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Bera S, Kabadwal LM, Banerjee D. Harnessing alcohols as sustainable reagents for late-stage functionalisation: synthesis of drugs and bio-inspired compounds. Chem Soc Rev 2024; 53:4607-4647. [PMID: 38525675 DOI: 10.1039/d3cs00942d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C-X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources.
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Affiliation(s)
- Sourajit Bera
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
| | - Lalit Mohan Kabadwal
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
| | - Debasis Banerjee
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
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2
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Zhang T, Luan YX, Lam NYS, Li JF, Li Y, Ye M, Yu JQ. A directive Ni catalyst overrides conventional site selectivity in pyridine C-H alkenylation. Nat Chem 2021; 13:1207-1213. [PMID: 34635815 PMCID: PMC8633040 DOI: 10.1038/s41557-021-00792-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/23/2021] [Indexed: 11/08/2022]
Abstract
Achieving the transition metal-catalysed pyridine C3-H alkenylation, with pyridine as the limiting reagent, has remained a long-standing challenge. Previously, we disclosed that the use of strong coordinating bidentate ligands can overcome catalyst deactivation and provide Pd-catalysed C3 alkenylation of pyridines. However, this strategy proved ineffective when using pyridine as the limiting reagent, as it required large excesses and high concentrations to achieve reasonable yields, which rendered it inapplicable to complex pyridines prevalent in bioactive molecules. Here we report that a bifunctional N-heterocyclic carbene-ligated Ni-Al catalyst can smoothly furnish C3-H alkenylation of pyridines. This method overrides the intrinsic C2 and/or C4 selectivity, and provides a series of C3-alkenylated pyridines in 43-99% yields and up to 98:2 C3 selectivity. This method not only allows a variety of pyridine and heteroarene substrates to be used as the limiting reagent, but is also effective for the late-stage C3 alkenylation of diverse complex pyridine motifs in bioactive molecules.
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Affiliation(s)
- Tao Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, China
| | - Yu-Xin Luan
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, China
| | | | - Jiang-Fei Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, China
| | - Yue Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, China
| | - Mengchun Ye
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, China.
| | - Jin-Quan Yu
- The Scripps Research Institute, La Jolla, CA, USA.
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3
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Dongbang S, Confair DN, Ellman JA. Rhodium-Catalyzed C-H Alkenylation/Electrocyclization Cascade Provides Dihydropyridines That Serve as Versatile Intermediates to Diverse Nitrogen Heterocycles. Acc Chem Res 2021; 54:1766-1778. [PMID: 33740369 PMCID: PMC8026680 DOI: 10.1021/acs.accounts.1c00027] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Nitrogen heterocycles are present in approximately 60% of drugs, with nonplanar heterocycles incorporating stereogenic centers being of considerable interest to the fields of medicinal chemistry, chemical biology, and synthetic methods development. Over the past several years, our laboratory has developed synthetic strategies to access highly functionalized nitrogen heterocycles with multiple stereogenic centers. This approach centers on the efficient preparation of diverse 1,2-dihydropyridines by a Rh-catalyzed C-H bond alkenylation/electrocyclization cascade from readily available α,β-unsaturated imines and alkynes. The often densely substituted 1,2-dihydropyridine products have proven to be extremely versatile intermediates that can be elaborated with high regioselectivity and stereoselectivity, often without purification or even isolation. Protonation or alkylation followed by addition of hydride or carbon nucleophiles affords tetrahydropyridines with divergent regioselectivity and stereoselectivity depending on the reaction conditions. Mechanistic experiments in combination with density functional theory (DFT) calculations provide a rationale for the high level of regiocontrol and stereocontrol that is observed. Further elaboration of the tetrahydropyridines by diastereoselective epoxidation and regioselective ring opening furnishes hydroxy-substituted piperidines. Alternatively, piperidines can be obtained directly from dihydropyridines by catalytic hydrogenation in good yields with high face selectivity.When trimethylsilyl alkynes or N-trimethylsilylmethyl imines are employed as starting inputs, the Rh-catalyzed C-H bond alkenylation/electrocyclization cascade provides silyl-substituted dihydropyridines that enable a host of new and useful transformations to different heterocycle classes. Protonation of these products under acidic conditions triggers the loss of the silyl group and the formation of unstabilized azomethine ylides that would be difficult to access by other means. Depending on the location of the silyl group, [3 + 2] cycloaddition of the azomethine ylides with dipolarophiles provides tropane or indolizidine privileged frameworks, which for intramolecular cycloadditions yield complex polycyclic products with up to five contiguous stereogenic centers. When different types of conditions are employed, loss of the silyl group can result in either rearrangement to cyclopropyl-fused pyrrolidines or to aminocyclopentadienes. Mechanistic experiments supported by DFT calculations provide reaction pathways for these unusual rearrangements.The transformations described in this Account are amenable to natural product synthesis and drug discovery applications because of the biological relevance of the structural motifs that are prepared, short reaction sequences that rely on readily available starting inputs, high regiocontrol and stereocontrol, and excellent functional group compatibility. For example, the methods have been applied to efficient asymmetric syntheses of morphinan drugs, including the opioid antagonist (-)-naltrexone, which is extensively used for the treatment of drug abuse.
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Affiliation(s)
- Sun Dongbang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Danielle N Confair
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Jonathan A Ellman
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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4
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Campbell MW, Yuan M, Polites VC, Gutierrez O, Molander GA. Photochemical C-H Activation Enables Nickel-Catalyzed Olefin Dicarbofunctionalization. J Am Chem Soc 2021; 143:3901-3910. [PMID: 33660996 PMCID: PMC8012054 DOI: 10.1021/jacs.0c13077] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Alkenes, ethers, and alcohols account for a significant percentage of bulk reagents available to the chemistry community. The petrochemical, pharmaceutical, and agrochemical industries each consume gigagrams of these materials as fuels and solvents each year. However, the utilization of such materials as building blocks for the construction of complex small molecules is limited by the necessity of prefunctionalization to achieve chemoselective reactivity. Herein, we report the implementation of efficient, sustainable, diaryl ketone hydrogen-atom transfer (HAT) catalysis to activate native C-H bonds for multicomponent dicarbofunctionalization of alkenes. The ability to forge new carbon-carbon bonds between reagents typically viewed as commodity solvents provides a new, more atom-economic outlook for organic synthesis. Through detailed experimental and computational investigation, the critical effect of hydrogen bonding on the reactivity of this transformation was uncovered.
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Affiliation(s)
- Mark W Campbell
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Mingbin Yuan
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Viktor C Polites
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
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5
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Abstract
The development of novel synthetic methods remains a cornerstone in simplifying complex molecule synthesis. Progress in the field of transition metal catalysis has enabled new mechanistic strategies to achieve difficult chemical transformations, increased the value of abundant chemical building blocks, and pushed the boundaries of creative and strategic route design to improve step economy in multistep synthesis. Methodologies to introduce an olefin into saturated molecules continue to be essential transformations because of the plethora of reactions available for alkene functionalization. Of particular importance are dehydrogenation reactions adjacent to electron-withdrawing groups such as carbonyls, which advantageously provide activated olefins that can be regioselectively manipulated. Palladium catalysis occupies a central role in the most widely adopted carbonyl dehydrogenation reactions, but limits to the scope of these protocols persist.In this Account, we describe our group's contributions to the area of transition-metal-catalyzed dehydrogenation using palladium catalysis and more sustainable and economical nickel catalysis. These metals are used in conjunction with allyl and aryl halides or pseudohalides that serve as oxidants to access a unique mechanistic approach for one-step α,β-dehydrogenation of various electron-withdrawing groups, including ketones, esters, nitriles, amides, carboxylic acids, and electron-deficient heteroarenes. The pivotal reaction parameters that can be modified to influence reaction efficiency are highlighted, including base and oxidant structure as well as ligand and salt additive effects. This discussion is expected to serve as a guide for troubleshooting challenging dehydrogenation reactions and provide insight for future reaction development in this area.In addition to enabling dehydrogenation reactions, our group's allyl-Pd and -Ni chemistry can be used for C-C and C-X bond-forming reactions, providing novel disconnections with practical applications for expediting multistep synthesis. These transformations include a telescoped process for ketone α,β-vicinal difunctionalization; an oxidative enone β-functionalization, including β-stannylation, β-silylation, and β-alkylation; and an oxidative cycloalkenylation between unstabilized ketone enolates and unactivated alkenes. These bond-forming methodologies broaden the range of transformations accessible from abundant ketone, enone, and alkene moieties. Both the dehydrogenation and C-C and C-X bond-forming methodologies have been implemented in our group's total synthesis campaigns to provide step-efficient synthetic routes toward diverse natural products.Through the lens of multistep synthesis, the utility and robustness of our dehydrogenation and dehydrogenative functionalization methodologies can be better appreciated, and we hope that this Account will inspire practitioners to apply our methodologies to their own synthetic challenges.
