1
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Luo Y, Zhao M, Wang Y. Mechanism and Origin of Stereoselectivity of N-Heterocyclic Carbene (NHC)-Catalyzed Transformation Reaction of Benzaldehyde with o-QDM as Key Intermediate: A DFT Study. J Phys Chem A 2024. [PMID: 39024177 DOI: 10.1021/acs.jpca.4c02522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
N-heterocyclic carbene (NHC)-bound ortho-quinodimethane, served as a nucleophile, has occupied an important position for constructing various all-carbon or heterocyclic compounds and attracted increasing attention for the functionalization of benzylic carbon of aromatic aldehydes, whereas the mechanistic studies on the generation and transformations of dienolate intermediate are rare. In the present study, the mechanism of activation/transformation of aldehyde catalyzed by NHC was theoretically studied using the density functional theory (DFT) method. Based on the calculations, the nucleophilic addition process is the stereoselectivity-determining step with RS-configured product being generated preferentially. Furthermore, non-covalent index (NCI) and atoms-in-molecules (AIM) analyses have been performed to disclose the origin of stereoselectivity, by which the larger number and stronger weak interactions are the key for stabilizing the low-energy transition state and thus leading to the stereoselectivity inducing.
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Affiliation(s)
- Yilu Luo
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Miao Zhao
- Department of Pathology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital & Zhengzhou Children's Hospital, Zhengzhou 450018, Henan, P. R. China
| | - Yang Wang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou 450001, Henan, P. R. China
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2
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Khezeli F, Plaisance C. Computational Design of an Electro-Organocatalyst for Conversion of CO 2 into Long Chain Aldehydes. J Phys Chem A 2024; 128:5445-5458. [PMID: 38962806 PMCID: PMC11264266 DOI: 10.1021/acs.jpca.4c00780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 06/10/2024] [Accepted: 06/18/2024] [Indexed: 07/05/2024]
Abstract
Density functional theory calculations employing a hybrid implicit/explicit solvation method were used to demonstrate that an electro-organocatalyst designed in our previous work for reducing CO2 to formaldehyde could also be capable of coupling formaldehyde to form long chain aldehydes. The catalytic activity is enabled by an electron-rich vicinal enediamine (>N-C═C-N<) backbone that activates formaldehyde by reversing the polarity on the carbon atom, enabling it to act as a nucleophile in the subsequent aldol addition step. The catalyst then enables reductive dehydroxylation of the aldol addition product by facilitating outer-sphere electron transfer. The optimal pH as well as the limiting potential and formaldehyde concentration are identified and related to the kinetic balance between several rate limiting steps. Finally, the optimal conditions for coupling with the CO2 reduction cycle are discussed, demonstrating that the electro-organocatalyst is capable of efficiently converting CO2 into aldehyde products with a turnover frequency (per carbon atom) on the order of 0.1-1 s-1.
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Affiliation(s)
- Foroogh Khezeli
- Cain
Department of Chemical Engineering, Louisiana
State University, Baton
Rouge, Louisiana 70803, United States
| | - Craig Plaisance
- Cain
Department of Chemical Engineering, Louisiana
State University, Baton
Rouge, Louisiana 70803, United States
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3
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Wang J, Zheng M, Jia Q, Ren Q, Wu J. Synthesis of Highly Substituted Furans via Intermolecular Enynone-Aldehyde Cross-Coupling/Cyclization Catalyzed by N-Heterocyclic Carbenes. Org Lett 2024; 26:4868-4872. [PMID: 38832854 DOI: 10.1021/acs.orglett.4c01253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
A new strategy for facile access to multifunctionalized furans via N-heterocyclic carbene-catalyzed cross-coupling/cyclization of ynenones with aldehydes has been explored. This protocol features readily obtainable starting materials, mild and metal-free conditions, broad substrate scope, good functional group tolerance, excellent yields, and easy scale-up. Synthetic utility of the protocol has been further corroborated through functionalization of complex substrates and postmodifications of the product.
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Affiliation(s)
- Jie Wang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, P. R. China
| | - Mingyue Zheng
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, P. R. China
| | - Qianfa Jia
- Chongqing Key Laboratory for New Chemical Materials of Shale Gas, College of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing 408100, P. R. China
| | - Qiao Ren
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Pharmaceutical Science, Southwest University, Chongqing 400715, P. R. China
| | - Jicheng Wu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, P. R. China
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4
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Debnath C, Bhoi SR, Gandhi S. N-Heterocyclic carbene/palladium synergistic catalysis in organic synthesis. Org Biomol Chem 2024; 22:4613-4624. [PMID: 38804684 DOI: 10.1039/d4ob00525b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The cooperation of two distinct catalytic cycles to activate different reactive centers leading to a chemical transformation has been classified as synergistic catalysis. The synergistic combination of NHC with palladium catalysis has emerged as a powerful strategy in the last few years. Merging the ability of NHCs to inverse the polarity of a functional group with the unique reactivity of palladium enables transformations that cannot be accomplished by either of these catalysts alone. Despite the associated challenges, such as quenching of catalysts, reactivity mismatch etc., significant development has been achieved in the field of NHC/Pd synergistic catalysis. The recent incorporation of photoredox catalysis with NHC/Pd synergistic catalysis has further advanced this area. This review highlights the developments made in the area of NHC/Pd synergistic catalysis.
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Affiliation(s)
- Chhanda Debnath
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, 760010, India.
| | - Saswat Ranjan Bhoi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, 760010, India.
| | - Shikha Gandhi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, 760010, India.
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5
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Kirschning A. Why pyridoxal phosphate could be a functional predecessor of thiamine pyrophosphate and speculations on a primordial metabolism. RSC Chem Biol 2024; 5:508-517. [PMID: 38846080 PMCID: PMC11151856 DOI: 10.1039/d4cb00016a] [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: 01/16/2024] [Accepted: 04/15/2024] [Indexed: 06/09/2024] Open
Abstract
The account attempts to substantiate the hypothesis that, from an evolutionary perspective, the coenzyme couple pyridoxal phosphate and pyridoxamine phosphate preceded the coenzyme thiamine pyrophosphate and acted as its less efficient chemical analogue in some form of early metabolism. The analysis combines mechanism-based chemical reactivity with biosynthetic arguments and provides evidence that vestiges of "TPP-like reactivity" are still found for PLP today. From these thoughts, conclusions can be drawn about the key elements of a primordial form of metabolism, which includes the citric acid cycle, amino acid biosynthesis and the pentose phosphate pathway.
