID: 37329283 DOI: 10.1002/anie.202303119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/16/2023] [Accepted: 06/16/2023] [Indexed: 06/19/2023]
Abstract
Toward a conversion of aldehydes into arenes, we designed a sequence involving the initial reaction of an aldehyde to give a fulvene, followed by photochemical and platinum-catalyzed rearrangements into a Dewar benzene derivative, which finally isomerizes into the targeted arene. While computational studies support the plausibility of this route, we found that fulvene irradiation resulted in an unexpected isomerization into a spiro[2.4]heptadiene. This unusual photorearrangement has been investigated mechanistically and provides access to a variety of spiro[2.4]heptadienes with different substituents.
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Affiliation(s)
- Monika M Lindner
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - M Wasim Alachraf
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin Mitschke
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Philipp Schulze
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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5
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Campbell A, Dos Santos NR, Alabugin I. Photochemical Uncaging of Aldehydes and Ketones via Photocyclization/Fragmentation Cascades of Enyne Alcohols: An Unusual Application for a Cycloaromatization Process. Molecules 2023; 28:5704. [PMID: 37570675 PMCID: PMC10420836 DOI: 10.3390/molecules28155704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/23/2023] [Accepted: 07/23/2023] [Indexed: 08/13/2023] Open
Abstract
We utilized a cycloaromatization reaction driven by relief of excited state antiaromaticity to photouncage aldehydes and ketones. We developed several synthetic routes towards the synthesis of photocaged carbonyls as allylically substituted 3-(2-(arylethynyl)phenyl)prop-2-en-1-ols. A library of photocaged aryl aldehydes and ketones containing donors and acceptors, as well as several photocaged fragrance aldehydes and the steroid 5α-cholestan- 3 -one, were synthesized and demonstrated photouncaging in good to excellent yields.
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Affiliation(s)
| | | | - Igor Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA; (A.C.); (N.R.D.S.)
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6
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Kuriakose F, Commodore M, Hu C, Fabiano CJ, Sen D, Li RR, Bisht S, Üngör Ö, Lin X, Strouse GF, DePrince AE, Lazenby RA, Mentink-Vigier F, Shatruk M, Alabugin IV. Design and Synthesis of Kekulè and Non-Kekulè Diradicaloids via the Radical Periannulation Strategy: The Power of Seven Clar's Sextets. J Am Chem Soc 2022; 144:23448-23464. [PMID: 36516873 DOI: 10.1021/jacs.2c09637] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This work introduces an approach to uncoupling electrons via maximum utilization of localized aromatic units, i.e., the Clar's π-sextets. To illustrate the utility of this concept to the design of Kekulé diradicaloids, we have synthesized a tridecacyclic polyaromatic system where a gain of five Clar's sextets in the open-shell form overcomes electron pairing and leads to the emergence of a high degree of diradical character. According to unrestricted symmetry-broken UCAM-B3LYP calculations, the singlet diradical character in this core system is characterized by the y0 value of 0.98 (y0 = 0 for a closed-shell molecule, y0 = 1 for pure diradical). The efficiency of the new design strategy was evaluated by comparing the Kekulé system with an isomeric non-Kekulé diradical of identical size, i.e., a system where the radical centers cannot couple via resonance. The calculated singlet-triplet gap, i.e., the ΔEST values, in both of these systems approaches zero: -0.3 kcal/mol for the Kekulé and +0.2 kcal/mol for the non-Kekulé diradicaloids. The target isomeric Kekulé and non-Kekulé systems were assembled using a sequence of radical periannulations, cross-coupling, and C-H activation. The diradicals are kinetically stabilized by six tert-butyl substituents and (triisopropylsilyl)acetylene groups. Both molecules are NMR-inactive but electron paramagnetic resonance (EPR)-active at room temperature. Cyclic voltammetry revealed quasi-reversible oxidation and reduction processes, consistent with the presence of two nearly degenerate partially occupied molecular orbitals. The experimentally measured ΔEST value of -0.14 kcal/mol confirms that K is, indeed, a nearly perfect singlet diradical.
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Affiliation(s)
- Febin Kuriakose
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Michael Commodore
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Chaowei Hu
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Catherine J Fabiano
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Debashis Sen
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Run R Li
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Shubham Bisht
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Ökten Üngör
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Xinsong Lin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Geoffrey F Strouse
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - A Eugene DePrince
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Robert A Lazenby
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Michael Shatruk
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida32306-4390, United States
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7
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Albrecht F, Fatayer S, Pozo I, Tavernelli I, Repp J, Peña D, Gross L. Selectivity in single-molecule reactions by tip-induced redox chemistry. Science 2022; 377:298-301. [DOI: 10.1126/science.abo6471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Controlling selectivity of reactions is an ongoing quest in chemistry. In this work, we demonstrate reversible and selective bond formation and dissociation promoted by tip-induced reduction-oxidation reactions on a surface. Molecular rearrangements leading to different constitutional isomers are selected by the polarity and magnitude of applied voltage pulses from the tip of a combined scanning tunneling and atomic force microscope. Characterization of voltage dependence of the reactions and determination of reaction rates demonstrate selectivity in constitutional isomerization reactions and provide insight into the underlying mechanisms. With support of density functional theory calculations, we find that the energy landscape of the isomers in different charge states is important to rationalize the selectivity. Tip-induced selective single-molecule reactions increase our understanding of redox chemistry and could lead to novel molecular machines.