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Affiliation(s)
- David Huang
- 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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Liniger M, Neuhaus CM, Altmann KH. Ring-Closing Metathesis Approaches towards the Total Synthesis of Rhizoxins. Molecules 2020; 25:E4527. [PMID: 33023218 PMCID: PMC7582377 DOI: 10.3390/molecules25194527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 02/01/2023] Open
Abstract
Efforts are described towards the total synthesis of the bacterial macrolide rhizoxin F, which is a potent tubulin assembly and cancer cell growth inhibitor. A significant amount of work was expanded on the construction of the rhizoxin core macrocycle by ring-closing olefin metathesis (RCM) between C(9) and C(10), either directly or by using relay substrates, but in no case was ring-closure achieved. Macrocycle formation was possible by ring-closing alkyne metathesis (RCAM) at the C(9)/C(10) site. The requisite diyne was obtained from advanced intermediates that had been prepared as part of the synthesis of the RCM substrates. While the direct conversion of the triple bond formed in the ring-closing step into the C(9)-C(10) E double bond of the rhizoxin macrocycle proved to be elusive, the corresponding Z isomer was accessible with high selectivity by reductive decomplexation of the biscobalt hexacarbonyl complex of the triple bond with ethylpiperidinium hypophosphite. Radical-induced double bond isomerization, full elaboration of the C(15) side chain, and directed epoxidation of the C(11)-C(12) double bond completed the total synthesis of rhizoxin F.
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Affiliation(s)
| | | | - Karl-Heinz Altmann
- ETH Zürich, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, 8093 Zürich, Switzerland; (M.L.); (C.M.N.)
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7
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Swain M, Sadykhov G, Wang R, Kwon O. Dealkenylative Alkenylation: Formal σ-Bond Metathesis of Olefins. Angew Chem Int Ed Engl 2020; 59:17565-17571. [PMID: 32652746 PMCID: PMC8232059 DOI: 10.1002/anie.202005267] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/15/2020] [Indexed: 11/07/2022]
Abstract
The dealkenylative alkenylation of alkene C(sp3 )-C(sp2 ) bonds has been an unexplored area for C-C bond formation. Herein 64 examples of β-alkylated styrene derivatives, synthesized through the reactions of readily accessible feedstock olefins with β-nitrostyrenes by ozone/FeII -mediated radical substitutions, are reported. These reactions proceed with good efficiencies and high stereoselectivities under mild reaction conditions and tolerate an array of functional groups. Also demonstrated is the applicability of the strategy through several synthetic transformations of the products, as well as the syntheses of the natural product iso-moracin and the drug (E)-metanicotine.
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Affiliation(s)
- Manisha Swain
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Gusein Sadykhov
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Ruoxi Wang
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA, 90095-1569, USA
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8
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Shaw R, Althagafi I, Elagamy A, Rai R, Shah C, Nemaysh V, Singh H, Pratap R. Transition metal-free synthesis of sterically hindered allylarenes from 5-hexene-2-one. Org Biomol Chem 2020; 18:6276-6286. [PMID: 32734988 DOI: 10.1039/d0ob01318h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A simple, efficient and transition metal-free strategy was established for the synthesis of highly functionalized, sterically hindered allylarenes (6, 7 & 8) by base-mediated ring transformation of 2-oxo-6-aryl-4-(methylthio/sec-amino)-2H-pyran-3-carbonitriles (3/4) with 5-hexene-2-one (5). This provides a method for the synthesis of allylarenes functionalized with different electron donating and withdrawing groups in one pot. The structures of isolated products 6c and 7a were ascertained by spectroscopic and single crystal X-ray diffraction analyses. In addition, we have performed a molecular docking study to predict the biological activity of the synthesized molecules for binding to estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ).
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Affiliation(s)
- Ranjay Shaw
- Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
| | - Ismail Althagafi
- Department of Chemistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Amr Elagamy
- Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
| | - Reeta Rai
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India
| | - Chandan Shah
- Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
| | - Vishal Nemaysh
- Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
| | - Harpreet Singh
- Indian Council of Medical Research, Ansari Nagar, New Delhi-110029, India
| | - Ramendra Pratap
- Department of Chemistry, University of Delhi, North Campus, Delhi-110007, India.
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9
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Park HS, Fan Z, Zhu RY, Yu JQ. Distal γ-C(sp 3 )-H Olefination of Ketone Derivatives and Free Carboxylic Acids. Angew Chem Int Ed Engl 2020; 59:12853-12859. [PMID: 32385966 PMCID: PMC7494175 DOI: 10.1002/anie.202003271] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/08/2020] [Indexed: 12/27/2022]
Abstract
Reported herein is the distal γ-C(sp3 )-H olefination of ketone derivatives and free carboxylic acids. Fine tuning of a previously reported imino-acid directing group and using the ligand combination of a mono-N-protected amino acid (MPAA) and an electron-deficient 2-pyridone were critical for the γ-C(sp3 )-H olefination of ketone substrates. In addition, MPAAs enabled the γ-C(sp3 )-H olefination of free carboxylic acids to form diverse six-membered lactones. Besides alkyl carboxylic acids, benzylic C(sp3 )-H bonds also could be functionalized to form 3,4-dihydroisocoumarin structures in a single step from 2-methyl benzoic acid derivatives. The utility of these protocols was demonstrated in large scale reactions and diversification of the γ-C(sp3 )-H olefinated products.
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Affiliation(s)
- Han Seul Park
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Zhoulong Fan
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Ru-Yi Zhu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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10
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Abstract
The first syntheses of the antibacterial natural products anaephenes A (1) and B (2) are reported. Both natural products were synthesized in five linear steps from commercially available tert-butyl(3-iodophenoxy)dimethylsilane. Key steps for the synthesis included a Sonogashira cross-coupling and a Julia-Kocienski olefination to selectively construct the E-alkene present in the natural products. This synthetic route allowed the identities and antimicrobial activities of anaephenes A (1) and B (2) to be confirmed. Additionally, these compounds displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 16 and 8 μg/mL, respectively.
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Affiliation(s)
- David L Kukla
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Juan Canchola
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
| | - Jonathan J Mills
- Department of Chemistry, Illinois State University, Campus Box 4160, Normal, Illinois 61790-4160, United States
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11
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Parfenova LV, Kovyazin PV, Bikmeeva AK. Bimetallic Zr,Zr-Hydride Complexes in Zirconocene Catalyzed Alkene Dimerization. Molecules 2020; 25:E2216. [PMID: 32397335 PMCID: PMC7248859 DOI: 10.3390/molecules25092216] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/23/2020] [Accepted: 05/07/2020] [Indexed: 11/16/2022] Open
Abstract
Being valuable precursors in the production of adhesives, lubricants, and other high-performance synthetic compounds, alkene dimers and oligomers can be obtained using homogeneous zirconocene catalytic systems. Further advances in such systems require precise control of their activity and chemoselectivity, increasing both the purity and yield of the products. This relies on the process mechanism usually built around the consideration of the hydride complexes as active intermediates in the alkene di- and oligomerization; however, the majority of studies lack the direct evidence of their involvement. Parallel studies on a well-known Cp2ZrCl2-AlR3 or HAlBui2 and a novel [Cp2ZrH2]2-ClAlR2 (R = Me, Et, Bui) systems activated by methylaluminoxane (MMAO-12) have shown a deep similarity both in the catalytic performance and intermediate composition. As a result of the NMR studies, among all the intermediates considered, we proved that new Zr,Zr- hydride complexes having the type x[Cp2ZrH2∙Cp2ZrHCl∙ClAlR2]∙yMAO appear to be specifically responsible for the alkene dimerization with high yield.
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Affiliation(s)
- Lyudmila V. Parfenova
- Institute of Petrochemistry and Catalysis of Russian Academy of Sciences, 141, Prospekt Oktyabrya, 450075 Ufa, Russia; (P.V.K.); (A.K.B.)
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12
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Salvadó O, Fernández E. Tri(boryl)alkanes and Tri(boryl)alkenes: The Versatile Reagents. Molecules 2020; 25:molecules25071758. [PMID: 32290330 PMCID: PMC7180881 DOI: 10.3390/molecules25071758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 11/16/2022] Open
Abstract
The interest of organoboron chemistry in organic synthesis is growing, together with the development of new and versatile polyborated reagents. Here, the preparation of 1,1,1-tri(boryl)alkanes, 1,2,3-tri(boryl)alkanes, 1,1,2-tri(boryl)alkanes, as well as 1,1,2-tri(boryl)alkenes as suitable and accessible polyborated systems is demonstrated as being easily applied in the construction of new carbon-carbon and carbon-heteroatom bonds. Synthetic procedures and limitations have been collected to demonstrate the powerful strategies to construct selective molecules, taking advantages of the easy transformation of carbon-boron bond in multiple functionalities, under the total control of chemo- and stereoselectivity.
