1
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Kloudová B, Vrkoslav V, Polášek M, Bosáková Z, Cvačka J. Structural characterization of wax esters using ultraviolet photodissociation mass spectrometry. Anal Bioanal Chem 2024:10.1007/s00216-024-05434-2. [PMID: 39030399 DOI: 10.1007/s00216-024-05434-2] [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: 04/02/2024] [Revised: 07/01/2024] [Accepted: 07/03/2024] [Indexed: 07/21/2024]
Abstract
Wax esters play critical roles in biological systems, serving functions from energy storage to chemical signaling. Their diversity is attributed to variations in alcohol and acyl chains, including their length, branching, and the stereochemistry of double bonds. Traditional analysis by mass spectrometry with collisional activations (CID, HCD) offers insights into acyl chain lengths and unsaturation level. Still, it falls short in pinpointing more nuanced structural features like the position of double bonds. As a solution, this study explores the application of 213-nm ultraviolet photodissociation (UVPD) for the detailed structural analysis of wax esters. It is shown that lithium adducts provide unique fragments as a result of Norrish and Norrish-Yang reactions at the ester moieties and photoinduced cleavages of double bonds. The product ions are useful for determining chain lengths and localizing double bonds. UVPD spectra of various wax esters are presented systematically, and the effect of activation time is discussed. The applicability of tandem mass spectrometry with UVPD is demonstrated for wax esters from natural sources. The UHPLC analysis of jojoba oil proves the compatibility of MS2 UVPD with the chromatography time scale, and a direct infusion is used to analyze wax esters from vernix caseosa. Data shows the potential of UVPD and its combination with CID or HCD in advancing our understanding of wax ester structures.
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Affiliation(s)
- Barbora Kloudová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 160 00, Prague 6, Czech Republic
- Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43, Prague 2, Czech Republic
| | - Vladimír Vrkoslav
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 160 00, Prague 6, Czech Republic
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 2155/3, 182 23, Prague 8, Czech Republic
| | - Zuzana Bosáková
- Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43, Prague 2, Czech Republic
| | - Josef Cvačka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 160 00, Prague 6, Czech Republic.
- Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43, Prague 2, Czech Republic.
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2
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Maag H, Lemcke DJ, Wahl JM. Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes. Beilstein J Org Chem 2024; 20:1671-1676. [PMID: 39076297 PMCID: PMC11285075 DOI: 10.3762/bjoc.20.148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/11/2024] [Indexed: 07/31/2024] Open
Abstract
α-Aminoacetophenones are identified as promising building blocks for the synthesis of highly substituted dioxolanes. The presented strategy is founded on the build and release of molecular strain and achieves a formal transposition of a methyl group. During light irradiation, 3-phenylazetidinols are forged as reaction intermediates, which readily undergo ring opening upon the addition of electron-deficient ketones or boronic acids. Key to the successful development of this two-step process is the identification of a benzhydryl-protecting group, which orchestrates the photochemical Norrish-Yang cyclization and facilitates the subsequent ring opening.
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Affiliation(s)
- Henning Maag
- Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10–14, 55128 Mainz, Germany
| | - Daniel J Lemcke
- Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10–14, 55128 Mainz, Germany
| | - Johannes M Wahl
- Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10–14, 55128 Mainz, Germany
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3
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Costa T, Sampaio-Marques B, Neves NM, Aguilar H, Fraga AG. Antimicrobial properties of hindered amine light stabilizers in polymer coating materials and their mechanism of action. Front Bioeng Biotechnol 2024; 12:1390513. [PMID: 38978720 PMCID: PMC11229053 DOI: 10.3389/fbioe.2024.1390513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/27/2024] [Indexed: 07/10/2024] Open
Abstract
UV-stabilizers are a class of additives that provide extended polymer resistance to UV-degradation, but have also been suggested to have antimicrobial activity, potentially preventing the spread of pathogens, and inhibiting microbial-induced biodegradation. In this work, we incorporated different UV-stabilizers, a hindered amine light stabilizer (HALS), Tinuvin 770 DF and Tinuvin PA 123, or a hybrid HALS/UV-absorber, Tinuvin 5151, in polyurethane formulations to produce lacquer-films, and tested their antimicrobial activity against Staphylococcus aureus (methicillin-resistant and -sensitive strains), Escherichia coli and Candida albicans. Lacquer-films incorporated with Tinuvin 770 DF showed strong antimicrobial performance against bacteria and fungi, while maintaining cytocompatibility. The mechanism of action revealed a positive relationship between Tinuvin 770 DF concentration, microbial death, and reactive nitrogen species (RNS), suggesting that RNS produced during autoxidation of Tinuvin 770 DF is responsible for the antimicrobial properties of this UV-stabilizer. Conversely, lacquer-films incorporated with Tinuvin 5151 or Tinuvin PA 123 exhibited no antimicrobial properties. Collectively, these results highlight the commercial potential of Tinuvin 770 DF to prevent photo- and biodegradation of polymers, while also inhibiting the spread of potentially harmful pathogens. Furthermore, we provide a better understanding of the mechanism underlying the biocidal activity of HALS associated to autooxidation of the amine group.
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Affiliation(s)
- Tiago Costa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Belém Sampaio-Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno M. Neves
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Portugal
- 3B’s Research Group on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal
| | - Helena Aguilar
- Têxtil Manuel Gonçalves—Tecidos Plastificados e Outros Revestimentos Para a Indústria Automóvel, S.A. (TMG Automotive), Largo Comendador Manuel Gonçalves, Guimarães, Portugal
| | - Alexandra G. Fraga
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Portugal
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4
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Garner SM, Haugen EA, Leone SR, Neuscamman E. Spin Coupling Effect on Geometry-Dependent X-Ray Absorption of Diradicals. J Am Chem Soc 2024; 146:2387-2397. [PMID: 38235992 DOI: 10.1021/jacs.3c08002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
We theoretically investigate the influence of diradical electron spin coupling on the time-resolved X-ray absorption spectra of the photochemical ring opening of furanone. We predict geometry-dependent carbon K-edge signals involving transitions from core orbitals to both singly and unoccupied molecular orbitals. The most obvious features of the ring opening come from the carbon atom directly involved in the bond breaking through its transition to both the newly formed singly occupied and the available lowest unoccupied molecular orbitals (SOMO and LUMO, respectively). In addition to this primary feature, the singlet spin coupling of four unpaired electrons that arises in the core-to-LUMO states creates additional geometry dependence in some spectral features with both oscillator strengths and relative excitation energies varying observably as a function of the ring opening. We attribute this behavior to a spin-occupancy-induced selection rule, which occurs when singlet spin coupling is enforced in the diradical state. Notably, one of these geometry-sensitive core-to-LUMO transitions excites core electrons from a backbone carbon not involved in the bond breaking, providing a novel nonlocal X-ray probe of chemical dynamics arising from electron spin coupling.
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Affiliation(s)
- Scott M Garner
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Eric A Haugen
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stephen R Leone
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Physics, University of California, Berkeley, California 94720, United States
| | - Eric Neuscamman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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5
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Yu X, Huang N, Huo Y, Li X, Liu Y, Maruoka K, Chen Q. Photoredox-Mediated Aerobic Oxidative Cleavage of 1,3-Diketones to Access 1,2-Diketones and ( Z)-1,4-Enediones. Org Lett 2024. [PMID: 38175988 DOI: 10.1021/acs.orglett.3c04247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
An aerobic oxidative cleavage of 1,3-diketones under visible light irradiation using an organic dye as a photocatalyst is disclosed. The newly developed reaction provides practical access to 1,2-diketones and (Z)-1,4-enediones in moderate to good yields with absolute regio- and stereoselectivity. Mechanistic studies of the reaction suggest that tetraketone intermediates might undergo a photocatalytic energy transfer from the excited photocatalyst to form biradical-like (n,π*) states of ketones.
