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Rölz M, Butschke B, Breit B. Azobenzene-Integrated NHC Ligands: A Versatile Platform for Visible-Light-Switchable Metal Catalysis. J Am Chem Soc 2024; 146:13210-13225. [PMID: 38709955 DOI: 10.1021/jacs.4c01138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
A new class of photoswitchable NHC ligands, named azImBA, has been developed by integrating azobenzene into a previously unreported imidazobenzoxazol-1-ylidene framework. These rigid photochromic carbenes enable precise control over confinement around a metal's coordination sphere. As a model system, gold(I) complexes of these NHCs exhibit efficient bidirectional E-Z isomerization under visible light, offering a versatile platform for reversibly photomodulating the reactivity of organogold species. Comprehensive kinetic studies of the protodeauration reaction reveal rate differences of up to 2 orders of magnitude between the E and Z isomers of the NHCs, resulting in a quasi-complete visible-light-gated ON/OFF switchable system. Such a high level of photomodulation efficiency is unprecedented for gold complexes, challenging the current state-of-the-art in photoswitchable organometallics. Thorough investigations into the ligand properties paired with structure-reactivity correlations underscored the unique ligand's steric features as a key factor for reactivity. This effective photocontrol strategy was further validated in gold(I) catalysis, enabling in situ photoswitching of catalytic activity in the intramolecular hydroalkoxylation and -amination of alkynes. Given the significance of these findings and its potential as a widely applicable, easily customizable photoswitchable ancillary ligand platform, azImBA is poised to stimulate the development of adaptive, multifunctional metal complexes.
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Affiliation(s)
- Martin Rölz
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Burkhard Butschke
- Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Bernhard Breit
- Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany
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2
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Greenlee A, Weitekamp RA, Foster JC, Leguizamon SC. PhotoROMP: The Future Is Bright. ACS Catal 2024; 14:6217-6227. [PMID: 38660608 PMCID: PMC11036397 DOI: 10.1021/acscatal.4c00972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/26/2024]
Abstract
Since the earliest investigations of olefin metathesis catalysis, light has been the choice for controlling the catalyst activity on demand. From the perspective of energy efficiency, temporal and spatial control, and selectivity, photochemistry is not only an attractive alternative to traditional thermal manufacturing techniques but also arguably a superior manifold for advanced applications like additive manufacturing (AM). In the last three decades, pioneering work in the field of ring-opening metathesis polymerization (ROMP) has broadened the scope of material properties achievable through AM, particularly using light as both an activating and deactivating stimulus. In this Perspective, we explore trends in photocontrolled ROMP systems with an emphasis on approaches to photoinduced activation and deactivation of metathesis catalysts. Recent work has yielded a myriad of commercial and synthetically accessible photosensitive catalyst systems, although comparatively little attention has been paid to achieving precise control over polymer morphology using light. Metal-free, photophysical, and living ROMP systems have also been relatively underexplored. To take fuller advantage of both the thermomechanical properties of ROMP polymers and the operational simplicity of photocontrol, clear directions for the field are to improve the reversibility of activation and deactivation strategies as well as to further develop photocontrolled approaches to tuning cross-link density and polymer tacticity.
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Affiliation(s)
- Andrew
J. Greenlee
- Sandia
National Laboratories, Albuquerque, New Mexico 87185, United States
| | | | - Jeffrey C. Foster
- Chemical
Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United
States
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3
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Zhou L, He K, Kang SM, Zhou XY, Zou H, Liu N, Wu ZQ. Photoswitchable Enantioselective and Helix-Sense Controlled Living Polymerization. Angew Chem Int Ed Engl 2023; 62:e202310105. [PMID: 37957131 DOI: 10.1002/anie.202310105] [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: 07/17/2023] [Revised: 10/28/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
A pair of enantiomeric photoswitchable PdII catalysts, alkyne-PdII /LR-azo and alkyne-PdII /LS-azo , were prepared via the coordination of alkyne-PdII and azobenzene-modified phosphine ligands LR-azo and LS-azo . Owing to the cis-trans photoisomerization of the azobenzene moiety, alkyne-PdII /LR-azo and alkyne-PdII /LS-azo exhibited different polymerization activities, helix-sense selectivities, and enantioselectivities during the polymerization of isocyanide monomers under irradiation of different wavelength lights. Furthermore, the achiral isocyanide monomer A-1 could be polymerized efficiently using alkyne-PdII /LR-azo under dark condition in a living/controlled manner. Further, it generated single right-handed helical poly-A-1m (LR-azo ), confirmed by the circular dichroism spectra and atomic force microscopy images. However, the polymerization of A-1 almost could not be initiated under 420 nm light in identical conditions of dark condition. Moreover, the photoswitchable catalyst alkyne-PdII /LR-azo exhibited high enantioselectivity for the polymerization of the racemates of L-1 and D-1, respectively. D-1 was polymerized preferentially under dark condition with a D-1/L-1 rate ratio of 70, yielding single right-handed polyisocyanides. Additionally, reversible enantioselectivity was observed under 420 nm light using alkyne-PdII /LR-azo , and the calculated polymerization rate ratio of L-1/D-1 was 57 because of the isomerization of the azobenzene moiety of the catalyst. Furthermore, alkyne-PdII /LS-azo showed opposite enantioselectivity and helix-sense selectivity during the polymerization of the racemates of L-1 and D-1.
