1
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Kevlishvili I, Duan C, Kulik HJ. Classification of Hemilabile Ligands Using Machine Learning. J Phys Chem Lett 2023:11100-11109. [PMID: 38051982 DOI: 10.1021/acs.jpclett.3c02828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Hemilabile ligands have the capacity to partially disengage from a metal center, providing a strategy to balance stability and reactivity in catalysis, but they are not straightforward to identify. We identify ligands in the Cambridge Structural Database that have been crystallized with distinct denticities and are thus identifiable as hemilabile ligands. We implement a semi-supervised learning approach using a label-spreading algorithm to augment a small negative set that is supported by heuristic rules of ligand and metal co-occurrence. We show that a heuristic based on coordinating atom identity alone is not sufficient to identify whether a ligand is hemilabile, and our trained machine-learning classification models are instead needed to predict whether a bi-, tri-, or tetradentate ligand is hemilabile with high accuracy and precision. Feature importance analysis of our models shows that the second, third, and fourth coordination spheres all play important roles in ligand hemilability.
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Affiliation(s)
- Ilia Kevlishvili
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Chenru Duan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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2
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Yu S, Zhang C, Wang F, Liang X, Yang M, An M. Promotion of B(C 6F 5) 3 as Ligand for Titanium (or Vanadium) Catalysts in the Copolymerization of Ethylene and 1-Hexene: A Computational Study. Polymers (Basel) 2023; 15:polym15112435. [PMID: 37299237 DOI: 10.3390/polym15112435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/21/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
Density functional theory (DFT) is employed to investigate the promotion of B(C6F5)3 as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions. The results reveal that (I) Ethylene insertion into TiB (with B(C6F5)3 as a ligand ) is preferred over TiH, both thermodynamically and kinetically. (II) In TiH and TiB catalysts, the 2,1 insertion reaction (TiH21 and TiB21) is the primary pathway for 1-hexene insertion. Furthermore, the 1-hexene insertion reaction for TiB21 is favored over TiH21 and is easier to perform. Consequently, the entire ethylene and 1-hexene insertion reaction proceeds smoothly using the TiB catalyst to yield the final product. (III) Analogous to the Ti catalyst case, VB (with B(C6F5)3 as a ligand) is preferred over VH for the entire ethylene/1-hexene copolymerization reaction. Moreover, VB exhibits higher reaction activity than TiB, thus agreeing with experimental results. Additionally, the electron localization function and global reactivity index analysis indicate that titanium (or vanadium) catalysts with B(C6F5)3 as a ligand exhibit higher reactivity. Investigating the promotion of B(C6F5)3 as a ligand for titanium (or vanadium) catalysts in ethylene/1-hexene copolymerization reactions will aid in designing novel catalysts and lead to more cost-effective polymerization production methods.
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Affiliation(s)
- Shuyuan Yu
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
| | - Chenggen Zhang
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
| | - Fei Wang
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
| | - Xinru Liang
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
| | - Mengyao Yang
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
| | - Mengyu An
- College of Chemistry and Material Science, Langfang Normal University, Langfang 065000, China
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3
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Messaoudi C, Jismy B, Jacquemin J, Allouchi H, M'Rabet H, Abarbri M. Stepwise synthesis of 2,6-difunctionalized ethyl pyrazolo[1,5- a]pyrimidine-3-carboxylate via site-selective cross-coupling reactions: experimental and computational studies. Org Biomol Chem 2022; 20:9684-9697. [PMID: 36416338 DOI: 10.1039/d2ob01760a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A variety of novel disubstituted 2-(alknyl, aryl and arylamine)-6-alkynylpyrazolo[1,5-a]pyrimidine derivatives was prepared via sequential site-selective cross-coupling reactions from 2,6-dibromopyrazolo[1,5-a]pyrimidine 3. The regio-controlled Sonogashira-type coupling of 3 with a wide range of terminal alkynes proceeded smoothly with excellent selectivity in favor of the C6-position through careful adjustment of the coupling conditions, followed by the subsequent introduction of alkynyl, aryl or arylamine groups at the C2-position via the Sonogashira, Suzuki-Miyaura and Buchwald-Hartwig coupling reactions, respectively. These promising results allow for further use and diversification of the chemically and biologically interesting pyrazolo[1,5-a]pyrimidine scaffold. In addition, computational studies were conducted to provide explanations for the origin of regioselectivity.
