LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 12386

Search options

  1. Article ; Online: Palladium Catalyzed Allylic C-H Oxidation Enabled by Bicyclic Sulfoxide Ligands

    Yuming Wen / Jianfeng Zheng / Alex H. Evans / Qiang Zhang

    Organics, Vol 4, Iss 23, Pp 289-

    2023  Volume 296

    Abstract: The activation of C-H bonds is a potent tool for modifying molecular structures in chemistry ... bissulfoxide moiety. A palladium catalyzed allylic C-H oxidation method enables a direct benzyl-allylic ... framework and it proved to be effective for enabling both N- and C-alkylation. A total of 13 C-H activation ...

    Abstract The activation of C-H bonds is a potent tool for modifying molecular structures in chemistry. This article details the steps involved in a novel ligand bearing a bicyclic [3.3.1]-nonane framework and bissulfoxide moiety. A palladium catalyzed allylic C-H oxidation method enables a direct benzyl-allylic functionalization with the bissulfoxide ligand. Bissulfoixde ligand possesses a rapidly constructed bicyclic [3.3.1] framework and it proved to be effective for enabling both N- and C-alkylation. A total of 13 C-H activation productions were reported with good to excellent yields. This report validated that it is necessary to include bissulfoxide as a ligand for superior reactivities. Naftifine was produced utilizing developed C-H functionalization methodology in good overall yields.
    Keywords C-H activation ; bicyclic ligand ; sulfoxide ; palladium ; amino acids ; Organic chemistry ; QD241-441
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: Rubidium and caesium aluminyls: synthesis, structures and reactivity in C-H bond activation of benzene.

    Gentner, Thomas X / Evans, Matthew J / Kennedy, Alan R / Neale, Sam E / McMullin, Claire L / Coles, Martyn P / Mulvey, Robert E

    Chemical communications (Cambridge, England)

    2022  Volume 58, Issue 9, Page(s) 1390–1393

    Abstract: ... enables C-H bond activation of benzene, but not the Rb aluminyl reflecting the importance ...

    Abstract Expanding knowledge of low valent aluminium chemistry, rubidium and caesium aluminyls are reported to complete the group 1 (Li-Cs) set of metal aluminyls. Both compounds crystallize as a contacted dimeric pair supported by M⋯π(arene) interactions with a pronounced twist between aluminyl units. Density functional theory calculations show symmetrical bonding between the M and Al atoms, with an Al centred lone-pair donating into vacant Rb and Cs orbitals. Interestingly, despite their structural similarity the Cs aluminyl enables C-H bond activation of benzene, but not the Rb aluminyl reflecting the importance of the alkali metal in these heterobimetallic systems.
    Language English
    Publishing date 2022-01-27
    Publishing country England
    Document type Journal Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc05379e
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article ; Online: Ligand switchable site selectivity in C-H alkenylation of thiophenes by turnover-limiting step control.

    Evans, Rebecca / Sampson, Jessica / Wang, Long / Lückemeier, Lukas / Carrow, Brad P

    Chemical communications (Cambridge, England)

    2021  Volume 57, Issue 72, Page(s) 9076–9079

    Abstract: The origin of switchable site selectivity during Pd-catalysed C-H alkenylation of heteroarenes has ... determining C-H cleavage to C-C bond formation, respectively. ...

    Abstract The origin of switchable site selectivity during Pd-catalysed C-H alkenylation of heteroarenes has been examined through More O'Ferrall-Jencks, isotope effect, and DFT computational analyses, which indicate substitution of ionic thioether for pyridine dative ligands induces a change from selectivity-determining C-H cleavage to C-C bond formation, respectively.
    Language English
    Publishing date 2021-09-09
    Publishing country England
    Document type Journal Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc03456a
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article: Rubidium and caesium aluminyls: synthesis, structures and reactivity in C–H bond activation of benzene

    Gentner, Thomas X. / Evans, Matthew J. / Kennedy, Alan R. / Neale, Sam E. / McMullin, Claire L. / Coles, Martyn P. / Mulvey, Robert E.

    Chemical communications. 2022 Jan. 27, v. 58, no. 9

    2022  

    Abstract: ... enables C–H bond activation of benzene, but not the Rb aluminyl reflecting the importance ...