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13
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Heinrich M, Murphy JJ, Ilg MK, Letort A, Flasz JT, Philipps P, Fürstner A. Chagosensine: A Riddle Wrapped in a Mystery Inside an Enigma. J Am Chem Soc 2020; 142:6409-6422. [PMID: 32142305 PMCID: PMC7307910 DOI: 10.1021/jacs.0c01700] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Indexed: 01/02/2023]
Abstract
The marine macrolide chagosensine is supposedly distinguished by a (Z,Z)-configured 1,3-chlorodiene contained within a highly strained 16-membered lactone ring, which also incorporates two trans-2,5-disubstituted tetrahydrofuran (THF) rings; this array is unique. After our initial synthesis campaign had shown that the originally proposed structure is incorrect, the published data set was critically revisited to identify potential mis-assignments. The "northern" THF ring and the anti-configured diol in the "southern" sector both seemed to be sites of concern, thus making it plausible that a panel of eight diastereomeric chagosensine-like compounds would allow the puzzle to be solved. To meet the challenge, the preparation of the required building blocks was optimized, and a convergent strategy for their assembly was developed. A key role was played by the cobalt-catalyzed oxidative cyclization of alken-5-ol derivatives ("Mukaiyama cyclization"), which is shown to be exquisitely chemoselective for terminal alkenes, leaving even terminal alkynes (and other sites of unsaturation) untouched. Likewise, a palladium-catalyzed alkyne alkoxycarbonylation reaction with formation of an α-methylene-γ-lactone proved instrumental, which had not found application in natural product synthesis before. Further enabling steps were a nickel-catalyzed "Tamaru-type" homocrotylation, stereodivergent aldehyde homologations, radical hydroindation, and palladium-catalyzed alkyne-1,2-bis-stannation. The different building blocks were assembled in a serial fashion to give the idiosyncratic chlorodienes by an unprecedented site-selective Stille coupling followed by copper-mediated tin/chlorine exchange. The macrolactones were closed under forcing Yamaguchi conditions, and the resulting products were elaborated into the targeted compound library. Yet, only one of the eight diastereomers turned out to be stable in the solvent mixture that had been used to analyze the natural product; all other isomers were prone to ring opening and/or ring expansion. In addition to this stability issue, our self-consistent data set suggests that chagosensine has almost certainly little to do with the structure originally proposed by the isolation team.
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Affiliation(s)
| | | | - Marina K. Ilg
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Aurélien Letort
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Jakub T. Flasz
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Petra Philipps
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
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14
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Fu L, Sui X, Crolais AE, Gutekunst WR. Modular Approach to Degradable Acetal Polymers Using Cascade Enyne Metathesis Polymerization. Angew Chem Int Ed Engl 2019; 58:15726-15730. [PMID: 31487416 PMCID: PMC7265103 DOI: 10.1002/anie.201909172] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/24/2019] [Indexed: 12/12/2022]
Abstract
A modular synthetic approach to degradable metathesis polymers is presented using acetal-containing enyne monomers. The monomers are prepared in a short and divergent synthetic sequence that features two points of modification to tune polymerization behavior and introduce molecular cargo. Steric and stereochemical elements are critical in the monomer design in order to provide rapid and living polymerizations capable of generating block polymers. The developed polyacetal materials readily undergo pH-dependent degradation in aqueous mixtures, and the rate of hydrolysis can be tuned through post-polymerization modification with triazolinedione click chemistry. This presents a new scaffold for responsive metathesis polymers that may find use in applications that requires controllable breakdown and release of small molecules.
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Affiliation(s)
- Liangbing Fu
- School of Chemistry and Biochemistry, Georgia Institute of Technology
| | - Xuelin Sui
- School of Chemistry and Biochemistry, Georgia Institute of Technology
| | - Alex E. Crolais
- School of Chemistry and Biochemistry, Georgia Institute of Technology
| | - Will R. Gutekunst
- School of Chemistry and Biochemistry, Georgia Institute of Technology
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15
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Park H, Li Y, Yu JQ. Utilizing Carbonyl Coordination of Native Amides for Palladium-Catalyzed C(sp 3 )-H Olefination. Angew Chem Int Ed Engl 2019; 58:11424-11428. [PMID: 31185132 PMCID: PMC6684442 DOI: 10.1002/anie.201906075] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/10/2019] [Indexed: 12/27/2022]
Abstract
PdII -catalyzed C(sp3 )-H olefination of weakly coordinating native amides is reported. Three major drawbacks of previous C(sp3 )-H olefination protocols, 1) in situ cyclization of products, 2) incompatibility with α-H-containing substrates, and 3) installation of exogenous directing groups, are addressed by harnessing the carbonyl coordination ability of amides to direct C(sp3 )-H activation. The method enables direct C(sp3 )-H functionalization of a wide range of native amide substrates, including secondary, tertiary, and cyclic amides, for the first time. The utility of this process is demonstrated by diverse transformations of the olefination products.
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Affiliation(s)
- Hojoon Park
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Yang Li
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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16
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Abstract
Iron(III)-catalyzed carbonyl-olefin ring-closing metathesis employs reactivity not typically observed in Lewis acid-catalyzed reactions. In converting a ketone with a pendant olefin into a cycloalkene and a simple carbonyl byproduct, the reaction requires the Lewis acid catalyst to differentiate between the carbonyl of the substrate and that of the byproduct. It is necessary to determine how this solution interaction imparts the desired reactivity to best employ this method. Herein, we report detailed kinetic, spectroscopic, and colligative measurements applied toward the identification of the solution structures of the active Fe(III) and Ga(III) carbonyl-olefin metathesis catalysts. These data are consistent with formation of Lewis acid-carbonyl pairs for both metal systems under stoichiometric conditions. However, they diverge in the presence of higher equivalents of carbonyl, with Fe(III) forming highly ligated complexes, and no observed change for Ga(III). These findings are consistent with the resting state identity of the Fe(III) metathesis catalyst changing over the course of the reaction.
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Affiliation(s)
- Carly S. Hanson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - Mary C. Psaltakis
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - Janiel J. Cortes
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - James J. Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
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17
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Wei C, Ye X, Xing Q, Hu Y, Xie Y, Shi X. Synergistic palladium/enamine catalysis for asymmetric hydrocarbon functionalization of unactivated alkenes with ketones. Org Biomol Chem 2019; 17:6607-6611. [PMID: 31237304 PMCID: PMC6677245 DOI: 10.1039/c9ob01165j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synergistic palladium and enamine catalysis was explored to promote ketone addition to unactivated olefins. A secondary amine-based organocatalyst was identified as the optimal co-catalyst for the directed Pd-catalyzed alkene activation. Furthermore, asymmetric hydrocarbon functionalization of unactivated alkenes was also achieved with good to excellent yield (up to 96% yields) and stereoselectivity (up to 96% ee). This strategy presented an efficient approach to prepare α-branched ketone derivatives under mild conditions.
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Affiliation(s)
- Chiyu Wei
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
| | - Xiaohan Ye
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
| | - Qingyu Xing
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
| | - Yong Hu
- Department of Neonatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, Shanghai 200040, P.R.China.
| | - Yan Xie
- College of Chemistry and Materials Engineering, Quzhou University, Quzhou 324000, P.R.China.
| | - Xiaodong Shi
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
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18
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Wen BY, Liang H, Guo HJ, Wu JH. Design, synthesis, and antitumor activity of desmosdumotin C analogues. J Asian Nat Prod Res 2019; 21:702-715. [PMID: 30596267 DOI: 10.1080/10286020.2018.1473383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 06/09/2023]
Abstract
Desmosdumotin C (Des C), a natural product isolated from the roots of Desmos dumosus, has shown good antitumor activity. A three dimensional quantitative structure-activity relationship (QSAR) study using the comparative molecular field analysis (CoMFA) method was performed on 32 Des C analogues. Based on the QSAR, 18 new Des C analogues were designed and synthesized. An efficient three-step synthetic strategy toward Des C and its analogues was developed from commercial available 2, 4, 6-trihydroxyacetophenone. All synthesized compounds were evaluated against a panel of human cancer cell lines and showed ED50 values ranging from 1.1 to 25.1 µΜ.
