Recent Advances in Catalytic Asymmetric Construction of Atropisomers

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(8), P. 4805 - 4902

Published: March 27, 2021

Atropisomerism is a stereochemical behavior portrayed by three-dimensional molecules that bear rotationally restricted σ bond. Akin to the well-represented point-chiral molecules, atropisomerically chiral compounds are finding increasing utilities in many disciplines where molecular asymmetry influential. This provides steady demand on atroposelective synthesis, numerous synthetic pursuits have been rewarded with conceptually novel and streamlined methods while expanding structural diversity of atropisomers. review summarizes key achievements stereoselective preparation biaryl, heterobiaryl, nonbiaryl atropisomers documented between 2015 2020. Emphasis placed strategies for each class, examples cited illustrate potential applications accessed atropochiral targets.

Language: Английский

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Recent advances in the synthesis of axially chiral biarylsviatransition metal-catalysed asymmetric C–H functionalization

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(59), P. 8514 - 8523

Published: Jan. 1, 2019

Recent advances in the synthesis of axially chiral biarylsviatransition metal-catalysed asymmetric C–H functionalization are reported.

Language: Английский

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Electronic and Steric Tuning of a Prototypical Piano Stool Complex: Rh(III) Catalysis for C–H Functionalization

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 51(1), P. 170 - 180

Published: Dec. 22, 2017

ConspectusThe history of transition metal catalysis is heavily steeped in ligand design, clearly demonstrating the importance this approach. The intimate relationship between and can profoundly affect outcome a reaction, often impacting selectivity, physical properties, lifetime catalyst. Importantly, metal–ligand provide near limitless opportunities for reaction discovery. Over past several years, transition-metal-catalyzed C–H bond functionalization reactions have been established as critical foundation organic chemistry that provides new forming strategies. Among d-block elements, palladium arguably one most popular metals to accomplish such transformations. One possible explanation achievement could be broad set phosphine amine based ligands available chemist's toolbox compatible with palladium. In parallel, other investigated functionalization. them, pentamethylcyclopentadienyl (Cp*) Rh(III) complexes emerged powerful mode transformations providing spectrum reactivity. This approach possesses advantage very low catalyst loading, are typically performed under mild conditions allowing functional group tolerance. Cp*Rh(III) considered privileged plethora involving cleavage event developed. search alternative cyclopentadienyl has eclipsed by tremendous effort devoted exploring considerable scope catalyzed complexes, despite potential strategy enabling Thus, modification efforts an exception research directed toward rhodium catalysts sparse. Recently, chiral appeared enantioselective Rh(III)-catalyzed performed. Alongside ligands, equally important collection achiral cyclopentadienyl-derived also emerged. design already translated significant success solving inherent problems reactivity selectivity encountered throughout development Account describes evolution skeletons Rh(III)-catalysis since introduction present. Specific emphasis placed on synthetic applications achieved mono-, di-, or pentasubstituted exhibiting stunning effect selectivity. Furthermore, underlying question when dealing strategies explain reason outperforms another. Conjecture speculation abound, but extensive characterization their steric electronic properties carried out information about all contribute our understanding give crucial pieces solve puzzle.

Language: Английский

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Access to P‐ and Axially Chiral Biaryl Phosphine Oxides by Enantioselective Cp^xIr^III‐Catalyzed C−H Arylations

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(39), P. 12901 - 12905

Published: July 25, 2018

An enantioselective C-H arylation of phosphine oxides with o-quinone diazides catalyzed by an iridium(III) complex bearing atropchiral cyclopentadienyl (Cpx ) ligand and phthaloyl tert-leucine as co-catalyst is reported. The method allows access to a) P-chiral biaryl oxides, b) atropo-enantioselective construction sterically demanding backbones, also c) selective assembly axial compounds in excellent yields diastereo- enantioselectivities. Enantiospecific reductions provide monodentate chiral phosphorus(III) having structures backbones proven importance ligands asymmetric catalysis.