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Affiliation(s)
- Xiaofeng Yu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Nan Huang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanping Huo
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Xianwei Li
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Yan Liu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Keiji Maruoka
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Qian Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
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6
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Nguyen TVT, Bossonnet A, Wodrich MD, Waser J. Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles. J Am Chem Soc 2023; 145:25411-25421. [PMID: 37934629 DOI: 10.1021/jacs.3c09789] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
We report the use of photocatalysis for the homolytic ring-opening of carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or a strong reductant. The carbonyl cyclopropanes can be employed for both [2σ + 2σ] and [2σ + 2π] annulation with either alkenes/alkynes or bicyclo[1.1.0]butanes, yielding cyclopent-anes/-enes and bicyclo[3.1.1]heptanes (BCHs), respectively. BCHs are promising bioisosteres for 1,2,4,5 tetra-substituted aromatic rings. Mechanistic studies, including density functional theory computation and a trapping experiment with DMPO, support a 1,3-biradical generated from cyclopropane as a key intermediate for these transformations.
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Affiliation(s)
- Tin V T Nguyen
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - André Bossonnet
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - Matthew D Wodrich
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
| | - Jerome Waser
- Laboratory of Catalysis and Organic Synthesis, Institute of Chemistry and Chemical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne Ch-1015, Switzerland
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7
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Ghosh SK, He L, Tang Z, Comito RJ. Selective and Functional-Group-Tolerant Photoalkylation of Imines by Energy-Transfer Photocatalysis. J Org Chem 2023; 88:15209-15217. [PMID: 37875007 DOI: 10.1021/acs.joc.3c01722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Basic amines show broad bioactivity and remain a promising source of new medicines. The direct photoalkylation of imines offers a promising strategy for complex amines. However, the lack of efficient imine photoreactivity hinders this reaction and remains a fundamental limitation in organic photochemistry. We report an efficient photoalkylation of imines that provides primary amines directly without protecting or leaving groups. The transformation effects C-H addition across N-H imines under energy-transfer photocatalysis by a ketone. Our method is distinguished from organometallic, metal-catalyzed, and photoredox approaches to imine alkylation by its lack of protecting groups and its broad scope, which includes unactivated alkanes, protic substrates, basic amines, heterocycles, and ketone imines. We highlight this scope through the condensation and alkylation of two pharmaceutical ketones, providing complex amines succinctly. Our mechanistic analysis supports a three-step process, involving hydrogen-atom transfer to an imine triplet excited state, intersystem crossing, and radical recombination, with photocatalytic enhancement through energy transfer. We further show that N-H imines are more photoreactive than N-substituted imines, a distinction partially explained by sterics and side reactions. To fully explain this distinction, we introduce the thermodynamic parameter excited-state hydrogen-atom affinity, which is highly effective at predicting the photoreactivity of imines.
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Affiliation(s)
- Subrata K Ghosh
- The University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Lizhe He
- The University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Zilu Tang
- The University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Robert J Comito
- The University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
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8
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Oya R, Ota K, Fuki M, Kobori Y, Higashi M, Nagao K, Ohmiya H. Biomimetic design of an α-ketoacylphosphonium-based light-activated oxygenation auxiliary. Chem Sci 2023; 14:10488-10493. [PMID: 37799983 PMCID: PMC10548508 DOI: 10.1039/d3sc03572g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/04/2023] [Indexed: 10/07/2023] Open
Abstract
The biomimetic design of a transition metal complex based on the iron(iv)-oxo porphyrin π-cation radical species in cytochrome P450 enzymes has been studied extensively. Herein, we translate the functions of this iron(iv)-oxo porphyrin π-cation radical species to an α-ketoacyl phosphonium species comprised of non-metal atoms and utilize it as a light-activated oxygenation auxiliary for ortho-selective oxygenation of anilines. Visible light irradiation converts the α-ketoacyl phosphonium species to the excited state, which acts as a transiently generated oxidant. The intramolecular nature of the process ensures high regioselectivity and chemoselectivity. The auxiliary is easily removable. A one-pot protocol is also described.
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Affiliation(s)
- Ryoto Oya
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University Kakuma-Machi Kanazawa 920-1192 Japan
| | - Kenji Ota
- Institute for Chemical Research, Kyoto University Gokasho, Uji Kyoto 611-0011 Japan
| | - Masaaki Fuki
- Molecular Photoscience Research Center, Department of Chemistry, Graduate School of Science, Kobe University Kobe 657-8501 Japan
| | - Yasuhiro Kobori
- Molecular Photoscience Research Center, Department of Chemistry, Graduate School of Science, Kobe University Kobe 657-8501 Japan
| | - Masahiro Higashi
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Kazunori Nagao
- Institute for Chemical Research, Kyoto University Gokasho, Uji Kyoto 611-0011 Japan
| | - Hirohisa Ohmiya
- Institute for Chemical Research, Kyoto University Gokasho, Uji Kyoto 611-0011 Japan
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9
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Sandvoß A, Wahl JM. From Cycloalkanols to Heterocycles via Nitrogen Insertion. Org Lett 2023; 25:5795-5799. [PMID: 37503963 DOI: 10.1021/acs.orglett.3c02048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
A variety of cyclic alcohols are found to undergo nitrogen insertion by subjection to O-mesitylsulfonylhydroxylamine. Critical to a successful process is the use of fluorinated alcoholic solvents, which ensures sufficient substrate activation to allow engagement with the ambiphilic aminating agent. This transition-metal-free nitrogen insertion provides access to a variety of medicinally relevant heterocycles such as pyrrolidenes, quinolines, and benzazepines (24 examples). Furthermore, combination with a photochemical Norrish-Yang-type cyclization allows an unprecedented access to indoles from ortho-substituted acetophenones.
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Affiliation(s)
- Alexander Sandvoß
- Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes M Wahl
- Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55128 Mainz, Germany
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10
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Zhao X, Yu X, Liu M, Huo Y, Ji S, Li X, Chen Q. Direct Benzylic C-H Functionalization with Fluorenones under Visible-Light Irradiation. J Org Chem 2023; 88:2612-2620. [PMID: 36725672 DOI: 10.1021/acs.joc.2c02766] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An external photocatalyst-free benzylic C-H functionalization with fluorenones under visible-light irradiation has been achieved. This transformation provides an efficient synthetic approach to 9-benzylated fluorenols in ≤91% yield with 100% atom economy under mild conditions. Spectroscopic studies suggest that a reductive quenching of photoexcited fluorenones with toluene derivatives generates ketyl radicals and benzyl radicals, which undergo a cross-coupling to afford the desired fluorenols.