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Affiliation(s)
| | - Shadi Fatayer
- IBM Research Europe – Zurich, 8803 Rüschlikon, Switzerland
- Applied Physics Program, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Iago Pozo
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | | | - Jascha Repp
- Institute of Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
| | - Diego Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Leo Gross
- IBM Research Europe – Zurich, 8803 Rüschlikon, Switzerland
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8
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Singha M, Bhattacharya P, Ray D, Basak A. Sterically hindering the trajectory of nucleophilic attack towards p-benzynes by a properly oriented hydrogen atom: an approach to achieve regioselectivity. Org Biomol Chem 2021; 19:5148-5154. [PMID: 34032259 DOI: 10.1039/d1ob00521a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nucleophilic addition to p-benzynes derived via Bergman cyclization has become a topic of keen interest. Studying the regioselectivity in such addition can reveal important information regarding the parameters controlling such addition. Recently, high regioselectivity has been achieved in nucleophilic addition to a p-benzyne derived from an ortho substituted benzo fused cyclic azaenediyne. Rather than having a freely rotating substitution, a rigid hydrogen atom coming from a suitable naptho fused enediyne and residing in the plane of the p-benzyne ring can offer hindrance to the trajectory of the nucleophile. This can lead to regioselectivity provided the other side remains relatively free of such hindrance. Based on that approach, halide addition to p-benzynes derived from naphtho fused cyclic azaenediynes was studied and a high level of regioselectivity was observed. Steric hindrance to the trajectory of nucleophile by the bay hydrogen was found to be the main cause of such regioselectivity; however, differential electrostatic potential as well as distortions at reactive centres have a minor role in controlling the regioselectivity. The products of such high yielding addition are the halo naphtho tetrahydroisoquinolines.
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Affiliation(s)
- Monisha Singha
- Department of Chemistry, Indian Institute of Technology, Kharagpur721302, India.
| | | | - Debashis Ray
- Department of Chemistry, Indian Institute of Technology, Kharagpur721302, India.
| | - Amit Basak
- Department of Chemistry, Indian Institute of Technology, Kharagpur721302, India. and School of Bioscience, Indian Institute of Technology, Kharagpur721302, India
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9
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Zhang M, Ma H, Li B, Sun K, Lu H, Wang W, Cheng X, Li X, Ding Y, Hu A. Nucleophilic Addition to Diradicals Derived From Cycloaromatization of Maleimide‐Based Enediynes. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mengsi Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Hailong Ma
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Baojun Li
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Ke Sun
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Haotian Lu
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Wenbo Wang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Xiaoyu Cheng
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Xiaoxuan Li
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Yun Ding
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Aiguo Hu
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
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10
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Mapping C−H⋅⋅⋅M Interactions in Confined Spaces: (α‐ICyD
Me
)Au, Ag, Cu Complexes Reveal “Contra‐electrostatic H Bonds” Masquerading as Anagostic Interactions**. Chemistry 2021; 27:8127-8142. [DOI: 10.1002/chem.202100263] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Indexed: 12/18/2022]
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11
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Wang W, Lu H, Zhang M, Ma H, Cheng X, Ding Y, Hu A. Synthesis of maleimide-based enediynes with cyclopropane moieties for enhanced cytotoxicity under normoxic and hypoxic conditions. J Mater Chem B 2021; 9:4502-4509. [PMID: 34019610 DOI: 10.1039/d1tb00142f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Myers-Saito cycloaromatization (MSC) is the working mechanism of many natural enediyne antibiotics with high antitumor potency. However, the presence of the equilibrium between diradical and zwitterionic intermediates in MSC severely hinders further improvement in cytotoxicity toward tumor cells. To this end, a series of maleimide-based enediynes with cyclopropane moieties were synthesized for enhanced cytotoxicity toward tumor cells. By taking advantage of radical clock reactions, the diradical intermediates generated from MSC would rearrange to new diradicals with much longer separation and weaker interactions between two radical centers. The computational study suggested a low energy barrier (4.4 kcal mol-1) for the radical rearrangement through the cyclopropane ring-opening process. Thermolysis experiments confirmed that this radical rearrangement results in the formation of a new diradical intermediate, followed by abstracting hydrogen atoms from 1,4-cyclohexadiene. Interestingly, the DNA cleavage ability and cytotoxicity of enediynes were significantly enhanced after the introduction of cyclopropane moieties. In addition, these maleimide-based enediynes exhibited a similar cytotoxicity under hypoxic conditions to that under normoxic conditions, which is beneficial for treating solid tumors where hypoxic environments frequently lead to deteriorated efficiency of many antitumor drugs. Docking studies indicated that the diradical intermediate was located between the minor groove of DNA with a binding energy of -7.40 kcal mol-1, which is in favor of intracellular DNA damage, and thereby inducing cell death via an apoptosis pathway as suggested by immunofluorescence analysis.
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Affiliation(s)
- Wenbo Wang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Haotian Lu
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Mengsi Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Hailong Ma
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Xiaoyu Cheng
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Yun Ding
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Aiguo Hu
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
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12
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Popescu MV, Mekereeya A, Alegre‐Requena JV, Paton RS, Smith MD. Visible-Light-Mediated Heterocycle Functionalization via Geometrically Interrupted [2+2] Cycloaddition. Angew Chem Int Ed Engl 2020; 59:23020-23024. [PMID: 32856748 PMCID: PMC7891567 DOI: 10.1002/anie.202009704] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/18/2020] [Indexed: 01/02/2023]
Abstract
The [2+2] photocycloaddition is the most valuable and intensively investigated photochemical process. Here we demonstrate that irradiation of N-acryloyl heterocycles with blue LED light (440 nm) in the presence of an IrIII complex leads to efficient and high yielding fused γ-lactam formation across a range of substituted heterocycles. Quantum calculations show that the reaction proceeds via cyclization in the triplet excited state to yield a 1,4-diradical; intersystem crossing leads preferentially to the closed shell singlet zwitterion. This is geometrically restricted from undergoing recombination to yield a cyclobutane by the planarity of the amide substituent. A prototropic shift leads to the observed bicyclic products in what can be viewed as an interrupted [2+2] cycloaddition.
