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Tejero AG, Castillo J, Viguri F, Carmona D, Passarelli V, Lahoz FJ, García-Orduña P, Rodríguez R. Dynamic Configuration on a Chiral-at-Rhodium Catalyst Featuring a Flexible Tetradentate Ligand. Chemistry 2024; 30:e202303935. [PMID: 38031971 DOI: 10.1002/chem.202303935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/01/2023]
Abstract
The unique dynamic configuration of an enantioselective chiral-at-metal catalyst based on Rh(III) and a non-chiral tetradentate ligand is described and resolved. At room temperature, the catalyst undergoes a dynamic configuration process leading to the formation of two interconvertible metal-stereoisomers, remarkably without racemization. Density functional theory (DFT) calculations indicate that this metal-isomerization proceeds via a concerted transition state, which features a trigonal bipyramidal geometry stabilized by the tetradentate ligand. Furthermore, the resolved enantiopure complex shows high catalytic enantioinduction in the Friedel-Crafts reaction, achieving enantiomeric ratios as high as 99 : 1.
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Affiliation(s)
- Alvaro G Tejero
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Javier Castillo
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Fernando Viguri
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Daniel Carmona
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Vincenzo Passarelli
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Fernando J Lahoz
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Pilar García-Orduña
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Ricardo Rodríguez
- Departamento de Catálisis y Procesos Catalíticos, Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain
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2
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Dhimba G, Muller A, Lammertsma K. Chiral-at-Metal Racemization Unraveled for MX 2 (a-chel) 2 by means of a Computational Analysis of MoO 2 (acnac) 2. Chemistry 2023; 29:e202302516. [PMID: 37730887 DOI: 10.1002/chem.202302516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 09/22/2023]
Abstract
Octahedral chiral-at-metal complexes MX2 (a-chel)2 (a-chel=asymmetric chelate) can rearrange their ligands by four mechanisms known as the Bailar (B), Ray-Dutt (RD), Conte-Hippler (CH), and Dhimba-Muller-Lammertsma (DML) twists. Racemization involves their interconnections, which were computed for MoO2 (acnac)2 (acnac=β-ketoiminate) using density functional theory at ωB97x-D with the 6-31G(d,p) and 6-311G(2d,p) basis sets and LANL2DZ for molybdenum. Racemizing the cis(NN) isomer, being the global energy minimum with trans oriented imine groups, is a three step process (DML-CH-DML) that requires 17.4 kcal/mol, while all three cis isomers (cis(NN), cis(NO), and cis(OO)) interconvert at ≤17.9 kcal/mol. The B and RD twists are energetically not competitive and neither are the trans isomers. The interconnection of all enantiomeric minima and transition structures is summarized in a graph that also visualizes valley ridge inflection points for two of the three CH twists. Geometrical features of the minima and twists are given. Lastly, the influence of N-substitution on the favored racemization pathway is evaluated. The present comprehensive study serves as a template for designing chiral-at-metal MX2 (a-chel)2 catalysts that may retain their chiral integrity.
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Affiliation(s)
- George Dhimba
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa
| | - Alfred Muller
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa
| | - Koop Lammertsma
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa
- Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
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3
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Tejero AG, Carmona M, Rodríguez R, Viguri F, Lahoz FJ, García-Orduña P, Carmona D. Synthesis of chiral-at-metal rhodium complexes from achiral tripodal tetradentate ligands: resolution and application to enantioselective Diels-Alder and 1,3-dipolar cycloadditions. RSC Adv 2022; 12:34704-34714. [PMID: 36545596 PMCID: PMC9717581 DOI: 10.1039/d2ra06982b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 11/23/2022] [Indexed: 12/04/2022] Open
Abstract
An improved synthesis of the racemic rhodium compound [RhCl2(κ4 C,N,N',P-L1)] (1) containing an achiral tripodal tetradentate ligand is reported. Their derived solvate complexes [Rh(κ4 C,N,N',P-L1)(Solv)2][SbF6]2 (Solv = NCMe, 2; H2O, 3) are resolved into their two enantiomers. Complexes 2 and 3 catalyze the Diels-Alder (DA) reaction between methacrolein and cyclopentadiene and the 1,3-dipolar cycloaddition reaction between methacrolein and the nitrone N-benzylidenphenylamine-N-oxide. When enantiopure (A Rh,R N)-2 was employed as the catalyst, enantiomeric ratios >99/1, in the R at C2 adduct, and up to 94/6, in the 3,5-endo isomer, were achieved in the DA reaction and in the 1,3-dipolar cycloaddition reaction, respectively. A plausible catalytic cycle that accounts for the origin of the observed enantioselectivity is proposed.
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Affiliation(s)
- Alvaro G. Tejero
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - María Carmona
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - Ricardo Rodríguez
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - Fernando Viguri
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - Fernando J. Lahoz
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - Pilar García-Orduña
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
| | - Daniel Carmona
- Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC – Universidad de ZaragozaPedro Cerbuna 1250009 ZaragozaSpain
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4
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Schmidt TA, Sparr C. Photocatalytic deracemisation of cobalt(III) complexes with fourfold stereogenicity. Chem Commun (Camb) 2022; 58:12172-12175. [PMID: 36254723 PMCID: PMC9623447 DOI: 10.1039/d2cc05196f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 10/05/2022] [Indexed: 08/25/2023]
Abstract
The deracemisation of fourfold stereogenic cobalt(III) diketonates with a chiral photocatalyst is described. With only 0.5 mol% menthyl Ru(bpy)32+ photocatalyst, an enantiomeric enrichment of up to 88 : 12 e.r. was obtained for the major meridional diastereomers. Moreover, a distribution of configurationally stable diastereomers distinct from the thermodynamic ratio was observed upon reaching the photostationary state.