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Affiliation(s)
- Li Zhou
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, and Anhui Key Laboratory of Advanced Functional Materials and Devices, Hefei University of Technology, Hefei, Anhui Province, 230009, China
| | - Kai He
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, and Anhui Key Laboratory of Advanced Functional Materials and Devices, Hefei University of Technology, Hefei, Anhui Province, 230009, China
| | - Shu-Ming Kang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Xing-Yu Zhou
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, and Anhui Key Laboratory of Advanced Functional Materials and Devices, Hefei University of Technology, Hefei, Anhui Province, 230009, China
| | - Hui Zou
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, and Anhui Key Laboratory of Advanced Functional Materials and Devices, Hefei University of Technology, Hefei, Anhui Province, 230009, China
| | - Na Liu
- The School of Pharmaceutical Sciences, Jilin University, 1266 Fujin Road, Changchun, Jilin 130021, P. R. China
| | - Zong-Quan Wu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China
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4
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Pham LD, Smith-Sweetser RO, Krupinsky B, Dewey CE, Lamb JR. Switchable Organocatalysis from N-heterocyclic Carbene-Carbodiimide Adducts with Tunable Release Temperature. Angew Chem Int Ed Engl 2023; 62:e202314376. [PMID: 37824288 DOI: 10.1002/anie.202314376] [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: 09/25/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/14/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are powerful organocatalysts, but practical applications often require in situ generation from stable precursors that "mask" the NHC reactivity via reversible binding. Previously established "masks" are often simple small molecules, such that the NHC structure is used to control both catalytic activity and activation temperature, leading to undesirable tradeoffs. Herein, we show that NHC-carbodiimide (CDI) adducts can be masked precursors for switchable organocatalysis and that the CDI substituents can control the reaction profile without changing the NHC structure. Large electronic variations on the CDI (e.g., alkyl versus aryl) drastically change the catalytically active temperature, whereas smaller perturbations (e.g., different para-substituted phenyls) tune the catalyst release within a narrower window. This control was demonstrated for three classic NHC-catalyzed reactions, each influencing the NHC-CDI equilibrium in different ways. Our results introduce a new paradigm for controlling NHC organocatalysis as well as present practical considerations for designing appropriate masks for various reactions.
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Affiliation(s)
- Le Dung Pham
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Red O Smith-Sweetser
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Briana Krupinsky
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Carolyn E Dewey
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Jessica R Lamb
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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5
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Zhang Y, El Sayed S, Kang L, Sanger M, Wiegand T, Jessop PG, DeBeer S, Bordet A, Leitner W. Adaptive Catalysts for the Selective Hydrogenation of Bicyclic Heteroaromatics using Ruthenium Nanoparticles on a CO 2 -Responsive Support. Angew Chem Int Ed Engl 2023; 62:e202311427. [PMID: 37677109 DOI: 10.1002/anie.202311427] [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: 08/07/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
Ruthenium nanoparticles (NPs) immobilized on an amine-functionalized polymer-grafted silica support act as adaptive catalysts for the hydrogenation of bicyclic heteroaromatics. Whereas full hydrogenation of benzofuran and quinoline derivatives is achieved under pure H2 , introducing CO2 into the H2 gas phase leads to an effective shutdown of the arene hydrogenation while preserving the activity for the hydrogenation of the heteroaromatic part. The selectivity switch originates from the generation of ammonium formate species on the surface of the materials by catalytic hydrogenation of CO2 . The CO2 hydrogenation is fully reversible, resulting in a robust and rapid switch between the two states of the catalyst adapting its performance in response to the feed gas composition. A variety of benzofuran and quinoline derivatives were hydrogenated to fully or partially saturated products in high selectivity and yields simply by altering the composition of the feed gas from H2 to H2 /CO2 . The adaptive catalytic system thus provides controlled access to valuable products using a single catalyst rather than two specific and distinct catalysts with static reactivity.
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Affiliation(s)
- Yuyan Zhang
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Sami El Sayed
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Liqun Kang
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Matthew Sanger
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Thomas Wiegand
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
| | - Philip G Jessop
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Alexis Bordet
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Walter Leitner
- Max Planck Institute for Chemical Energy Conversion, Department of Molecular Catalysis, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
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6
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Liu J, Bobylev EO, de Bruin B, Reek JNH. A photoresponsive gold catalyst based on azobenzene-functionalized NHC ligands. Chem Commun (Camb) 2023. [PMID: 37377028 DOI: 10.1039/d3cc01726e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
An azobenzene-bearing N-heterocyclic carbene-based gold catalyst is reported of which the reactivity in a cyclization reaction depends on the isomeric state of the azobenzene. The configurations of the catalyst can be reversibly switched by light and are stable during the reaction, effectively leading to a switchable catalyst system.