    Abstract Expanding knowledge of low valent aluminium chemistry, rubidium and caesium aluminyls are reported to complete the group 1 (Li–Cs) set of metal aluminyls. Both compounds crystallize as a contacted dimeric pair supported by M⋯π(arene) interactions with a pronounced twist between aluminyl units. Density functional theory calculations show symmetrical bonding between the M and Al atoms, with an Al centred lone-pair donating into vacant Rb and Cs orbitals. Interestingly, despite their structural similarity the Cs aluminyl enables C–H bond activation of benzene, but not the Rb aluminyl reflecting the importance of the alkali metal in these heterobimetallic systems.
    Keywords aluminum ; benzene ; carbon-hydrogen bond activation ; cesium ; crystallization ; density functional theory ; rubidium
    Language English
    Dates of publication 2022-0127
    Size p. 1390-1393.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc05379e
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Mn-salen catalysed benzylic C-H activation for the synthesis of aryl [(18)F]CF3-containing PET probes.

    Carroll, L / Evans, H L / Spivey, A C / Aboagye, E O

    Chemical communications (Cambridge, England)

    2015  Volume 51, Issue 40, Page(s) 8439–8441

    Abstract: The development of a Mn-salen complex catalysed oxidative benzylic fluorination of non-activated C ... H bonds using [(18)F]fluoride is described for installation of [(18)F]CHRF, [(18)F]CR2F and ...

    Abstract The development of a Mn-salen complex catalysed oxidative benzylic fluorination of non-activated C-H bonds using [(18)F]fluoride is described for installation of [(18)F]CHRF, [(18)F]CR2F and particularly [(18)F]CF3 containing groups in the presence of other functional groups.
    MeSH term(s) Catalysis ; Fluorescent Dyes/chemical synthesis ; Fluorine Radioisotopes ; Naphthalenes/chemistry ; Organometallic Compounds/chemistry ; Positron-Emission Tomography
    Chemical Substances Fluorescent Dyes ; Fluorine Radioisotopes ; Mn-salen ; Naphthalenes ; Organometallic Compounds
    Language English
    Publishing date 2015-02-24
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/c4cc05762g
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  6. Article: Ligand switchable site selectivity in C–H alkenylation of thiophenes by turnover-limiting step control

    Evans, Rebecca / Sampson, Jessica / Wang, Long / Lückemeier, Lukas / Carrow, Brad P.

    Chemical communications. 2021 Sept. 9, v. 57, no. 72

    2021  

    Abstract: The origin of switchable site selectivity during Pd-catalysed C–H alkenylation of heteroarenes has ... determining C–H cleavage to C–C bond formation, respectively. ...

    Abstract The origin of switchable site selectivity during Pd-catalysed C–H alkenylation of heteroarenes has been examined through More O’Ferrall–Jencks, isotope effect, and DFT computational analyses, which indicate substitution of ionic thioether for pyridine dative ligands induces a change from selectivity-determining C–H cleavage to C–C bond formation, respectively.
    Keywords isotopes ; ligands ; pyridines ; thiophenes
    Language English
    Dates of publication 2021-0909
    Size p. 9076-9079.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d1cc03456a
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  7. Article ; Online: Rhodium Indenyl NHC and Fluorenyl-Tethered NHC Half-Sandwich Complexes: Synthesis, Structures and Applications in the Catalytic C-H Borylation of Arenes and Alkanes.

    Evans, Kieren J / Morton, Paul A / Luz, Christian / Miller, Callum / Raine, Olivia / Lynam, Jason M / Mansell, Stephen M

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2021  Volume 27, Issue 71, Page(s) 17824–17833

    Abstract: Indenyl (Ind) rhodium N-heterocyclic carbene (NHC) complexes [Rh( ... ...

    Abstract Indenyl (Ind) rhodium N-heterocyclic carbene (NHC) complexes [Rh(η
    Language English
    Publishing date 2021-11-18
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-X
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.202102961
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  8. Article ; Online: Activation of B-H, Si-H, and C-F bonds with Tp'Rh(PMe3) complexes: kinetics, mechanism, and selectivity.

    Procacci, Barbara / Jiao, Yunzhe / Evans, Meagan E / Jones, William D / Perutz, Robin N / Whitwood, Adrian C

    Journal of the American Chemical Society

    2015  Volume 137, Issue 3, Page(s) 1258–1272

    Abstract: ... Tp' = tris(3,5-dimethylpyrazolyl)borate) with substrates containing B-H, Si-H, C-F, and C-H bonds are ... reported. Complexes 1 and 1a are known activators of C-H bonds, including those of alkanes. Kinetic studies ... selectivity for B-H over C-H activation of HBpin (pin = pinacolate) leading to Tp'Rh(PMe3)(Bpin)H is observed ...