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Affiliation(s)
- Chaima Messaoudi
- Laboratoire de Physico-Chimie des Matériaux et des Electrolytes pour l'Energie (PCM2E), EA 6299. Université de Tours, Faculté des Sciences et Techniques, Avenue Monge Faculté des Sciences, Parc de Grandmont, 37200 Tours, France. .,Laboratoire de Synthese Organique Sélective et Hétérocyclique-Evaluation de l'Activité Biologique, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
| | - Badr Jismy
- Laboratoire de Physico-Chimie des Matériaux et des Electrolytes pour l'Energie (PCM2E), EA 6299. Université de Tours, Faculté des Sciences et Techniques, Avenue Monge Faculté des Sciences, Parc de Grandmont, 37200 Tours, France.
| | - Johan Jacquemin
- Materials Science and Nano-Engineering (MSN) Department, Mohammed VI Polytechnic University (UM6P), Lot 660-Hay Moulay Rachid, Benguerir 43150, Morocco
| | - Hassan Allouchi
- Faculté de Pharmacie, Université de Tours, EA 7502 SIMBA, 31 Avenue Monge, 37200 Tours, France
| | - Hédi M'Rabet
- Laboratoire de Synthese Organique Sélective et Hétérocyclique-Evaluation de l'Activité Biologique, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
| | - Mohamed Abarbri
- Laboratoire de Physico-Chimie des Matériaux et des Electrolytes pour l'Energie (PCM2E), EA 6299. Université de Tours, Faculté des Sciences et Techniques, Avenue Monge Faculté des Sciences, Parc de Grandmont, 37200 Tours, France.
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4
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Firsan S, Sivakumar V, Colacot TJ. Emerging Trends in Cross-Coupling: Twelve-Electron-Based L 1Pd(0) Catalysts, Their Mechanism of Action, and Selected Applications. Chem Rev 2022; 122:16983-17027. [PMID: 36190916 PMCID: PMC9756297 DOI: 10.1021/acs.chemrev.2c00204] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Monoligated palladium(0) species, L1Pd(0), have emerged as the most active catalytic species in the cross-coupling cycle. Today, there are methods available to generate the highly active but unstable L1Pd(0) catalysts from stable precatalysts. While the size of the ligand plays an important role in the formation of L1Pd(0) during in situ catalysis, the latter can be precisely generated from the precatalyst by various technologies. Computational, kinetic, and experimental studies indicate that all three steps in the catalytic cycle─oxidative addition, transmetalation, and reductive elimination─contain monoligated Pd. The synthesis of precatalysts, their mode of activation, application studies in model systems, as well as in industry are discussed. Ligand parametrization and AI based data science can potentially help predict the facile formation of L1Pd(0) species.
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Affiliation(s)
- Sharbil
J. Firsan
- Science
and Lab Solutions−Chemistry, MilliporeSigma, 6000 North Teutonia Avenue, Milwaukee, Wisconsin53209, United States
| | - Vilvanathan Sivakumar
- Merck
Life Science Pvt Ltd, No-12, Bommasandra-Jigani Link Road, Industrial Area, Bangalore560100, India
| | - Thomas J. Colacot
- Science
and Lab Solutions−Chemistry, MilliporeSigma, 6000 North Teutonia Avenue, Milwaukee, Wisconsin53209, United States,
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5
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Han S. “
K‐synthesis
”: Recent advancements in natural product synthesis enabled by unique methods and strategies development in Korea. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Sunkyu Han
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea
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6
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Density Functional Theory Analysis of the Copolymerization of Cyclopropenone with Ethylene Using a Palladium Catalyst. Polymers (Basel) 2022; 14:polym14235273. [PMID: 36501667 PMCID: PMC9739415 DOI: 10.3390/polym14235273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/11/2022] Open
Abstract
Density functional theory has been used to elucidate the mechanism of Pd copolymerization of cyclopropenone with ethylene. The results reveal that introducing ethylene and cyclopropenone to Pd catalyst is thermodynamically feasible and generates the α,β-unsaturated ketone unit (UnitA). Cis-mode insertion and Path A1a are the most favorable reaction routes for ethylene and cyclopropenone, respectively. Moreover, cyclopropenone decomposition can generate CO in situ without a catalyst or with a Pd catalyst. The Pd-catalyzed decomposition of cyclopropenone exhibits a lower reaction barrier (22.7 kcal/mol) than its direct decomposition. Our study demonstrates that incorporating CO into the Pd catalyst can generate the isolated ketone unit (UnitB). CO is formed first; thereafter, UnitB is generated. Therefore, the total energy barrier of UnitB generation, accounting for the CO barrier, is 22.7 kcal/mol, which is slightly lower than that of UnitA generation (24.0 kcal/mol). Additionally, the possibility of copolymerizing ethylene, cyclopropenone, and allyl acetate (AAc) has been investigated. The free energy and global reactivity index analyses indicate that the cyclopropenone introduction reaction is more favorable than the AAc insertion, which is consistent with the experimental results. Investigating the copolymerization mechanism will help to develop of a functionalization strategy for polyethylene polymers.