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Affiliation(s)
- Xi Zhao
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Xiaofeng Yu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Mingjun Liu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Yanping Huo
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Shaomin Ji
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Xianwei Li
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
| | - Qian Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China
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11
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Oddy MJ, Kusza DA, Epton RG, Lynam JM, Unsworth WP, Petersen WF. Visible-Light-Mediated Energy Transfer Enables the Synthesis of β-Lactams via Intramolecular Hydrogen Atom Transfer. Angew Chem Int Ed Engl 2022; 61:e202213086. [PMID: 36205440 PMCID: PMC9828223 DOI: 10.1002/anie.202213086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Indexed: 11/07/2022]
Abstract
The synthesis of 2-azetidinones (β-lactams) from simple acrylamide starting materials by visible-light-mediated energy transfer catalysis is reported. The reaction features a C(sp3 )-H functionalization via a variation of the Norrish-Yang photocyclization involving a carbon-to-carbon 1,5-hydrogen atom transfer (supported by deuterium labelling and DFT calculations) and can be used for the construction of a diverse range of β-lactam products.
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Affiliation(s)
- Meghan J. Oddy
- Department of ChemistryUniversity of Cape TownRondebosch, Cape Town7700South Africa
| | - Daniel A. Kusza
- Department of ChemistryUniversity of Cape TownRondebosch, Cape Town7700South Africa
| | - Ryan G. Epton
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | | | | | - Wade F. Petersen
- Department of ChemistryUniversity of Cape TownRondebosch, Cape Town7700South Africa
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12
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Singh M, Gaskins B, Johnson DR, Elles CG, Boskovic Z. Synthesis of Cycloheptatriene-Containing Azetidine Lactones. J Org Chem 2022; 87:15001-15010. [PMID: 35605105 PMCID: PMC10091648 DOI: 10.1021/acs.joc.2c00367] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We prepared a collection of complex cycloheptatriene-containing azetidine lactones by applying two key photochemical reactions: "aza-Yang" cyclization and Buchner carbene insertion into aromatic rings. While photolysis of phenacyl amines leads to a rapid charge transfer and elimination, we found that a simple protonation of the amine enables the formation of azetidinols as single diastereomers. We provide evidence, through ultrafast spectroscopy, for the electron transfer from free amines in the excited state. Further, we characterize the aza-Yang reaction by establishing the dependence of the initial reaction rates on the rates of photon absorption. An unanticipated change in reactivity in morpholine analogues is explained through interactions with the tosylate anion. The Buchner reaction proceeds with a slight preference for one diastereomer over the other, and successful reaction requires electron-donating carbene-stabilizing substituents. Overall, 16 compounds were prepared over seven steps. Guided by an increase in structural complexity, efforts such as this one extend the reach of chemists into unexplored chemical space and provide useful quantities of new compounds for studies focused on their properties.
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Affiliation(s)
- Manvendra Singh
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Bryce Gaskins
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Daniel R Johnson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Zarko Boskovic
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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13
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Di Sabato A, D’Acunzo F, Filippini D, Vetica F, Brasiello A, Corinti D, Bodo E, Michenzi C, Panzetta E, Gentili P. Unusually Chemoselective Photocyclization of 2-(Hydroxyimino)aldehydes to Cyclobutanol Oximes: Synthetic, Stereochemical, and Mechanistic Aspects. J Org Chem 2022; 87:13803-13818. [PMID: 36198009 PMCID: PMC9639046 DOI: 10.1021/acs.joc.2c01503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Photocyclization of carbonyl compounds (known as the Norrish-Yang reaction) to yield cyclobutanols is, in general, accompanied by fragmentation reactions. The latter are predominant in the case of aldehydes so that secondary cyclobutanols are not considered accessible via the straightforward Norrish-Yang reaction. A noteworthy exception has been reported in our laboratory, where cyclobutanols bearing a secondary alcohol function were observed upon UV light irradiation of 2-(hydroxyimino)aldehydes (HIAs). This reaction is here investigated in detail by combining synthesis, spectroscopic data, molecular dynamics, and DFT calculations. The synthetic methodology is generally applicable to a series of HIAs, affording the corresponding cyclobutanol oximes (CBOs) chemoselectively (i.e., without sizable fragmentation side-reactions), diastereoselectively (up to >99:1), and in good to excellent yields (up to 95%). CBO oxime ether derivatives can be purified and diastereomers isolated by standard column chromatography. The mechanistic and stereochemical picture of this photocyclization reaction, as well as of the postcyclization E/Z isomerization of the oxime double bond is completed.
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Affiliation(s)
- Antonio Di Sabato
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,Institute
of Biological Systems (ISB), Sezione Meccanismi di Reazione, Italian
National Research Council (CNR), c/o Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Francesca D’Acunzo
- Institute
of Biological Systems (ISB), Sezione Meccanismi di Reazione, Italian
National Research Council (CNR), c/o Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Dario Filippini
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Fabrizio Vetica
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,
| | - Antonio Brasiello
- Department
of Chemical Engineering Materials Environment, Sapienza University of Rome, via Eudossiana 18, 00184 Rome, Italy
| | - Davide Corinti
- Department
of Chemistry and Technology of Drugs, Sapienza
University of Rome, Piazzale
Aldo Moro 5, 00185 Rome, Italy
| | - Enrico Bodo
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Cinzia Michenzi
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Edoardo Panzetta
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Patrizia Gentili
- Department
of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,Institute
of Biological Systems (ISB), Sezione Meccanismi di Reazione, Italian
National Research Council (CNR), c/o Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy,
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14
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Alvarez-Dorta D, León EI, Martín Á, Kennedy AR, Pérez-Martín I, Shankland K, Suárez E. Regio- and Stereoselectivity of the Norrish-Yang Photocyclization of Dialkyl 1,2-Diketones: Solution versus Solid State Photochemistry of Two Polymorphs. J Org Chem 2022; 87:14940-14947. [PMID: 36283069 PMCID: PMC9639068 DOI: 10.1021/acs.joc.2c01855] [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] [Indexed: 01/07/2023]
Abstract
As shown by X-ray crystallography, crystals of 3β-acetoxy-16,17-seco-17,20-dioxopregn-5-ene-16-nitrile are dimorphic. The regioselectivity of the Norrish-Yang type II photocyclization under visible light of this steroidal 1,2-diketone, which bears primary, secondary, and tertiary nonequivalent abstractable γ-hydrogens, dramatically increases in the crystalline state of both polymorphs. X-ray crystallography and molecular mechanics calculations reveal crystal structure-solid state photochemistry relationships.