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Affiliation(s)
- Tanno A Schmidt
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, Basel CH-4056, Switzerland.
| | - Christof Sparr
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, Basel CH-4056, Switzerland.
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5
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Dhimba G, Muller A, Lammertsma K. Racemization Pathway for MoO 2(acac) 2 Favored over Ray-Dutt, Bailar, and Conte-Hippler Twists. Inorg Chem 2022; 61:14918-14923. [PMID: 35980189 PMCID: PMC9516665 DOI: 10.1021/acs.inorgchem.2c00824] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chiral cis-MoO2(acac)2 racemizes via four pathways that agree with and extend upon Muetterties' topological analysis for dynamic MX2(chel)2 complexes. Textbook Ray-Dutt and Bailar twists are the least favored with barriers of 27.5 and 28.7 kcal/mol, respectively. Rotating both acac ligands of the Bailar structure by 90° gives the lower Conte-Hippler twist (20.0 kcal/mol), which represents a valley-ridge inflection that invokes the trans isomer. The most favorable is a new twist that was found by 90° rotation of only one acac ligand of the Bailar structure. The gas-phase barrier of 17.4 kcal/mol for this Dhimba-Muller-Lammertsma twist further decreases upon inclusion of the effects of solvents to 16.3 kcal/mol (benzene), 16.2 kcal/mol (toluene), and 15.4 kcal/mol (chloroform), which are in excellent agreement with the reported experimental values.
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Affiliation(s)
- George Dhimba
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa
| | - Alfred Muller
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa
| | - Koop Lammertsma
- Department of Chemical Sciences, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa.,Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, Amsterdam 1081 HZ, The Netherlands
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6
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Findlay MT, Domingo-Legarda P, McArthur G, Yen A, Larrosa I. Catalysis with cycloruthenated complexes. Chem Sci 2022; 13:3335-3362. [PMID: 35432864 PMCID: PMC8943884 DOI: 10.1039/d1sc06355c] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/08/2022] [Indexed: 12/03/2022] Open
Abstract
Cycloruthenated complexes have been studied extensively over the last few decades. Many accounts of their synthesis, characterisation, and catalytic activity in a wide variety of transformations have been reported to date. Compared with their non-cyclometallated analogues, cycloruthenated complexes may display enhanced catalytic activities in known transformations or possess entirely new reactivity. In other instances, these complexes can be chiral, and capable of catalysing stereoselective reactions. In this review, we aim to highlight the catalytic applications of cycloruthenated complexes in organic synthesis, emphasising the recent advancements in this field. We discuss recent advances in the applications of cycloruthenated complexes in organic synthesis, comprising C–H activation, chiral-at-metal catalysis, Z-selective olefin metathesis, transfer hydrogenation, enantioselective cyclopropanations and cycloadditions.![]()
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Affiliation(s)
- Michael T Findlay
- School of Chemistry, University of Manchester Oxford Road Manchester M13 9PL UK
| | | | - Gillian McArthur
- School of Chemistry, University of Manchester Oxford Road Manchester M13 9PL UK
| | - Andy Yen
- School of Chemistry, University of Manchester Oxford Road Manchester M13 9PL UK
| | - Igor Larrosa
- School of Chemistry, University of Manchester Oxford Road Manchester M13 9PL UK
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7
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Dey P, Rai P, Maji B. Recent Development of Bis-Cyclometalated Chiral-at-Iridium and Rhodium Complexes for Asymmetric Catalysis. ACS ORGANIC & INORGANIC AU 2021; 2:99-125. [PMID: 36855455 PMCID: PMC9954445 DOI: 10.1021/acsorginorgau.1c00032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The field of asymmetric catalysis has been developing to access synthetically efficacious chiral molecules from the last century. Although there are many sustainable ways to produce nonracemic molecules, simplified and unique methodologies are always appreciated. In the recent developments of asymmetric catalysis, chiral-at-metal Lewis acid catalysis has been recognized as an attractive strategy. The catalysts coordinatively activate a substrate while serving the sole source of chirality by virtue of its helical environment. These configurationally stable complexes were utilized in a large number of asymmetric transformations, ranging from asymmetric Lewis acid catalysis to photoredox and electrocatalysis. Here we provide a comprehensive review of the current advancements in asymmetric catalysis utilizing iridium and rhodium-based chiral-at-metal complexes as catalysts. First, the asymmetric transformations via LUMO and HOMO activation assisted by a chiral Lewis acid catalyst are reviewed. In the second part, visible-light-induced asymmetric catalysis is summarized. The asymmetric transformation via the electricity-driven method is discussed in the final section.
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8
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Emelyanov MA, Stoletova NV, Smol'yakov AF, Il'in MM, Maleev VI, Larionov VA. Synthesis and a Catalytic Study of Diastereomeric Cationic Chiral-at-Cobalt Complexes Based on ( R, R)-1,2-Diphenylethylenediamine. Inorg Chem 2021; 60:13960-13967. [PMID: 34449202 DOI: 10.1021/acs.inorgchem.1c00855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Here we report the first synthesis of two diastereomeric cationic octahedral Co(III) complexes based on commercially available (R,R)-1,2-diphenylethylenediamine and salicylaldehyde. Both diastereoisomers with opposite chiralities at the metal center (Λ and Δ configurations) were prepared. The new Co(III) complexes possessed both acidic hydrogen-bond donating (HBD) NH moieties and nucleophilic counteranions and operate as bifunctional chiral catalysts for the challenging kinetic resolution of terminal and disubstituted epoxides by the reaction with CO2 under mild conditions. The highest selectivity factor (s) of 2.8 for the trans-chalcone epoxide was achieved at low catalyst loading (2 mol %) in chlorobenzene, which is the best achieved result currently for this type of substrate.