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Affiliation(s)
- Andreas Kirschning
- Institute of Organic Chemistry, Leibniz University Hannover, Schneiderberg 1B 30167 Hannover Germany
- Uppsala Biomedical Center (BMC), University Uppsala, Husargatan 3 752 37 Uppsala Sweden
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6
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Medvedko S, Wagner JP. From Criegee to Breslow: How π-Donors Steer the Route of Olefin Ozonolysis. Chemistry 2024; 30:e202400026. [PMID: 38501221 DOI: 10.1002/chem.202400026] [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: 01/03/2024] [Revised: 03/16/2024] [Accepted: 03/19/2024] [Indexed: 03/20/2024]
Abstract
While π-bonds typically undergo cycloaddition with ozone, resulting in the release of much-noticed carbonyl O-oxide Criegee intermediates, lone-pairs of electrons tend to selectively accept a single oxygen atom from O3, producing singlet dioxygen. We questioned whether the introduction of potent electron-donating groups, akin to N-heterocyclic olefins, could influence the reactivity of double bonds - shifting from cycloaddition to oxygen atom transfer or generating lesser-known, yet stabilized, donor-substituted Criegee intermediates. Consequently, we conducted a comparative computational study using density functional theory on a series of model olefins with increasing polarity due to (asymmetric) π-donor substitution. Reaction path computations indicate that highly polarized double bonds, instead of forming primary ozonides in their reaction with O3, exhibit a preference for accepting a single oxygen atom, resulting in a zwitterionic species formally identified as a carbene-carbonyl adduct. This previously unexplored reactivity potentially introduces aldehyde umpolung chemistry (Breslow intermediate) through olefin ozonolysis. Considering solvent effects implicitly reveals that increased solvent polarity further directs the trajectories toward a single oxygen atom transfer reactivity by stabilizing the zwitterionic character of the transition state. The competing modes of chemical reactivity can be explained by a bifurcation of the reaction valley in the post-transition state region.
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Affiliation(s)
- Serhii Medvedko
- Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
- Department of Organic Chemistry, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Peremohy Ave. 37, 03056, Kyiv, Ukraine
| | - J Philipp Wagner
- Institut für Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
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7
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Huang GT, Yu JSK. Catalytic role of the enol ether intermediate in the intramolecular Stetter reaction: a computational perspective. Phys Chem Chem Phys 2024; 26:11833-11853. [PMID: 38567403 DOI: 10.1039/d3cp06051a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The intramolecular Stetter reaction catalyzed by a carbene is investigated by density functional theory (DFT) calculations and kinetic simulations. Catalyst 1 first reacts with aldehyde 2 to give the primary adduct (PA). The PA undergoes the intramolecular oxa-Michael reaction to irreversibly generate enol ether intermediate 9. The conversion of the enol ether to the Breslow intermediate (BI) requires the assistance of a base such as the PA. The next step involves formation of a carbon-carbon bond through the Michael addition, and expulsion of the catalyst generates the Stetter product 7. Calculations show that the catalytic cycle is composed of two irreversible processes: the first one involves the exergonic formation of the enol ether intermediate, while the second one is the conversion of the enol ether to the final product. Kinetic simulations using initial concentrations of [1]0 = 0.005 M and [2]0 = 0.025 M demonstrate that under a steady-state condition, 35% of the catalyst rests on the state of the enol ether (0.0018 M). The catalyst resting state therefore consists of the unbound form (the free catalyst) and its bound form (the enol ether species). According to variable time normalization analysis, the reaction exhibits a second-order dependence (first order in catalyst and first order in substrate), which agrees with experiments. The oxa-Michael reaction to form the enol ether is identified to be turnover limiting in the intramolecular Stetter reaction, which rationalizes the observed electronic effect of the Michael acceptor on the reactivity, as well as the measured isotope effect with respect to the aldehydic proton/deuteron. The base that participates in the BI formation has a significant effect on the build-up of the resting state 9 and the active catalyst concentration. In addition, the thermodynamic stability of the enol ether is found to depend on the tether length between the aromatic aldehyde and the Michael acceptor, as well as the chemical nature of the carbene catalyst. The favorability for the oxa-Michael reaction is therefore suggested to govern the reactivity of the intramolecular Stetter transformation.
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Affiliation(s)
- Gou-Tao Huang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu City 300, Taiwan.
| | - Jen-Shiang K Yu
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu City 300, Taiwan.
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu City 300, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu City 300, Taiwan
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8
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Aysin RR, Galkin KI. Impact of Backbone Substitution on Organocatalytic Activity of Sterically Encumbered NHC in Benzoin Condensation. Molecules 2024; 29:1704. [PMID: 38675524 PMCID: PMC11051995 DOI: 10.3390/molecules29081704] [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: 02/29/2024] [Revised: 03/28/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
In this study, we provide a theoretical explanation for the experimentally observed decrease in the organocatalytic activity of N-aryl imidazolylidenes methylated at the C4/5-H positions in the benzoin condensation of aromatic aldehydes. A comparative quantum chemical study of energy profiles for the NHC-mediated benzoin condensation of furfural has revealed a high energy barrier to the formation of the IPrMe-based furanic Breslow intermediate that can be attributed to the negative steric interactions between the imidazole backbone methyl groups and N-aryl substituents.
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Affiliation(s)
- Rinat R. Aysin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Street 28, bld. 1, 119991 Moscow, Russia;
| | - Konstantin I. Galkin
- N. D. Zelinsky Institute of Organic Chemistry, Leninsky Prospect 47, Russian Academy of Sciences, 119991 Moscow, Russia
- Laboratory of Green Chemistry, Bauman Moscow State Technical University, 2nd Baumanskaya Street 5/1, 105005 Moscow, Russia
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9
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Khezeli F, Plaisance C. Computational Design of an Electro-Organocatalyst for Conversion of CO 2 into Formaldehyde. J Phys Chem A 2024; 128:1576-1592. [PMID: 38412517 PMCID: PMC10926098 DOI: 10.1021/acs.jpca.3c07806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/29/2024]
Abstract
Density functional theory calculations employing a hybrid implicit/explicit solvation method were used to explore a new strategy for electrochemical conversion of CO2 using an electro-organocatalyst. A particular structural motif is identified that consists of an electron-rich vicinal enediamine (>N-C═C-N<) backbone, which is capable of activating CO2 by the formation of a C-C bond while subsequently facilitating the transfer of electrons from a chemically inert cathode to ultimately produce formaldehyde. Unlike transition metal-based electrocatalysts, the electro-organocatalyst is not constrained by scaling relations between the formation energies of activated CO2 and adsorbed CO, nor is it expected to be active for the competing hydrogen evolution reaction. The rate-limiting steps are found to occur during two proton-coupled electron transfer (PCET) sequences and are associated with the transfer of a proton from a proton transfer mediator to a carbon atom on the electro-organocatalyst. The difficulty of this step in the second PCET sequence necessitates an electrode potential of -0.85 V vs RHE to achieve the maximum turnover frequency. In addition, it is postulated that the electro-organocatalyst should also be capable of forming long-chain aldehydes by successively carrying out reductive aldol condensation to grow the alkyl chain one carbon at a time.
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Affiliation(s)
- Foroogh Khezeli
- Cain Department
of Chemical
Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Craig Plaisance
- Cain Department
of Chemical
Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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10
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Hou XX, Wei D. Mechanism and Origin of Stereoselectivity for the NHC-Catalyzed Desymmetrization Reaction for the Synthesis of Axially Chiral Biaryl Aldehydes. J Org Chem 2024; 89:3133-3142. [PMID: 38359780 DOI: 10.1021/acs.joc.3c02575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Organocatalytic desymmetrization reaction is a powerful tool for constructing axial chirality, but the theoretical study on the origin of stereoselectivity still lags behind even now. In this work, the N-heterocyclic carbene (NHC)-catalyzed desymmetrization reaction of biaryl frameworks for the synthesis of axially chiral aldehydes has been selected and theoretically investigated by using density functional theory (DFT). The fundamental pathway involves several steps, i.e., desymmetrization, formation of Breslow oxidation, esterification, and NHC regeneration. The desymmetrization and formation of Breslow processes have been identified as stereoselectivity-determining and rate-determining steps. Further weak interaction analyses proved that the C-H···O hydrogen bond and C-H···π interactions are responsible for the stability of the key stereoselective desymmetrization transition states. This research contributes to understanding the nature of NHC-catalyzed desymmetrization reactions for the synthesis of axially chiral compounds.
