Catalytic Asymmetric C–H Arylation of (η<sup>6</sup>-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines

Batuecas, M.T.; Luo, Junfei; Gergelitsová, Ivana; Krämer, Katrina; Whitaker, Daniel; Vitórica-Yrezábal, Iñigo J.; Larrosa, Igor

doi:10.1021/acscatal.9b00918

Cited by 44 publications

(28 citation statements)

References 146 publications

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“…H 8 -BINAPO ( L11 ) performed best in terms of selectivity (95:5 er ) and reactivity (79% yield) (entry 12). This finding correlates with the very recently reported results from Larrosa on Pd(0)-catalyzed arylations of (η 6 -arene)chromium complexes . The observed enantioselectivity roughly correlates to the dihedral angle θ of the ligand, with a larger θ providing a higher enantioselectivity (Figure S1).…”

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confidence: 90%

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

et al. 2020

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General Methods Experimental Procedures, Reagents and Glassware All commercially available chemicals were used as purchased for the synthesis of substrates. All reactions were carried out under an atmosphere of nitrogen in oven-dried glassware with magnetic stirring, unless otherwise indicated. Acetonitrile (MeCN) was dried over CaH2, distilled and stored inside the N2-filled glovebox. Toluene, THF and dichloromethane were purified by the Innovative Technology Solvent Delivery System. Chemicals were used as obtained from the suppliers unless otherwise stated. Solvent compositions are given in (v/v). Chromatography Flash chromatography was performed with Silicycle silica gel 60 (0.040-0.063 μm grade). Analytical thin-layer chromatography was performed with commercial glass plates coated with 0.25 mm silica gel (E. Merck, Kieselgel 60 F254). Compounds were visualized under UV-light at 254 nm and oxidized in standard KMnO4 dye followed by heating if necessary. NMR Spectroscopy Proton nuclear magnetic resonance (1 H NMR) data were acquired at 400 MHz on a Bruker AVANCEIII-400 spectrometer or at 600 MHz on a Bruker DRX-600 spectrometer. Chemical shifts (δ) are reported in parts per million (ppm) relative to residual chloroform (s, 7.26 ppm) or residual acetone (2.05 ppm). Proton decoupled Carbon-13 nuclear magnetic resonance (13 C NMR) data were acquired at 101 MHz or 126 MHz on a Bruker AVANCEIII-400. Chemical shifts are reported in ppm relative to residual chloroform (77.16 ppm) or residual acetone (29.84 ppm, 206.26 ppm). Proton decoupled Fluorine-19 nuclear magnetic resonance (19 F{ 1 H} NMR) were acquired at 377 MHz on a Bruker AV400 spectrometer. Proton decoupled Phosphorus-31 nuclear magnetic resonance (31P{1H} NMR) were acquired at 162 MHz on a Bruker AV400 spectrometer. The assignment of proton and carbon signals was assisted by COSY, HSQC, HMBC and DEPT-135 experiments where necessary. Splitting patterns are designated as s, singlet; d, doublet; t, triplet; q, quartet; p, pentet; hept, heptet; dd, doublet of doublets; dt, doublet of triplets; ddd, doublet of doublets of doublets; tt, triplet of triplets; tq, triplet of quartets; qt, quartet of triplets; m, multiplet. All NMR data were recorded at 298 K. Infrared Spectroscopy Infrared (IR) data were recorded on an Alpha-P Bruker FT-IR Spectrometer. Absorbance frequencies are reported in reciprocal centimeters (cm-1). Mass Spectrometry HRMS measurements were performed on an Agilent LC-MS TOF (Multimode: ESI + APCI + APPI). High resolution mass are given in m/z. Melting Points Melting points were measured on a Büchi B-540 and are uncorrected. Enantiomeric excesses Enantiomeric excesses were measured on an Agilent HPLC and Shimadzu HPLC. Optical rotations were measured on a Polartronic M polarimeter using a 0.5 cm cell with a Na 589 nm filter.

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confidence: 90%

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

et al. 2020

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“…To minimize this energetic penalty, solvents of relatively low dielectric constant are often used, which can present solubility challenges when cationic/anionic charges are used to generate the electric field. In the early 1990s, Wilcox and co-workers demonstrated the electrostatic acceleration of chemical reactions in nonpolar solvents using intramolecular salt effects. − Ion-pairing in transition metal complexes has been used to achieve regioselectivity either through directed substrate–ligand interactions, − steric adjustment, or energetic differentiation of transition states. − Cation-π interactions have also been utilized to increase the acidity of select C–H bonds; however, this is more of an inductive effect, allowing for site-selective bond activation. , …”

Section: Synthetic Systemsmentioning

confidence: 99%

Electric Fields in Catalysis: From Enzymes to Molecular Catalysts

et al. 2021

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Electric fields underlie all reactions and impact reactivity by interacting with the dipoles and net charges of transition states, products, and reactants to modify the free energy landscape. However, they are rarely given deliberate consideration in synthetic design to rationally control reactivity. This Perspective discusses the commonalities of electric field effects across multiple platforms, from enzymes to molecular catalysts, and identifies practical challenges to applying them in synthetic molecular systems to mediate reactivity.

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“…In 2019, Larrosa and co‐workers reported the first Pd 0 ‐catalyzed intermolecular enantioselective C−H functionalization of metallocenes (Scheme 39). [102] Prochiral (η 6 ‐arene)chromium complexes 87 underwent enantioselective C−H arylation with aryl iodides in the presence of a chiral BPMO ligand to provide planar chiral compounds. During the optimization of the reaction conditions, it was found that Segphos, possessing a smaller bite angle than BINAP, led to a decreased enantioselectivity.…”

Section: Bidentate and Hemilabile Ligandsmentioning

confidence: 99%

Chiral Catalysts for Pd⁰‐Catalyzed Enantioselective C−H Activation

Vyhivskyi

Kudashev

Miyakoshi

et al. 2020

Chemistry A European J

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In the past few decades, processes that involve transition-metal catalysis have represented am ajor parto f the synthetic chemist'st oolbox. Recently,t he interesth as shifted from the well-established cross-coupling reactions to CÀHb ond functionalization, thus making it ac urrent frontier of transition-metal-catalyzed reactions. Constant progress in this field has led to the discoveryo fe nantioselective methods to generate and control various types of stereogenic elements, thereby demonstrating its high value to generate scalemic chiral molecules.The present review is dedicated to enantioselective Pd 0-catalyzed CÀHa ctivation,w hich may be considered as an evolution of Pd 0-catalyzed cross-couplings, with af ocus on the different chiral ligands and catalysts that enable theset ransformations.

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Catalytic Asymmetric C–H Arylation of (η⁶-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines

Cited by 44 publications

References 146 publications

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

Electric Fields in Catalysis: From Enzymes to Molecular Catalysts

Chiral Catalysts for Pd⁰‐Catalyzed Enantioselective C−H Activation

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Catalytic Asymmetric C–H Arylation of (η6-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines

Cited by 44 publications

References 146 publications

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

Intermolecular Palladium(0)-Catalyzed Atropo-enantioselective C–H Arylation of Heteroarenes

Electric Fields in Catalysis: From Enzymes to Molecular Catalysts

Chiral Catalysts for Pd0‐Catalyzed Enantioselective C−H Activation

Contact Info

Product

Resources

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Catalytic Asymmetric C–H Arylation of (η⁶-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines

Chiral Catalysts for Pd⁰‐Catalyzed Enantioselective C−H Activation