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Affiliation(s)
- Mikhail A Emelyanov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation
| | - Nadezhda V Stoletova
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation
| | - Alexander F Smol'yakov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation
| | - Mikhail M Il'in
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation
| | - Victor I Maleev
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation
| | - Vladimir A Larionov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, 119991 Moscow, Russian Federation.,Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya Str. 6, 117198 Moscow, Russian Federation
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9
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Asymmetric construction of tetrahedral chiral zinc with high configurational stability and catalytic activity. Nat Commun 2020; 11:6263. [PMID: 33298960 PMCID: PMC7726038 DOI: 10.1038/s41467-020-20074-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022] Open
Abstract
Chiral metal complexes show promise as asymmetric catalysts and optical materials. Chiral-at-metal complexes composed of achiral ligands have expanded the versatility and applicability of chiral metal complexes, especially for octahedral and half-sandwich complexes. However, Werner-type tetrahedral complexes with a stereogenic metal centre are rarely used as chiral-at-metal complexes because they are too labile to ensure the absolute configuration of the metal centre. Here we report the asymmetric construction of a tetrahedral chiral-at-zinc complex with high configurational stability, using an unsymmetric tridentate ligand. Coordination/substitution of a chiral auxiliary ligand on zinc followed by crystallisation yields an enantiopure chiral-only-at-zinc complex (> 99% ee). The enantiomer excess remains very high at 99% ee even after heating at 70 °C in benzene for one week. With this configurationally stable zinc complex of the tridentate ligand, the remaining one labile site on the zinc can be used for a highly selective asymmetric oxa-Diels-Alder reaction (98% yield, 87% ee) without substantial racemisation.
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10
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Ponomarenko NS, Kokhan O, Pokkuluri PR, Mulfort KL, Tiede DM. Examination of abiotic cofactor assembly in photosynthetic biomimetics: site-specific stereoselectivity in the conjugation of a ruthenium(II) tris(bipyridine) photosensitizer to a multi-heme protein. PHOTOSYNTHESIS RESEARCH 2020; 143:99-113. [PMID: 31925630 PMCID: PMC6989566 DOI: 10.1007/s11120-019-00697-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 12/02/2019] [Indexed: 05/18/2023]
Abstract
To understand design principles for assembling photosynthetic biohybrids that incorporate precisely-controlled sites for electron injection into redox enzyme cofactor arrays, we investigated the influence of chirality in assembly of the photosensitizer ruthenium(II)bis(2,2'-bipyridine)(4-bromomethyl-4'-methyl-2,2'-bipyridine), Ru(bpy)2(Br-bpy), when covalently conjugated to cysteine residues introduced by site-directed mutagenesis in the triheme periplasmic cytochrome A (PpcA) as a model biohybrid system. For two investigated conjugates that show ultrafast electron transfer, A23C-Ru and K29C-Ru, analysis by circular dichroism spectroscopy, CD, demonstrated site-specific chiral discrimination as a factor emerging from the close association between [Ru(bpy)3]2+ and heme cofactors. CD analysis showed the A23C-Ru and K29C-Ru conjugates to have distinct, but opposite, stereoselectivity for the Λ and Δ-Ru(bpy)2(Br-bpy) enantiomers, with enantiomeric excesses of 33.1% and 65.6%, respectively. In contrast, Ru(bpy)2(Br-bpy) conjugation to a protein site with high flexibility, represented by the E39C-Ru construct, exhibited a nearly negligible chiral selectivity, measured by an enantiomeric excess of 4.2% for the Λ enantiomer. Molecular dynamics simulations showed that site-specific stereoselectivity reflects steric constraints at the conjugating sites and that a high degree of chiral selectivity correlates to reduced structural disorder for [Ru(bpy)3]2+ in the linked assembly. This work identifies chiral discrimination as means to achieve site-specific, precise geometric positioning of introduced photosensitizers relative to the heme cofactors in manner that mimics the tuning of cofactors in photosynthesis.