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Affiliation(s)
- Mihai V. Popescu
- Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Aroonroj Mekereeya
- Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Juan V. Alegre‐Requena
- Department of ChemistryColorado State University1301 Center AveFt. CollinsCO80523-1872USA
| | - Robert S. Paton
- Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
- Department of ChemistryColorado State University1301 Center AveFt. CollinsCO80523-1872USA
| | - Martin D. Smith
- Chemistry Research LaboratoryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
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13
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Visible‐Light‐Mediated Heterocycle Functionalization via Geometrically Interrupted [2+2] Cycloaddition. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202009704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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14
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Lu H, Zhang M, Li B, Ma H, Wang W, Ding Y, Li X, Hu A. Experimental and Computational Study on the Reaction Pathways of Diradical Intermediates Formed from Myers‐Saito Cyclization of Maleimide‐Based Enediynes. ASIAN J ORG CHEM 2020. [DOI: 10.1002/ajoc.202000432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Haotian Lu
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Mengsi Zhang
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Baojun Li
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Hailong Ma
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Wenbo Wang
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Yun Ding
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Xinxin Li
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
| | - Aiguo Hu
- Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 P. R. China
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15
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Sanders JN, Jun H, Yu RA, Gleason JL, Houk KN. Mechanism of an Organocatalytic Cope Rearrangement Involving Iminium Intermediates: Elucidating the Role of Catalyst Ring Size. J Am Chem Soc 2020; 142:16877-16886. [PMID: 32865415 DOI: 10.1021/jacs.0c08427] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The mechanism of the organocatalytic Cope rearrangement is elucidated through a combined computational and experimental approach. As reported previously, hydrazides catalyze the Cope rearrangement of 1,5-hexadiene-2-carboxaldehydes via iminium ion formation, and seven- and eight-membered ring catalysts are more active than smaller ring sizes. In the present work, quantum mechanical computations and kinetic isotope effect experiments demonstrate that the Cope rearrangement step, rather than iminium formation, is rate-limiting. The computations further explain how the hydrazide catalyst lowers the free-energy barrier of the Cope rearrangement via an associative transition state that is stabilized by enehydrazine character. The computations also explain the catalyst ring size effect, as larger hydrazide rings are able to accommodate optimal transition-state geometries that minimize the unfavorable lone-pair repulsion between neighboring nitrogen atoms and maximize the favorable hyperconjugative donation from each nitrogen atom into neighboring electron-poor sigma bonds, with the seven-membered catalyst achieving a nearly ideal transition-state geometry that is comparable to that of an unconstrained acyclic catalyst. Experimental kinetics studies support the computations, showing that the seven-membered and acyclic hydrazide catalysts react 10 times faster than the six-membered catalyst. Unraveling the mechanism of this reaction is an important step in understanding other reactions catalyzed by hydrazides, and explaining the ring size effect is critical because cyclic catalysts provide a constrained scaffold, enabling the development of asymmetric variants of these reactions.
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Affiliation(s)
- Jacob N Sanders
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - HyunJune Jun
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - Roland A Yu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - James L Gleason
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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16
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Affiliation(s)
- Joshua P. Peterson
- Department of Chemistry, Iowa State University, 1605 Gilman
Hall, Ames, Iowa 50010, United States
| | - Arthur H. Winter
- Department of Chemistry, Iowa State University, 1605 Gilman
Hall, Ames, Iowa 50010, United States
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17
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Das E, Basak A. Regioselective Synthesis of Benzo-Fused Tetrahydroisoquinoline-Based Biaryls through a Tandem One-Pot Halogenation of p-Benzynes from Enediynes and Suzuki-Miyaura Coupling. J Org Chem 2020; 85:2697-2703. [PMID: 31880452 DOI: 10.1021/acs.joc.9b02874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A regioselective halogenation of p-benzyne derived from a nonaromatic enediyne core via Bergman cyclization and Suzuki-Miyaura coupling of the resulting haloarene in one-pot is disclosed. For the one-pot protocol to work, the reaction conditions were modified compared to an earlier reported procedure ( J. Org. Chem. 2019 , 84 , 2911 - 2921 ) by reducing the amount of lithium iodide and exclusion of pivalic acid. Under these modified conditions, the products, benzo-fused tetrahydroisoquinoline-based biaryl derivatives were obtained in overall high to excellent yields (71-90%).
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18
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Vidhani DV, Alabugin IV. Controlled Evolution of the Cope Rearrangement: Transition from Concerted to Interrupted and Aborted Pericyclic Reactions Regulated by a Switch Built from an Intramolecular Frustrated Lewis Pair. J Org Chem 2019; 84:14844-14853. [DOI: 10.1021/acs.joc.9b02633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | - Igor V. Alabugin
- Florida State University, Tallahassee, Florida 32306, United States
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19
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dos Passos Gomes G, Wimmer A, Smith JM, König B, Alabugin IV. CO2 or SO2: Should It Stay, or Should It Go? J Org Chem 2019; 84:6232-6243. [DOI: 10.1021/acs.joc.9b00503] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Gabriel dos Passos Gomes
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
| | - Alexander Wimmer
- Institut für Organische Chemie, Universität Regensburg, Universitätsstraße 31, Regensburg 93040, Germany
| | - Joel M. Smith
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
| | - Burkhard König
- Institut für Organische Chemie, Universität Regensburg, Universitätsstraße 31, Regensburg 93040, Germany
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
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20
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Enantioselective Rhodium-Catalyzed Cycloisomerization of 1,6-Allenynes to access 5/6-Fused Bicycle[4.3.0]nonadienes. Nat Commun 2019; 10:949. [PMID: 30814517 PMCID: PMC6393573 DOI: 10.1038/s41467-019-08900-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/11/2019] [Indexed: 11/08/2022] Open
Abstract
Transition-metal-catalyzed cycloisomerization of 1,n-allenynes represents a powerful synthetic tool to rapidly assemble complex polycyclic skeletons from simple linear substrates. Nevertheless, there are no reports of the asymmetric version of these reactions. Moreover, most of these reactions proceed through a 6-endo-dig cyclization pathway, which preferentially delivers the distal product (via 5/5 rhodacyclic intermediate) rather than the proximal one (via 6/5 rhodacyclic intermediate). Herein, we report an enantioselective rhodium(I)-catalyzed cycloisomerization of 1,6-allenynes to provide the proximal product 5/6-fused bicycle[4.3.0]nonadienes in good yields and with excellent enantioselectivities. Remarkably, this chemistry works perfectly for 1,6-allenynes having a cyclic substituent within the allene component, thereby affording synthetically formidable tricyclic products with excellent enantioselectivities. Moreover, extensive DFT calculations suggest an uncommon pathway involving 5-exo-dig cycloisomerization, ring-expansion, rate-determining alkene isomerization involving Csp3-H activation, C-C activation of the cyclobutene moiety and finally reductive elimination. Deuterium labeling experiments support the rate-determining step involving the C–H bond activation in this transformation. Cycloisomerization of 1,n-allenynes allows to efficiently assembly polycyclic skeletons, however its asymmetric variant remains elusive. Here, the authors report the enantioselective Rh(I)-catalyzed cycloisomerization of 1,6-allenynes and disclose an uncommon 5-exo-dig pathway via DFT calculations.