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Affiliation(s)
- Bin-Yu Wen
- a Dongfang Hospital, Beijing University of Chinese Medicine , Beijing 100078 , China
| | - Hai Liang
- b Department of Pharmacy , Beijing 100101 , China
- c Department of Pharmacy , The People's Hospital of Bozhou , Bozhou 236800 , China
| | - Hong-Ju Guo
- a Dongfang Hospital, Beijing University of Chinese Medicine , Beijing 100078 , China
- b Department of Pharmacy , Beijing 100101 , China
| | - Jiu-Hong Wu
- b Department of Pharmacy , Beijing 100101 , China
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19
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Abstract
Olefin metathesis is now one of the most efficient ways to create new carbon-carbon bonds. While most efforts focused on the development of ever-more efficient catalysts, a particular attention has recently been devoted to developing latent metathesis catalysts, inactive species that need an external stimulus to become active. This furnishes an increased control over the reaction which is crucial for applications in materials science. Here, we report our work on the development of a new system to achieve visible-light-controlled metathesis by merging olefin metathesis and photoredox catalysis. The combination of a ruthenium metathesis catalyst bearing two N-heterocyclic carbenes with an oxidizing pyrylium photocatalyst affords excellent temporal and spatial resolution using only visible light as stimulus. Applications of this system in synthesis, as well as in polymer patterning and photolithography with spatially resolved ring-opening metathesis polymerization, are described.
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Affiliation(s)
- Cédric Theunissen
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Melissa A. Ashley
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Tomislav Rovis
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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20
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Mikusek J, Nugent J, Lan P, Banwell MG. Chemical Synthesis Study Establishes the Correct Structure of the Potent Anti-Inflammatory Agent Myrsinoic Acid F. J Nat Prod 2019; 82:96-100. [PMID: 30589258 DOI: 10.1021/acs.jnatprod.8b00778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A total synthesis of compound 3 from p-bromophenol is reported and thereby establishing that this, rather than its cyclodehydrated counterpart 1 (as postulated originally), is the correct structure of the natural product myrsinoic acid F. The biological evaluation of compound 3 in a mouse-ear edema assay established that it is a significantly more potent anti-inflammatory agent than the NSAID indometacin.
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Affiliation(s)
- Jiri Mikusek
- Research School of Chemistry, Institute of Advanced Studies , The Australian National University , Canberra , Australian Capital Territory 2601 , Australia
| | - Jeremy Nugent
- Research School of Chemistry, Institute of Advanced Studies , The Australian National University , Canberra , Australian Capital Territory 2601 , Australia
| | - Ping Lan
- Institute of Advanced and Applied Chemical Synthesis , Jinan University , Zhuhai 519070 , People's Republic of China
- Department of Food Science and Engineering , Jinan University , Guangzhou 510632 , People's Republic of China
| | - Martin G Banwell
- Research School of Chemistry, Institute of Advanced Studies , The Australian National University , Canberra , Australian Capital Territory 2601 , Australia
- Institute of Advanced and Applied Chemical Synthesis , Jinan University , Zhuhai 519070 , People's Republic of China
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21
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Abstract
The development of a general, nickel-catalyzed alkyl-Mizoroki-Heck reaction of unactivated alkyl bromides is described. The mild reaction proceeds efficiently using a wide range of primary and secondary alkyl bromides, and examples of intermolecular cross-couplings are provided. Reaction alkene regioselectivity is significantly enhanced over prior carbocyclizations using palladium catalysis. Mechanistic investigations are consistent with a direct carbocyclization in contrast to the auto-tandem atom-transfer cyclization and halide elimination previously observed with palladium catalysis.
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Affiliation(s)
- Megan R. Kwiatkowski
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (USA),
| | - Erik J. Alexanian
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (USA),
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22
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McAlpine NJ, Wang L, Carrow BP. A Diverted Aerobic Heck Reaction Enables Selective 1,3-Diene and 1,3,5-Triene Synthesis through C-C Bond Scission. J Am Chem Soc 2018; 140:13634-13639. [PMID: 30289691 PMCID: PMC6424333 DOI: 10.1021/jacs.8b10007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Substituted 1,3-dienes are valuable synthetic intermediates used in myriad catalytic transformations, yet modern catalytic methods for their preparation in a highly modular fashion using simple precursors are relatively few. We report here an aerobic boron Heck reaction with cyclobutene that forms exclusively linear 1-aryl-1,3-dienes using (hetero)arylboronic acids, or 1,3,5-trienes using alkenylboronic acids, rather than typical Heck products (i.e., substituted cyclobutenes). Experimental and computational mechanistic data support a pericyclic mechanism for C-C bond cleavage that enables the cycloalkene to circumvent established limitations associated with diene reagents in Heck-type reactions.
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Affiliation(s)
- Neil J. McAlpine
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Long Wang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Brad P. Carrow
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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23
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Silva WD, Bento JMS, Hanks LM, Millar JG. (Z)-7-Hexadecene is an Aggregation-Sex Pheromone Produced by Males of the South American Cerambycid Beetle Susuacanga octoguttata. J Chem Ecol 2018; 44:1115-1119. [PMID: 30306314 DOI: 10.1007/s10886-018-1024-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/02/2018] [Accepted: 10/05/2018] [Indexed: 11/26/2022]
Abstract
We describe the identification, synthesis, and field bioassays of a novel aggregation-sex pheromone produced by males of Susuacanga octoguttata (Germar), a South American cerambycid beetle. Analyses of extracts of headspace volatiles produced by adult beetles revealed a sex-specific compound emitted by males which was identified as (Z)-7-hexadecene by microchemical and spectroscopic analyses. The synthesized pheromone was attractive to beetles of both sexes in field trials. This unsaturated hydrocarbon motif is unprecedented among cerambycid pheromones identified to date. During field bioassays, we serendipitously discovered that adults of S. octoguttata trapped in two Brazilian biomes differed considerably in elytral markings, although males from both populations produced (Z)-7-hexadecene as an aggregation-sex pheromone.
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Affiliation(s)
- Weliton D Silva
- Department of Entomology and Acarology, University of São Paulo, Piracicaba, SP, 13418900, Brazil.
| | - José Maurício S Bento
- Department of Entomology and Acarology, University of São Paulo, Piracicaba, SP, 13418900, Brazil
| | - Lawrence M Hanks
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jocelyn G Millar
- Departments of Entomology and Chemistry, University of California, Riverside, CA, 92521, USA
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24
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Kashyap A, Bokosike TK, Bhuvanesh N, Pattabiraman M. Stereo- and regioselective photocycloaddition of extended alkenes using γ-cyclodextrin. Org Biomol Chem 2018; 16:6870-6875. [PMID: 30229798 PMCID: PMC6215711 DOI: 10.1039/c8ob01966e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoexcitation of dibenzalacetones (1a-d) in homogeneous media and solid state yields a mixture of products with poor conversions. Irradiation of the reactants complexed to γ-cyclodextrin predominantly affords a single dimer (syn adduct 6) despite the possibility for several monomeric and dimeric products. High selectivity in the cavitand-mediated reaction along with the structural characterization of the inclusion complex provides insight into the supramolecular interactions that drive the self-assembly of the host-guest system.
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Affiliation(s)
- Akshay Kashyap
- Department of Chemistry, University of Nebraska Kearney, NE-68845, USA.
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25
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Angello NH, Wiley RE, Elmore TG, Perry RS, Scheerer JR. Domino Reaction Sequence for the Synthesis of [2.2.2]Diazabicycloalkenes and Base-Promoted Cycloreversion to 2-Pyridone Alkaloids. Org Lett 2018; 20:5203-5207. [PMID: 30095269 PMCID: PMC6220673 DOI: 10.1021/acs.orglett.8b02145] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new domino reaction sequence for the construction of 2-pyridone structures is reported. The reaction sequence begins with diacetyldiketopiperazine and proceeds via aldol condensation, alkene isomerization, and intramolecular Diels-Alder cycloaddition. The intermediate [2.2.2]diazabicycloalkene cycloadducts can be isolated or can engage in a base-accelerated extrusion of one lactam bridge to provide the 2-pyridone cycloreversion products. The operation leading to pyridone products can occur in one reaction vessel and proceeds at convenient temperatures.
