Enantioselective Iridium-Catalyzed Allylic Cyclizations

Organic Letters, Journal Year: 2017, Volume and Issue: 19(12), P. 3235 - 3238

Published: June 2, 2017

A method for the enantioselective synthesis of carbo- and heterocyclic ring systems enabled through combination Lewis acid activation iridium-catalyzed allylic substitution is described. The reaction proceeds with branched, alcohols carbon nucleophiles as well heteronucleophiles to give a diverse set in good yields high enantioselectivities. utility highlighted by asymmetric syntheses erythrococcamides B.

Language: Английский

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Iridium-Catalyzed Intramolecular Asymmetric Allylic Alkylation of Hydroxyquinolines: Simultaneous Weakening of the Aromaticity of Two Consecutive Aromatic Rings

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(8), P. 3114 - 3119

Published: Feb. 12, 2018

Intramolecular asymmetric allylic alkylation reactions of 5- and 7-hydroxyquinoline derivatives were realized by a chiral Ir/NHC catalyst. A series functionalized cyclic enones afforded in excellent yields (up to 99%) high enantioselectivity 97% ee). Theoretical computations revealed that the aromaticity two consecutive rings hydroxyquinoline substrates is significantly weakened. highly efficient formal synthesis (-)-gephyrotoxin was accomplished based on this method.

Language: Английский

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Regio‐ and Enantioselective Iridium‐Catalyzed N‐Allylation of Indoles and Related Azoles with Racemic Branched Alkyl‐Substituted Allylic Acetates

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(23), P. 7762 - 7766

Published: April 9, 2019

Abstract Cyclometallated π‐allyliridium C,O‐benzoates modified with ( S )‐tol‐BINAP, which are stable to air, water, and SiO 2 , catalyze highly enantioselective N‐allylations of indoles related azoles. This reaction complements previously reported metal‐catalyzed indole allylations in that complete levels N versus C3 branched linear regioselectivity observed.

Language: Английский

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Advancing Heterogeneous Organic Synthesis With Coordination Chemistry‐Empowered Single‐Atom Catalysts

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

Abstract For traditional metal complexes, intricate chemistry is required to acquire appropriate ligands for controlling the electron and steric hindrance of active centers. Comparatively, preparation single‐atom catalysts much easier with more straightforward effective accesses arrangement control The presence coordination atoms or neighboring functional on supports' surface ensures stability single‐atoms their interactions individual substantially regulate performance Therefore, collaborative interaction between surrounding environment enhances initiation reaction substrates formation transformation crucial intermediate compounds, which imparts significant catalytic efficacy, rendering them a valuable framework investigating correlation structure activity, as well mechanism in organic reactions. Herein, comprehensive overviews both homogeneous complexes reactions are provided. Additionally, reflective conjectures about advancement synthesis also proposed present reference later development.

Language: Английский

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Recent Advances in the Chemistry of N‐Heterocyclic‐Carbene‐Functionalized Metal‐Nanoparticles and Their Applications

Chinese Journal of Chemistry, Journal Year: 2018, Volume and Issue: 37(1), P. 76 - 87

Published: Nov. 15, 2018

Metal‐nanoparticles (M‐NPs) have been widely applied in catalysis, imaging, sensing and medicine. One particularly active area of this research is the modification surface nanoparticles to prevent aggregation through coordination ligands. N‐Heterocyclic carbenes (NHCs) emerged as suitable ligands for purpose due their affinity metals strongly electron donating nature. A number rationally designed NHC‐modified M‐NPs developed using strategies based on metal complex decomposition ligand exchange. Herein, NHC‐stabilized a range transition metals, especially recent advances, were summarized.

Language: Английский

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Amphiphilic π-Allyliridium C,O-Benzoates Enable Regio- and Enantioselective Amination of Branched Allylic Acetates Bearing Linear Alkyl Groups

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(4), P. 1275 - 1279

Published: Jan. 19, 2018

The first examples of amphiphilic reactivity in the context enantioselective catalysis are described. Commercially available π-allyliridium C,O-benzoates, which stable to air, water and SiO2 chromatography, well-known catalyze allyl acetate-mediated carbonyl allylation, now shown highly chemo-, regio- substitutions branched allylic acetates bearing linear alkyl groups with primary amines.

Language: Английский

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Regio- and Enantioselective Iridium-Catalyzed Amination of Racemic Branched Alkyl-Substituted Allylic Acetates with Primary and Secondary Aromatic and Heteroaromatic Amines

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 141(1), P. 671 - 676

Published: Dec. 20, 2018

The air- and water-stable π-allyliridium C,O-benzoate modified by (S)-tol-BINAP, (S)-Ir-II, catalyzes highly regio- enantioselective Tsuji–Trost-type aminations of racemic branched alkyl-substituted allylic acetates using primary or secondary (hetero)aromatic amines. Specifically, in the presence (S)-Ir-II (5 mol%) DME solvent at 60–70 °C, α-methyl allyl acetate 1a (100 reacts with amines 2a–2l (200 3a–3l to form products amination 4a–4l 5a–5l, respectively, as single regioisomers good excellent yield uniformly high levels enantioselectivity. As illustrated conversion heteroaromatic amine 3m adducts 6a–6g, enantioselectivity are retained across diverse bearing normal alkyl substituents. For reactants 3n-3p, which incorporate both aryl moieties, occurs complete site-selectivity furnish 7a–7c. Mechanistic studies involving enantiomerically enriched, deuterium-labeled 1h corroborate C–N bond formation via outer-sphere addition.

Language: Английский

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Iridium complexes with monodentate N-heterocyclic carbene ligands

Coordination Chemistry Reviews, Journal Year: 2017, Volume and Issue: 375, P. 13 - 68

Published: Dec. 27, 2017

Language: Английский

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Facile synthesis of chiral [2,3]-fused hydrobenzofuran via asymmetric Cu(i)-catalyzed dearomative 1,3-dipolar cycloaddition

Chemical Communications, Journal Year: 2018, Volume and Issue: 55(4), P. 553 - 556

Published: Dec. 10, 2018

Intermolecular asymmetric dearomative 1,3-dipolar cycloaddition of 2-nitrobenzofurans with azomethine ylides was enabled by using a chiral Cu(i)/(S,Sp)-iPr-Phosferrox catalyst. As result, series highly stereoselective [2,3]-fused hydrobenzofurans possessing four contiguous stereogenic centers were obtained good to high yields, diastereoselectivities and enantioselectivities. The reaction has broad substrate scope tolerating various functional groups.

Language: Английский

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Highly Efficient Supramolecular Catalysis by Endowing the Reaction Intermediate with Adaptive Reactivity

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(21), P. 6077 - 6081

Published: April 12, 2018

A new strategy of highly efficient supramolecular catalysis is developed by endowing the reaction intermediate with adaptive reactivity. The catalyst, prepared host-guest complexation between 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) and cucurbit[7]uril (CB[7]), was used for biphasic oxidation alcohols. Cationic TEMPO+ , key intermediate, stabilized electrostatic effect CB[7] in aqueous phase, thus promoting formation inhibiting side reactions. Moreover, through migration into organic separated from recovered high reactivity to drive a fast substrates. induced an integral optimization catalytic cycle greatly improved conversion reaction. This work highlights unique advantages dynamic noncovalent interactions on modulating activity intermediates, which may open horizons catalysis.

Language: Английский

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