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21
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Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Hochkonversion von Reduktionsmitteln. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201807247] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mikhail A. Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
| | - Febin Kuriakose
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
| | - Evgeniya A. Saverina
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
- UMR CNRS 6226 ISCR University of Rennes 1 Rennes Frankreich
| | | | - Mikhail P. Egorov
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
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22
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Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Upconversion of Reductants. Angew Chem Int Ed Engl 2019; 58:5532-5550. [DOI: 10.1002/anie.201807247] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Mikhail A. Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
| | - Febin Kuriakose
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
| | - Evgeniya A. Saverina
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
- UMR CNRS 6226 ISCR University of Rennes 1 Rennes France
| | | | - Mikhail P. Egorov
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
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23
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Gold-catalyzed cyclization of enediynes and arenediynes to 6H-benzo[c]chromen-6-one and dibenzo[c,h]chromen-6-one derivatives. Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.01.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Hughes AM, dos Passos Gomes G, Alabugin IV. Stereoelectronic Influence of a “Spectator” Propargylic Substituent Can Override Aromaticity Effects in Radical Peri-Cyclizations en Route to Expanded Polyaromatics. J Org Chem 2019; 84:1853-1862. [DOI: 10.1021/acs.joc.8b02779] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Audrey M. Hughes
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Gabriel dos Passos Gomes
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
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25
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Das E, Basak S, Anoop A, Chand S, Basak A. How To Achieve High Regioselectivity in Barrier-less Nucleophilic Addition to p-Benzynes Generated via Bergman Cyclization of Unsymmetrical Cyclic Azaenediyne? J Org Chem 2019; 84:2911-2921. [DOI: 10.1021/acs.joc.9b00060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eshani Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Shyam Basak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Anakuthil Anoop
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Santanu Chand
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Amit Basak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
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26
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Janiszewski A, Fax J, Haberhauer G. Dimerization of substituted 4-aryl-1,3-diacetylenes – quantum chemical calculations and kinetic studies. Org Chem Front 2019. [DOI: 10.1039/c9qo00119k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Thermal dimerization of 4-aryl-1,3-diacetylenes resulting in diradical intermediates were investigated by experimental and quantum chemical studies.
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Affiliation(s)
| | - Jonas Fax
- Institut für Organische Chemie
- Universität Duisburg-Essen
- D-45117 Essen
- Germany
| | - Gebhard Haberhauer
- Institut für Organische Chemie
- Universität Duisburg-Essen
- D-45117 Essen
- Germany
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27
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Jangra H, Chen Q, Fuks E, Zenz I, Mayer P, Ofial AR, Zipse H, Mayr H. Nucleophilicity and Electrophilicity Parameters for Predicting Absolute Rate Constants of Highly Asynchronous 1,3-Dipolar Cycloadditions of Aryldiazomethanes. J Am Chem Soc 2018; 140:16758-16772. [DOI: 10.1021/jacs.8b09995] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Harish Jangra
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Quan Chen
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Elina Fuks
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Ivo Zenz
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Peter Mayer
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Armin R. Ofial
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Hendrik Zipse
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
| | - Herbert Mayr
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany
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28
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Wenthold PG, Winter AH. Nucleophilic Addition to Singlet Diradicals: Homosymmetric Diradicals. J Org Chem 2018; 83:12390-12396. [DOI: 10.1021/acs.joc.8b01413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul G. Wenthold
- The Department of Chemistry and Biochemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Arthur H. Winter
- The Department of Chemistry and Biochemistry, Iowa State University, Ames, Iowa 52101, United States
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29
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Wenthold PG, Winter AH. Nucleophilic Addition to Singlet Diradicals: Heterosymmetric Diradicals. J Org Chem 2018; 83:12397-12403. [DOI: 10.1021/acs.joc.8b01414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paul G. Wenthold
- The Department of Chemistry and Biochemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Arthur H. Winter
- The Department of Chemistry and Biochemistry, Iowa State University, Ames, Iowa 52101, United States
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30
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Das E, Basak S, Anoop A, Basak A. Experiment and Computational Study on the Regioselectivity of Nucleophilic Addition to Unsymmetrical p-Benzynes Derived from Bergman Cyclization of Enediynes. J Org Chem 2018; 83:7730-7740. [PMID: 29790752 DOI: 10.1021/acs.joc.8b00624] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The regioselectivity in addition of nucleophiles to the p-benzyne intermediates derived from unsymmetrical aza-substituted enediynes via Bergman cyclization was studied. Computational studies [using UB3LYP/6-31G(d,p) level of theory] suggest that the p-benzyne intermediate retains its similar electrophilic character at the two radical centers even under unsymmetrical electronic perturbation, thus supporting the predicted model of nucleophilic addition to p-benzyne proposed by Perrin and co-workers (Perrin et al. J. Am. Chem. Soc. 2007, 129, 4795-4799) and later by Alabugin and co-workers (Peterson et al. Eur. J. Org. Chem. 2013, 2013, 2505-2527). However, observed experimental results suggest that there was small but definite regioselectivity (∼5-25%), the extent varying with the electronic nature of the substituents. Differential solvated halide ion concentrations around the vicinity of two radical centers arising due to surrounding surface electrostatic potential (computationally calculated) may be one of the possible factors for such selectivity in some of the examined p-benzynes. However, other complicated dynamical issues like the trajectory of the attacking nucleophile to the radical center which can be influenced by electronic and/or steric perturbation of starting enediyne conformation cannot be ruled out. The overall yield of the anionic addition was in the range of 80-99%.