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Affiliation(s)
- Dimitri Alvarez-Dorta
- Síntesis
de Productos Naturales, Instituto de Productos
Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez
3, 38206 La Laguna, Tenerife, Spain
| | - Elisa I. León
- Síntesis
de Productos Naturales, Instituto de Productos
Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez
3, 38206 La Laguna, Tenerife, Spain,
| | - Ángeles Martín
- Síntesis
de Productos Naturales, Instituto de Productos
Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez
3, 38206 La Laguna, Tenerife, Spain
| | - Alan R. Kennedy
- WestCHEM
Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, Scotland, United Kingdom
| | - Inés Pérez-Martín
- Síntesis
de Productos Naturales, Instituto de Productos
Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez
3, 38206 La Laguna, Tenerife, Spain
| | - Kenneth Shankland
- School
of Pharmacy, University of Reading, Reading RG6 6AD, United Kingdom
| | - Ernesto Suárez
- Síntesis
de Productos Naturales, Instituto de Productos
Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez
3, 38206 La Laguna, Tenerife, Spain,
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15
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Dey J, Paul S, Bhakat M, Guin J. Photocatalytic Incorporation of an Oxime Ether Functional Group at Inert C(sp 3)–H Bonds via HAT. Org Lett 2022; 24:8047-8051. [DOI: 10.1021/acs.orglett.2c03300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jayanta Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Subhasis Paul
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Manotosh Bhakat
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
| | - Joyram Guin
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, West Bengal 700032, India
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16
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Yang L, Li WY, Hou L, Zhan T, Cao W, Liu X, Feng X. Nickel II-catalyzed asymmetric photoenolization/Mannich reaction of (2-alkylphenyl) ketones. Chem Sci 2022; 13:8576-8582. [PMID: 35974747 PMCID: PMC9337722 DOI: 10.1039/d2sc02721f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/21/2022] [Indexed: 11/21/2022] Open
Abstract
A diastereo- and enantioselective photoenolization/Mannich (PEM) reaction of ortho-alkyl aromatic ketones with benzosulfonimides was established by utilizing a chiral N,N'-dioxide/Ni(OTf)2 complex as the Lewis acid catalyst. It afforded a series of benzosulfonamides and the corresponding ring-closure products, and a reversal of diastereoselectivity was observed through epimerization of the benzosulfonamide products under continuous irradiation. On the basis of the control experiments, the role of the additive LiNTf2 in achieving high stereoselectivity was elucidated. This PEM reaction was proposed to undergo a direct nucleophilic addition mechanism rather than a hetero-Diels-Alder/ring-opening sequence. A possible transition state model with a photoenolization process was proposed to explain the origin of the high level of stereoinduction.
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Affiliation(s)
- Liangkun Yang
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Wang-Yuren Li
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Liuzhen Hou
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Tangyu Zhan
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Weidi Cao
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Xiaohua Liu
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
| | - Xiaoming Feng
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
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17
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Liu X, Liu P, Li H, Xu Z, Jia L, Xia Y, Yu M, Tang W, Zhu X, Chen C, Zhang Y, Nango E, Tanaka R, Luo F, Kato K, Nakajima Y, Kishi S, Yu H, Matsubara N, Owada S, Tono K, Iwata S, Yu LJ, Shen JR, Wang J. Excited-state intermediates in a designer protein encoding a phototrigger caught by an X-ray free-electron laser. Nat Chem 2022; 14:1054-1060. [DOI: 10.1038/s41557-022-00992-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/01/2022] [Indexed: 11/09/2022]
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18
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Ka CH, Lee DS, Cho EJ. Solvent‐dependent Photochemistry for Diverse and Selective C‐H Functionalization of 2‐tert‐Butyl‐1,4‐Benzoquinones. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202200136] [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)
- Cheol Hyeon Ka
- Chung-Ang University - Seoul Campus: Chung-Ang University Chemistry KOREA, REPUBLIC OF
| | - Da Seul Lee
- Chung-Ang University - Seoul Campus: Chung-Ang University Chemistry KOREA, REPUBLIC OF
| | - Eun Jin Cho
- Chung-Ang University Department of Chemistry 84 Heukseok-Ro, Dongjak-Gu 156-756 Seoul KOREA, REPUBLIC OF
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19
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Xiong Y, Großkopf J, Jandl C, Bach T. Visible Light-Mediated Dearomative Hydrogen Atom Abstraction/ Cyclization Cascade of Indoles. Angew Chem Int Ed Engl 2022; 61:e202200555. [PMID: 35213774 PMCID: PMC9314014 DOI: 10.1002/anie.202200555] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Indexed: 11/24/2022]
Abstract
The photochemical synthesis of yet unknown 2‐oxospiro[azetidine‐3,3′‐indolines] (17 examples, 80–95 % yield), 2,4‐dioxospiro[azetidine‐3,3′‐indolines] (eight examples, 87–97 % yield), and 1‐oxo‐1,3‐dihydrospiro[indene‐2,3′‐indolines] (17 examples, 85–97 % yield) is described. Starting from readily accessible 3‐substituted indoles, a dearomatization of the indole core was accomplished upon irradiation at λ=420 nm in the presence of thioxanthen‐9‐one (10 mol%) as the sensitizer. Based on mechanistic evidence (triplet energy determination, deuteration experiments, by‐product analysis) it is proposed that the reaction proceeds by energy transfer via a 1,4‐ or 1,5‐diradical intermediate. The latter intermediates are formed by excited state hydrogen atom transfer from suitable alkyl groups within the C3 substituent to the indole C2 carbon atom. Subsequent ring closure proceeds with pronounced diastereoselectivity to generate a 4‐ or 5‐membered spirocyclic dearomatized product with several options for further functionalization.
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Affiliation(s)
- Yang Xiong
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Johannes Großkopf
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Christian Jandl
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Thorsten Bach
- Department Chemie and Catalysis Research Center (CRC), School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
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20
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Yu H, Zhan T, Zhou Y, Chen L, Liu X, Feng X. Visible-Light-Activated Asymmetric Addition of Hydrocarbons to Pyridine-Based Ketones. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00789] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Han Yu
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Tangyu Zhan
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Yuqiao Zhou
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Long Chen
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Xiaohua Liu
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Xiaoming Feng
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
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21
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Xiong Y, Großkopf J, Jandl C, Bach T. Visible Light‐Mediated Dearomative Hydrogen Atom Abstraction/ Cyclization Cascade of Indoles. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200555] [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)
- Yang Xiong
- Technische Universität München: Technische Universitat Munchen Chemistry GERMANY
| | - Johannes Großkopf
- Technische Universität München: Technische Universitat Munchen Chemistry GERMANY
| | - Christian Jandl
- Technische Universität München: Technische Universitat Munchen Chemistry GERMANY
| | - Thorsten Bach
- Technische Universität München Lehrstuhl für Organische Chemie I Lichtenbergstr. 4 85747 Garching GERMANY
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22
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Zhu Y, Huang HY, He YQ, Wang M, Wang XY, Song XR, Mao ZJ, Tian WF, Xiao Q. Visible-light enabled photochemical reduction of 1,2-dicarbonyl compounds by Hünig's base. Org Chem Front 2022. [DOI: 10.1039/d1qo01841h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A visible-light enabled, chemoselective photoreduction of 1,2-dicarbonyl compounds by using Hünig's base as reductant is reported.
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Affiliation(s)
- Yao Zhu
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Hai-Yang Huang
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Yong-Qin He
- School of Pharmaceutical Science, Nanchang University, Nanchang, 330006, P. R. China
| | - Mei Wang
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Xiao-Yu Wang
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Xian-Rong Song
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Zhi-Jie Mao
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Wan-Fa Tian
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
| | - Qiang Xiao
- Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, 330013, P. R. China
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23
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Manna S, Kakumachi S, Das KK, Tsuchiya Y, Adachi C, Panda S. Mechanistic Dichotomy in Solvent Dependent Access to E vs Z-allylic Amines via Decarboxylative Vinylation of Amino Acids. Chem Sci 2022; 13:9678-9684. [PMID: 36091905 PMCID: PMC9400591 DOI: 10.1039/d2sc02090d] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/15/2022] [Indexed: 12/03/2022] Open
Abstract
The solvent plays an important role in the photophysical properties of donor–acceptor based photocatalysts. The solvent-dependent access to E vs. Z-allylic amines was achieved via decarboxylative vinylation of amino acids with vinyl sulfones. Detailed experimental studies have been conducted to understand the role of the solvent in the reactivity and stereoselectivity of the vinylation reactions. A solvent-dependent access to E vs. Z-allylic amines was achieved via decarboxylative vinylation of amino acids. Detailed experimental studies have been conducted to understand the role of the solvent in the reactivity and stereoselectivity of the vinylation reactions.![]()
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Affiliation(s)
- Samir Manna
- Department of Chemistry, Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Shunta Kakumachi
- Department of Chemistry and Biochemistry, Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Kanak Kanti Das
- Department of Chemistry, Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Youichi Tsuchiya
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Chihaya Adachi
- Department of Chemistry and Biochemistry, Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Santanu Panda
- Department of Chemistry, Indian Institute of Technology Kharagpur Kharagpur 721302 India
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24
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25
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Hou M, Xu M, Yang B, He H, Gao S. Exo-Selective and Enantioselective Photoenolization/Diels-Alder Reaction. Org Lett 2021; 23:7487-7491. [PMID: 34550708 DOI: 10.1021/acs.orglett.1c02719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
An unusual exo-selective photoenolization/Diels-Alder reaction of electron-rich 2-methylbenzaldehydes and dienophiles containing a benzoyl group at its α position was reported herein. The chiral TADDOL-type ligand plays a key role in this process: (1) accelerating the reaction; (2) controlling the enantioselectivity; and (3) improving and tuning the diastereoselectivity of the reaction.