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Affiliation(s)
- Nicholas H. Angello
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Robert E. Wiley
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Tristan G. Elmore
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Ryan S. Perry
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Jonathan R. Scheerer
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
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26
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Wang R, Yin X, Zhang Y, Yan W. Design, synthesis and antimicrobial evaluation of propylene-tethered ciprofloxacin-isatin hybrids. Eur J Med Chem 2018; 156:580-586. [PMID: 30025351 DOI: 10.1016/j.ejmech.2018.07.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/07/2018] [Accepted: 07/09/2018] [Indexed: 11/19/2022]
Abstract
Twelve novel propylene-tethered ciprofloxacin-isatin hybrids 3a-f and 4a-f were designed, synthesized and characterized by MS, HRMS, 1H NMR and 13C NMR. All hybrids were evaluated for their in vitro antimicrobial activities against representative Gram-positive, Gram-negative and mycobacterial pathogens, cytotoxicity in VERO cell line as well as metabolic stability and in vivo pharmacokinetic (PK) properties. The preliminary results indicated that all mono-isatin-ciprofloxacin hybrids exhibited excellent antibacterial activities with MIC ranging from ≤0.03 to 0.5 μg/mL against most of the tested strains. In particular, ciprofloxacin-isatin hybrid 3d was highly potent against all tested Gram-positive and Gram-negative strains including clinically important drug-resistant pathogens, which was comparable to or more potent than the parent ciprofloxacin and reference levofloxacin. Whereas, conjugate 3b (MIC: 0.10 and 0.5 μg/mL) was 4- and 8-fold more active than ciprofloxacin (MIC: 0.78 μg/mL) and rifampicin (MIC: 0.39 μg/mL) against MTB H37Rv, and 4->256 times more potent than the three references ciprofloxacin (MIC: 2.0 μg/mL), rifampicin (MIC: 32 μg/mL) and isoniazid (>128 μg/mL) against MDR-TB. Both hybrid 3b and 3d with low cytotoxicity (CC50: 64 and 256 μg/mL) also showed acceptable metabolic stability and in vivo PK properties, could act as leads for further optimization.
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Affiliation(s)
- Ruo Wang
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
| | - Xueyang Yin
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
| | - Yaohuan Zhang
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
| | - Weitao Yan
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China
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27
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Abstract
Nickel-catalyzed cross-electrophile couplings have recently emerged as highly effective and practical methods for the formation of C-C bonds. By merging this process with well-established π-π coupling chemistry, a new method for the synthesis of tetrasubstituted alkenes has been developed. The procedure relies on the use of chlorosilanes as a means of generating reactive vinylnickel intermediates, which are capable of undergoing a reductive cross-electrophile coupling with alkyl halides. The method not only generates highly substituted allylic alcohol derivatives but also obviates the need for stoichiometric organometallic nucleophiles and provides greatly improved scope and functional group tolerance compared with previously developed methods.
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Affiliation(s)
- Kirk W. Shimkin
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan, 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan, 48109-1055, United States
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28
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Lamparelli DH, Ricca A, Palma V, Oliva L. High Conversion of Styrene, Ethylene, and Hydrogen to Linear Monoalkylbenzenes. Molecules 2018; 23:E1260. [PMID: 29799449 PMCID: PMC6100200 DOI: 10.3390/molecules23061260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/21/2018] [Accepted: 05/23/2018] [Indexed: 11/02/2022] Open
Abstract
1-Alkylbenzenes as a precursor of surfactants, can be produced from ethylene, styrene, and hydrogen. These intermediates, lacking tertiary carbons, are environmentally more benign than commercial ones that bear the aromatic ring linked to an internal carbon of the aliphatic chain. The one-pot synthesis of highly linear 1-alkylbenzenes (LABs) through the homogeneous catalysis of olefin poly-insertion from cheap and largely available reagents can be carried out with a high turnover and selectivity. A purposely designed reactor that allows for the fine control of the three components feed, along with temperature, plays a key role in this achievement. A turnover of 194 g of LABs per mmol of catalyst per hour can be obtained with the simultaneous removal of polyethylene as a by-product.
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Affiliation(s)
- David Hermann Lamparelli
- Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università di Salerno, I-84084 Fisciano, Italy.
| | - Antonio Ricca
- Dipartimento di Ingegneria Industriale, Università di Salerno, I-84084 Fisciano, Italy.
| | - Vincenzo Palma
- Dipartimento di Ingegneria Industriale, Università di Salerno, I-84084 Fisciano, Italy.
| | - Leone Oliva
- Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università di Salerno, I-84084 Fisciano, Italy.
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29
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Schinkel L, Lehner S, Knobloch M, Lienemann P, Bogdal C, McNeill K, Heeb NV. Transformation of chlorinated paraffins to olefins during metal work and thermal exposure - Deconvolution of mass spectra and kinetics. Chemosphere 2018; 194:803-811. [PMID: 29253825 DOI: 10.1016/j.chemosphere.2017.11.168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 05/26/2023]
Abstract
Chlorinated paraffins (CPs) are high production volume chemicals widely used as additives in metal working fluids. Thereby, CPs are exposed to hot metal surfaces which may induce degradation processes. We hypothesized that the elimination of hydrochloric acid would transform CPs into chlorinated olefins (COs). Mass spectrometry is widely used to detect CPs, mostly in the selected ion monitoring mode (SIM) evaluating 2-3 ions at mass resolutions R < 20'000. This approach is not suited to detected COs, because their mass spectra strongly overlap with CPs. We applied a mathematical deconvolution method based on full-scan MS data to separate interfered CP/CO spectra. Metal drilling indeed induced HCl-losses. CO proportions in exposed mixtures of chlorotridecanes increased. Thermal exposure of chlorotridecanes at 160, 180, 200 and 220 °C also induced dehydrohalogenation reactions and CO proportions also increased. Deconvolution of respective mass spectra is needed to study the CP transformation kinetics without bias from CO interferences. Apparent first-order rate constants (kapp) increased up to 0.17, 0.29 and 0.46 h-1 for penta-, hexa- and heptachloro-tridecanes exposed at 220 °C. Respective half-life times (τ1/2) decreased from 4.0 to 2.4 and 1.5 h. Thus, higher chlorinated paraffins degrade faster than lower chlorinated ones. In conclusion, exposure of CPs during metal drilling and thermal treatment induced HCl losses and CO formation. It is expected that CPs and COs are co-released from such processes. Full-scan mass spectra and subsequent deconvolution of interfered signals is a promising approach to tackle the CP/CO problem, in case of insufficient mass resolution.
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Affiliation(s)
- Lena Schinkel
- Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland; ETH, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamic, Universitätsstrasse 16, CH-8092 Zurich, Switzerland
| | - Sandro Lehner
- Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland; ZHAW, Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, CH-8820 Wädenswil, Switzerland
| | - Marco Knobloch
- Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland; ZHAW, Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, CH-8820 Wädenswil, Switzerland
| | - Peter Lienemann
- ZHAW, Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, CH-8820 Wädenswil, Switzerland
| | - Christian Bogdal
- ETH, Swiss Federal Institute of Technology, Institute of Chemical and Bioengineering, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland
| | - Kristopher McNeill
- ETH, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamic, Universitätsstrasse 16, CH-8092 Zurich, Switzerland
| | - Norbert V Heeb
- Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Advanced Analytical Technologies, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
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30
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Cuesta S, Arias J, Gallegos F, Alzate-Morales J, Meneses L. On the Reaction Mechanism of the 3,4-Dimethoxybenzaldehyde Formation from 1-(3',4'-Dimethoxyphenyl)Propene. Molecules 2018; 23:E412. [PMID: 29443875 PMCID: PMC6017041 DOI: 10.3390/molecules23020412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/25/2018] [Accepted: 01/29/2018] [Indexed: 11/17/2022] Open
Abstract
Lignin peroxidase (LiP) is an important enzyme for degrading aromatic hydrocarbons not only in nature but also in industry. In the presence of H₂O₂, this enzyme can easily decompose lignin and analogue compounds under mild conditions. In this reaction mechanism, LiP catalyzes the C-C cleavage of a propenyl side chain, being able to produce veratraldehyde (VAD) from 1-(3',4'-dimethoxyphenyl) propene (DMPP). One of the few and complete proposed mechanisms includes several non-enzymatic reactions. In this study, we performed a computational study to gain insight about the non-enzymatic steps involved in the reaction mechanism of VAD formation from DMPP using LiP as a catalyst. A kinetic characterization of the reaction using the reaction force and the reaction force constant concepts within the density functional theory (DFT) framework is proposed. All theoretical calculations for the reaction pathway were performed using the Minnesota Global Hybrid functional M06-2X and a 6-31++G(d,p) basis set. The complete reaction comprises seven steps (five steps not including LiP as a catalyst), which include radical species formation, bond transformation, water and oxygen addition, atom reordering, and deacetylation. The overall mechanism is an endothermic process with mixed activation energies depending on the four transition states. These results are the first attempt to fully understand the catalytic role of LiP in the degradation of lignin and its aromatic derivative compounds in terms of the electronic structure methods and future hybrid calculation approaches that we have recently been performing.