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Affiliation(s)
- Xiao-Xiao Hou
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
| | - Donghui Wei
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou 450001, Henan, P. R. China
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11
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Abdellaoui M, Oppel K, Vianna A, Soleilhavoup M, Yan X, Melaimi M, Bertrand G. 1 H-1,2,3-Triazol-5-ylidenes as Catalytic Organic Single-Electron Reductants. J Am Chem Soc 2024; 146:2933-2938. [PMID: 38253007 DOI: 10.1021/jacs.3c14360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Most of the known single-electron reductants are either metal based reagents, used in a stoichiometric amount, or a combination of an organic species and a photocatalyst. Here we report that 1H-1,2,3-triazol-5-ylidenes act not only as stoichiometric one-electron donors but also as catalytic organic reducing agents, without the need of a photocatalyst. As a proof of concept, we studied the reduction of quinones, which are well-known electron conveyors that are involved in various biological and industrial processes. This work also provides experimental evidence for the formation of a bis(triazolium)carbonate adduct, which acts as the resting state of the catalytic cycle and as the carbene reservoir.
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Affiliation(s)
- Mehdi Abdellaoui
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
| | - Kai Oppel
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
| | - Adam Vianna
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
| | - Michele Soleilhavoup
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
| | - Xiaoyu Yan
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing,100872, China
| | - Mohand Melaimi
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093-0358, United States
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12
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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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13
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Aysin RR, Galkin KI. Adaptive carbonyl umpolung involving a carbanionic carbene Breslow intermediate: an alternative mechanism for NHC-mediated organocatalysis. Org Biomol Chem 2023; 21:8702-8707. [PMID: 37867444 DOI: 10.1039/d3ob01195j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
Herein, we propose a novel mechanistic model for NHC-mediated carbonyl umpolung which involves the formation of a carbanionic carbene Breslow intermediate (CCBI). We have demonstrated theoretically that this reactive intermediate can be formed by inserting an aldehyde into the C4-H position of an N-aryl-substituted imidazolium-derived NHC via the generation of an H-bonded ditopic carbanionic NHC (dcNHC). Our DFT study on benzoin condensation has revealed that the mechanism of polarity inversion proceeding through the CCBI may be more energetically favorable than the classical mechanism of umpolung that uses the C2 carbene position in NHC. The potential existence of the CCBI highlights the dynamic and adaptive nature of NHC-mediated organocatalysis, particularly in relation to carbonyl umpolung. This finding also sheds light on new pathways in organocatalytic transformations employing the ambident reactivity of NHC, which may be particularly attractive for reactions involving furanic aldehydes and sterically encumbered N-aryl-substituted carbenes.
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Affiliation(s)
- Rinat R Aysin
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ul. Vavilova, 28, 119991 Moscow, Russia
| | - Konstantin I Galkin
- Bauman Moscow State Technical University, 2nd Baumanskaya ul., 5/1, 105005 Moscow, Russia.
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, ul. Leninsky Prospekt, 47, 119991, Moscow, Russia
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14
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Li Y, Zhang M, Zhang Z. Mechanisms and Stereoselectivities in the NHC-Catalyzed [4 + 2] Annulation of 2-Bromoenal and 6-Methyluracil-5-carbaldehyde. J Org Chem 2023; 88:12997-13008. [PMID: 37642149 DOI: 10.1021/acs.joc.3c01015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
To disclose the reaction mechanism and selectivity in the NHC-catalyzed reaction of 2-bromoenal and 6-methyluracil-5-carbaldehyde, a systematic computational study has been performed. According to DFT computations, the catalytic cycle is divided into eight elementary steps: nucleophilic attack of the NHC on 2-bromoenal, 1,2-proton transfer, C-Br bond dissociation, 1,3-proton transfer, addition to 6-methyluracil-5-carbaldehyde, [2 + 2] cycloaddition, NHC dissociation, and decarboxylation. The Bronsted acid DABCO·H+ plays a crucial role in proton transfer and decarboxylation steps. The addition to 6-methyluracil-5-carbaldehyde determines both chemoselectivity and stereoselectivity, leading to R-configured carbocycle-fused uracil, in agreement with experimental results. NCI analysis indicates that the CH···N, CH···π, and LP···π interactions should be the key factor for determining the stereoselectivity. ELF analysis shows the main role of the NHC in promoting C-Br bond dissociation. The mechanistic insights obtained in the present work may guide the rational design of potential NHC catalysts.
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Affiliation(s)
- Yan Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
| | - Mingchao Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
| | - Zhiqiang Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
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15
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Li G, Li Z, Gao L, Chen S, Wang G, Li S. Combined molecular dynamics and coordinate driving method for automatically searching complicated reaction pathways. Phys Chem Chem Phys 2023; 25:23696-23707. [PMID: 37610711 DOI: 10.1039/d3cp02443a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The combined molecular dynamics and coordinate driving (MD/CD) method is updated and generalized in this work to broaden its applications in automatically searching reaction pathways for complicated reactions. In this updated version, MD simulations are performed with the GFN's family of methods to systematically sample conformers for almost any systems with atomic numbers Z ≤ 86. The improved CD procedure is greatly accelerated by applying a pre-screening stage at the semiempirical GFN2-xTB level. An automatic module based on the Marcus theory and its improved version (the Wolynes theory) is designed to include single electron transfer (SET) processes into reaction pathways. The capabilities of this method are demonstrated by exploring the most possible reaction pathways of three experimentally reported reactions: the organophosphine-catalyzed trans phosphinoboration, the Fe(II) complex-mediated C(sp2)-H borylation reaction, and the SET-triggered deaminative radical cross-coupling reaction. Comprehensive reaction networks are obtained for all three reactions with reasonable computational costs. Detailed mechanisms for these reactions can account for the reported experimental facts.
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Affiliation(s)
- Guoao Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Zhenxing Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Liuzhou Gao
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Shengda Chen
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Guoqiang Wang
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
| | - Shuhua Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, New Cornerstone Science Laboratory, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People's Republic of China.
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16
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Takekawa Y, Nakagawa M, Nagao K, Ohmiya H. A Quadruple Catalysis Enabling Intermolecular Branch-Selective Hydroacylation of Styrenes. Chemistry 2023; 29:e202301484. [PMID: 37260048 DOI: 10.1002/chem.202301484] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/02/2023]
Abstract
A quadruple N-heterocyclic carbene/cobalt/photoredox/Brønsted base catalysis to realize branch-selective hydroacylation of styrenes with aromatic and aliphatic aldehydes is demonstrated. This protocol allows access to branched ketones from readily available materials in an atom-economical manner. The quadruple catalysis can transfer a formyl hydrogen of aldehydes as a hydrogen radical equivalent onto the terminal carbon of an alkene by controlled electron and proton transfers.