Language: Английский

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Synthesis of Atropisomers by Transition-Metal-Catalyzed Asymmetric C–H Functionalization Reactions

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(35), P. 14025 - 14040

Published: Aug. 25, 2021

Transition-metal-catalyzed enantioselective C-H functionalization has become a powerful strategy for the formation of C-C or C-X bonds, enabling highly asymmetric synthesis wide range enantioenriched compounds. Atropisomers are widely found in natural products and pharmaceutically relevant molecules, have also applications as privileged frameworks chiral ligands catalysts. Thus, research into routes atropisomers garnered great interest recent years. In this regard, transition-metal-catalyzed emerged an atom-economic efficient toward their synthesis. Perspective, approaches by reactions summarized. The main focus here is on catalysis via Pd, Rh, Ir complexes, which been most frequently utilized catalysts among reported reactions. Finally, we discuss limitations available protocols give outlook possible future avenues research.

Language: Английский

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Rh(III)-Catalyzed Asymmetric Synthesis of Axially Chiral Biindolyls by Merging C–H Activation and Nucleophilic Cyclization

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(24), P. 9527 - 9532

Published: June 4, 2019

Enantiomeric access to pentatomic biaryls is challenging due their relatively low rotational barrier. Reported herein the mild and highly enantioselective synthesis of 2,3′-biindolyls via underexplored integration C–H activation alkyne cyclization using a unified chiral Rh(III) catalyst. The reaction proceeded initial followed by cyclization. A rhodacyclic intermediate has been isolated from stoichiometric activation, which offers direct mechanistic insight.

Language: Английский

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Enantioselective C(sp³)–H Amidation of Thioamides Catalyzed by a Cobalt^III/Chiral Carboxylic Acid Hybrid System

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(4), P. 1153 - 1157

Published: Nov. 27, 2018

Abstract Recent advances in Cp x M III catalysis (M=Co, Rh, Ir) have enabled a variety of enantioselective C(sp 2 )−H functionalization reactions, but 3 is still largely unexplored. We describe an asymmetric amidation thioamides using achiral Co /chiral carboxylic acid hybrid catalytic system, which provides easy and straightforward access to chiral β‐amino thiocarbonyl carbonyl building blocks with quaternary carbon stereocenter.

Language: Английский

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Metal-Catalyzed Intermolecular Hydrofunctionalization of Allenes: Easy Access to Allylic Structures via the Selective Formation of C–N, C–C, and C–O Bonds

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(24), P. 13545 - 13598

Published: Dec. 10, 2020

Following a strong regain of interest over the past 20 years in chemistry allenes, this "forgotten" family unsaturated molecules is undergoing renaissance. In context, metal-catalyzed hydrofunctionalization allenes nowadays one most studied transformations. The latter great because it opens way to produce selectively functionalized allylic structures. These motifs are important synthesis, particularly for formation asymmetric centers. Hydrofunctionalization also totally atom economical strategy, avoiding generation any waste, Compared main pathway obtain (aka Tsuji-Trost substitution), does not require prefunctionalization starting material with leaving group. This review presents state art exploration all existing transition methods allowing selective intermolecular N–H, C–H, and O–H nucleophiles or electrophiles.

Language: Английский

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Cross‐Coupling of α‐Carbonyl Sulfoxonium Ylides with C−H Bonds

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(42), P. 13117 - 13121

Published: Aug. 29, 2017

Abstract The functionalization of carbon–hydrogen bonds in non‐nucleophilic substrates using α‐carbonyl sulfoxonium ylides has not been so far investigated, despite the potential safety advantages that such reagents would provide over either diazo compounds or their situ precursors. Described herein are cross‐coupling reactions with C(sp 2 )−H arenes and heteroarenes presence a rhodium catalyst. reaction proceeds by succession C−H activation, migratory insertion ylide into carbon–metal bond, protodemetalation, last step being turnover‐limiting. method is applied to synthesis benz[c]acridines when allied an iridium‐catalyzed dehydrative cyclization.

Language: Английский

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Chiral Cyclopentadienyl Ligands: Design, Syntheses, and Applications in Asymmetric Catalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(24), P. 13198 - 13224

Published: July 16, 2020

The creation of new chiral ligands capable providing high stereocontrol in metal-catalyzed reactions is crucial modern organic synthesis. production bioactive molecules as single enantiomers increasingly required, and asymmetric catalysis with metal complexes constitutes one the most efficient synthetic strategies to access optically active compounds. Herein we offer a historical overview on development derivatives ubiquitous cyclopentadienyl ligand (CpX ), detail their successful application broad range transformations. Those include functionalization challenging C-H bonds beyond, giving an extensive catalogue valuable molecules. A critical comparison existing families, design, synthesis, complexation different metals also provided. In addition, future research directions are discussed further enhance performance CpX enantioselective catalysis.

Language: Английский

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