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31
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Kita Y, Yata T, Nishimoto Y, Chiba K, Yasuda M. Selective oxymetalation of terminal alkynes via 6- endo cyclization: mechanistic investigation and application to the efficient synthesis of 4-substituted isocoumarins. Chem Sci 2018; 9:6041-6052. [PMID: 30079217 PMCID: PMC6053900 DOI: 10.1039/c8sc01537f] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/13/2018] [Indexed: 01/05/2023] Open
Abstract
The cyclization of heteroatom-containing alkynes with π acidic metal salts is an attractive method to prepare heterocycles because the starting materials are readily available and the organometallic compounds are useful synthetic intermediates. A new organometallic species in the heterocyclization provides an opportunity to synthesize heterocycles that are difficult to obtain. Herein, we describe a novel cyclic oxymetalation of 2-alkynylbenzoate with indium or gallium salts that proceeds with an unusual regioselectivity to give isocoumarins bearing a carbon-metal bond at the 4-position. This new type of metalated isocoumarin provided 3-unsubstituted isocoumarins that have seldom been investigated despite their important pharmacological properties. Indium and gallium salts showed high performance in the selective 6-endo cyclization of terminal alkynes while boron or other metals such as Al, Au, and Ag caused 5-exo cyclization or decomposition of terminal alkynes, respectively. The metalated isocoumarin and its reaction intermediate were unambiguously identified by X-ray crystallographic analysis. The theoretical calculation of potential energy profiles showed that oxyindation could proceed via 6-endo cyclization under thermodynamic control while previously reported oxyboration would give a 5-membered ring under kinetic control. The investigation of electrostatic potential maps suggested that the differences in the atomic characters of indium, boron and their ligands would contribute to such a regioselective switch. The metalated isocoumarins were applied to organic synthetic reactions. The halogenation of metalated isocoumarins proceeded to afford 4-halogenated isocoumarins bearing various functional groups. The palladium-catalyzed cross coupling of organometallic species with organic halides gave various 4-substituted isocoumarins. A formal total synthesis of oosponol, which exhibits strong antifungal activity, was accomplished.
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Affiliation(s)
- Yuji Kita
- Department of Applied Chemistry , Graduate School of Engineering , Osaka University , 2-1 Yamadaoka, Suita , Osaka 565-0871 , Japan .
| | - Tetsuji Yata
- Department of Applied Chemistry , Graduate School of Engineering , Osaka University , 2-1 Yamadaoka, Suita , Osaka 565-0871 , Japan .
| | - Yoshihiro Nishimoto
- Frontier Research Base for Global Young Researchers Center for Open Innovation Research and Education (COiRE) , Graduate School of Engineering , Osaka University , 2-1 Yamadaoka, Suita , Osaka 565-0871 , Japan .
| | - Kouji Chiba
- Material Science Division , MOLSIS Inc. , 1-28-38 Shinkawa, Chuo-ku , Tokyo 104-0033 , Japan
| | - Makoto Yasuda
- Department of Applied Chemistry , Graduate School of Engineering , Osaka University , 2-1 Yamadaoka, Suita , Osaka 565-0871 , Japan .