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Affiliation(s)
- Jianghua Liu
- Homogeneous, Supramolecular and Bio-Inspired Catalysis (HomKat), Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam (UvA), Science Park 904, Amsterdam 1098XH, The Netherlands.
| | - Eduard O Bobylev
- Homogeneous, Supramolecular and Bio-Inspired Catalysis (HomKat), Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam (UvA), Science Park 904, Amsterdam 1098XH, The Netherlands.
| | - Bas de Bruin
- Homogeneous, Supramolecular and Bio-Inspired Catalysis (HomKat), Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam (UvA), Science Park 904, Amsterdam 1098XH, The Netherlands.
| | - Joost N H Reek
- Homogeneous, Supramolecular and Bio-Inspired Catalysis (HomKat), Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam (UvA), Science Park 904, Amsterdam 1098XH, The Netherlands.
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7
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Zhao F, Li Y, Houk KN, Lu Q, Liu F. Computational Elucidation on the Conformational Control of Selectivity in Intramolecular Ring-Closing Metathesis vs Intermolecular Homometathesis. J Org Chem 2023. [PMID: 37364253 DOI: 10.1021/acs.joc.3c00466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
The ring-closing metathesis reaction of diene plays an important role in the construction of cyclic compounds. In this research, density functional theory (DFT) calculations were conducted to elucidate the mechanisms and origins of the selectivity of ring-closing metathesis and homometathesis. The computational results suggest that the selectivity is determined by the substrate conformation. For the ester-tethered substrate, the homometathesis is more favorable, due to the planar structure of ester facilitating the conjugative effect of the formed E-homometathesis product. For the amide-tethered substrate, the ring-closing metathesis product is the only observed product because the steric hindrance of N-substituents disfavors homometathesis.
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Affiliation(s)
- Fengyue Zhao
- College of Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yixuan Li
- College of Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Qianqian Lu
- College of Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Fang Liu
- College of Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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8
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Musso JV, Gebel P, Gramm V, Frey W, Buchmeiser MR. Tungsten Oxo and Tungsten Imido Alkylidene N-Heterocyclic Carbene Complexes for the Visible-Light-Induced Ring-Opening Metathesis Polymerization of Dicyclopentadiene. Macromolecules 2023. [DOI: 10.1021/acs.macromol.3c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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9
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Majee D, Ramanauskaite G, Presolski S. Electronic Influences on the Dynamic Range of Photoswitchable Dithienylethene-Thiourea Organocatalysts. J Org Chem 2023; 88:4372-4378. [PMID: 36939093 DOI: 10.1021/acs.joc.2c02987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Thiourea-based organocatalysts bearing a photoswitchable dithienylethene (DTE) core and a wide range of substituents were prepared and extensively tested for their ability to accelerate the Michael reaction between acetylacetone and trans-β-nitrostyrene. There is a strong correlation between the Hammett parameter of the modulating groups and catalytic activity following UV irradiation. Electron-withdrawing groups afford the largest reactivity difference between the catalysts in their ring-open form and their ring-closed isomer, with evidence for electronic coupling between the two halves in both oDTE and cDTE.
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Affiliation(s)
- Debashis Majee
- Division of Science, Yale-NUS College, Singapore 138527, Singapore
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10
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Kim M, Kim H, Kim S, Hong S, Lee E. Syntheses and Applications of Indol-2-ylidene-Ligated Ruthenium-Based Olefin Metathesis Catalysts. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Minseop Kim
- Department of Chemistry, Pohang University of Science and Technology. Pohang 37673, Republic of Korea
| | - Hyunho Kim
- Department of Chemistry, Pohang University of Science and Technology. Pohang 37673, Republic of Korea
| | - Seyong Kim
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Sukwon Hong
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology. Pohang 37673, Republic of Korea
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Liu R, Zhang X, Xia F, Dai Y. Azobenzene-based photoswitchable catalysts: State of the art and perspectives. J Catal 2022. [DOI: 10.1016/j.jcat.2022.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Vermersch F, Oliveira L, Hunter J, Soleilhavoup M, Jazzar R, Bertrand G. Cyclic (Alkyl)(amino)carbenes: Synthesis of Iminium Precursors and Structural Properties. J Org Chem 2022; 87:3511-3518. [PMID: 35133152 DOI: 10.1021/acs.joc.1c03075] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using readily available preallylated aldehydes, we report a simple and divergent synthesis of cyclic (alkyl)(amino)carbene (CAAC) iminium precursors. Using a combination of crystallographic data and steric maps, we further elaborate on the specific steric properties of CAAC ligands with respect to state-of-the-art phosphine and carbene ligands.
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Affiliation(s)
- François Vermersch
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Luana Oliveira
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Joseph Hunter
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Michele Soleilhavoup
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
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