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Affiliation(s)
- Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Mengmeng Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Baochao Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
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26
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Xu M, Hou M, He H, Gao S. Asymmetric Total Synthesis of Aglacins A, B, and E. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202105395] [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)
- Mengmeng Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes School of Chemistry and Molecular Engineering East China Normal University China
| | - Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes School of Chemistry and Molecular Engineering East China Normal University China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes School of Chemistry and Molecular Engineering East China Normal University China
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
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27
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Xu M, Hou M, He H, Gao S. Asymmetric Total Synthesis of Aglacins A, B, and E. Angew Chem Int Ed Engl 2021; 60:16655-16660. [PMID: 34008314 DOI: 10.1002/anie.202105395] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Indexed: 12/16/2022]
Abstract
An asymmetric photoenolization/Diels-Alder (PEDA) reaction between electron-rich 2-methylbenzaldehydes and unsaturated γ-lactones was developed to directly construct the basic tricyclic core of aryltetralin lactone lignans. This methodology enabled the first asymmetric total synthesis of aglacins A, B, and E and revision of the absolute configuration of these natural lignans. The strategy was also used to prepare the naturally occurring aryldihydronaphthalene-type lignans (-)-7,8-dihydroisojusticidin B and (+)-linoxepin in four and six steps, as well as 27 natural-product-like molecules containing a C8' quaternary center. We believe that the synthetic aglacins and small-molecule library provide new opportunities to carry out the SAR studies of the podophyllotoxin family of natural products.
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Affiliation(s)
- Mengmeng Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes, School of Chemistry and Molecular Engineering, East China Normal University, China
| | - Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes, School of Chemistry and Molecular Engineering, East China Normal University, China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical, Processes, School of Chemistry and Molecular Engineering, East China Normal University, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China
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28
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Yang B, Wen G, Zhang Q, Hou M, He H, Gao S. Asymmetric Total Synthesis and Biosynthetic Implications of Perovskones, Hydrangenone, and Hydrangenone B. J Am Chem Soc 2021; 143:6370-6375. [PMID: 33886312 DOI: 10.1021/jacs.1c02674] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Perovskones and hydrangenones are a family of structurally complex triterpenoids that were mainly isolated from the genus Salvia medicinal plants. These isoprenoids exhibit a broad range of biological activities, such as antitumor and antiplasmodial activities. Here, we report the collective total synthesis of perovskone, perovskones C, D, F, hydrangenone, and hydrangenone B. The key strategies in this work include the following: (1) an asymmetric photoenolization/Diels-Alder reaction was developed to construct a tricyclic ring bearing three contiguous quaternary centers, which was used to build the core icetexane skeleton; (2) a bioinspired Diels-Alder reaction of perovskatone D with trans-α-ocimene was applied to stereospecifically generate perovskones; (3) late-stage oxidations and ring forming steps were developed to synthesize perovskones and hydrangenones. Our synthetic work suggests that (1) perovskatone D may serve as the precursor of the biosynthesis of perovskones and (2) the formation of hydrangenone and hydrangenone B, containing a five-membered D ring, may involve an oxidative ring cleavage and ring regeneration process.
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Affiliation(s)
- Baochao Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Guoen Wen
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Quan Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University, 3663N Zhongshan Road, Shanghai 200062, China.,Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
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29
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Hou M, Xu M, Yang B, He H, Gao S. Construction of polycyclic structures with vicinal all-carbon quaternary stereocenters via an enantioselective photoenolization/Diels-Alder reaction. Chem Sci 2021; 12:7575-7582. [PMID: 34163849 PMCID: PMC8171339 DOI: 10.1039/d1sc00883h] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 04/25/2021] [Indexed: 11/21/2022] Open
Abstract
All-carbon quaternary stereocenters are ubiquitous in natural products and significant in drug molecules. However, construction of all-carbon stereocenters is a challenging project due to their congested chemical environment. And, when vicinal all-carbon quaternary stereocenters are present in one molecule, they will dramatically increase its synthetic challenge. A chiral titanium promoted enantioselective photoenolization/Diels-Alder (PEDA) reaction allows largely stereohindered tetra-substituted dienophiles to interact with highly active photoenolized hydroxy-o-quinodimethanes, delivering fused or spiro polycyclic rings bearing vicinal all-carbon quaternary centers in excellent enantiomeric excess through one-step operation. This newly developed enantioselective PEDA reaction will inspire other advances in asymmetric excited-state reactions, and could be used in the total synthesis of structurally related complex natural products or drug-like molecules for drug discovery.
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Affiliation(s)
- Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
| | - Mengmeng Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
| | - Baochao Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
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30
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Albini A. Norrish’ type I and II reactions and their role in the building of photochemical science. Photochem Photobiol Sci 2021; 20:161-181. [DOI: 10.1007/s43630-020-00003-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 11/25/2020] [Indexed: 11/30/2022]
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31
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D'Acunzo F, Carbonaro L, Cort AD, Di Sabato A, Filippini D, Leonelli F, Mancini L, Gentili P. Click‐Connected 2‐(Hydroxyimino)aldehydes for the Design of UV‐Responsive Functional Molecules. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Francesca D'Acunzo
- Istituto per i Sistemi Biologici Sezione Meccanismi di Reazione Consiglio Nazionale delle Ricerche, c/o Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Linda Carbonaro
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Antonella Dalla Cort
- Istituto per i Sistemi Biologici Sezione Meccanismi di Reazione Consiglio Nazionale delle Ricerche, c/o Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Antonio Di Sabato
- Istituto per i Sistemi Biologici Sezione Meccanismi di Reazione Consiglio Nazionale delle Ricerche, c/o Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Dario Filippini
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Francesca Leonelli
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Laura Mancini
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
| | - Patrizia Gentili
- Istituto per i Sistemi Biologici Sezione Meccanismi di Reazione Consiglio Nazionale delle Ricerche, c/o Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
- Dipartimento di Chimica Sapienza Università di Roma P.le A. Moro 5 00185 Roma Italy
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32
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Zheng J, Dong X, Yoon TP. Divergent Photocatalytic Reactions of α-Ketoesters under Triplet Sensitization and Photoredox Conditions. Org Lett 2020; 22:6520-6525. [PMID: 32806138 PMCID: PMC7470625 DOI: 10.1021/acs.orglett.0c02314] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The long-lived triplet excited states of transition metal photocatalysts can activate organic substrates via either energy- or electron-transfer pathways, and the rates of these processes can be influenced by rational tuning of the reaction conditions. The characteristic reactive intermediates generated, however, are distinct and can exhibit very different reactivity patterns. This mechanistic diversity available to photocatalytic reactions might thus offer an opportunity to engineer divergent reactions that give markedly different chemical outcomes under superficially similar conditions. Herein, we show that the photocatalytic reactions of benzoylformate esters with alkenes can be directed toward either Paternò-Büchi cycloadditions or allylic functionalization reactions under conditions favoring energy transfer or electron transfer, respectively. These studies provide a framework for designing other divergent photocatalytic methods that produce different sets of reaction outcomes under photoredox and triplet sensitization conditions.