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7
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Gardner KE, Sarpong R. Synthesis of substituted benzoates using a rhodium-mediated Hopf cyclization of 1,3-dien-5-ynes accessed from 2-pyrones. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Sennari G, Gardner KE, Wiesler S, Haider M, Eggert A, Sarpong R. Unified Total Syntheses of Benzenoid Cephalotane-Type Norditerpenoids: Cephanolides and Ceforalides. J Am Chem Soc 2022; 144:19173-19185. [PMID: 36198090 DOI: 10.1021/jacs.2c08803] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Detailed herein are our synthetic studies toward the preparation of the C18- and C19-benzenoid cephalotane-type norditerpenoids. Guided by chemical network analysis, the core structure of this natural product family was constructed in a concise manner using an iterative cross-coupling, followed by a formal inverse-electron-demand [4 + 2] cycloaddition. Initial efforts to functionalize an alkene group in the [4 + 2] cycloadduct using a Mukaiyama hydration and a subsequent olefination led to the complete C18-carbon framework. While effective, this approach proved lengthy and prompted the development of a direct alkene difunctionalization that relies on borocupration to advance the cycloadduct to the natural products. Late-stage peripheral C-H functionalization facilitated access to all of the known cephanolides in 6-10 steps as well as five recently isolated ceforalides in 8-13 steps.
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Affiliation(s)
- Goh Sennari
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
| | - Kristen E Gardner
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
| | - Stefan Wiesler
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
| | - Maximilian Haider
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
| | - Alina Eggert
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
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9
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Density Functional Theory Study of the Regioselectivity in Copolymerization of bis-Styrenic Molecules with Propylene Using Zirconocene Catalyst. Catalysts 2022. [DOI: 10.3390/catal12091039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Density functional theory (DFT) was used to study the regioselectivity of the copolymerization of propylene and the bis-styrenic molecules (DVB and BVPE) using a zirconocene catalyst. This study reveals the following: when hydrogen is introduced to reactivate the catalyst on the vinyl bonds containing DVB or BVPE, the second vinyl bond is inserted into the polymer in a regio-irregular 1,2-way. (I) The 1,2-insertion mode forms more thermodynamically stable products. (II) The 2,1 insertion, DVB-PP1, or BVPE-PP1 needs to rotate 180° along the Zr-C1 bond to complete the process; thus, it is easier to accomplish the 1,2 insertion. (III) The analysis of the local electrophilicity/nucleophilicity index and the Fukui functions also indicate that the 1,2-insertion mode is the optimal insertion mode. Investigating the mechanism of this experimental phenomenon is important in the development of a functionalization strategy for polypropylene (PP) polymers.
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10
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Bellotti P, Rogge T, Paulus F, Laskar R, Rendel N, Ma J, Houk KN, Glorius F. Visible-Light Photocatalyzed peri-(3 + 2) Cycloadditions of Quinolines. J Am Chem Soc 2022; 144:15662-15671. [PMID: 35984989 DOI: 10.1021/jacs.2c05687] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cycloaddition reactions─epitomized by the Diels-Alder reaction─offer an arguably unmatched springboard for achieving chemical complexity, often with excellent selectivity, in a modular single step. We report the synthesis of aza-acenaphthenes in a single step by an unprecedented formal peri-(3 + 2) cycloaddition of simple quinolines with alkynes. A commercially available iridium complex exerts a dual role of photosensitizer and photoredox catalyst, fostering a cyclization/rearomatization cascade. The initial energy-transfer phase leads to the acenaphthene skeleton, while the ensuing redox shuttling step leads to aromatization. We applied this technology to 8-substituted quinolines and phenanthrolines, which smoothly reacted with both terminal and internal alkynes with excellent levels of regio- and diastereoselectivity. Density functional theory calculations revealed the intertwined EnT/SET nature of the process and offered guiding design principles for the synthesis of new aza-acenaphthenes.