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Affiliation(s)
- Sebastián Cuesta
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Josefa Arias
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Felipe Gallegos
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Jans Alzate-Morales
- Center for Bioinformatics and Molecular Simulations, Faculty of Engineering, University of Talca, 2 Norte 685, Casilla 721, Talca 3640000, Chile.
| | - Lorena Meneses
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
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31
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Lang SB, Wiles RJ, Kelly CB, Molander GA. Photoredox Generation of Carbon-Centered Radicals Enables the Construction of 1,1-Difluoroalkene Carbonyl Mimics. Angew Chem Int Ed Engl 2017; 56:15073-15077. [PMID: 28960656 PMCID: PMC5688010 DOI: 10.1002/anie.201709487] [Citation(s) in RCA: 234] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 11/08/2022]
Abstract
Described is a facile, scalable route to access functional-group-rich gem-difluoroalkenes. Using visible-light-activated catalysts in conjunction with an arsenal of carbon-radical precursors, an array of trifluoromethyl-substituted alkenes undergoes radical defluorinative alkylation. Nonstabilized primary, secondary, and tertiary radicals can be used to install functional groups in a convergent manner, which would otherwise be challenging by two-electron pathways. The process readily extends to other perfluoroalkyl-substituted alkenes. In addition, we report the development of an organotrifluoroborate reagent to expedite the synthesis of the requisite trifluoromethyl-substituted alkene starting materials.
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Affiliation(s)
- Simon B Lang
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Rebecca J Wiles
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Christopher B Kelly
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Gary A Molander
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
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32
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Bradley MJ, Ananth R, Willauer HD, Baldwin JW, Hardy DR, Williams FW. The Effect of Copper Addition on the Activity and Stability of Iron-Based CO₂ Hydrogenation Catalysts. Molecules 2017; 22:molecules22091579. [PMID: 28930186 PMCID: PMC6151512 DOI: 10.3390/molecules22091579] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/13/2017] [Indexed: 12/04/2022] Open
Abstract
Iron-based CO2 catalysts have shown promise as a viable route to the production of olefins from CO2 and H2 gas. However, these catalysts can suffer from low conversion and high methane selectivity, as well as being particularly vulnerable to water produced during the reaction. In an effort to improve both the activity and durability of iron-based catalysts on an alumina support, copper (10–30%) has been added to the catalyst matrix. In this paper, the effects of copper addition on the catalyst activity and morphology are examined. The addition of 10% copper significantly increases the CO2 conversion, and decreases methane and carbon monoxide selectivity, without significantly altering the crystallinity and structure of the catalyst itself. The FeCu/K catalysts form an inverse spinel crystal phase that is independent of copper content and a metallic phase that increases in abundance with copper loading (>10% Cu). At higher loadings, copper separates from the iron oxide phase and produces metallic copper as shown by SEM-EDS. An addition of copper appears to increase the rate of the Fischer–Tropsch reaction step, as shown by modeling of the chemical kinetics and the inter- and intra-particle transport of mass and energy.
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Affiliation(s)
- Matthew J Bradley
- ASEE Postdoctoral Research Associate, Naval Research Laboratory, Materials Science and Technology Division, Washington, DC 20375, USA.
| | - Ramagopal Ananth
- Naval Research Laboratory, Chemistry Division, Washington, DC 20375, USA.
| | - Heather D Willauer
- Naval Research Laboratory, Materials Science and Technology Division, Washington, DC 20375, USA.
| | - Jeffrey W Baldwin
- Naval Research Laboratory, Acoustics Division, Washington, DC 20375, USA.
| | - Dennis R Hardy
- NOVA Research Inc., 1900 Elkin Street, Alexandria, VA 22308, USA.
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33
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McCulley C, Geier MJ, Hudson BM, Gagné MR, Tantillo DJ. Biomimetic Platinum-Promoted Polyene Polycyclizations: Influence of Alkene Substitution and Pre-cyclization Conformations. J Am Chem Soc 2017; 139:11158-11164. [PMID: 28719198 PMCID: PMC5699452 DOI: 10.1021/jacs.7b05381] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Results of kinetic experiments and quantum chemical computations on a series of platinum-promoted polycyclization reactions are described. Analyses of these results reveal a reactivity model that reaches beyond the energetics of the cascade itself, incorporating an ensemble of pre-cyclization conformations of the platinum-alkene reactant complex, only a subset of which are productive for bi- (or larger) cyclization and lead to products. Similarities and differences between this scenario, including reaction coordinates for polycyclization, for platinum- and enzyme-promoted polycyclization reactions are highlighted.
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Affiliation(s)
- Christina McCulley
- Department of Chemistry, University of California–Davis, Davis, CA 95616, USA
| | - Michael J. Geier
- Caudill Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brandi M. Hudson
- Department of Chemistry, University of California–Davis, Davis, CA 95616, USA
| | - Michel R. Gagné
- Caudill Laboratories, Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dean J. Tantillo
- Department of Chemistry, University of California–Davis, Davis, CA 95616, USA
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34
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Griffin JD, Cavanaugh CL, Nicewicz DA. Reversing the Regioselectivity of Halofunctionalization Reactions through Cooperative Photoredox and Copper Catalysis. Angew Chem Int Ed Engl 2017; 56:2097-2100. [PMID: 28105772 PMCID: PMC5512862 DOI: 10.1002/anie.201610722] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Indexed: 12/24/2022]
Abstract
Halofunctionalization of alkenes is a classical method for olefin difunctionalization. It gives rise to adducts which are found in many natural products and biologically active molecules, and offers a synthetic handle for further manipulation. Classically, this reaction is performed with an electrophilic halogen source and leads to regioselective formation of the halofunctionalized adducts. Herein, we demonstrate a reversal of the native regioselectivity for alkene halofunctionalization through the use of an acridinium photooxidant in conjunction with a copper cocatalyst.
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Affiliation(s)
- Jeremy D Griffin
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA
| | - Cortney L Cavanaugh
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA
| | - David A Nicewicz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA
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35
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Abstract
Fostriecin and related natural products present a significant challenge for synthetic chemists due to their structural complexity and chemical sensitivity. This review will chronicle the successful efforts of synthetic chemists in the construction of these biologically active molecules. Key carbon-carbon bond forming reactions will be highlighted, as well as the methods used to install the numerous stereocenters present in this class of compounds.
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Affiliation(s)
- Barry M. Trost
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Joshua D. Knopf
- Department of Chemistry, Trinity College, 300 Summit Street, Hartford, Connecticut 06106, United States
| | - Cheyenne S. Brindle
- Department of Chemistry, Trinity College, 300 Summit Street, Hartford, Connecticut 06106, United States
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36
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Hosseyni S, Smith CA, Shi X. Gold-Catalyzed Vinyl Ether Hydroalkynylation: An Alternative Pathway for the Gold-Catalyzed Intermolecular Reaction of Alkenes and Alkynes. Org Lett 2016; 18:6336-6339. [PMID: 27978688 PMCID: PMC6430632 DOI: 10.1021/acs.orglett.6b03228] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In this report, the gold-catalyzed intermolecular reaction of vinyl ethers and terminal alkynes is investigated. Utilizing a triazole gold catalyst lessens gold decomposition in the presence of the vinyl ether and affords an alkynylation product instead of the [2 + 2] product. This protocol has been expanded to include glycal substrates, which undergo a one-pot alkynylation-Ferrier reaction to produce functionalized sugars in moderate to excellent yields with high diastereoselectivity.
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Affiliation(s)
- Seyedmorteza Hosseyni
- The Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
| | - Courtney A. Smith
- The Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
| | - Xiaodong Shi
- The Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, United States
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37
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Yamamoto E, Hilton MJ, Orlandi M, Saini V, Toste FD, Sigman MS. Development and Analysis of a Pd(0)-Catalyzed Enantioselective 1,1-Diarylation of Acrylates Enabled by Chiral Anion Phase Transfer. J Am Chem Soc 2016; 138:15877-15880. [PMID: 27960315 PMCID: PMC5217716 DOI: 10.1021/jacs.6b11367] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Enantioselective 1,1-diarylation of terminal alkenes enabled by the combination of Pd catalysis with a chiral anion phase transfer (CAPT) strategy is reported herein. The reaction of substituted benzyl acrylates with aryldiazonium salts and arylboronic acids gave the corresponding 3,3-diarylpropanoates in moderate to good yields with high enantioselectivies (up to 98:2 er). Substituents on the benzyl acrylate and CAPT catalyst significantly affect the enantioselectivity, and multidimensional parametrization identified correlations suggesting structural origins for the high stereocontrol.
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Affiliation(s)
- Eiji Yamamoto
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - Margaret J. Hilton
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - Manuel Orlandi
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - Vaneet Saini
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
| | - F. Dean Toste
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew S. Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, USA
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38
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Abstract
The sequenced addition of RLi to nitriles, trapping with isopropylformate, and dehydration with phosphoryl chloride provides an efficient, direct synthesis of alkene isocyanides. The one-pot sequence involves a series of carefully orchestrated steps: addition, formylation, tautomerization, and dehydration, with CuCN catalyzing a key equilibration of a formyl imine to an N-formyl enamine. The resulting aromatic alkeneisocyanides, that are otherwise challenging to synthesize, engage in an unusual [4+2]-type cycloaddition/1,3-H shift/decyanation sequence to afford substituted naphthalenes.
