The Experts below are selected from a list of 10683 Experts worldwide ranked by ideXlab platform
Eric Meggers - One of the best experts on this subject based on the ideXlab platform.
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chiral at metal Iridium Complex for efficient enantioselective transfer hydrogenation of ketones
Chemical Communications, 2016Co-Authors: Cheng Tian, Lei Gong, Eric MeggersAbstract:A bis-cyclometalated Iridium(III) Complex with metal-centered chirality catalyzes the enantioselective transfer hydrogenation of ketones with high enantioselectivities at low catalyst loadings down to 0.002 mol%. Importantly, the rate of catalysis and enantioselectivity are markedly improved in the presence of a pyrazole co-ligand. The reaction is proposed to proceed via an Iridium-hydride intermediate exploiting metal–ligand cooperativity (bifunctional catalysis).
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asymmetric radical radical cross coupling through visible light activated Iridium catalysis
Angewandte Chemie, 2016Co-Authors: Chuanyong Wang, Klaus Harms, Eric Meggers, Jie Qin, Xiaodong Shen, Radostan RiedelAbstract:Combining single electron transfer between a donor substrate and a catalyst-activated acceptor substrate with a stereocontrolled radical–radical recombination enables the visible-light-driven catalytic enantio- and diastereoselective synthesis of 1,2-amino alcohols from trifluoromethyl ketones and tertiary amines. With a chiral Iridium Complex acting as both a Lewis acid and a photoredox catalyst, enantioselectivities of up to 99 % ee were achieved. A quantum yield of <1 supports the proposed catalytic cycle in which at least one photon is needed for each asymmetric CC bond formation mediated by single electron transfer.
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enantioselective catalytic trichloromethylation through visible light activated photoredox catalysis with a chiral Iridium Complex
Journal of the American Chemical Society, 2015Co-Authors: Chuanyong Wang, Klaus Harms, Eric MeggersAbstract:An enantioselective, catalytic trichloromethylation of 2-acyl imidazoles and 2-acylpyridines is reported. Several products are formed with enantiomeric excess of ≥99%. In this system, a chiral Iridium Complex serves a dual function, as a catalytically active chiral Lewis acid and simultaneously as a precursor for an in situ assembled visible-light-triggered photoredox catalyst.
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asymmetric catalysis with an inert chiral at metal Iridium Complex
ChemInform, 2014Co-Authors: Liangan Chen, Weici Xu, Biao Huang, Lun Wang, Jianwei Xi, Klaus Harms, Lei Gong, Eric MeggersAbstract:Novel chiral Iridium Complexes are synthesized and used as a catalyst for the asymmetric hydrogenation reaction of β,β-disubstituted nitroolefins.
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asymmetric catalysis with an inert chiral at metal Iridium Complex
Journal of the American Chemical Society, 2013Co-Authors: Liangan Chen, Weici Xu, Biao Huang, Lun Wang, Jianwei Xi, Klaus Harms, Lei Gong, Eric MeggersAbstract:The development of a chiral-at-metal Iridium(III) Complex for the highly efficient catalytic asymmetric transfer hydrogenation of β,β′-disubstituted nitroalkenes is reported. Catalysis by this inert, rigid metal Complex does not involve any direct metal coordination but operates exclusively through weak interactions with functional groups properly arranged in the ligand sphere of the Iridium Complex. Although the Iridium Complex relies only on the formation of three hydrogen bonds, it exceeds the performance of most organocatalysts with respect to enantiomeric excess (up to 99% ee) and catalyst loading (down to 0.1 mol %). This work hints at an advantage of structurally complicated rigid scaffolds for non-covalent catalysis, which especially relies on conformationally constrained cooperative interactions between the catalyst and substrates.
Max C Holthausen - One of the best experts on this subject based on the ideXlab platform.
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an Iridium iii iv v redox series featuring a terminal imido Complex with triplet ground state
Chemical Science, 2018Co-Authors: Markus Kinauer, Heiko Bamberger, Christian Volkmann, Martin Diefenbach, Bas De Bruin, Serhiy Demeshko, Christian Wurtele, Joris Van Slageren, Edward J Reijerse, Max C HolthausenAbstract:The Iridium(III/IV/V) imido redox series [Ir(NtBu){N(CHCHPtBu2)2}]0/+/2+ was synthesized and examined spectroscopically, magnetically, crystallographically and computationally. The monocationic Iridium(IV) imide exhibits an electronic doublet ground state with considerable ‘imidyl’ character as a result of covalent Ir–NtBu bonding. Reduction gives the neutral imide [Ir(NtBu){N(CHCHPtBu2)2}] as the first example of an Iridium Complex with a triplet ground state. Its reactivity with respect to nitrene transfer to selected electrophiles (CO2) and nucleophiles (PMe3), respectively, is reported.
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An Iridium( iii / iv / v ) redox series featuring a terminal imido Complex with triplet ground state
Chemical Science, 2018Co-Authors: Markus Kinauer, Heiko Bamberger, Christian Volkmann, Martin Diefenbach, Bas De Bruin, Serhiy Demeshko, Christian Wurtele, Joris Van Slageren, Edward J Reijerse, Max C HolthausenAbstract:The Iridium(III/IV/V) imido redox series [Ir(NtBu){N(CHCHPtBu2)2}]0/+/2+ was synthesized and examined spectroscopically, magnetically, crystallographically and computationally. The monocationic Iridium(IV) imide exhibits an electronic doublet ground state with considerable ‘imidyl’ character as a result of covalent Ir–NtBu bonding. Reduction gives the neutral imide [Ir(NtBu){N(CHCHPtBu2)2}] as the first example of an Iridium Complex with a triplet ground state. Its reactivity with respect to nitrene transfer to selected electrophiles (CO2) and nucleophiles (PMe3), respectively, is reported.