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Affiliation(s)
- Peter Bellotti
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
| | - Torben Rogge
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Fritz Paulus
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
| | - Ranjini Laskar
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
| | - Nils Rendel
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
| | - Jiajia Ma
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Frank Glorius
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 36, 48149 Münster, Germany
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11
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Palladium-Catalyzed Cross-Coupling Reactions of Borylated Alkenes for the Stereoselective Synthesis of Tetrasubstituted Double Bond. ORGANICS 2022. [DOI: 10.3390/org3030017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The stereoselective formation of tetrasubstituted alkenes remains one of the key goals of modern organic synthesis. In addition to other methods, the stereoselective synthesis of tetrasubstituted alkenes can be achieved by means of cross-coupling reactions of electrophilic and nucleophilic alkene templates. The use of electrophilic templates for the stereoselective synthesis of tetrasubstituted alkenes has previously been described. Therefore, the present review summarizes the procedures available for the stereoselective preparation of tetrasubstituted alkenes using stable and isolable nucleophilic templates.
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12
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Palani V, Perea MA, Sarpong R. Site-Selective Cross-Coupling of Polyhalogenated Arenes and Heteroarenes with Identical Halogen Groups. Chem Rev 2021; 122:10126-10169. [PMID: 34402611 DOI: 10.1021/acs.chemrev.1c00513] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Methods to functionalize arenes and heteroarenes in a site-selective manner are highly sought after for rapidly constructing value-added molecules of medicinal, agrochemical, and materials interest. One effective approach is the site-selective cross-coupling of polyhalogenated arenes bearing multiple, but identical, halogen groups. Such cross-coupling reactions have proven to be incredibly effective for site-selective functionalization. However, they also present formidable challenges due to the inherent similarities in the reactivities of the halogen substituents. In this Review, we discuss strategies for site-selective cross-couplings of polyhalogenated arenes and heteroarenes bearing identical halogens, beginning first with an overview of the reaction types that are more traditional in nature, such as electronically, sterically, and directing-group-controlled processes. Following these examples is a description of emerging strategies, which includes ligand- and additive/solvent-controlled reactions as well as photochemically initiated processes.
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Affiliation(s)
- Vignesh Palani
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Melecio A Perea
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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13
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Scott NWJ, Ford MJ, Jeddi N, Eyles A, Simon L, Whitwood AC, Tanner T, Willans CE, Fairlamb IJS. A Dichotomy in Cross-Coupling Site Selectivity in a Dihalogenated Heteroarene: Influence of Mononuclear Pd, Pd Clusters, and Pd Nanoparticles-the Case for Exploiting Pd Catalyst Speciation. J Am Chem Soc 2021; 143:9682-9693. [PMID: 34152135 PMCID: PMC8297865 DOI: 10.1021/jacs.1c05294] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Site-selective dihalogenated heteroarene
cross-coupling with organometallic
reagents usually occurs at the halogen proximal to the heteroatom,
enabled by intrinsic relative electrophilicity, particularly in strongly
polarized systems. An archetypical example is the Suzuki–Miyaura
cross-coupling (SMCC) of 2,4-dibromopyridine with organoboron species,
which typically exhibit C2-arylation site-selectivity using mononuclear
Pd (pre)catalysts. Given that Pd speciation, particularly aggregation,
is known to lead to the formation of catalytically competent multinuclear
Pdn species, the influence of these species
on cross-coupling site-selectivity remains largely unknown. Herein,
we disclose that multinuclear Pd species, in the form of Pd3-type clusters and nanoparticles, switch arylation site-selectivity
from C2 to C4, in 2,4-dibromopyridine cross-couplings with both organoboronic
acids (SMCC reactions) and Grignard reagents (Kumada-type reactions).
The Pd/ligand ratio and the presence of suitable stabilizing salts
were found to be critically important in switching the site-selectivity.
More generally, this study provides experimental evidence that aggregated
Pd catalyst species not only are catalytically competent but also
alter reaction outcomes through changes in product selectivity.