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Affiliation(s)
- Yunosuke Takekawa
- Division of Pharmaceutical Sciences, Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Masanari Nakagawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Kazunori Nagao
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Hirohisa Ohmiya
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
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17
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Mulks FF, Melaimi M, Yan X, Baik MH, Bertrand G. How To Enhance the Efficiency of Breslow Intermediates for SET Catalysis. J Org Chem 2023; 88:2535-2542. [PMID: 36719963 DOI: 10.1021/acs.joc.2c02978] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Oxidative carbene organocatalysis, which proceeds via single electron transfer (SET) pathways, has been limited by the moderately reducing properties of deprotonated Breslow intermediates BI-s derived from thiazol-2-ylidene 1 and 1,2,4-triazolylidene 2. Using computational methods, we assess the redox potentials of BI-s based on ten different types of known stable carbenes and report our findings concerning the key parameters influencing the steps of the catalytic cycle. From the calculated values of the first oxidation potential of BI-s derived from carbenes 1 to 10, it appears that, apart from the diamidocarbene 7, all the others are more reducing than thiazol-2-ylidene 1 and the 1,2,4-triazolylidene 2. We observed that while the reducing power of BI-s significantly decreases with increasing solvent polarity, the redox potential of the oxidant can increase at a greater rate, thus facilitating the reaction. The cation, associated with the base, also plays an important role when a nonpolar solvent is used; large and weakly coordinating cations such as Cs+ are beneficial. The radical-radical coupling step is probably the most challenging step due to both electronic and steric constraints. Based on our results, we predict that mesoionic carbene 3 and abnormal NHC 4 are the most promising candidates for oxidative carbene organocatalysis.
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Affiliation(s)
- Florian F Mulks
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea.,Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.,UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Mohand Melaimi
- UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
| | - Xiaoyu Yan
- Department of Chemistry, Renmin University of China, Beijing 100872, People's Republic of China
| | - Mu-Hyun Baik
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Republic of Korea.,Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Guy Bertrand
- UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, United States
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18
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Dubey G, Singh T, Bharatam PV. The importance of four-membered NHCs in stabilizing Breslow intermediates on benzoin condensation pathway. J Comput Chem 2023; 44:346-354. [PMID: 35652523 DOI: 10.1002/jcc.26935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/27/2022] [Accepted: 05/07/2022] [Indexed: 01/03/2023]
Abstract
N-heterocyclic carbenes (NHCs) have been established to be effective organocatalysts for facilitating the benzoin condensation and many other reactions. These reactions involve the formation of a Breslow intermediate (BI), which exhibits umpolung chemistry. To facilitate organocatalysis, several new cyclic carbenes are being introduced, four-membered NHCs are of special interest. Whether these NHCs can exhibit catalytic influence or not, can be evaluated by exploring the potential energy surface (PES) of the benzoin condensation reaction. Quantum chemical analysis has been carried out to compare the PES of these four-membered NHCs with that of standard five-membered NHCs to explore their catalytic ability. The barrier for the first step of the reaction for the formation of BI is comparable in all the cases. But the barrier for the second step of the reaction leading to the benzoin formation from BI is estimated to be very high for the four membered NHCs. These results indicate that the probability of identifying and isolating the BI is very high in comparison to the completion of benzoin condensation reaction in the case of the four-membered NHCs.
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Affiliation(s)
- Gurudutt Dubey
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, India
| | - Tejender Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, India
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19
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De Risi C, Brandolese A, Di Carmine G, Ragno D, Massi A, Bortolini O. Oxidative N-Heterocyclic Carbene Catalysis. Chemistry 2023; 29:e202202467. [PMID: 36205918 PMCID: PMC10099058 DOI: 10.1002/chem.202202467] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Indexed: 11/05/2022]
Abstract
N-Heterocyclic carbene (NHC) catalysis is a by now consolidated organocatalytic platform for a number of synthetic (asymmetric) transformations via diverse reaction modes/intermediates. In addition to the typical umpolung processes involving acyl anion/homoenolate equivalent species, implementation of protocols under oxidative conditions greatly expands the possibilities of this methodology. Oxidative NHC-catalysis allows for oxidative and oxygenative transformations through specific manipulations of Breslow-type species depending upon the oxidant used (external oxidant or O2 /air), the derived NHC-bound intermediates paving the way to non-umpolung processes through activation of carbon atoms and heteroatoms. This review is intended to update the state of the art in oxidative NHC-catalyzed reactions that appeared in the literature from 2014 to present, with a strong focus to crucial intermediates and their mechanistic implications.
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Affiliation(s)
- Carmela De Risi
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
| | - Arianna Brandolese
- Dipartimento di Scienze dell'Ambiente e della Prevenzione, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
| | - Graziano Di Carmine
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
| | - Daniele Ragno
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
| | - Alessandro Massi
- Dipartimento di Scienze Chimiche, Farmaceutiche ed Agrarie, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
| | - Olga Bortolini
- Dipartimento di Scienze dell'Ambiente e della Prevenzione, Università di Ferrara, Via L. Borsari, 46, 44121, Ferrara, Italy
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20
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Barman D, Lo R, Maiti DK, Manna D, Ghosh T. Mechanistic Exploration of Umpolung Guided Stetter‐Aldol Reaction and Its Dependence on the Choice of Imine. ChemistrySelect 2023. [DOI: 10.1002/slct.202204558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Debabrata Barman
- Department of Chemistry University of Calcutta Kolkata 700009 India
| | - Rabindranath Lo
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences v.v.i., Flemingovo nám. 2 16610 Prague 6 Czech Republic
- Regional Centre of Advanced Technologies and Materials Czech Advanced Technology and Research Institute Palacký University Olomouc Křížkovského 511/8 Olomouc 77900 Czech Republic
| | - Dilip K. Maiti
- Department of Chemistry University of Calcutta Kolkata 700009 India
| | - Debashree Manna
- Department of Applied Chemistry Maulana Abul Kalam Azad University of Technology West Bengal, Simhat Haringhata 741249, W.B. India
| | - Tapas Ghosh
- Department of Chemistry Jadavpur University Kolkata 700032 India
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21
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Athira C, Sreenithya A, Hadad CM, Sunoj RB. Cooperative Asymmetric Dual Catalysis Involving a Chiral N-Heterocyclic Carbene Organocatalyst and Palladium in an Annulation Reaction: Mechanism and Origin of Stereoselectivity. ACS Catal 2023. [DOI: 10.1021/acscatal.2c05725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- C. Athira
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - A. Sreenithya
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Christopher M. Hadad
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Raghavan B. Sunoj
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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22
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Wang X, Wang YN, Pei Z, Li SJ, Wei D, Lan Y. N-Heterocyclic Carbene/Brønsted Acid Cooperatively Catalyzed Conversions of α, β-Unsaturated Carbonyls: Hydrogen Bond Donor/Acceptor-Electrophile/Nucleophile Combination Models. ACS Catal 2022. [DOI: 10.1021/acscatal.2c05373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Xinghua Wang
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Ya-Nan Wang
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 400030, China
| | - Zhipeng Pei
- Institue for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
- Department of Chemistry, Faculty of Science, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Shi-Jun Li
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Donghui Wei
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Yu Lan
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 400030, China
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23
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Duan Z, Young CM, Zhu J, Slawin AMZ, O'Donoghue AC, Smith AD. Rate and equilibrium constants for the addition of triazolium salt derived N-heterocyclic carbenes to heteroaromatic aldehydes. Chem Sci 2022; 14:162-170. [PMID: 36605738 PMCID: PMC9769090 DOI: 10.1039/d2sc05704b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/13/2022] [Indexed: 11/16/2022] Open
Abstract
Heteroaromatic aldehydes are often used preferentially or exclusively in a range of NHC-catalysed processes that proceed through the generation of a reactive diaminoenol or Breslow Intermediate (BI), with the reason for their unique reactivity currently underexplored. This manuscript reports measurement of rate and equilibrium constants for the reaction between N-aryl triazolium NHCs and heteroaromatic aldehydes, providing insight into the effect of the NHC and heteroaromatic aldehyde structure up to formation of the BI. Variation in NHC catalyst and heteroaromatic aldehyde structure markedly affect the observed kinetic parameters of adduct formation, decay to starting materials and onward reaction to BI. In particular, large effects are observed with both 3-halogen (Br, F) and 3-methyl substituted pyridine-2-carboxaldehyde derivatives which substantially favour formation of the tetrahedral intermediate relative to benzaldehyde derivatives. Key observations indicate that increased steric hindrance leads to a reduction in both k 2 and k -1 for large (2,6-disubstituted)-N-Ar groups within the triazolium scaffold, and sterically demanding aldehyde substituents in the 3-position, but not in the 6-position of the pyridine-2-carboxaldehyde derivatives. As part of this study, the isolation and characterisation of twenty tetrahedral adducts formed upon addition of N-aryl triazolium derived NHCs into heteroaromatic aldehydes are described. These adducts are key intermediates in NHC-catalysed umpolung addition of heteroaromatic aldehydes and are BI precursors.