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Affiliation(s)
- Nina S Ponomarenko
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
| | - Oleksandr Kokhan
- Department of Chemistry and Biochemistry, James Madison University, 901 Carrier Drive, Harrisonburg, VA, 22807, USA
| | - Phani R Pokkuluri
- Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Karen L Mulfort
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - David M Tiede
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
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11
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Cui T, Qin J, Harms K, Meggers E. Chiral-at-Ruthenium Catalyst with Sterically Demanding Furo[3,2-b
]pyridine Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201801362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tianjiao Cui
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Jie Qin
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Klaus Harms
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Eric Meggers
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
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12
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Cruchter T, Larionov VA. Asymmetric catalysis with octahedral stereogenic-at-metal complexes featuring chiral ligands. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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13
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Haghdoost MM, Zwettler N, Golbaghi G, Belaj F, Bagherzadeh M, Schachner JA, Mösch‐Zanetti NC. Diastereoselective Synthesis and Catalytic Activity of Two Chiral
cis
‐Dioxidomolybdenum(VI) Complexes. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
| | - Niklas Zwettler
- Institute of Chemistry University of Graz Schubertstr. 1 8010 Graz Austria
| | - Golara Golbaghi
- Chemistry Department Sharif University of Technology P.O. Box 11155 3615 Tehran Iran
| | - Ferdinand Belaj
- Institute of Chemistry University of Graz Schubertstr. 1 8010 Graz Austria
| | - Mojtaba Bagherzadeh
- Chemistry Department Sharif University of Technology P.O. Box 11155 3615 Tehran Iran
| | - Jörg A. Schachner
- Institute of Chemistry University of Graz Schubertstr. 1 8010 Graz Austria
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14
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Tan Y, Harms K, Meggers E. A Chiral‐at‐Metal Iridium Catalyst with Two Simple but Sterically Demanding Cyclometalated N‐Heterocyclic Carbene Ligands. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800450] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yuqi Tan
- Fachbereich Chemie Philipps‐Universität Marburg Hans‐Meerwein‐Straße 4 35043 Marburg Germany
| | - Klaus Harms
- Fachbereich Chemie Philipps‐Universität Marburg Hans‐Meerwein‐Straße 4 35043 Marburg Germany
| | - Eric Meggers
- Fachbereich Chemie Philipps‐Universität Marburg Hans‐Meerwein‐Straße 4 35043 Marburg Germany
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15
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Huang X, Lin J, Shen T, Harms K, Marchini M, Ceroni P, Meggers E. Asymmetric [3+2] Photocycloadditions of Cyclopropanes with Alkenes or Alkynes through Visible-Light Excitation of Catalyst-Bound Substrates. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201802316] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaoqiang Huang
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Jiahui Lin
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Tianqi Shen
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Klaus Harms
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Marianna Marchini
- Department of Chemistry “Giacomo Ciamician”; University of Bologna; 40126 Bologna Italy
| | - Paola Ceroni
- Department of Chemistry “Giacomo Ciamician”; University of Bologna; 40126 Bologna Italy
| | - Eric Meggers
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
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16
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Huang X, Lin J, Shen T, Harms K, Marchini M, Ceroni P, Meggers E. Asymmetric [3+2] Photocycloadditions of Cyclopropanes with Alkenes or Alkynes through Visible-Light Excitation of Catalyst-Bound Substrates. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/anie.201802316] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Xiaoqiang Huang
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Jiahui Lin
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Tianqi Shen
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Klaus Harms
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Marianna Marchini
- Department of Chemistry “Giacomo Ciamician”; University of Bologna; 40126 Bologna Italy
| | - Paola Ceroni
- Department of Chemistry “Giacomo Ciamician”; University of Bologna; 40126 Bologna Italy
| | - Eric Meggers
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Germany
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17
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Comparative studies on DNA-binding and in vitro antitumor activity of enantiomeric ruthenium(II) complexes. J Inorg Biochem 2018; 180:54-60. [DOI: 10.1016/j.jinorgbio.2017.11.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/31/2017] [Accepted: 11/26/2017] [Indexed: 02/07/2023]
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18
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Preparation of chiral-at-metal catalysts and their use in asymmetric photoredox chemistry. Nat Protoc 2018; 13:605-632. [PMID: 29494576 DOI: 10.1038/nprot.2017.138] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Asymmetric catalysis is a powerful approach for the synthesis of optically active compounds, and visible light constitutes an abundant source of energy to enable chemical transformations, which are often triggered by photoinduced electron transfer (photoredox chemistry). Recently, bis-cyclometalated iridium(III) and rhodium(III) complexes were introduced as a novel class of catalysts for combining asymmetric catalysis with visible-light-induced photoredox chemistry. These catalysts are attractive because of their unusual feature of chirality originating exclusively from a stereogenic metal center, which offers the prospect of an especially effective asymmetric induction upon direct coordination of the substrate to the metal center. As these chiral catalysts contain only achiral ligands, special strategies are required for their synthesis. In this protocol, we describe strategies for preparing two types of chiral-at-metal catalysts, namely the Λ- and Δ-enantiomers (left- and right-handed propellers, respectively) of the iridium complex IrS and the rhodium complex RhS. Both contain two cyclometalating 5-tert-butyl-2-phenylbenzothiazoles in addition to two acetonitrile ligands and a hexafluorophosphate counterion. The two cyclometalated ligands set the propeller-shaped chiral geometry, but the acetonitriles are labile and can be replaced by substrate molecules. The synthesis protocol consists of three stages: first, preparation of the ligand 5-tert-butyl-2-phenylbenzothiazole; second, preparation of salicylthiazoline (used for iridium) and salicyloxazoline (used for rhodium) chiral auxiliaries; and third, the auxiliary-mediated synthesis of the individual enantiopure Λ- and Δ-configured catalysts. This class of stereogenic-only-at-metal complexes is of substantial value in the field of asymmetric catalysis, offering stereocontrolled radical reactions based on visible-light-activated photoredox chemistry. Representative examples of visible-light-induced asymmetric catalysis are provided.
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20
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Bryliakov KP. Catalytic Asymmetric Oxygenations with the Environmentally Benign Oxidants H2O2 and O2. Chem Rev 2017; 117:11406-11459. [DOI: 10.1021/acs.chemrev.7b00167] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Konstantin P. Bryliakov
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
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21
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Zhang L, Meggers E. Stereogenic-Only-at-Metal Asymmetric Catalysts. Chem Asian J 2017; 12:2335-2342. [PMID: 28782915 DOI: 10.1002/asia.201700739] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/06/2017] [Indexed: 11/10/2022]
Abstract
Chirality is an essential feature of asymmetric catalysts. This review summarizes asymmetric catalysts that derive their chirality exclusively from stereogenic metal centers. Reported chiral-at-metal catalysts can be divided into two classes, namely, inert metal complexes, in which the metal fulfills a purely structural role, so catalysis is mediated entirely through the ligand sphere, and reactive metal complexes. The latter are particularly appealing because structural simplicity (only achiral ligands) is combined with the prospect of particularly effective asymmetric induction (direct contact of the substrate with the chiral metal center). Challenges and solutions for the design of such reactive stereogenic-only-at-metal asymmetric catalysts are discussed.