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Rinaldi A, Petrović M, Magnolfi S, Scarpi D, Occhiato EG. Pentannulation Reaction by Tandem Gold(I)-Catalyzed Propargyl Claisen Rearrangement/Nazarov Cyclization of Enynyl Vinyl Ethers. Org Lett 2018; 20:4713-4717. [DOI: 10.1021/acs.orglett.8b02141] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Antonia Rinaldi
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Florence, Italy
| | - Martina Petrović
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Florence, Italy
| | - Stefano Magnolfi
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Florence, Italy
| | - Dina Scarpi
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Florence, Italy
| | - Ernesto G. Occhiato
- Department of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019, Sesto Fiorentino (FI), Florence, Italy
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33
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Alabugin IV, Gonzalez-Rodriguez E. Alkyne Origami: Folding Oligoalkynes into Polyaromatics. Acc Chem Res 2018; 51:1206-1219. [PMID: 29676896 DOI: 10.1021/acs.accounts.8b00026] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Do not bend the triple bonds! This familiar undergraduate mantra must be disobeyed if the alkyne group is used as a building block in molecular construction. This Account will describe our exploits in "alkyne origami", that is, folding oligoalkynes into new shapes via cyclization cascades. This research stems from a set of guidelines for the cyclizations of alkynes that we suggested in 2011 ( Gilmore Chem. Rev. 2011 , 111 , 6513 ; Alabugin J. Am. Chem. Soc. 2011 , 133 , 12608 ). The guidelines blended critical analysis of ∼40 years of experimental research with computations into the comprehensive predictions of the relative favorability of dig-cyclizations of anions and radicals. In this Account, we will show how this new understanding has been instrumental in building polyaromatics. In particular, we illustrate the utility of these stereoelectronic models by developing a toolbox of practical, selective, and efficient synthetic transformations. The high energy and high carbon content render alkynes the perfect precursors for the preparation of polyaromatic ribbons and other carbon-rich materials with precisely controlled structure and reactivity. Still, the paradox of alkyne reactivity (alkynes store a lot of energy but are protected kinetically by their relatively strong π-bonds) requires precise use of stereoelectronic factors for lowering the activation barriers for alkyne cyclizations. These factors are drastically different in the "all-exo" and the "all-endo" cyclization cascades of oligoynes. This Account will highlight the interplay between the stereoelectronics of bond formation and topology of acyclic precursor "folding" into a polycyclic ribbon. The topology of folding is simpler for the endo cascades, which are compatible with initiation either at the edge or at the center. In contrast, the exo cascades require precise folding of an oligoalkyne ribbon by starting the cascade exactly at the center of the chain. These differences define the key challenges in the design of these two types of alkyne cyclization cascades. For the endo processes, the folding is simple, but these processes require a strategy ("LUMO Umpolung") for inverting the usual stereoelectronic requirements of alkyne cyclizations. We also show how alkenes can be used as alkyne equivalents in cyclizations coupled with fragmentations and how one can make endo cyclization products without ever going through an endo cyclization. In contrast, each elementary step of the exo cascades benefits from the inherent exo preference for the radical attack, but these cascades require precise initiation by starting exactly at the central alkyne unit of the oligoyne. This strict selectivity requirement led to the development of traceless directing groups capable of supramolecular assistance to the initiation step and self-terminating departure at the end of the cascade. With attention to electronic effects that can stop radical cascades, oligoalkynes can be selectively converted into precisely shaped and functionalized polyaromatic products. The generality of these concepts is further illustrated by the development of radical "peri annulations" at the zigzag edge of acenes.
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Affiliation(s)
- Igor V. Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Edgar Gonzalez-Rodriguez
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
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34
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Arndt S, Borstelmann J, Eshagh Saatlo R, Antoni PW, Rominger F, Rudolph M, An Q, Vaynzof Y, Hashmi ASK. The Gold(I)-Mediated Domino Reaction to Fused Diphenyl Phosphoniumfluorenes: Mechanistic Consequences for Gold-Catalyzed Hydroarylations and Application in Solar Cells. Chemistry 2018; 24:7882-7889. [DOI: 10.1002/chem.201800460] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Sebastian Arndt
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Jan Borstelmann
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Rebeka Eshagh Saatlo
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Patrick W. Antoni
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Frank Rominger
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Matthias Rudolph
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Qingzhi An
- Kirchhoff-Institute for Physics; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 227 69120 Heidelberg Germany
- Centre for Advanced Materials; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - Yana Vaynzof
- Kirchhoff-Institute for Physics; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 227 69120 Heidelberg Germany
- Centre for Advanced Materials; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 225 69120 Heidelberg Germany
| | - A. Stephen K. Hashmi
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
- Chemistry Department; Faculty of Science; King Abdulaziz University (KAU); Jeddah 21589 Saudi Arabia
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35
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Sharma P, Jadhav PD, Skaria M, Liu RS. Stereoselective annulation between an allene, an alkene, and two nitrosoarenes to access bis(isoxazoliodine) derivatives. Org Biomol Chem 2018; 15:9389-9397. [PMID: 29091104 DOI: 10.1039/c7ob02087b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This work reports metal-free annulations between one allene, two nitrosoarenes and one electron-deficient alkene to afford bis(isoxazolidine) derivatives stereoselectively. This process involves an initial formation of isoxazolidin-4-imine oxides, followed by their dipolar [3 + 2]-cycloaddition with electron-deficient alkenes. To highlight the utility, the annulations of 5-alleneyl-1-enes with nitrosoarenes were also feasible to afford the desired bis(isoxazolidine) products with excellent stereocontrol. The resulting bis(isoxazolidine) products produced from two systems were reduced with Zn/MeOH to induce reductive N-O cleavages, yielding branched polyaminols stereoselectively.
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Affiliation(s)
- Pankaj Sharma
- Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan, 30013, Republic of China.
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36
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Saraswat M, Venkataramani S. Through bond and through space interactions in dehydro-diazine radicals: a case study of 3c-5e interactions. Phys Chem Chem Phys 2018; 20:4386-4395. [PMID: 29369313 DOI: 10.1039/c7cp07579k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Owing to the 3c-5e (3-centred-5-electrons) interactions between two nitrogen lone pairs and a radical electron, the dehydrodiazine radical isomers are very interesting from the fundamental point of view. Among them, pyrimidine has three (1a-1c), pyridazine has two (2a and 2b) and pyrazine has only one (3a) radical isomer. Based on quantum chemical calculations at the (U)B3LYP, (U)M06-2X, (U)BLYP, CBS-QB3 and (U)CCSD(T) levels with cc-pVTZ as the basis set, we found the 4-dehydropyrimidine (1b) radical to be the most stable isomer among the three pyrimidine radicals, followed by the 2-dehydropyrimidine (1a) and 5-dehydropyrimidine (1c) radical isomers. In the case of pyridazine, 3-dehydro radical isomer (2a) is more stable than 4-dehydropyridazine (2b). Bond dissociation energy (BDE) calculations and estimation of radical stabilization energies (RSE) using isodesmic reactions revealed the stability order among the six isomeric diazine radicals as 1c < 2b < 2a < 1a < 3a < 1b. Spin densities at each radical centre and non-zero values at nitrogen centres provided information about the extent of delocalization of radical electrons, which was consistent with the relative stability order of all the isomers. The multiconfigurational CASSCF and natural bond orbital (NBO) calculations suggested the presence of direct through space interactions (between lone pairs and a radical, TS) that play a dominant role over the through bond (through intervening bonds, TB) interactions in deciding the stability order. To confirm these results, we have also estimated the proton affinities (PAs) for each nitrogen atom and compared them with their respective parent diazines, where lowering of the PA values convincingly envisaged the extent and strength of interactions between the nitrogen and radical centre. Atoms-in-molecules (AIM) analysis and estimation of hyperfine coupling constants have also been performed to verify these results. All these results showed that the through space interaction between the lone pair and the radical electron is very important for the electronic structural and stability aspects in dehydrodiazine radicals.