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Affiliation(s)
- Zhuan Duan
- EaStCHEM, School of Chemistry, University of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Claire M. Young
- EaStCHEM, School of Chemistry, University of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | - Jiayun Zhu
- Department of Chemistry, Durham UniversitySouth RoadDurham DH1 3LEUK
| | - Alexandra M. Z. Slawin
- EaStCHEM, School of Chemistry, University of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
| | | | - Andrew D. Smith
- EaStCHEM, School of Chemistry, University of St AndrewsNorth HaughSt AndrewsFifeKY16 9STUK
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24
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Sicard AJ, Ghaffari B, Gabidullin BM, Ovens JS, Hughes RP, Baker RT. Nickel-Catalyzed Homologation of Vinylidene Difluoride (CH 2═CF 2): Selective β-F vs β-H Elimination. J Am Chem Soc 2022; 144:22713-22721. [PMID: 36469940 DOI: 10.1021/jacs.2c10448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hydrofluoroolefins (HFOs) constitute the newest generation of fluorocarbon refrigerants and foam-blowing agents due to their reduced global warming potential vs their saturated analogues. To identify new synthetic routes to HFOs, we show that reactions of bulky Ni(0) phosphine and -NHC complexes with vinylidene difluoride (VF2) afford μ-fluoro-1,1,3-trifluorobut-3-enyl Ni complexes. Moreover, addition of triisopropylsilane allows for reductive elimination of the reduced product─2,4,4-trifluoro-1-butene─demonstrating the Ni-catalyzed hydrodefluorodimerization of VF2. Accompanying DFT calculations identify the T-shaped nickelacyclopentane intermediate that spontaneously undergoes selective intramolecular β-F (vs β-H) elimination.
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Affiliation(s)
- Alexandre J Sicard
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Behnaz Ghaffari
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Bulat M Gabidullin
- Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Jeffrey S Ovens
- Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Russell P Hughes
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - R Tom Baker
- Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
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25
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Lopat’eva ER, Krylov IB, Lapshin DA, Terent’ev AO. Redox-active molecules as organocatalysts for selective oxidative transformations - an unperceived organocatalysis field. Beilstein J Org Chem 2022; 18:1672-1695. [PMID: 36570566 PMCID: PMC9749543 DOI: 10.3762/bjoc.18.179] [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: 09/16/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
Organocatalysis is widely recognized as a key synthetic methodology in organic chemistry. It allows chemists to avoid the use of precious and (or) toxic metals by taking advantage of the catalytic activity of small and synthetically available molecules. Today, the term organocatalysis is mainly associated with redox-neutral asymmetric catalysis of C-C bond-forming processes, such as aldol reactions, Michael reactions, cycloaddition reactions, etc. Organophotoredox catalysis has emerged recently as another important catalysis type which has gained much attention and has been quite well-reviewed. At the same time, there are a significant number of other processes, especially oxidative, catalyzed by redox-active organic molecules in the ground state (without light excitation). Unfortunately, many of such processes are not associated in the literature with the organocatalysis field and thus many achievements are not fully consolidated and systematized. The present article is aimed at overviewing the current state-of-art and perspectives of oxidative organocatalysis by redox-active molecules with the emphasis on challenging chemo-, regio- and stereoselective CH-functionalization processes. The catalytic systems based on N-oxyl radicals, amines, thiols, oxaziridines, ketone/peroxide, quinones, and iodine(I/III) compounds are the most developed catalyst types which are covered here.
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Affiliation(s)
- Elena R Lopat’eva
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russia
| | - Igor B Krylov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russia
| | - Dmitry A Lapshin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russia
| | - Alexander O Terent’ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow, 119991, Russia
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26
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Dong Z, Jiang C, Zhao C. A Review on Generation and Reactivity of the N-Heterocyclic Carbene-Bound Alkynyl Acyl Azolium Intermediates. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27227990. [PMID: 36432089 PMCID: PMC9696695 DOI: 10.3390/molecules27227990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
Abstract
N-heterocyclic carbene (NHC) has been widely used as an organocatalyst for both umpolung and non-umpolung chemistry. Previous works mainly focus on species including Breslow intermediate, azolium enolate intermediate, homoenolate intermediate, alkenyl acyl azolium intermediate, etc. Notably, the NHC-bound alkynyl acyl azolium has emerged as an effective intermediate to access functionalized cyclic molecular skeleton until very recently. In this review, we summarized the generation and reactivity of the NHC-bound alkynyl acyl azolium intermediates, which covers the efforts and advances in the synthesis of achiral and axially chiral cyclic scaffolds via the NHC-bound alkynyl acyl azolium intermediates. In particular, the mechanism related to this intermediate is discussed in detail.
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27
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Abstract
α-Amino acids are essential molecular constituents of life, twenty of which are privileged because they are encoded by the ribosomal machinery. The question remains open as to why this number and why this 20 in particular, an almost philosophical question that cannot be conclusively resolved. They are closely related to the evolution of the genetic code and whether nucleic acids, amino acids, and peptides appeared simultaneously and were available under prebiotic conditions when the first self-sufficient complex molecular system emerged on Earth. This report focuses on prebiotic and metabolic aspects of amino acids and proteins starting with meteorites, followed by their formation, including peptides, under plausible prebiotic conditions, and the major biosynthetic pathways in the various kingdoms of life. Coenzymes play a key role in the present analysis in that amino acid metabolism is linked to glycolysis and different variants of the tricarboxylic acid cycle (TCA, rTCA, and the incomplete horseshoe version) as well as the biosynthesis of the most important coenzymes. Thus, the report opens additional perspectives and facets on the molecular evolution of primary metabolism.
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Affiliation(s)
- Andreas Kirschning
- Institute of Organic ChemistryLeibniz University HannoverSchneiderberg 1B30167HannoverGermany
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28
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Yadav S, Nanubolu JB, Suresh S. Sequential One-Pot Carbene-Catalyzed Intramolecular Stetter Reaction and Acid-Mediated Condensation: Access to Heteroatom Analogues of π-Extended Polyaromatic Hydrocarbons. Org Lett 2022; 24:6930-6935. [PMID: 36129395 DOI: 10.1021/acs.orglett.2c02693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this Letter, we disclose a simple and effective method to access a variety of phenanthro[9,10-b]furan and 1H-dibenzo[e,g]indole derivatives based on the design of a carbene-catalyzed intramolecular Stetter reaction followed by a Paal-Knorr reaction in one-pot. These compounds are a class of π-extended polycyclic aromatic hydrocarbon (PAH) derivatives containing an oxygen/nitrogen atom. The practical utility of the developed transformation was demonstrated on the gram scales and postsynthetic transformations thereof.