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Affiliation(s)
- Neil W J Scott
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Mark J Ford
- Bayer AG, Alfred-Nobel-Strasse 50, 40789 Monheim, Germany
| | - Neda Jeddi
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Anthony Eyles
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Lauriane Simon
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Adrian C Whitwood
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Theo Tanner
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
| | - Charlotte E Willans
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Ian J S Fairlamb
- Department of Chemistry, University of York, Heslington, York, North Yorkshire YO10 5DD, United Kingdom
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14
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Khoshbakht M, Thanaussavadate B, Zhu C, Cao Y, Zakharov LN, Loesgen S, Blakemore PR. Total Synthesis of Chalaniline B: An Antibiotic Aminoxanthone from Vorinostat-Treated Fungus Chalara sp. 6661. J Org Chem 2021; 86:7773-7780. [PMID: 34000192 DOI: 10.1021/acs.joc.1c00528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Chalaniline B [1-anilino-2,8-dihydroxy-3-(hydroxymethyl)xanthone], an antibiotic previously isolated from vorinostat-treated Chalara sp., was prepared in 7 steps from 2-hydroxyxanthone by a route incorporating regioselective oxidative transformations (bromination at C1/C3, ketone directed Pd(II)-catalyzed hydroxylation at C8), installation of the C1-anilino moiety by a regioselective Buchwald-Hartwig amination reaction from 1,3-dibromo-2,8-dimethoxyxanthone, and late-stage hydroxymethylation at C3 using a Stille cross-coupling. Biological evaluation of deshydroxymethylchalaniline B (1-anilino-2,8-dihydroxyxanthone) revealed MIC values of 8 μg mL-1 (25 μM) against both methicillin resistant S. aureus and B. subtilis.
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Affiliation(s)
- Mahsa Khoshbakht
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| | | | - Chenxi Zhu
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080-8610, United States
| | - Yang Cao
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| | - Lev N Zakharov
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| | - Sandra Loesgen
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080-8610, United States
| | - Paul R Blakemore
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
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15
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Bian JH, Tong WY, Pitsch CE, Wu YB, Wang X. Mechanism of nickel-catalyzed direct carbonyl-Heck coupling reaction: the crucial role of second-sphere interactions. Dalton Trans 2021; 50:2654-2662. [PMID: 33527940 DOI: 10.1039/d0dt04121a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We present a detailed DFT mechanistic study on the first Ni-catalyzed direct carbonyl-Heck coupling of aryl triflates and aldehydes to afford ketones. The precatalyst Ni(COD)2 is activated with the phosphine (phos) ligand, followed by coordination of the substrate PhOTf, to form [Ni(phos)(PhOTf)] for intramolecular PhOTf to Ni(0) oxidative addition. The ensuing phenyl-Ni(ii) triflate complex substitutes benzaldehyde for triflate by an interchange mechanism, leaving the triflate anion in the second coordination sphere held by Coulomb attraction. The Ni(ii) complex cation undergoes benzaldehyde C[double bond, length as m-dash]O insertion into the Ni-Ph bond, followed by β-hydride elimination, to produce Ni(ii)-bound benzophenone, which is released by interchange with triflate. The resulting neutral Ni(ii) hydride complex leads to regeneration of the active catalyst following base-mediated deprotonation/reduction. The benzaldehyde C[double bond, length as m-dash]O insertion is the rate-determining step. The triflate anion, while remaining in the second sphere, engages in electrostatic interactions with the first sphere, thereby stabilizing the intermediate/transition state and enabling the desired reactivity. This is the first time that such second-sphere interaction and its impact on cross-coupling reactivity has been elucidated. The new insights gained from this study can help better understand and improve Heck-type reactions.
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Affiliation(s)
- Jian-Hong Bian
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province and Institute of Molecular Science, Shanxi University, Taiyuan 030006, P. R. China.
| | - Wen-Yan Tong
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province and Institute of Molecular Science, Shanxi University, Taiyuan 030006, P. R. China.
| | - Chloe E Pitsch
- Department of Chemistry, University of Colorado Denver, Campus Box 194, P. O. Box 173364, Denver, Colorado 80217-3364, USA.
| | - Yan-Bo Wu
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province and Institute of Molecular Science, Shanxi University, Taiyuan 030006, P. R. China.
| | - Xiaotai Wang
- Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard, Nanshan District, Shenzhen 518055, P. R. China and Department of Chemistry, University of Colorado Denver, Campus Box 194, P. O. Box 173364, Denver, Colorado 80217-3364, USA.