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Affiliation(s)
- Lilu Zhang
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043, Marburg, Germany
| | - Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043, Marburg, Germany
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22
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Meggers E. Ausnutzung oktaedrischer Stereozentren: von Enzymhemmung bis hin zu asymmetrischer Photoredoxkatalyse. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612516] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Eric Meggers
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 4 35043 Marburg Deutschland
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23
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Meggers E. Exploiting Octahedral Stereocenters: From Enzyme Inhibition to Asymmetric Photoredox Catalysis. Angew Chem Int Ed Engl 2017; 56:5668-5675. [DOI: 10.1002/anie.201612516] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg; Hans-Meerwein-Strasse 4 35043 Marburg Germany
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24
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Octahedral Ruthenium Complex with Exclusive Metal-Centered Chirality for Highly Effective Asymmetric Catalysis. J Am Chem Soc 2017; 139:4322-4325. [PMID: 28290685 DOI: 10.1021/jacs.7b01098] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A novel ruthenium catalyst is introduced which contains solely achiral ligands and acquires its chirality entirely from octahedral centrochirality. The configurationally stable catalyst is demonstrated to catalyze the alkynylation of trifluoromethyl ketones with very high enantioselectivity (up to >99% ee) at low catalyst loadings (down to 0.2 mol%).
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25
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Zhang L, Meggers E. Steering Asymmetric Lewis Acid Catalysis Exclusively with Octahedral Metal-Centered Chirality. Acc Chem Res 2017; 50:320-330. [PMID: 28128920 DOI: 10.1021/acs.accounts.6b00586] [Citation(s) in RCA: 233] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Catalysts for asymmetric synthesis must be chiral. Metal-based asymmetric catalysts are typically constructed by assembling chiral ligands around a central metal. In this Account, a new class of effective chiral Lewis acid catalysts is introduced in which the octahedral metal center constitutes the exclusive source of chirality. Specifically, the here discussed class of catalysts are composed of configurationally stable, chiral-at-metal Λ-configured (left-handed propeller) or Δ-configured (right-handed propeller) iridium(III) or rhodium(III) complexes containing two bidentate cyclometalating 5-tert-butyl-2-phenylbenzoxazole (dubbed IrO and RhO) or 5-tert-butyl-2-phenylbenzothiazole (dubbed IrS and RhS) ligands in addition to two exchange-labile acetonitriles. They are synthetically accessible in an enantiomerically pure fashion through a convenient auxiliary-mediated synthesis. Such catalysts are of interest due to their intrinsic structural simplicity (only achiral ligands) and the prospect of an especially effective asymmetric induction due to the intimate contact between the chiral metal center and the metal-coordinated substrates or reagents. With respect to chiral Lewis acid catalysis, the bis-cyclometalated iridium and rhodium complexes provide excellent catalytic activities and asymmetric inductions for a variety of reactions including Michael additions, Friedel-Crafts reactions, cycloadditions, α-aminations, α-fluorinations, Mannich reactions, and a cross-dehydrogenative coupling. Mechanistically, substrates such as 2-acyl imidazoles are usually activated by two-point binding. Exceptions exist as for example for an efficient iridium-catalyzed enantioselective transfer hydrogenation of arylketones with ammonium formate, which putatively proceeds through an iridium-hydride intermediate. The bis-cyclometalated iridium complexes catalyze visible-light-induced asymmetric reactions by intertwining asymmetric catalysis and photoredox catalysis in a unique fashion. This has been applied to the visible-light-induced α-alkylation of 2-acyl imidazoles (and in some instances 2-acylpyridines) with acceptor-substituted benzyl, phenacyl, trifluoromethyl, perfluoroalkyl, and trichloromethyl groups, in addition to photoinduced oxidative α-aminoalkylations and a photoinduced stereocontrolled radical-radical coupling, each employing a single iridium complex. In all photoinduced reaction schemes, the iridium complex serves as a chiral Lewis acid catalyst and at the same time as precursor of in situ assembled photoactive species. The nature of these photoactive intermediates then determines their photochemical properties and thereby the course of the asymmetric photoredox reactions. The bis-cyclometalated rhodium complexes are also very useful for asymmetric photoredox catalysis. Less efficient photochemical properties are compensated with a more rapid ligand exchange kinetics, which permits higher turnover frequencies of the catalytic cycle. This has been applied to a visible-light-induced enantioselective radical α-amination of 2-acyl imidazoles. In this reaction, an intermediate rhodium enolate is supposed to function as a photoactivatable smart initiator to initiate and reinitiate an efficient radical chain process. If a more efficient photoactivation is required, a rhodium-based Lewis acid can be complemented with a photoredox cocatalyst, and this has been applied to efficient catalytic asymmetric alkyl radical additions to acceptor-substituted alkenes. We believe that this class of chiral-only-at-metal Lewis acid catalysts will be of significant value in the field of asymmetric synthesis, in particular in combination with visible-light-induced redox chemistry, which has already resulted in novel strategies for asymmetric synthesis of chiral molecules. Hopefully, this work will also pave the way for the development of other asymmetric catalysts featuring exclusively octahedral centrochirality.
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Affiliation(s)
- Lilu Zhang
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
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26
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Deng T, Thota GK, Li Y, Kang Q. Enantioselective conjugate addition of hydroxylamines to α,β-unsaturated 2-acyl imidazoles catalyzed by a chiral-at-metal Rh(iii) complex. Org Chem Front 2017. [DOI: 10.1039/c6qo00865h] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A highly efficient chiral-at-metal Rh(iii) complex catalyzed asymmetric aza-Michael addition was developed, affordingN-protected β-amino acid derivatives with excellent enantioselectivity.