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Affiliation(s)
- Sanjay Yadav
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Jagadeesh Babu Nanubolu
- Laboratory of X-ray Crystallography, Department of Analytical Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India
| | - Surisetti Suresh
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
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29
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Wang Z, Yang T, Liu D, Chen R, Wang N, Liu H, Li J, Wang K, Liu H. Catalyst-Controlled Selectivity Switch in Three-Component Reaction: An NHC-Catalyzed Strategy for the Synthesis of δ-Lactone-Fused Spirobenzofuran-3-ones. Molecules 2022; 27:molecules27185952. [PMID: 36144686 PMCID: PMC9503435 DOI: 10.3390/molecules27185952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 11/28/2022] Open
Abstract
An efficient, three-component reaction of aldehydes and benzofuran-3-ones was developed. This process provides a new approach for the preparation of synthetically and biologically important spirobenzofuran-3-one derivatives with moderate-to-good yields under mild conditions. A switch of intramolecular to intermolecular domino Michael–aldol–lactonization leading to differential product formation was achieved by different NHCs catalysis.
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Affiliation(s)
- Zhanyong Wang
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
| | - Ting Yang
- Nursing College, Xinxiang University, Xinxiang 453003, China
| | - Dongfang Liu
- Xinxiang Runyu Material Co., Ltd., Xinxiang 453003, China
| | - Rongxiang Chen
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
| | - Nan Wang
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
| | - Hong Liu
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
| | - Jiarong Li
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
| | - Kaikai Wang
- School of Pharmacy, Xinxiang University, Xinxiang 453003, China
- Correspondence: (K.W.); (H.L.)
| | - Hongxin Liu
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China
- Institute of New Materials & Industrial Technology, Wenzhou University, Wenzhou 325035, China
- Correspondence: (K.W.); (H.L.)
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30
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Cai BG, Li Q, Empel C, Li L, Koenigs RM, Xuan J. Dark and Light Reactions of Carbenes─Merging Carbene Transfer Reactions with N-Heterocyclic Carbene Catalysis for the Synthesis of Hydroxamic Acid Esters. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02875] [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)
- Bao-Gui Cai
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Qian Li
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Claire Empel
- Institute of Organic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
| | - Lei Li
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Rene M. Koenigs
- Institute of Organic Chemistry, RWTH Aachen University, D-52074 Aachen, Germany
| | - Jun Xuan
- Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, College of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, China
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials, Ministry of Education, Anhui University, Hefei 230601, China
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31
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Yuan XA, Li D, Wang S, Jiang YY, Liu P, Bi S. Distinctive Mechanistic Scenarios and Substituent Effects of Gold(I) versus Copper(I) Catalysis for Hydroacylation of Terminal Alkynes with Glyoxal Derivatives. J Org Chem 2022; 87:11681-11692. [PMID: 35984222 DOI: 10.1021/acs.joc.2c01316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Density functional theory (DFT) calculations have been conducted to study the mechanisms, substituent effects, and the role of bases in Au- and Cu-catalyzed hydroacylation of terminal alkyne with glyoxal derivatives. The two reactions, despite being catalyzed by the same group of transition metals, follow distinctive reaction mechanisms. Through the detailed DFT calculations, insights into the mechanisms are obtained, and the substituent effects and the role of the bases are understood.
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Affiliation(s)
- Xiang-Ai Yuan
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
| | - Dan Li
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
| | - Shanshan Wang
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
| | - Yuan-Ye Jiang
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
| | - Peng Liu
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
| | - Siwei Bi
- School of Chemistry and Chemical Engineering, Qufu Normal University, 57 Jingxuan West Road, Qufu, Shandong 273165, People's Republic of China
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32
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Partl G, Rauter M, Fliri L, Gelbrich T, Kreutz C, Müller T, Kahlenberg V, Nerdinger S, Schottenberger H. A Fluoroponytailed NHC–Silver Complex Formed from Vinyl-imidazolium/AgNO3 under Aqueous–Ammoniacal Conditions. Molecules 2022; 27:molecules27134137. [PMID: 35807382 PMCID: PMC9268170 DOI: 10.3390/molecules27134137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022] Open
Abstract
3-(1H,1H,2H,2H-Perfluorooctyl)-1-vinylimidazolium chloride [2126844–17–3], a strong fluorosurfactant with remarkably high solubility in water, was expediently converted into the respective doubly NHC-complexed silver salt with nitrate as counter ion in quantitative yield. Due to its vinyl substituents, [bis(3-(1H,1H,2H,2H-perfluorooctyl)-1-vinylimidazol-2-ylidene)silver(I)] nitrate, Ag(FNHC)2NO3, represents a polymerizable N-heterocyclic carbene transfer reagent, thus potentially offering simple and robust access to coordination polymers with crosslinking metal bridges. The compound was characterized by infrared and NMR spectroscopy, mass spectrometry as well as elemental analysis, and supplemented by X-ray single-crystal structure determination. It crystallizes in the monoclinic crystal system in the space group P21/c. With 173.3°, the geometry of the Ag-carbene bridge deviates slightly from linearity. The disordered perfluoroalkyl side chains exhibit a helical conformation.
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Affiliation(s)
- Gabriel Partl
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, CCB, Innrain 80-82, 6020 Innsbruck, Austria;
| | - Marcus Rauter
- Infineon Technologies AG, Siemensstrasse 2, 9500 Villach, Austria;
| | - Lukas Fliri
- Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076 Aalto, Finland;
| | - Thomas Gelbrich
- Institute of Pharmacy, Leopold Franzens University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria;
| | - Christoph Kreutz
- Institute Organic Chemistry, University of Innsbruck, CCB, Innrain 80-82, 6020 Innsbruck, Austria; (C.K.); (T.M.)
| | - Thomas Müller
- Institute Organic Chemistry, University of Innsbruck, CCB, Innrain 80-82, 6020 Innsbruck, Austria; (C.K.); (T.M.)
| | - Volker Kahlenberg
- Institute of Mineralogy & Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria;
| | - Sven Nerdinger
- Sandoz GmbH, Biochemiestr. 10, 6250 Kundl, Austria
- Correspondence: (S.N.); (H.S.)
| | - Herwig Schottenberger
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, CCB, Innrain 80-82, 6020 Innsbruck, Austria;
- Correspondence: (S.N.); (H.S.)
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33
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Abstract
This Perspective article highlights the recent development of mesoionic N-heterocyclic olefins (mNHOs), where the exo-cyclic olefinic carbon is not bonded to strongly electron-withdrawing groups. The unquenched basicity and nucleophilicity of the exo-cyclic olefinic carbon make mNHOs strong σ-donors and enable unique reactivity patterns.
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Affiliation(s)
- Qiuming Liang
- Davenport Chemical Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6.
| | - Datong Song
- Davenport Chemical Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6.