Masaya Sawamura - One of the best experts on this subject based on the ideXlab platform.
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ester directed regioselective borylation of heteroarenes catalyzed by a silica supported Iridium Complex
ChemInform, 2010Co-Authors: Soichiro Kawamorita, Hirohisa Ohmiya, Masaya SawamuraAbstract:Heteroarenes bearing an ester substituent undergo regioselective borylation at the position adjacent to the ester group.
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directed ortho borylation of phenol derivatives catalyzed by a silica supported Iridium Complex
Organic Letters, 2010Co-Authors: Kenji Yamazaki, Soichiro Kawamorita, Hirohisa Ohmiya, Masaya SawamuraAbstract:The directed ortho borylation of phenol derivatives protected with an N,N-diethylcarbamoyl group was efficiently catalyzed by an immobilized monophosphine−Ir system, which was prepared in situ from [Ir(OMe)(cod)]2 and a silica-supported, compact phosphine. The utility of the carbamoyloxy group as a leaving group for metal-catalyzed cross-coupling reactions was demonstrated by its utilization in the synthesis of a terphenyl derivative.
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ester directed regioselective borylation of heteroarenes catalyzed by a silica supported Iridium Complex
Journal of Organic Chemistry, 2010Co-Authors: Soichiro Kawamorita, Hirohisa Ohmiya, Masaya SawamuraAbstract:The ester-directed regioselective borylation of arenes catalyzed by a silica-supported monophosphine−Ir Complex displayed a significantly broad substrate scope toward heteroaromatic compounds, including thiophene, pyrrole, furan, benzothiophene, benzofuran, indole, and carbazole derivatives. The regioselectivity is complementary to the selectivities observed in the heteroarene C−H borylation with the dtbpy-Ir catalyst system.
Markus Kinauer - One of the best experts on this subject based on the ideXlab platform.
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an Iridium iii iv v redox series featuring a terminal imido Complex with triplet ground state
Chemical Science, 2018Co-Authors: Markus Kinauer, Heiko Bamberger, Christian Volkmann, Martin Diefenbach, Bas De Bruin, Serhiy Demeshko, Christian Wurtele, Joris Van Slageren, Edward J Reijerse, Max C HolthausenAbstract:The Iridium(III/IV/V) imido redox series [Ir(NtBu){N(CHCHPtBu2)2}]0/+/2+ was synthesized and examined spectroscopically, magnetically, crystallographically and computationally. The monocationic Iridium(IV) imide exhibits an electronic doublet ground state with considerable ‘imidyl’ character as a result of covalent Ir–NtBu bonding. Reduction gives the neutral imide [Ir(NtBu){N(CHCHPtBu2)2}] as the first example of an Iridium Complex with a triplet ground state. Its reactivity with respect to nitrene transfer to selected electrophiles (CO2) and nucleophiles (PMe3), respectively, is reported.
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An Iridium( iii / iv / v ) redox series featuring a terminal imido Complex with triplet ground state
Chemical Science, 2018Co-Authors: Markus Kinauer, Heiko Bamberger, Christian Volkmann, Martin Diefenbach, Bas De Bruin, Serhiy Demeshko, Christian Wurtele, Joris Van Slageren, Edward J Reijerse, Max C HolthausenAbstract:The Iridium(III/IV/V) imido redox series [Ir(NtBu){N(CHCHPtBu2)2}]0/+/2+ was synthesized and examined spectroscopically, magnetically, crystallographically and computationally. The monocationic Iridium(IV) imide exhibits an electronic doublet ground state with considerable ‘imidyl’ character as a result of covalent Ir–NtBu bonding. Reduction gives the neutral imide [Ir(NtBu){N(CHCHPtBu2)2}] as the first example of an Iridium Complex with a triplet ground state. Its reactivity with respect to nitrene transfer to selected electrophiles (CO2) and nucleophiles (PMe3), respectively, is reported.
Michele Sessolo - One of the best experts on this subject based on the ideXlab platform.
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Phosphorescent hybrid organic-inorganic light-emitting diodes
Advanced Materials, 2010Co-Authors: Henk J Bolink, Hicham Brine, Eugenio Coronado, Michele SessoloAbstract:Competitive efficacy and power conversion efficiency (15 cd A(-1) and above 9 lm W-1, respectively) are obtained for a hybrid organic inorganic light-emitting diode (HyLED) with air-stable metal oxides as electrodes. Thanks to the use of a phosphorescent Iridium Complex and a Cs-doped ZnO cathode, performances approaching those of standard solution-processed organic LEDs can be obtained.
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White Hybrid Organic−Inorganic Light-Emitting Diode Using ZnO as the Air-Stable Cathode
Chemistry of Materials, 2009Co-Authors: Henk J Bolink, Eugenio Coronado, Michele SessoloAbstract:An efficient white light emitting hybrid organic−inorganic device utilizing air-stable metal oxides as anode and cathode and a polyfluorene mixed with a phosphorescent Iridium Complex as the emitting material is presented.