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Affiliation(s)
- Tao Deng
- Department of Chemistry
- Fuzhou University
- P. R. China
| | - Ganesh Kumar Thota
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou
- P. R. China
| | - Yi Li
- Department of Chemistry
- Fuzhou University
- P. R. China
| | - Qiang Kang
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou
- P. R. China
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27
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Carmona M, Rodríguez R, Méndez I, Passarelli V, Lahoz FJ, García-Orduña P, Carmona D. Stereospecific control of the metal-centred chirality of rhodium(iii) and iridium(iii) complexes bearing tetradentate CNN′P ligands. Dalton Trans 2017; 46:7332-7350. [DOI: 10.1039/c7dt01446e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Complexes of formula [MCl2(κ4C,N,N′,P-L)] (M = Rh, Ir) were diastereoselectively obtained with predetermined absolute configuration from MCl3·xH2O and tripodal tetradentate ligands.
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Affiliation(s)
- María Carmona
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Ricardo Rodríguez
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Isabel Méndez
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Vincenzo Passarelli
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Fernando J. Lahoz
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Pilar García-Orduña
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
| | - Daniel Carmona
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC – Universidad de Zaragoza
- Departamento de Química Inorgánica
- 50009 Zaragoza
- Spain
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28
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Humbert N, Mazet C. The diastereoselective synthesis of octahedral cationic iridium hydride complexes with a stereogenic metal centre. Chem Commun (Camb) 2016; 52:10629-31. [PMID: 27498763 DOI: 10.1039/c6cc06020j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report herein the highly diastereoselective synthesis of octahedral cationic Ir(iii) hydride complexes with a stereogenic metal centre following various strategies. The configurational stability of these compounds has also been investigated.
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Affiliation(s)
- Nicolas Humbert
- Department of Organic Chemistry, University of Geneva, 30 quai Ernest Ansermet, 1211 Geneva, Switzerland.
| | - Clément Mazet
- Department of Organic Chemistry, University of Geneva, 30 quai Ernest Ansermet, 1211 Geneva, Switzerland.
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29
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Li ZZ, Yao SY, Wen AH, Ye BH. Asymmetric Oxidation Synthesis of Modafinil Acid by Use of a Recyclable Chiral-at-Metal Complex. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500617] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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30
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Hazari AS, Das A, Ray R, Agarwala H, Maji S, Mobin SM, Lahiri GK. Tunable Electrochemical and Catalytic Features of BIAN- and BIAO-Derived Ruthenium Complexes. Inorg Chem 2015; 54:4998-5012. [PMID: 25928272 DOI: 10.1021/acs.inorgchem.5b00615] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article deals with a class of ruthenium-BIAN-derived complexes, [Ru(II)(tpm)(R-BIAN)Cl]ClO4 (tpm = tris(1-pyrazolyl)methane, R-BIAN = bis(arylimino)acenaphthene, R = 4-OMe ([1a]ClO4), 4-F ([1b]ClO4), 4-Cl ([1c]ClO4), 4-NO2 ([1d]ClO4)) and [Ru(II)(tpm)(OMe-BIAN)H2O](2+) ([3a](ClO4)2). The R-BIAN framework with R = H, however, leads to the selective formation of partially hydrolyzed BIAO ([N-(phenyl)imino]acenapthenone)-derived complex [Ru(II)(tpm)(BIAO)Cl]ClO4 ([2]ClO4). The redox-sensitive bond parameters involving -N═C-C═N- or -N═C-C═O of BIAN or BIAO in the crystals of representative [1a]ClO4, [3a](PF6)2, or [2]ClO4 establish its unreduced form. The chloro derivatives 1a(+)-1d(+) and 2(+) exhibit one oxidation and successive reduction processes in CH3CN within the potential limit of ±2.0 V versus SCE, and the redox potentials follow the order 1a(+) < 1b(+) < 1c(+) < 1d(+) ≈ 2(+). The electronic structural aspects of 1a(n)-1d(n) and 2(n) (n = +2, +1, 0, -1, -2, -3) have been assessed by UV-vis and EPR spectroelectrochemistry, DFT-calculated MO compositions, and Mulliken spin density distributions in paramagnetic intermediate states which reveal metal-based (Ru(II) → Ru(III)) oxidation and primarily BIAN- or BIAO-based successive reduction processes. The aqua complex 3a(2+) undergoes two proton-coupled redox processes at 0.56 and 0.85 V versus SCE in phosphate buffer (pH 7) corresponding to {Ru(II)-H2O}/{Ru(III)-OH} and {Ru(III)-OH}/{Ru(IV)═O}, respectively. The chloro (1a(+)-1d(+)) and aqua (3a(2+)) derivatives are found to be equally active in functioning as efficient precatalysts toward the epoxidation of a wide variety of alkenes in the presence of PhI(OAc)2 as oxidant in CH2Cl2 at 298 K, though the analogous 2(+) remains virtually inactive. The detailed experimental analysis with the representative precatalyst 1a(+) suggests the involvement of the active {Ru(IV)═O} species in the catalytic cycle, and the reaction proceeds through the radical mechanism, as also supported by the DFT calculations.