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34
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Formation of Breslow Intermediates from N‐Heterocyclic Carbenes and Aldehydes Involves Autocatalysis by the Breslow Intermediate, and a Hemiacetal. Angew Chem Int Ed Engl 2022; 61:e202117682. [PMID: 35238462 PMCID: PMC9325009 DOI: 10.1002/anie.202117682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Indexed: 11/23/2022]
Abstract
Under aprotic conditions, the stoichiometric reaction of N‐heterocyclic carbenes (NHCs) such as imidazolidin‐2‐ylidenes with aldehydes affords Breslow Intermediates (BIs), involving a formal 1,2‐C‐to‐O proton shift. We herein report kinetic studies (NMR), complemented by DFT calculations, on the mechanism of this kinetically disfavored H‐translocation. Variable time normalization analysis (VTNA) revealed that the kinetic orders of the reactants vary for different NHC‐to‐aldehyde ratios, indicating different and ratio‐dependent mechanistic regimes. We propose that for high NHC‐to‐aldehyde ratios, the H‐shift takes place in the primary, zwitterionic NHC‐aldehyde adduct. With excess aldehyde, the zwitterion is in equilibrium with a hemiacetal, in which the H‐shift occurs. In both regimes, the critical H‐shift is auto‐catalyzed by the BI. Kinetic isotope effects observed for R‐CDO are in line with our proposal. Furthermore, we detected an H‐bonded complex of the BI with excess NHC (NMR).
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Affiliation(s)
- Alina Wessels
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Germany
| | - Martin Breugst
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Nils E. Schlörer
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
| | - Albrecht Berkessel
- Department of Chemistry Organic Chemistry University of Cologne Greinstraße 4 50939 Cologne Germany
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35
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Shen J, Zhang Y, Xue Y. Theoretical Insights into Enantioselective [3 + 2] Cycloaddition between Cinnamaldehyde and Cyclic N-Sulfonyl Trifluoromethylated Ketimine Catalyzed by N-Heterocyclic Carbene. J Phys Chem A 2022; 126:3124-3134. [PMID: 35549275 DOI: 10.1021/acs.jpca.2c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The density functional theory (DFT) method was used to investigate the mechanism and the origin of stereoselectivity of N-heterocyclic carbene (NHC)-catalyzed [3 + 2] cycloaddition between enals and cyclic imine N-sulfonyl trifluoromethyl ketimines at the M06-2X/SMD/6-311+G(d,p)//M06-2X/SMD/6-31G (d,p) level. The results show that the favorable reaction path consists of five steps: nucleophilic attack, proton transfer, the formation of the C-C bond, the tautomerism of the enol intermediate, the formation of the five-membered ring, and the regeneration of the catalyst. For the process of proton transfer, the base-assisted reaction can reduce the activation free energy and make the reaction easier to occur compared with the direct proton transfer process. The formation of the C-C bond is the crucial step of stereoselectivity, in which two chiral centers and four configurations of intermediates (RR/RS/SR/SS) were generated. The free energy barriers obtained and the noncovalent interaction analysis confirm that the dominant configuration is SS, becoming the final trans-type product observed in experiment. Furthermore, through the analyses of the conceptual DFT and natural atomic charges, it is revealed that NHC acts as a double catalyst, which can not only increase the nucleophilicity of reactants by Lewis base but also activate the C-H bond and promote the proton transfer process. The understanding of the mechanism obtained in this study should be helpful to the other organic catalytic reactions with high stereoselectivity.
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Affiliation(s)
- Jingyi Shen
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
| | - Yan Zhang
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
| | - Ying Xue
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
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36
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Wessels A, Klussmann M, Breugst M, Schlörer NE, Berkessel A. Die Bildung von Breslow‐Intermediaten aus N‐heterocyclischen Carbenen und Aldehyden verläuft autokatalytisch und mit einem Halbacetal als Intermediat. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alina Wessels
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Martin Klussmann
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
- Borchers GmbH Berghausener Straße 100 40764 Langenfeld Deutschland
| | - Martin Breugst
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Nils E. Schlörer
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Albrecht Berkessel
- Department für Chemie Organische Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
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37
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NHC Catalyzed β-Carbon functionalization of carboxylic esters towards formation of δ-Lactams: A mechanistic study. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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38
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Ito S, Fujimoto H, Tobisu M. Non-Stabilized Vinyl Anion Equivalents from Styrenes by N-Heterocyclic Carbene Catalysis and Its Use in Catalytic Nucleophilic Aromatic Substitution. J Am Chem Soc 2022; 144:6714-6718. [PMID: 35404600 DOI: 10.1021/jacs.2c02579] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A protocol for the catalytic nucleophilic activation of unactivated styrenes is reported, which enables the generation of a non-stabilized alkenyl anion equivalent as a transient intermediate. In the reaction, N-heterocyclic carbenes add across styrenes to generate ylide intermediates, which can then be used in intramolecular nucleophilic aromatic substitution reactions of aryl fluorides, chlorides, and methyl ethers. The method allows for straightforward access to complex polyaromatic compounds.
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Affiliation(s)
- Sora Ito
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hayato Fujimoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Mamoru Tobisu
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Suita, Osaka 565-0871, Japan
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39
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Zhen G, Jiang K, Yin B. Progress in Organocatalytic Dearomatization Reactions Catalyzed by Heterocyclic Carbenes. ChemCatChem 2022. [DOI: 10.1002/cctc.202200099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Guangjin Zhen
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Kai Jiang
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Biaolin Yin
- South China University of Technology Dept. of Chenistry and chemical engineering Wushan Street 510640 Guangzhou CHINA
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40
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Li L, Mayer P, Stephenson DS, Ofial AR, Mayer RJ, Mayr H. An Overlooked Pathway in 1,3‐Dipolar Cycloadditions of Diazoalkanes with Enamines. Angew Chem Int Ed Engl 2022; 61:e202117047. [PMID: 35023245 PMCID: PMC9306659 DOI: 10.1002/anie.202117047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Indexed: 11/25/2022]
Abstract
Methyl diazoacetate reacts with 1‐(N‐pyrrolidino)cycloalkenes to give products of 1,3‐dipolar cycloadditions and azo couplings. The kinetics and mechanisms of these reactions were investigated by NMR spectroscopy and DFT calculations. Orthogonal π‐systems in the 1,3‐dipoles of the propargyl‐allenyl type allow for two separate reaction pathways for the (3+2)‐cycloadditions. The commonly considered concerted pathway is rationalized by the interaction of the enamine HOMO with LUMO+1, the lowest unoccupied orbital of the heteropropargyl anion fragment of methyl diazoacetate. We show that HOMO/LUMO(π*N=N) interactions between enamines and methyl diazoacetate open a previously unrecognized reaction path for stepwise cycloadditions through zwitterionic intermediates with barriers approximately 40 kJ mol−1 lower in energy in CHCl3 (DFT calculations) than for the concerted path.