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Affiliation(s)
- Mayank Saraswat
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, Knowledge City, SAS Nagar, Mohali, Punjab - 140306, India.
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37
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Fiser B, Cuerva JM, Gómez-Bengoa E. Baldwin-Type Rules for Metal-Controlled Intramolecular Migratory Insertions. A Computational Study of Ni, Pd, and Pt Case. Organometallics 2018. [DOI: 10.1021/acs.organomet.7b00812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Béla Fiser
- Department
of Organic Chemistry I, University of the Basque Country (UPV-EHU), Donostia−San
Sebastián, 20018, Spain
- Institute
of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Ferenc
Rákóczi II, Transcarpathian Hungarian Institute, Beregszász,
Transcarpathia, 90200, Ukraine
| | - Juan M. Cuerva
- Department
of Organic Chemistry, University of Granada, Granada, 18071, Spain
| | - Enrique Gómez-Bengoa
- Department
of Organic Chemistry I, University of the Basque Country (UPV-EHU), Donostia−San
Sebastián, 20018, Spain
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38
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Bhattacharya P, Basak A, Campbell A, Alabugin IV. Photochemical Activation of Enediyne Warheads: A Potential Tool for Targeted Antitumor Therapy. Mol Pharm 2018; 15:768-797. [DOI: 10.1021/acs.molpharmaceut.7b00911] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - Amit Basak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Adam Campbell
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Igor V. Alabugin
- Department of Chemistry & Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States
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39
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Valenzuela SA, Cortés AJ, Tippins ZJE, Daly MH, Keel TE, Gherman BF, Spence JD. Effect of Extended Benzannelation Orientation on Bergman and Related Cyclizations of Isomeric Quinoxalenediynes. J Org Chem 2017; 82:13297-13312. [PMID: 29121468 DOI: 10.1021/acs.joc.7b02420] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A combined computational and experimental study was conducted to examine the effect of extended benzannelation orientation on C1-C5 and C1-C6 cyclization of acyclic quinoxalenediynes. Calculations (mPW1PW91/cc-pVTZ//mPW1PW91/6-31G(d,p)) on terminal and phenylethynyl-substituted 5,6-diethynylquinoxaline and 6,7-diethynylquinoxaline showed C1-C6 Bergman cyclization as the favored thermodynamic reaction pathway, with larger C1-C6 preference for the angular quinoxalenediynes due to gain of a new aromatic sextet. Kinetic studies, as a function of 1,4-cyclohexadiene concentration, revealed retro-Bergman ring opening predominates over hydrogen atom abstraction (k-1 > k2) for 6,7-diethynylquinoxaline while 5,6-diethynylquinoxaline undergoes irreversible Bergman cyclization indicative of a large retro-Bergman ring opening barrier (k2 > k-1). The effect of extended linear versus angular benzannelation on reaction pathway shows in the contrasting photocyclizations of phenylethynyl derivatives. While angular 5,6-diethynylquinoxalines gave exclusive C1-C6 photocyclization, linear 6,7-diethynylquinoxaline afforded C1-C5 fulvene products. Computed singlet-triplet gaps and biradical stabilization energies indicated weak interaction between the nitrogen lone pair and proximal radical center in angular 5,6-diethynylquinoxalines. The overall data indicates extended angular benzannelation effectively renders Bergman cyclization irreversible due to favorable aromatic stabilization energy, while extended linear benzannelation results in increased retro-Bergman ring opening, allowing C1-C5 cyclization to become a competitive reaction channel.
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Affiliation(s)
- Stephanie A Valenzuela
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - Alondra J Cortés
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - Zakery J E Tippins
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - Morgan H Daly
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - Terell E Keel
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - Benjamin F Gherman
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
| | - John D Spence
- Department of Chemistry, California State University, Sacramento , 6000 J Street, Sacramento, California 95819, United States
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40
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Qin P, Cope SK, Steger H, Veccharelli KM, Holland RL, Hitt DM, Moore CE, Baldridge KK, O’Connor JM. Photoactivated Transition-Metal Triggers for Ambient Temperature Enediyne and Dienyne Cyclization: Ruthenium-η6-Naphthalene Complexes. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00589] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Pengjin Qin
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Stephen K. Cope
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Han Steger
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Kate M. Veccharelli
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Ryan L. Holland
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - David M. Hitt
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Curtis E. Moore
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Kim K. Baldridge
- School
of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, People’s Republic of China
| | - Joseph M. O’Connor
- Department
of Chemistry, University of California, San Diego, La Jolla, California 92093, United States
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41
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Cycloaromatization of Enediyne Compounds under the Action of Bromide Ions: Diradical/Zwitterionic/Anionic Pathways. ASIAN J ORG CHEM 2017. [DOI: 10.1002/ajoc.201700136] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Pedroli C, Ravelli D, Protti S, Albini A, Fagnoni M. Singlet vs Triplet Reactivity of Photogenerated α,n-Didehydrotoluenes. J Org Chem 2017; 82:6592-6603. [DOI: 10.1021/acs.joc.7b00610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Chiara Pedroli
- Department of Chemistry, PhotoGreen Lab, Viale
Taramelli 12, 27100 Pavia, Italy
| | - Davide Ravelli
- Department of Chemistry, PhotoGreen Lab, Viale
Taramelli 12, 27100 Pavia, Italy
| | - Stefano Protti
- Department of Chemistry, PhotoGreen Lab, Viale
Taramelli 12, 27100 Pavia, Italy
| | - Angelo Albini
- Department of Chemistry, PhotoGreen Lab, Viale
Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- Department of Chemistry, PhotoGreen Lab, Viale
Taramelli 12, 27100 Pavia, Italy
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43
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Chen CC, Wu MY, Chen HY, Wu MJ. Halogen-Mediated Cascade Cyclization Reaction of Aryldiynes to Indeno[1,2-c]chromene Derivatives. J Org Chem 2017; 82:6071-6081. [DOI: 10.1021/acs.joc.7b00538] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chin-Chau Chen
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Man-Yun Wu