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Palani V, Perea MA, Gardner KE, Sarpong R. A pyrone remodeling strategy to access diverse heterocycles: application to the synthesis of fascaplysin natural products. Chem Sci 2020; 12:1528-1534. [PMID: 34163915 PMCID: PMC8179101 DOI: 10.1039/d0sc06317g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The synthesis of diverse N-fused heterocycles, including the pyrido[1,2-a]indole scaffold, using an efficient pyrone remodeling strategy is described. The pyrido[1,2-a]indole core was demonstrated to be a versatile scaffold that can be site-selectively functionalized. The utility of this novel annulation strategy was showcased in a concise formal synthesis of three fascaplysin congeners. The synthesis of diverse N-fused heterocycles, including the pyrido[1,2-a]indole scaffold, using an efficient pyrone remodeling strategy is described.![]()
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Affiliation(s)
- Vignesh Palani
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Melecio A Perea
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Kristen E Gardner
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Richmond Sarpong
- Department of Chemistry, University of California Berkeley California 94720 USA
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17
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Inuki S, Sato K, Zui N, Yamaguchi R, Matsumaru T, Fujimoto Y. Synthetic Studies on FNC-RED and Its Analogues Containing an All syn-Cyclopentanetetrol Moiety. J Org Chem 2019; 84:12680-12685. [PMID: 31507185 DOI: 10.1021/acs.joc.9b02101] [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
FNC-RED exhibits innate immune receptor Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD2) stimulatory activity. We have developed a divergent synthetic route to FNC-RED derivatives containing various alkyl side chains. Key features of the synthetic study include stepwise palladium catalyzed cross-coupling reactions and the construction of an all syn-cyclopentanetetrol moiety.
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Affiliation(s)
- Shinsuke Inuki
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan.,Graduate School of Pharmaceutical Sciences , Kyoto University , Sakyo-ku , Kyoto 606-8501 , Japan
| | - Keisuke Sato
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan
| | - Naoto Zui
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan
| | - Ryosuke Yamaguchi
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan
| | - Takanori Matsumaru
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan
| | - Yukari Fujimoto
- Graduate School of Science and Technology , Keio University , Hiyoshi, Kohoku-ku, Yokohama , Kanagawa 223-8522 , Japan
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18
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Palani V, Hugelshofer CL, Sarpong R. A Unified Strategy for the Enantiospecific Total Synthesis of Delavatine A and Formal Synthesis of Incarviatone A. J Am Chem Soc 2019; 141:14421-14432. [DOI: 10.1021/jacs.9b07693] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Vignesh Palani
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Cedric L. Hugelshofer
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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19
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Jeon T, Kang H, Svirid A, Lyakhov A, Kovalenko V, Cho C. Chiral Resolution of Racemic 2‐Pyrone Diels‐Alder Cycloadduct by Diastereomeric Salt Formation. B KOREAN CHEM SOC 2019. [DOI: 10.1002/bkcs.11838] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Tae‐Hong Jeon
- Center for New Directions in Organic Synthesis, Department of ChemistryHanyang University Seoul 04763 Republic of Korea
| | - Hyung‐Joon Kang
- Center for New Directions in Organic Synthesis, Department of ChemistryHanyang University Seoul 04763 Republic of Korea
| | - Anastasia Svirid
- Department of Natural SciencesBelarusian State Pedagogical University Minsk 220030 Republic of Belarus
| | - Alexander Lyakhov
- Department of Chemistry and Research Institute for Physical Chemical ProblemsBelarusian State University Minsk 220030 Republic of Belarus
| | - Vitaly Kovalenko
- Department of Natural SciencesBelarusian State Pedagogical University Minsk 220030 Republic of Belarus
- Department of Chemistry and Research Institute for Physical Chemical ProblemsBelarusian State University Minsk 220030 Republic of Belarus
| | - Cheon‐Gyu Cho
- Center for New Directions in Organic Synthesis, Department of ChemistryHanyang University Seoul 04763 Republic of Korea
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20
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Richmond Sarpong. ChemCatChem 2019. [DOI: 10.1002/cctc.201900804] [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]
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21
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Schuppe AW, Zhao Y, Liu Y, Newhouse TR. Total Synthesis of (+)-Granatumine A and Related Bislactone Limonoid Alkaloids via a Pyran to Pyridine Interconversion. J Am Chem Soc 2019; 141:9191-9196. [PMID: 31117671 DOI: 10.1021/jacs.9b04508] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report the first total synthesis of (+)-granatumine A, a limonoid alkaloid with PTP1B inhibitory activity, in ten steps. Over the course of this study, two key methodological advances were made: a cost-effective procedure for ketone α,β-dehydrogenation using allyl-Pd catalysis, and a Pd-catalyzed protocol to convert epoxyketones to 1,3-diketones. The central tetrasubstituted pyridine is formed by a convergent Knoevenagel condensation and carbonyl-selective electrocyclization cascade, which was followed by a direct transformation of a 2 H-pyran to a pyridine. These studies have led to the structural revision of two members of this family.
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Affiliation(s)
- Alexander W Schuppe
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Yizhou Zhao
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Yannan Liu
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Timothy R Newhouse
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
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