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Affiliation(s)
- Le Li
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13 81377 München Germany
| | - Peter Mayer
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13 81377 München Germany
| | - David S. Stephenson
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13 81377 München Germany
| | - Armin R. Ofial
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13 81377 München Germany
| | - Robert J. Mayer
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS) Université de Strasbourg & CNRS 8 Allée Gaspard Monge 67000 Strasbourg France
| | - Herbert Mayr
- Department Chemie Ludwig-Maximilians-Universität München Butenandtstraße 5–13 81377 München Germany
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41
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Direct Synthesis of Vinylene Carbonates from Aromatic Aldehydes. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Liu SL, Liu X, Wang Y, Wei D. Unraveling the mechanism and substituent effects on the N-heterocyclic carbene-catalyzed transformation reaction of enals and imines. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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43
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Wang P, Fitzpatrick KP, Scheidt KA. Combined Photoredox and Carbene Catalysis for the Synthesis of γ-Aryloxy Ketones. Adv Synth Catal 2022; 364:518-524. [PMID: 35431717 PMCID: PMC9012476 DOI: 10.1002/adsc.202101354] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
N-heterocyclic carbenes (NHCs) have emerged as catalysts for the construction of C-C bonds in the synthesis of substituted ketones under single-electron processes. Despite these recent reports, there still remains a need to increase the utility and practicality of these reactions by exploring new radical coupling partners. Herein, we report the synthesis of γ-aryloxyketones via combined NHC/photoredox catalysis. In this reaction, an α-aryloxymethyl radical is generated via oxidation of an aryloxymethyl potassium trifluoroborate salt, which is then added into styrene derivatives to provide a stabilized benzylic radical. Subsequent radical-radical coupling reaction with an azolium radical affords the γ-aryloxy ketone products.
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Affiliation(s)
- Pengzhi Wang
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, Silverman Hall, Evanston, Illinois 60208
| | - Keegan P Fitzpatrick
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, Silverman Hall, Evanston, Illinois 60208
| | - Karl A Scheidt
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, Silverman Hall, Evanston, Illinois 60208
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44
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Song X, Chen Y, Lu F, Zhang K, Yu C, Li T, Yao C. NHC-catalyzed [4 + 2] annulations of allenoates and 2,3-dioxopyrrolidine derivatives. Org Biomol Chem 2022; 20:1219-1225. [PMID: 35040844 DOI: 10.1039/d1ob02180j] [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 facile NHC-catalyzed [2 + 4] annulation of allenoates with 2,3-dioxypyrrolidine derivatives was discovered, which paved a new avenue for the construction of highly substituted pyranopyrrole with moderate to good yields, high atom economy and mild reaction conditions.
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Affiliation(s)
- Xue Song
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Yangxu Chen
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Fangfang Lu
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Kai Zhang
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Chenxia Yu
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Tuanjie Li
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | - Changsheng Yao
- School of Chemistry and Materials Science, Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials. Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
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45
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Huang GT, Hsieh MH, Yu JSK. Formation of Breslow Intermediates under Aprotic Conditions: A Computational Study. J Org Chem 2022; 87:2501-2507. [PMID: 35029105 DOI: 10.1021/acs.joc.1c02408] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The mechanism of formation of the Breslow intermediate (BI) under aprotic conditions is investigated with density functional theory (DFT) calculations. The zwitterionic adduct (ZA) is formed by the first addition of an imidazolinylidene to benzaldehyde. The forward reaction is found to proceed through the second addition of the ZA to another benzaldehyde, and subsequent proton migration gives a hemiacetal. The bimolecular reaction enables the conversion of the ZA to a more reactive hemiacetal, which is further decomposed to the BI with the assistance of the ZA. During the ZA-assisted process, the hemiacetal and the BI act as hydrogen bond donors to stabilize the ZA. The hydrogen bond interactions between the ZA and the BI or hemiacetal are analyzed. The DFT computations demonstrate that along the proposed route, the proton migration leading to the hemiacetal intermediate is the rate-determining step (ΔG⧧ = 21.2 kcal mol-1). The bimolecular mechanism provides an alternative pathway to explain BI formation under aprotic conditions.
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46
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Li L, Mayer P, Stephenson DS, Ofial AR, Mayer RJ, Mayr H. An Overlooked Pathway in 1,3‐Dipolar Cycloadditions of Diazoalkanes with Enamines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117047] [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)
- Le Li
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Peter Mayer
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - David S. Stephenson
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Armin R. Ofial
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Robert J. Mayer
- Université de Strasbourg: Universite de Strasbourg Institut de Science et d'Ingenierie Supramoleculaire (ISIS) FRANCE
| | - Herbert Mayr
- Ludwig-Maximilians-Universität München Fakultät für Chemie und Pharmazie: Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie Butenandtstr. 5-13 81377 München GERMANY
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47
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Guo L, Wang J, Luo J, Shi Q, Wei D, Chen X. Prediction on chemoselectivity for selected organocatalytic reactions by the DFT version of the Hückel-defined free valence index. Catal Sci Technol 2022. [DOI: 10.1039/d2cy01118b] [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
The DFT version of the Hückel-defined free valence (HFV) index has been suggested and successfully used for predicting the origin of chemoselectivity in the selected organocatalytic reactions.
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Affiliation(s)
- Limin Guo
- College of Chemistry, Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China
| | - Juanjuan Wang
- Key Laboratory of Theoretical and Computational Photochemistry of the Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875, China
- Key Laboratory of Beam Technology of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China
| | - Jing Luo
- College of Chemistry, Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China
| | - Qianqian Shi
- College of Chemistry, Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China
| | - Donghui Wei
- College of Chemistry, Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China
| | - Xuebo Chen
- College of Chemistry, Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, China
- Key Laboratory of Theoretical and Computational Photochemistry of the Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875, China
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48
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Wang Y, Gong K, Zhang H, Liu Y, Wei D. Mechanism of a cobalt-catalyzed hydroarylation reaction and origin of stereoselectivity. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00780k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In the present study, the mechanism of a cobalt-catalyzed hydroarylation reaction between N-pyridylindole and 1,6-enynes and the origin of its stereoselectivity have been systematically investigated using the DFT calculation method.
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Affiliation(s)
- Yang Wang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou, Henan Province, 450002, PR China
| | - Kaili Gong
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou, Henan Province, 450002, PR China
| | - Han Zhang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou, Henan Province, 450002, PR China
| | - Yue Liu
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 136 Science Avenue, Zhengzhou, Henan Province, 450002, PR China
| | - Donghui Wei
- College of Chemistry (Center of Green Catalysis), Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan Province, 450001, PR China
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49
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Luo J, Han LL, Chen K, Song J, Wei D. A DFT study on the mechanism and regioselectivity of NHC-catalyzed double acylation of aromatic 1,2-diketones with α,β-unsaturated ketones. NEW J CHEM 2022. [DOI: 10.1039/d2nj03147g] [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
The possible mechanisms and the origin of regioselectivity of the N-heterocyclic carbene (NHC)-catalyzed double acylation reaction of aromatic 1,2-diketones with α,β-unsaturated ketones have been theoretically studied using density functional theory.
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Affiliation(s)
- Jing Luo
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, Henan, P. R. China
| | - Li-Li Han
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, Henan, P. R. China
| | - Kuohong Chen
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, Henan, P. R. China
| | - Jinshuai Song
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, Henan, P. R. China
| | - Donghui Wei
- College of Chemistry, and Institute of Green Catalysis, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, Henan, P. R. China
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50
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Bołt M, Hanek K, Żak P. Metal-free thioesterification of α,β-unsaturated aldehydes with thiols. Org Chem Front 2022. [DOI: 10.1039/d2qo00678b] [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
For the first time, the synthesis of thioesters starting from enals and thiols has been performed in the presence of a bulky N-heterocyclic carbene (NHC) as a catalyst.
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Affiliation(s)
- Małgorzata Bołt
- Department of Organometallic Chemistry, Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
| | - Kamil Hanek
- Department of Organometallic Chemistry, Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
| | - Patrycja Żak
- Department of Organometallic Chemistry, Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
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