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Affiliation(s)
- Arijit Singha Hazari
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Ankita Das
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Ritwika Ray
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Hemlata Agarwala
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Somnath Maji
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Shaikh M Mobin
- ‡Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore, Indore 452017, India
| | - Goutam Kumar Lahiri
- †Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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31
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Iza N, Guerrero-Martínez A, Tardajos G, Ortiz MJ, Palao E, Montoro T, Radulescu A, Dreiss CA, González-Gaitano G. Using inclusion complexes with cyclodextrins to explore the aggregation behavior of a ruthenium metallosurfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2677-2688. [PMID: 25672530 DOI: 10.1021/la504929x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aggregation behavior of a chiral metallosurfactant, bis(2,2'-bipyridine)(4,4'-ditridecyl-2,2'-bipyridine)ruthenium(II) dichloride (Ru2(4)C13), synthesized as a racemic mixture was characterized by small-angle neutron scattering, light scattering, NMR, and electronic spectroscopies. The analysis of the SANS data indicates that micelles are prolate ellipsoids over the range of concentrations studied, with a relatively low aggregation number, and the micellization takes place gradually with increasing concentration. The presence of cyclodextrins (β-CD and γ-CD) induces the breakup of the micelles and helps to establish that micellization occurs at a very slow exchange rate compared to the NMR time scale. The open structure of this metallosurfactant enables the formation of very stable complexes of 3:1 stoichiometry, in which one CD threads one of the hydrocarbon tails and two CDs the other, in close contact with the polar head. The complex formed with β-CD, more stable than the one formed with the wider γ-CD, is capable of resolving the Δ and Λ enantiomers at high CD/surfactant molar ratios. The chiral recognition is possible due to the very specific interactions taking place when the β-CD covers-via its secondary rim-part of the diimine moiety connected to the hydrophobic tails. A SANS model comprising a binary mixture of hard spheres (complex + micelles) was successfully used to study quantitatively the effect of the CDs on the aggregation of the surfactant.
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Affiliation(s)
- Nerea Iza
- Departamento de Química Física I, and ‡Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid , Ciudad Universitaria s/n, Madrid 28040, Spain
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32
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Li ZZ, Wen AH, Yao SY, Ye BH. Enantioselective Syntheses of Sulfoxides in Octahedral Ruthenium(II) Complexes via a Chiral-at-Metal Strategy. Inorg Chem 2015; 54:2726-33. [DOI: 10.1021/ic502898e] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Zheng-Zheng Li
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry,
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - A-Hao Wen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry,
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Su-Yang Yao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry,
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Bao-Hui Ye
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry,
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
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33
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Wang C, Chen LA, Huo H, Shen X, Harms K, Gong L, Meggers E. Asymmetric Lewis acid catalysis directed by octahedral rhodium centrochirality. Chem Sci 2015; 6:1094-1100. [PMID: 29560197 PMCID: PMC5811158 DOI: 10.1039/c4sc03101f] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 11/07/2014] [Indexed: 01/10/2023] Open
Abstract
A rhodium-based asymmetric catalyst is introduced which derives its optical activity from octahedral centrochirality. Besides providing the exclusive source of chirality, the rhodium center serves as a Lewis acid by activating 2-acyl imidazoles through two point binding and enabling a very effective asymmetric induction mediated by the propeller-like C2-symmetrical ligand sphere. Applications to asymmetric Michael additions (electrophile activation) as well as asymmetric α-aminations (nucleophile activation) are disclosed, for which the rhodium catalyst is found to be overall superior to its iridium congener. Due to its straightforward proline-mediated synthesis, high catalytic activity (catalyst loadings down to 0.1 mol%), and tolerance towards moisture and air, this novel class of chiral-at-rhodium catalysts will likely to become of widespread use as chiral Lewis acid catalysts for a large variety of asymmetric transformations.
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Affiliation(s)
- Chuanyong Wang
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße , 35043 Marburg , Germany .
| | - Liang-An Chen
- Department of Chemical Biology and Key Laboratory for Chemical Biology of Fujian Province , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , People's Republic of China
| | - Haohua Huo
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße , 35043 Marburg , Germany .
| | - Xiaodong Shen
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße , 35043 Marburg , Germany .
| | - Klaus Harms
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße , 35043 Marburg , Germany .
| | - Lei Gong
- Department of Chemical Biology and Key Laboratory for Chemical Biology of Fujian Province , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , People's Republic of China
| | - Eric Meggers
- Fachbereich Chemie , Philipps-Universität Marburg , Hans-Meerwein-Straße , 35043 Marburg , Germany .
- Department of Chemical Biology and Key Laboratory for Chemical Biology of Fujian Province , College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , People's Republic of China
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34
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Cao ZY, Brittain WDG, Fossey JS, Zhou F. Recent advances in the use of chiral metal complexes with achiral ligands for application in asymmetric catalysis. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00182j] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent progress in asymmetric catalysis using chiral only-at-metal complexes is reviewed, with emphasis on Ir(iii) and Rh(iii) systems.
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Affiliation(s)
- Zhong-Yan Cao
- Department of Chemistry
- East China Normal University 3663N
- Shanghai 200062
- China
| | | | | | - Feng Zhou
- Department of Chemistry
- East China Normal University 3663N
- Shanghai 200062
- China
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35
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Wang C, Lu Z. Catalytic enantioselective organic transformations via visible light photocatalysis. Org Chem Front 2015. [DOI: 10.1039/c4qo00306c] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Enantioselective transformations via visible light photocatalysis are discussed and could have a strong impact on asymmetric photoreactions.
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Affiliation(s)
| | - Zhan Lu
- Department of chemistry
- Zhejiang University
- Hangzhou
- China
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36
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Li Z, Yao S, Ye B. Enantioselective Oxidation of Thioethers to Sulfoxides by Means of a Structural Template with Chiral‐at‐Metal Ruthenium Complexes. Chempluschem 2014. [DOI: 10.1002/cplu.201402243] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Zheng‐Zheng Li
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat‐Sen University, Guangzhou 510275 (P. R. China), Fax: (+86) 20 84112245
| | - Su‐Yang Yao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat‐Sen University, Guangzhou 510275 (P. R. China), Fax: (+86) 20 84112245
| | - Bao‐Hui Ye
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat‐Sen University, Guangzhou 510275 (P. R. China), Fax: (+86) 20 84112245
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37
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Gong L, Chen LA, Meggers E. Asymmetric catalysis mediated by the ligand sphere of octahedral chiral-at-metal complexes. Angew Chem Int Ed Engl 2014; 53:10868-74. [PMID: 25156957 DOI: 10.1002/anie.201404305] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Indexed: 12/13/2022]
Abstract
Due to the relationship between structure and function in chemistry, access to novel chemical structures ultimately drives the discovery of novel chemical function. In this light, the formidable utility of the octahedral geometry of six-coordinate metal complexes is founded in its stereochemical complexity combined with the ability to access chemical space that might be unavailable for purely organic compounds. In this Minireview we wish to draw attention to inert octahedral chiral-at-metal complexes as an emerging class of metal-templated asymmetric "organocatalysts" which exploit the globular, rigid nature and stereochemical options of octahedral compounds and promise to provide new opportunities in the field of catalysis.