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Affiliation(s)
- Yajun Li
- Department of Chemistry, Drexel University, 32 S. 32 nd Street, Philadelphia, PA 19104-2875
| | - Fraser F. Fleming
- Department of Chemistry, Drexel University, 32 S. 32 nd Street, Philadelphia, PA 19104-2875
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39
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Banerjee S, Sinha S, Pradhan P, Caruso A, Liebowitz D, Parrish D, Rossi M, Zajc B. Regiospecifically Fluorinated Polycyclic Aromatic Hydrocarbons via Julia-Kocienski Olefination and Oxidative Photocyclization. Effect of Fluorine Atom Substitution on Molecular Shape. J Org Chem 2016; 81:3983-93. [PMID: 27009471 PMCID: PMC4874880 DOI: 10.1021/acs.joc.5b02580] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A modular synthesis of regiospecifically fluorinated polycyclic aromatic hydrocarbons (PAHs) is described. 1,2-Diarylfluoroalkenes, synthesized via Julia-Kocienski olefination (70-99% yields), were converted to isomeric 5- and 6-fluorobenzo[c]phenanthrene, 5-and 6-fluorochrysene, and 9- and 10-benzo[g]chrysene (66-83% yields) by oxidative photocyclization. Photocyclization to 6-fluorochrysene proceeded more slowly than conversion of 1-styrylnaphthalene to chrysene. Higher fluoroalkene dilution led to a more rapid cyclization. Therefore, photocyclizations were performed at higher dilutions. To evaluate the effect of fluorine atom on molecular shapes, X-ray data for 5- and 6-fluorobenzo[c]phenanthrene, 6-fluorochrysene, 9- and 10-fluorobenzo[g]chrysene, and unfluorinated chrysene as well as benzo[g]chrysene were obtained and compared. The fluorine atom caused a small deviation from planarity in the chrysene series and decreased nonplanarity in the benzo[c]phenanthrene derivatives, but its influence was most pronounced in the benzo[g]chrysene series. A remarkable flattening of the molecule was observed in 9-fluorobenzo[g]chrysene, where the short 2.055 Å interatomic distance between bay-region F-9 and H-8, downfield shift of H-8, and a 26.1 Hz coupling between F-9 and C-8 indicate a possible F-9···H-8 hydrogen bond. In addition, in 9-fluorobenzo[g]chrysene, the stacking distance is short at 3.365 Å and there is an additional interaction between the C-11-H and C-10a of a nearby molecule that is almost perpendicular.
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Affiliation(s)
- Shaibal Banerjee
- Department of Chemistry, The City College of New York, 160
Convent Avenue, New York, New York 10031, United States
| | - Saikat Sinha
- Department of Chemistry, The City College of New York, 160
Convent Avenue, New York, New York 10031, United States
| | - Padmanava Pradhan
- Department of Chemistry, The City College of New York, 160
Convent Avenue, New York, New York 10031, United States
| | - Alessio Caruso
- Department of Chemistry, Vassar College, Poughkeepsie, New
York 12604, United States
| | - Daniel Liebowitz
- Department of Chemistry, Vassar College, Poughkeepsie, New
York 12604, United States
| | - Damon Parrish
- Naval Research Laboratory, Code 6030, 4555 Overlook Avenue,
Washington D.C. 20375, United States
| | - Miriam Rossi
- Department of Chemistry, Vassar College, Poughkeepsie, New
York 12604, United States
| | - Barbara Zajc
- Department of Chemistry, The City College of New York, 160
Convent Avenue, New York, New York 10031, United States
- The Ph.D. Program in Chemistry, The Graduate Center of The
City University of New York, New York, New York 10016, United States
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40
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Abstract
A Pd-catalyzed/N-heterocycle-directed C(sp(3) )-H olefination has been developed. The monoprotected amino acid ligand (MPAA) is found to significantly promote Pd-catalyzed C(sp(3) )-H olefination for the first time. Cu(OAc)2 instead of Ag(+) salts are used as the terminal oxidant. This reaction provides a useful method for the synthesis of alkylated pyrazoles.
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Affiliation(s)
- Weibo Yang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Shengqing Ye
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Yvonne Schmidt
- Medicinal Chemistry, Vertex Pharmaceuticals, 11010 Torreyana Rd., San Diego, CA, 92121, USA
| | - Dean Stamos
- Medicinal Chemistry, Vertex Pharmaceuticals, 11010 Torreyana Rd., San Diego, CA, 92121, USA
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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41
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Abstract
Organic azides are key motifs in compounds of relevance to chemical biology, medicinal chemistry and materials science. In addition, they also serve as useful building blocks due to their remarkable reactivity. Therefore, the development of efficient protocols to synthesize these compounds is of great significance. This paper reviews the major applications and development of azidation in difunctionalization of olefins using azide reagents.
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Affiliation(s)
- Kai Wu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. 38, Beijing 100191, China.
| | - Yujie Liang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. 38, Beijing 100191, China.
| | - Ning Jiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. 38, Beijing 100191, China.
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Huang JQ, Cai ZB, Jin F, Li SL, Tian YP. A new series of two-photon blue/violet fluorescent trans-alkenes: Green synthesis and optical properties. Spectrochim Acta A Mol Biomol Spectrosc 2016; 154:164-170. [PMID: 26520477 DOI: 10.1016/j.saa.2015.10.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/19/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
A new series of trans-alkenes (3a-3e) containing different electron-donating groups were synthesized by the solvent-free Horner-Wadsworth-Emmons reaction, and characterized by infrared, hydrogen nuclear magnetic resonance, mass spectrometry and elemental analysis. Their UV-visible absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. Experimental results show different trends in linear and nonlinear optical properties with different donor units. 3a with triphenylamine donor exhibits the best optical properties. It emits strong blue up-converted fluorescence, and the two-photon absorption cross-section can be as large as 218 GM in DCM.
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Affiliation(s)
- Jiu-Qiang Huang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Zhi-Bin Cai
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Fan Jin
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Sheng-Li Li
- Department of Chemistry, Anhui Province Key Laboratory of Functional Inorganic Materials, Anhui University, Hefei 230039, PR China
| | - Yu-Peng Tian
- Department of Chemistry, Anhui Province Key Laboratory of Functional Inorganic Materials, Anhui University, Hefei 230039, PR China
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Poater A. Moving from Classical Ru-NHC to Neutral or Charged Rh-NHC Based Catalysts in Olefin Metathesis. Molecules 2016; 21:177. [PMID: 26840290 PMCID: PMC6273139 DOI: 10.3390/molecules21020177] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/13/2016] [Accepted: 01/28/2016] [Indexed: 11/26/2022] Open
Abstract
Considering the versatility of oxidation states of rhodium together with the successful background of ruthenium-N-heterocyclic carbene based catalysts in olefin metathesis, it is envisaged the exchange of the ruthenium of the latter catalysts by rhodium, bearing an open-shell neutral rhodium center, or a +1 charged one. In the framework of in silico experiments, density functional theory (DFT) calculations have been used to plot the first catalytic cycle that as a first step includes the release of the phosphine. DFT is, in this case, the tool that allows the discovery of the less endergonic reaction profile from the precatalytic species for the neutral catalyst with respect to the corresponding ruthenium one; increasing the endergonic character when dealing with the charged system.
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Affiliation(s)
- Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus Montilivi, 17071 Girona, Catalonia, Spain.
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44
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Wang C, Sui J, Lu W, Li B, Li G, Ding Y, Huang Y, Geng J. Synergetic deoxy reforming of cellulose and fatty acid esters for liquid hydrocarbon-rich oils. Bioresour Technol 2015; 196:217-224. [PMID: 26241841 DOI: 10.1016/j.biortech.2015.07.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 06/04/2023]
Abstract
A series of liquid hydrocarbons (alkylbenzenes, alkanes, and alkenes) were obtained by a synergetic deoxy reforming (SDR) process of cellulose and linoleic acid methyl ester (LAME) at 350°C and 4-6MPa in a closed system without external source of hydrogen. The liquid product was obtained with a yield of 15wt% at a LAME/cellulose ratio of 0.2. In contrast, the direct deoxy reforming of cellulose produces oil that contains plenty of phenols and oxygen-containing compounds. Due to the insufficiency of water employed (30wt%), a radical reaction pathway was proposed. Quantum chemical calculations indicate that the radicals from LAME interfere with the reactions of the intermediate products from cellulose, being responsible for the removal of phenols and the formation of hydrocarbons. The SDR process offers an embryonic insight in an alternative technique for preparation of hydrocarbon fuels.