    Abstract The photochemical reactions of Tp'Rh(PMe3)H2 (1) and thermal reactions of Tp'Rh(PMe3)(CH3)H (1a, Tp' = tris(3,5-dimethylpyrazolyl)borate) with substrates containing B-H, Si-H, C-F, and C-H bonds are reported. Complexes 1 and 1a are known activators of C-H bonds, including those of alkanes. Kinetic studies of reactions with HBpin and PhSiH3 show that photodissociation of H2 from 1 occurs prior to substrate attack, whereas thermal reaction of 1a proceeds by bimolecular reaction with the substrate. Complete intramolecular selectivity for B-H over C-H activation of HBpin (pin = pinacolate) leading to Tp'Rh(PMe3)(Bpin)H is observed. Similarly, the reaction with Et2SiH2 shows a strong preference for Si-H over C-H activation, generating Tp'Rh(PMe3)(SiEt2H)H. The Rh(Bpin)H and Rh(SiEt2H)H products were stable to heating in benzene in accord with DFT calculations that showed that reaction with benzene is endoergic. The intramolecular competition with PhSiH3 yields a ∼1:4 mixture of Tp'Rh(PMe3)(C6H4SiH3)H and Tp'Rh(PMe3)(SiPhH2)H, respectively. Reaction with pentafluoropyridine generates Tp'Rh(PMe3)(C5NF4)F, while reaction with 2,3,5,6-tetrafluoropyridine yields a mixture of C-H and C-F activated products. Hexafluorobenzene proves unreactive. Crystal structures are reported for B-H, Si-H, and C-F activated products, but in the latter case a bifluoride complex Tp'Rh(PMe3)(C5NF4)(FHF) was crystallized. Intermolecular competition reactions were studied by photoreaction of 1 in C6F6 with benzene and another substrate (HBpin, PhSiH3, or pentafluoropyridine) employing in situ laser photolysis in the NMR probe, resulting in a wide-ranging map of kinetic selectivities. The mechanisms of intramolecular and intermolecular selection are analyzed.
    Language English
    Publishing date 2015-01-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/ja5113172
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article: Mn–salen catalysed benzylic C–H activation for the synthesis of aryl [¹⁸F]CF₃-containing PET probes

    Carroll, L / Evans, H. L / Spivey, A. C / Aboagye, E. O

    Chemical communications. 2015 May 5, v. 51, no. 40

    2015  

    Abstract: The development of a Mn–salen complex catalysed oxidative benzylic fluorination of non-activated C ... H bonds using [¹⁸F]fluoride is described for installation of [¹⁸F]CHRF, [¹⁸F]CR₂F and particularly ...

    Abstract The development of a Mn–salen complex catalysed oxidative benzylic fluorination of non-activated C–H bonds using [¹⁸F]fluoride is described for installation of [¹⁸F]CHRF, [¹⁸F]CR₂F and particularly [¹⁸F]CF₃ containing groups in the presence of other functional groups.
    Keywords aromatic compounds ; carbon-hydrogen bond activation ; catalytic activity ; chemical bonding ; chemical reactions ; fluorides ; moieties
    Language English
    Dates of publication 2015-0505
    Size p. 8439-8441.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/c4cc05762g
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  10. Article ; Online: Using Diamagnetic Yttrium and Lanthanum Complexes to Explore Ligand Reduction and C-H Bond Activation in a Tris(aryloxide)mesitylene Ligand System.

    Palumbo, Chad T / Halter, Dominik P / Voora, Vamsee K / Chen, Guo P / Ziller, Joseph W / Gembicky, Milan / Rheingold, Arnold L / Furche, Filipp / Meyer, Karsten / Evans, William J

    Inorganic chemistry

    2018  Volume 57, Issue 20, Page(s) 12876–12884

    Abstract: ... Y(N( ... ...

    Abstract [Y(N(SiMe
    Language English
    Publishing date 2018-09-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1484438-2
    ISSN 1520-510X ; 0020-1669
    ISSN (online) 1520-510X
    ISSN 0020-1669
    DOI 10.1021/acs.inorgchem.8b02053
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top