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Affiliation(s)
| | - Xiao Dong
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Tehshik P. Yoon
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
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33
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Secci F, Porcu S, Luridiana A, Frongia A, Ricci PC. Visible light promoted continuous flow photocyclization of 1,2-diketones. Org Biomol Chem 2020; 18:3684-3689. [PMID: 32352131 DOI: 10.1039/d0ob00532k] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The continuous flow Norrish-Yang photocyclization of 1,2-diketones has been developed and used for the synthesis of a large number of functionalized 2-hydroxycyclobutanones, under blue light irradiation and employing acetone as a solvent. This eco-friendly procedure represents a valid alternative to the reactions carried out in batches thus reducing the reaction times, the formation of secondary products and simplifying the purification steps. The use of differently substituted diketone compounds has allowed us to obtain a wide range of 2 and 3-functionalized cyclobutanones, thus allowing the evaluation of the scope and limitations of this procedure.
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Affiliation(s)
- Francesco Secci
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554, bivio per Sestu, 09042, Monserrato (Ca), Italy.
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34
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Roque JB, Kuroda Y, Jurczyk J, Xu LP, Ham JS, Göttemann LT, Roberts CA, Adpressa D, Saurí J, Joyce LA, Musaev DG, Yeung CS, Sarpong R. C─C Cleavage Approach to C─H Functionalization of Saturated Aza-Cycles. ACS Catal 2020; 10:2929-2941. [PMID: 33569242 DOI: 10.1021/acscatal.9b04551] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Saturated cyclic amines (aza-cycles) are ubiquitous structural motifs found in pharmaceuticals, agrochemicals, and bioactive natural products. Given their importance, methods that directly functionalize aza-cycles are in high demand. Herein, we disclose a fundamentally different approach to functionalizing cyclic amines which relies on C─C cleavage and attendant cross-coupling. The initial functionalization step is the generation of underexplored N-fused bicyclo α-hydroxy-β-lactams under mild, visible light conditions using a Norrish-Yang process to affect α-functionalization of saturated cyclic amines. This approach is complementary to previous methods for the C─H functionalization of aza-cycles and provides unique access to various cross-coupling adducts. In the course of these studies, we have also uncovered an orthogonal, base-promoted opening of the N-fused bicyclo α-hydroxy-β-lactams. Computational studies have provided insight into the origin of the complementary C─C cleavage processes.
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Affiliation(s)
- Jose B. Roque
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Yusuke Kuroda
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Justin Jurczyk
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Li-Ping Xu
- Cherry L. Emerson Center for Scientific Computation, and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jin Su Ham
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Lucas T. Göttemann
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Charis A. Roberts
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Donovon Adpressa
- Structure Elucidation Group, Department of Analytical Research & Development, Merck & Company Inc., 33 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Josep Saurí
- Structure Elucidation Group, Department of Analytical Research & Development, Merck & Company Inc., 33 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Leo A. Joyce
- Department of Process Research & Development, Merck & Company Inc., 90 E. Scott Avenue, Rahway, New Jersey 07065, United States
| | - Djamaladdin G. Musaev
- Cherry L. Emerson Center for Scientific Computation, and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Charles S. Yeung
- Disruptive Chemistry Fellow, Department of Discovery Chemistry, Merck & Company Inc., 33 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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35
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Mavroskoufis A, Rajes K, Golz P, Agrawal A, Ruß V, Götze JP, Hopkinson MN. N-Heterocyclic Carbene Catalyzed Photoenolization/Diels-Alder Reaction of Acid Fluorides. Angew Chem Int Ed Engl 2020; 59:3190-3194. [PMID: 31814280 PMCID: PMC7027522 DOI: 10.1002/anie.201914456] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Indexed: 11/23/2022]
Abstract
The combination of light activation and N-heterocyclic carbene (NHC) organocatalysis has enabled the use of acid fluorides as substrates in a UVA-light-mediated photochemical transformation previously observed only with aromatic aldehydes and ketones. Stoichiometric studies and TD-DFT calculations support a mechanism involving the photoactivation of an ortho-toluoyl azolium intermediate, which exhibits "ketone-like" photochemical reactivity under UVA irradiation. Using this photo-NHC catalysis approach, a novel photoenolization/Diels-Alder (PEDA) process was developed that leads to diverse isochroman-1-one derivatives.
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Affiliation(s)
- Andreas Mavroskoufis
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Keerthana Rajes
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Paul Golz
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Arush Agrawal
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Vincent Ruß
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Jan P. Götze
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
| | - Matthew N. Hopkinson
- Institute of Chemistry and BiochemistryFreie Universität BerlinTakustraße 314195BerlinGermany
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36
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Mavroskoufis A, Rajes K, Golz P, Agrawal A, Ruß V, Götze JP, Hopkinson MN. Durch N‐heterocyclische Carbene katalysierte Photoenolisierungs‐Diels‐Alder‐Reaktion von Säurefluoriden. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914456] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Andreas Mavroskoufis
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Keerthana Rajes
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Paul Golz
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Arush Agrawal
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Vincent Ruß
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Jan P. Götze
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
| | - Matthew N. Hopkinson
- Institut für Chemie und Biochemie Freie Universität Berlin Takustraße 3 14195 Berlin Deutschland
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37
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Qiu Z, Pham HDM, Li J, Li CC, Castillo-Pazos DJ, Khaliullin RZ, Li CJ. Light-enabled metal-free pinacol coupling by hydrazine. Chem Sci 2019; 10:10937-10943. [PMID: 32190250 PMCID: PMC7066673 DOI: 10.1039/c9sc03737c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 10/06/2019] [Indexed: 11/21/2022] Open
Abstract
A light-driven pinacol coupling protocol without any metals, but with N2H4 as a clean non-metallic hydrogen-atom-transfer (HAT) reductant was described.
Efficient carbon–carbon bond formation is of great importance in modern organic synthetic chemistry. The pinacol coupling discovered over a century ago is still one of the most efficient coupling reactions to build the C–C bond in one step. However, traditional pinacol coupling often requires over-stoichiometric amounts of active metals as reductants, causing long-lasting metal waste issues and sustainability concerns. A great scientific challenge is to design a metal-free approach to the pinacol coupling reaction. Herein, we describe a light-driven pinacol coupling protocol without use of any metals, but with N2H4, used as a clean non-metallic hydrogen-atom-transfer (HAT) reductant. In this transformation, only traceless non-toxic N2 and H2 gases were produced as by-products with a relatively broad aromatic ketone scope and good functional group tolerance. A combined experimental and computational investigation of the mechanism suggests that this novel pinacol coupling reaction proceeds via a HAT process between photo-excited ketone and N2H4, instead of the common single-electron-transfer (SET) process for metal reductants.