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Affiliation(s)
- Lei Gong
- Key Laboratory for Chemical Biology of Fujian Province and Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (P.R. China)
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38
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Gong L, Chen LA, Meggers E. Asymmetrische Katalyse über die Ligandensphäre von oktaedrischen Komplexen mit chiralem Metallzentrum. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201404305] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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39
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Metal-templated chiral Brønsted base organocatalysis. Nat Commun 2014; 5:4531. [DOI: 10.1038/ncomms5531] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 06/26/2014] [Indexed: 11/08/2022] Open
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40
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Huo H, Fu C, Harms K, Meggers E. Asymmetric Catalysis with Substitutionally Labile yet Stereochemically Stable Chiral-at-Metal Iridium(III) Complex. J Am Chem Soc 2014; 136:2990-3. [DOI: 10.1021/ja4132505] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Haohua Huo
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
| | - Chen Fu
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
| | - Klaus Harms
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
| | - Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
- College
of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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41
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Li ZZ, Yao SY, Wu JJ, Ye BH. In situ generation of sulfoxides with predetermined chirality via a structural template with a chiral-at-metal ruthenium complex. Chem Commun (Camb) 2014; 50:5644-7. [DOI: 10.1039/c4cc01907e] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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42
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Chen LA, Tang X, Xi J, Xu W, Gong L, Meggers E. Chiral-at-Metal Octahedral Iridium Catalyst for the Asymmetric Construction of an All-Carbon Quaternary Stereocenter. Angew Chem Int Ed Engl 2013; 52:14021-5. [DOI: 10.1002/anie.201306997] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/09/2013] [Indexed: 12/12/2022]
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43
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Chen LA, Tang X, Xi J, Xu W, Gong L, Meggers E. Chiral-at-Metal Octahedral Iridium Catalyst for the Asymmetric Construction of an All-Carbon Quaternary Stereocenter. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201306997] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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44
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Srour H, Le Maux P, Chevance S, Simonneaux G. Metal-catalyzed asymmetric sulfoxidation, epoxidation and hydroxylation by hydrogen peroxide. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.05.010] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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45
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Kraack M, Harms K, Meggers E. Reductive Labilization of a Cyclometalating Ligand Applied to Auxiliary-Mediated Asymmetric Coordination Chemistry. Organometallics 2013. [DOI: 10.1021/om4006627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marianne Kraack
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
| | - Klaus Harms
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
| | - Eric Meggers
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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46
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Chen LA, Xu W, Huang B, Ma J, Wang L, Xi J, Harms K, Gong L, Meggers E. Asymmetric catalysis with an inert chiral-at-metal iridium complex. J Am Chem Soc 2013; 135:10598-601. [PMID: 23672419 DOI: 10.1021/ja403777k] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
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.
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Affiliation(s)
- Liang-An Chen
- Fujian Provincial Key Laboratory of Chemical Biology, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
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47
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Seo MS, Kim K, Kim H. Controlling helical chirality of cobalt complexes by chirality transfer from vicinal diamines. Chem Commun (Camb) 2013; 49:11623-5. [DOI: 10.1039/c3cc46887a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Wenzel M, Meggers E. Chiral (Mercaptophenyl)oxazolines as Auxiliaries for Asymmetric Coordination Chemistry. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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49
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Türkoglu G, Tampier S, Strinitz F, Heinemann FW, Hübner E, Burzlaff N. Ruthenium Carbonyl Complexes Bearing Bis(pyrazol-1-yl)carboxylato Ligands. Organometallics 2012. [DOI: 10.1021/om2009155] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gazi Türkoglu
- Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Stefan Tampier
- Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Frank Strinitz
- Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Frank W. Heinemann
- Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Eike Hübner
- Organic
Chemistry, Technical University Clausthal, Leibnizstraße 6, 38678 Clausthal-Zellerfeld,
Germany
| | - Nicolai Burzlaff
- Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), University of Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
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50
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Bauer EB. Chiral-at-metal complexes and their catalytic applications in organic synthesis. Chem Soc Rev 2012; 41:3153-67. [PMID: 22306968 DOI: 10.1039/c2cs15234g] [Citation(s) in RCA: 204] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This tutorial review provides an introduction to the synthesis and characterization of chiral-at-metal complexes and their catalytic application in organic transformations. The synthetic access to these architectures either via chiral resolution or by employment of chiral ligands is described, characterization techniques for the complexes are referenced and the application of the R/S nomenclature is explained. Racemization and epimerization processes are often observed for the title compounds; the article gives mechanistic insights to these processes and describes how to recognize and document them. Finally, key catalytic applications in organic synthesis are presented and how the molecular architectures of the chiral-at-metal complexes lead to stereodifferentiation and, thus to enantiomeric excesses in the products.
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Affiliation(s)
- Eike B Bauer
- University of Missouri-St. Louis, Department of Chemistry and Biochemistry, One University Boulevard, St. Louis, MO 63121, USA.
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