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Affiliation(s)
- Chao Wang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China
| | - Jingjing Sui
- A State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Weipeng Lu
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China
| | - Baopeng Li
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China
| | - Guoxing Li
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China
| | - Yihong Ding
- A State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Yong Huang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China
| | - Jianxin Geng
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
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45
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Miles DH, Guasch J, Toste FD. A Nucleophilic Strategy for Enantioselective Intermolecular α-Amination: Access to Enantioenriched α-Arylamino Ketones. J Am Chem Soc 2015; 137:7632-5. [PMID: 26066512 PMCID: PMC5152760 DOI: 10.1021/jacs.5b04518] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The enantioselective addition of anilines to azoalkenes was accomplished through the use of a chiral phosphoric acid catalyst. The resulting α-arylamino hydrazones were obtained in good yields and excellent enantioselectivities and provide access to enantioenriched α-arylamino ketones. A serendipitous kinetic resolution of racemic α-arylamino hydrazones is also described.
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López-Frías G, Camacho-Dávila AA, Chávez-Flores D, Zaragoza-Galán G, Ramos-Sánchez VH. Synthesis of a Functionalized Benzofuran as a Synthon for Salvianolic Acid C Analogues as Potential LDL Antioxidants. Molecules 2015; 20:8654-65. [PMID: 26007172 PMCID: PMC6272376 DOI: 10.3390/molecules20058654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 05/07/2015] [Indexed: 12/27/2022] Open
Abstract
A palladium mediated synthesis of a common synthon for the syntheses of antioxidant analogues of naturally occurring salvianolic acids is presented. The synthetic route may be used to obtain analogues with a balanced lipophilicity/hydrophilicity which may result in potentially interesting LDL antioxidants for the prevention of cardiovascular diseases.
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Affiliation(s)
| | - Alejandro A. Camacho-Dávila
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +52-61-423-6600 (ext. 4251); Fax: +52-61-423-6607
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Cheung CW, Zhurkin FE, Hu X. Z-Selective Olefin Synthesis via Iron-Catalyzed Reductive Coupling of Alkyl Halides with Terminal Arylalkynes. J Am Chem Soc 2015; 137:4932-5. [PMID: 25831473 PMCID: PMC4415033 DOI: 10.1021/jacs.5b01784] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Indexed: 12/23/2022]
Abstract
Selective catalytic synthesis of Z-olefins has been challenging. Here we describe a method to produce 1,2-disubstituted olefins in high Z selectivity via reductive cross-coupling of alkyl halides with terminal arylalkynes. The method employs inexpensive and nontoxic catalyst (iron(II) bromide) and reductant (zinc). The substrate scope encompasses primary, secondary, and tertiary alkyl halides, and the reaction tolerates a large number of functional groups. The utility of the method is demonstrated in the synthesis of several pharmaceutically relevant molecules. Mechanistic study suggests that the reaction proceeds through an iron-catalyzed anti-selective carbozincation pathway.
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Affiliation(s)
- Chi Wai Cheung
- Laboratory of Inorganic
Synthesis
and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne
(EPFL), ISIC-LSCI, BCH
3305, Lausanne 1015, Switzerland
| | - Fedor E. Zhurkin
- Laboratory of Inorganic
Synthesis
and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne
(EPFL), ISIC-LSCI, BCH
3305, Lausanne 1015, Switzerland
| | - Xile Hu
- Laboratory of Inorganic
Synthesis
and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne
(EPFL), ISIC-LSCI, BCH
3305, Lausanne 1015, Switzerland
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Yu M, Schrock RR, Hoveyda AH. Catalyst-controlled stereoselective olefin metathesis as a principal strategy in multistep synthesis design: a concise route to (+)-neopeltolide. Angew Chem Int Ed Engl 2015; 54:215-20. [PMID: 25377347 PMCID: PMC4285691 DOI: 10.1002/anie.201409120] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Indexed: 11/10/2022]
Abstract
Molybdenum-, tungsten-, and ruthenium-based complexes that control the stereochemical outcome of olefin metathesis reactions have been recently introduced. However, the complementary nature of these systems through their combined use in multistep complex molecule synthesis has not been illustrated. A concise diastereo- and enantioselective route that furnishes the anti-proliferative natural product neopeltolide is now disclosed. Catalytic transformations are employed to address every stereochemical issue. Among the featured processes are an enantioselective ring-opening/cross-metathesis promoted by a Mo monoaryloxide pyrrolide (MAP) complex and a macrocyclic ring-closing metathesis that affords a trisubstituted alkene and is catalyzed by a Mo bis(aryloxide) species. Furthermore, Z-selective cross-metathesis reactions, facilitated by Mo and Ru complexes, have been employed in the stereoselective synthesis of the acyclic dienyl moiety of the target molecule.
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Affiliation(s)
- Miao Yu
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA)
| | - Richard R. Schrock
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA)
| | - Amir H. Hoveyda
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA)
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NEGISHI EI, XU S. Catalytic enantioselective synthesis of chiral organic compounds of ultra-high purity of >99% ee. Proc Jpn Acad Ser B Phys Biol Sci 2015; 91:369-93. [PMID: 26460317 PMCID: PMC4729854 DOI: 10.2183/pjab.91.369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/22/2015] [Indexed: 06/05/2023]
Abstract
Shortly after the discovery of Zr-catalyzed carboalumination of alkynes in 1978, we sought expansion of the scope of this reaction so as to develop its alkene version for catalytic asymmetric C-C bond formation, namely the ZACA (Zr-catalyzed asymmetric carboalumination of alkenes). However, this seemingly easy task proved to be quite challenging. The ZACA reaction was finally discovered in 1995 by suppressing three competitive side reactions, i.e., (i) cyclic carbometalation, (ii) β-H transfer hydrometalation, and (iii) alkene polymerization. The ZACA reaction has been used to significantly modernize and improve syntheses of various natural products including deoxypolypropionates and isoprenoids. This review focuses on our recent progress on the development of ZACA-lipase-catalyzed acetylation-transition metal-catalyzed cross-coupling processes for highly efficient and enantioselective syntheses of a wide range of chiral organic compounds with ultra-high enantiomeric purities.
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Affiliation(s)
- Ei-ichi NEGISHI
- Herbert C. Brown Laboratories of Chemistry, Purdue University, Indiana, U.S.A.
| | - Shiqing XU
- Herbert C. Brown Laboratories of Chemistry, Purdue University, Indiana, U.S.A.
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50
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Tran BL, Driess M, Hartwig JF. Copper-catalyzed oxidative dehydrogenative carboxylation of unactivated alkanes to allylic esters via alkenes. J Am Chem Soc 2014; 136:17292-301. [PMID: 25389772 PMCID: PMC4262675 DOI: 10.1021/ja510093x] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Indexed: 01/15/2023]
Abstract
We report copper-catalyzed oxidative dehydrogenative carboxylation (ODC) of unactivated alkanes with various substituted benzoic acids to produce the corresponding allylic esters. Spectroscopic studies (EPR, UV-vis) revealed that the resting state of the catalyst is [(BPI)Cu(O2CPh)] (1-O2CPh), formed from [(BPI)Cu(PPh3)2], oxidant, and benzoic acid. Catalytic and stoichiometric reactions of 1-O2CPh with alkyl radicals and radical probes imply that C-H bond cleavage occurs by a tert-butoxy radical. In addition, the deuterium kinetic isotope effect from reactions of cyclohexane and d12-cyclohexane in separate vessels showed that the turnover-limiting step for the ODC of cyclohexane is C-H bond cleavage. To understand the origin of the difference in products formed from copper-catalyzed amidation and copper-catalyzed ODC, reactions of an alkyl radical with a series of copper-carboxylate, copper-amidate, and copper-imidate complexes were performed. The results of competition experiments revealed that the relative rate of reaction of alkyl radicals with the copper complexes follows the trend Cu(II)-amidate > Cu(II)-imidate > Cu(II)-benzoate. Consistent with this trend, Cu(II)-amidates and Cu(II)-benzoates containing more electron-rich aryl groups on the benzamidate and benzoate react faster with the alkyl radical than do those with more electron-poor aryl groups on these ligands to produce the corresponding products. These data on the ODC of cyclohexane led to preliminary investigation of copper-catalyzed oxidative dehydrogenative amination of cyclohexane to generate a mixture of N-alkyl and N-allylic products.
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Affiliation(s)
- Ba L. Tran
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthias Driess
- Metallorganische
Chemie und Anorganische Materialien, Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr.
C2, 10623 Berlin, Germany
| | - John F. Hartwig
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
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