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Affiliation(s)
- Zihang Qiu
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Hanh D M Pham
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Jianbin Li
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Chen-Chen Li
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Durbis J Castillo-Pazos
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Rustam Z Khaliullin
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
| | - Chao-Jun Li
- Department of Chemistry , FQRNT Centre for Green Chemistry and Catalysis , McGill University , 801 Sherbrooke St. W. , Montreal , Quebec H3A 0B8 , Canada . ;
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38
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Hipwell VM, Garcia-Garibay MA. Mechanistic Studies of Adamantylacetophenones with Competing Reaction Pathways in Solution and in the Crystalline Solid State. J Org Chem 2019; 84:11103-11113. [PMID: 31412205 DOI: 10.1021/acs.joc.9b01720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photochemical reactions in crystals occur under conditions of highly restricted molecular mobility such that only one product is generally obtained, even when there are many others that can be observed in the gas phase or in solution. A series of 2-(1-adamantyl)-o-alkyl-acetophenones with γ-hydrogen atoms on both the adamantyl and ortho aromatic groups was selected to determine whether one can engineer and observe competing Norrish type II reaction pathways in the crystalline state. It was shown that excited state competition for hydrogen abstraction between secondary adamantyl and benzylic hydrogens is affected not only by the relative bond dissociation energies but also by the molecular conformation in the crystal. The subsequent fate of the resulting biradical species is determined by competition between radical recombination to form the photoproduct and reverse hydrogen atom transfer to regenerate the starting ketone. Crystallographic information, photoproduct distributions in solution and in the solid state, and the results of multiple mechanistic experiments, including transient absorption spectroscopy in acetonitrile and with nanocrystals suspended in water, are reported. The results demonstrate that it is possible to engineer competing reactions in crystals and that consideration of all of the aforementioned factors is necessary to account for the observed photoproduct selectivity.
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Affiliation(s)
- Vince M Hipwell
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , United States
| | - Miguel A Garcia-Garibay
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , United States
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39
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Zhu K, Ohtani T, Tripathi CB, Uraguchi D, Ooi T. Formal Hydroformylation of α,β-Unsaturated Carboxylic Acids under Photoexcited Ketone Catalysis. CHEM LETT 2019. [DOI: 10.1246/cl.190197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Kailong Zhu
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Tsuyoshi Ohtani
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Chandra Bhushan Tripathi
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Daisuke Uraguchi
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Takashi Ooi
- Institute of Transformative Bio-Molecules (WPI-ITbM) and Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8601, Japan
- CREST, Japan Science and Technology Agency (JST), Nagoya University, Nagoya, Aichi 464-8601, Japan
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40
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Peez T, Schmalz V, Harms K, Koert U. Synthesis of Naphthocyclobutenes from α-Naphthyl Acrylates by Visible-Light Energy-Transfer Catalysis. Org Lett 2019; 21:4365-4369. [PMID: 31140814 DOI: 10.1021/acs.orglett.9b01585] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Methyl (α-naphthyl) acrylates bearing an ortho-substituent with a hydrogen atom produce naphthocyclobutenes upon Ir(Fppy)3-mediated photosensitization. This reaction can be described as a carbon analogue of the Norrish-Yang reaction: upon triplet excitation of the acrylate a 1,5-HAT results in a 1,4-diradical which forms the cyclobutene. Diastereoselectivities up to >20:1 were observed for the ring-closure reaction.
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Affiliation(s)
- Theodor Peez
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35032 Marburg , Germany
| | - Veronika Schmalz
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35032 Marburg , Germany
| | - Klaus Harms
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35032 Marburg , Germany
| | - Ulrich Koert
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35032 Marburg , Germany
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41
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Dantas JA, Correia JTM, Paixão MW, Corrêa AG. Photochemistry of Carbonyl Compounds: Application in Metal‐Free Reactions. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900044] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Juliana A. Dantas
- Centre of Excellence for Research in Sustainable Chemistry Department of ChemistryFederal University of São Carlos 13565-905 São Carlos, SP Brazil
| | - José Tiago M. Correia
- Centre of Excellence for Research in Sustainable Chemistry Department of ChemistryFederal University of São Carlos 13565-905 São Carlos, SP Brazil
| | - Marcio W. Paixão
- Centre of Excellence for Research in Sustainable Chemistry Department of ChemistryFederal University of São Carlos 13565-905 São Carlos, SP Brazil
| | - Arlene G. Corrêa
- Centre of Excellence for Research in Sustainable Chemistry Department of ChemistryFederal University of São Carlos 13565-905 São Carlos, SP Brazil
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42
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Xue D, Xu M, Zheng C, Yang B, Hou M, He H, Gao S. Titanium-promoted Intramolecular Photoenolization/Diels-Alder Reaction to Construct Polycyclic Terpenoids: Formal Synthesis of Mycoleptodiscin A. CHINESE J CHEM 2019. [DOI: 10.1002/cjoc.201800555] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Dongsheng Xue
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Mengmeng Xu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Chaoying Zheng
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Baochao Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Min Hou
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Haibing He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
| | - Shuanhu Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development; East China Normal University; 3663N Zhongshan Road, Shanghai 200062 China
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43
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Shen Y, Gu Y, Martin R. sp 3 C-H Arylation and Alkylation Enabled by the Synergy of Triplet Excited Ketones and Nickel Catalysts. J Am Chem Soc 2018; 140:12200-12209. [PMID: 30184423 DOI: 10.1021/jacs.8b07405] [Citation(s) in RCA: 229] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Triplet ketone sensitizers are of central importance within the realm of photochemical transformations. Although the radical-type character of triplet excited states of diaryl ketones suggests the viability for triggering hydrogen-atom transfer (HAT) and single-electron transfer (SET) processes, among others, their use as multifaceted catalysts in C-C bond-formation via sp3 C-H functionalization of alkane feedstocks still remains rather unexplored. Herein, we unlock a modular photochemical platform for forging C( sp3)-C( sp2) and C( sp3)-C( sp3) linkages from abundant alkane sp3 C-H bonds as functional handles using the synergy between nickel catalysts and simple, cheap and modular diaryl ketones. This method is distinguished by its wide scope that is obtained from cheap catalysts and starting precursors, thus complementing existing inner-sphere C-H functionalization protocols or recent photoredox scenarios based on iridium polypyridyl complexes. Additionally, such a platform provides a new strategy for streamlining the synthesis of complex molecules with high levels of predictable site-selectivity and preparative utility. Mechanistic experiments suggest that sp3 C-H abstraction occurs via HAT from the ketone triplet excited state. We believe this study will contribute to a more systematic utilization of triplet excited ketones as catalysts in metallaphotoredox scenarios.