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Hsing-Yin Chen
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Ming-Jung Wu
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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44
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Construction of Polyarylenes with Various Structural Features via Bergman Cyclization Polymerization. Top Curr Chem (Cham) 2017; 375:60. [PMID: 28534207 DOI: 10.1007/s41061-017-0145-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 05/06/2017] [Indexed: 12/18/2022]
Abstract
Synthetic polymer chemistry is a fundamental part of polymer science, and highly efficient polymerization reactions are essential for the synthesis of high-performance polymers. Development of new synthetic methods for emerging polymer science is of great importance in this regard. Bergman cyclization is a chemical process in which highly reactive aryl diradicals form from enediyne precursors, having a strong impact in a number of fields including pharmaceutics, synthetic chemistry, and materials science. Diradical intermediates stemming from enediynes can cause DNA cleavage under physiological conditions, leading to the strong cytotoxicity of many naturally occurring enediyne antibiotics. Meanwhile, diradical intermediates can quickly couple with each other to construct polyarylenes, providing a novel method to synthesize these conjugated polymers with the advantages of facile and catalyst-free operation, high efficiency, and tailored structure. Moreover, conjugated polymers generated by Bergman cyclization exhibit many remarkable properties, such as excellent thermal stability and good solubility and processability, enabling their further processing into carbon-rich materials. This review presents a brief overview of the trajectory of Bergman cyclization in polymer science, followed by an introduction to research advances, mainly from our group, in developing polymerization methods based on Bergman cyclization, taking advantages of its catalyst-free, byproduct-free, in situ polymerization mechanism to synthesize new polymeric materials with various structures and morphologies. These synthetic strategies include fabrication of rod-like polymers with polyester, dendrimer, and chiral imide side chains, functionalization of carbon nanomaterials by surface-grafting conjugated polymers, formation of nanoparticles by intramolecular collapse of single polymer chains, and construction of carbon nanomembranes on the external and internal surface of inorganic nanomaterials. These polymers with novel structural features have been used in a variety of fields, such as energy transformation, energy storage, catalyst support, and fluorescent detection. Finally, the outlook for future developments of Bergman cyclization in polymer science is presented.
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46
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dos Passos Gomes G, Alabugin IV. Drawing Catalytic Power from Charge Separation: Stereoelectronic and Zwitterionic Assistance in the Au(I)-Catalyzed Bergman Cyclization. J Am Chem Soc 2017; 139:3406-3416. [DOI: 10.1021/jacs.6b11054] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Gabriel dos Passos Gomes
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-439, United States
| | - Igor V. Alabugin
- Department of Chemistry and
Biochemistry, Florida State University, Tallahassee, Florida 32306-439, United States
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47
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Chen S, Li Q, Sun S, Ding Y, Hu A. A Novel Approach toward Polyfulvene: Cationic Polymerization of Enediynes. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02321] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Shudan Chen
- Shanghai Key Laboratory of
Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Qiaoping Li
- Shanghai Key Laboratory of
Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Shiyuan Sun
- Shanghai Key Laboratory of
Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yun Ding
- Shanghai Key Laboratory of
Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Aiguo Hu
- Shanghai Key Laboratory of
Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
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48
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Das J, Roy S, Halnor S, Das AK, Basak A. Enediyne-based protein capture agents: demonstration of an enediyne moiety acting as a photoaffinity label. Org Biomol Chem 2017; 15:1122-1129. [DOI: 10.1039/c6ob02075e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Two enediyne based protein-capture compounds 1 and 2 were synthesized.
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Affiliation(s)
- Joyee Das
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur-721302
- India
| | - Sayantani Roy
- School of Bioscience
- Indian Institute of Technology Kharagpur
- Kharagpur-721302
- India
| | - Swapnil Halnor
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur-721302
- India
| | - Amit Kumar Das
- School of Bioscience
- Indian Institute of Technology Kharagpur
- Kharagpur-721302
- India
| | - Amit Basak
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur-721302
- India
- School of Bioscience
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49
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Peterson PW, Shevchenko N, Breiner B, Manoharan M, Lufti F, Delaune J, Kingsley M, Kovnir K, Alabugin IV. Orbital Crossings Activated through Electron Injection: Opening Communication between Orthogonal Orbitals in Anionic C1–C5 Cyclizations of Enediynes. J Am Chem Soc 2016; 138:15617-15628. [DOI: 10.1021/jacs.6b08540] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Paul W. Peterson
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Nikolay Shevchenko
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Boris Breiner
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Mariappan Manoharan
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Forat Lufti
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Jess Delaune
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Margaret Kingsley
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Kirill Kovnir
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
| | - Igor V. Alabugin
- Department of Chemistry and
Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, Florida 32301, United States
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50
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Morrison AE, Hrudka JJ, Dudley GB. Thermal Cycloisomerization of Putative Allenylpyridines for the Synthesis of Isoquinoline Derivatives. Org Lett 2016; 18:4104-7. [DOI: 10.1021/acs.orglett.6b02034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alec E. Morrison
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Jeremy J. Hrudka
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Gregory B. Dudley
- Department
of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
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