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Affiliation(s)
- Yangyang Shen
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Av. Països Catalans 16 , 43007 Tarragona , Spain.,Departament de Química Analítica i Química Orgànica , Universitat Rovira i Virgili , c/Marcel·lí Domingo 1 , 43007 Tarragona , Spain
| | - Yiting Gu
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Av. Països Catalans 16 , 43007 Tarragona , Spain.,Departament de Química Analítica i Química Orgànica , Universitat Rovira i Virgili , c/Marcel·lí Domingo 1 , 43007 Tarragona , Spain
| | - Ruben Martin
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Av. Països Catalans 16 , 43007 Tarragona , Spain.,ICREA , Passeig Lluïs Companys 23 , 08010 Barcelona , Spain
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44
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Chapman LM, Beck JC, Lacker CR, Wu L, Reisman SE. Evolution of a Strategy for the Enantioselective Total Synthesis of (+)-Psiguadial B. J Org Chem 2018; 83:6066-6085. [PMID: 29728045 PMCID: PMC5990278 DOI: 10.1021/acs.joc.8b00728] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
(+)-Psiguadial B is a diformyl phloroglucinol meroterpenoid that exhibits antiproliferative activity against the HepG2 human hepatoma cancer cell line. This full account details the evolution of a strategy that culminated in the first enantioselective total synthesis of (+)-psiguadial B. A key feature of the synthesis is the construction of the trans-cyclobutane motif by a Wolff rearrangement with in situ catalytic, asymmetric trapping of the ketene. An investigation of the substrate scope of this method to prepare enantioenriched 8-aminoquinolinamides is disclosed. Three routes toward (+)-psiguadial B were evaluated that featured the following key steps: (1) an ortho-quinone methide hetero-Diels-Alder cycloaddition to prepare the chroman framework, (2) a Prins cyclization to form the bridging bicyclo[4.3.1]decane system, and (3) a modified Norrish-Yang cyclization to generate the chroman. Ultimately, the successful strategy employed a ring-closing metathesis to form the seven-membered ring and an intramolecular O-arylation reaction to complete the polycyclic framework of the natural product.
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Affiliation(s)
- Lauren M. Chapman
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | | | | | - Linglin Wu
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Sarah E. Reisman
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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45
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Markley JL, Morse TL, Rath NP, Wencewicz TA. Stream-lined synthesis of 3-hydroxy-β-lactams: Norrish-Yang type II photocyclizations of β-ketoformamides. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.04.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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46
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Rapid access to the core skeleton of the [3 + 2]-type dimeric pyrrole-imidazole alkaloids by triplet ketone-mediated C-H functionalization. Tetrahedron 2018; 74:769-772. [PMID: 29622843 DOI: 10.1016/j.tet.2017.12.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ability of triplet ketones to abstract a hydrogen atom from hydrocarbons is reminiscent of that of the high-spin metal-oxo complexes in C-H oxidation enzymes. In practice, the reactivity of triplet ketones is easier to control and applicable to promoting a wider range of reactions. We demonstrate herein the synthetic utility of triplet ketone-mediated C-addition of methanol to cyclopentenone derivatives with an expedient synthesis of the core skeleton of the [3+2]-type dimeric pyrrole-imidazole alkaloids. Remarkably, this photochemical C-H functionalization reaction is highly regioselective and can tolerate a good range of functional groups.
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Ma J, Rosales AR, Huang X, Harms K, Riedel R, Wiest O, Meggers E. Visible-Light-Activated Asymmetric β-C-H Functionalization of Acceptor-Substituted Ketones with 1,2-Dicarbonyl Compounds. J Am Chem Soc 2017; 139:17245-17248. [PMID: 29161036 PMCID: PMC8103785 DOI: 10.1021/jacs.7b09152] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a visible-light-activated asymmetric β-C(sp3)-H functionalization of 2-acyl imidazoles and 2-acylpyridines with 1,2-dicarbonyl compounds (typically α-ketoesters) catalyzed by a tailored stereogenic-at-rhodium Lewis acid catalyst. The C-C bond formation products are obtained in high yields (up to 99%) and with excellent stereoselectivities (up to >20:1 dr and up to >99% ee). Experimental and computational studies support a mechanism in which a photoactivated Rh-enolate transfers a single electron to the 1,2-dicarbonyl compound followed by proton transfer and a subsequent stereocontrolled radical-radical recombination.
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Affiliation(s)
- Jiajia Ma
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Anthony R. Rosales
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Xiaoqiang Huang
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Klaus Harms
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Radostan Riedel
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Laboratory of Computational Chemistry and Drug Design, School of Chemical Biology and Biotechnology, Peking University, Shenzhen Graduate School, Shenzhen 518055, People’s Republic of China
| | - Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
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Tripathi CB, Ohtani T, Corbett MT, Ooi T. Photoredox ketone catalysis for the direct C-H imidation and acyloxylation of arenes. Chem Sci 2017; 8:5622-5627. [PMID: 28989599 PMCID: PMC5620997 DOI: 10.1039/c7sc01700f] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 06/04/2017] [Indexed: 01/05/2023] Open
Abstract
The photoexcited aryl ketone-catalyzed C-H imidation of arenes and heteroarenes is reported. Using 3,6-dimethoxy-9H-thioxanthen-9-one as a catalyst in combination with a bench-stable imidating reagent, C-N bond formation proceeds with high efficiency and a broad substrate scope. A key part of this method is that the thioxanthone catalyst acts as an excited-state reductant, thus establishing an oxidative quenching cycle for radical aromatic substitution. The synthetic potential of this photoexcited ketone catalysis is further demonstrated by application to the direct C-H acyloxylation of arenes.
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Affiliation(s)
- Chandra Bhushan Tripathi
- Institute of Transformative Bio-Molecules (WPI-ITbM) , Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Nagoya 464-8601 , Japan .
| | - Tsuyoshi Ohtani
- Institute of Transformative Bio-Molecules (WPI-ITbM) , Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Nagoya 464-8601 , Japan .
| | - Michael T Corbett
- Institute of Transformative Bio-Molecules (WPI-ITbM) , Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Nagoya 464-8601 , Japan .
| | - Takashi Ooi
- Institute of Transformative Bio-Molecules (WPI-ITbM) , Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Nagoya 464-8601 , Japan .
- CREST , Japan Science and Technology Agency (JST) , Nagoya University , Nagoya 464-8601 , Japan
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Matsui JK, Lang SB, Heitz DR, Molander GA. Photoredox-Mediated Routes to Radicals: The Value of Catalytic Radical Generation in Synthetic Methods Development. ACS Catal 2017; 7:2563-2575. [PMID: 28413692 PMCID: PMC5388068 DOI: 10.1021/acscatal.7b00094] [Citation(s) in RCA: 420] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/17/2017] [Indexed: 01/19/2023]
Abstract
Photoredox catalysis has experienced a revitalized interest from the synthesis community during the past decade. For example, photoredox/Ni dual catalysis protocols have been developed to overcome several inherent limitations of palladium-catalyzed cross-couplings by invoking a single-electron transmetalation pathway. This Perspective highlights advances made by our laboratory since the inception of the photoredox/Ni cross-coupling of benzyltrifluoroborates with aryl bromides. In addition to broadening the scope of trifluoroborate coupling partners, research using readily oxidized hypervalent silicates as radical precursors that demonstrate functional group compatibility is highlighted. The pursuit of electrophilic coupling partners beyond (hetero)aryl bromides has also led to the incorporation of several new classes of C(sp2)-hybridized substrates into light-mediated cross-coupling. Advances to expand the radical toolbox by utilizing feedstock chemicals (e.g., aldehydes) to access radicals that were previously inaccessible from trifluoroborates and silicates are also emphasized. Additionally, several organic photocatalysts have been investigated as replacements for their expensive iridium- and ruthenium-based counterparts. Lastly, the net C-H functionalization of the radical partner in an effort to improve atom economy is presented. An underlying theme in all of these studies is the value of generating radicals in a catalytic manner, rather than stoichiometrically.
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Affiliation(s)
- Jennifer K. Matsui
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Simon B. Lang
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Drew R. Heitz
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Gary A. Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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