Optimization of Catalysts and Conditions in Gold(I) Catalysis—Counterion and Additive Effects

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(14), P. 8452 - 8477

Published: Jan. 21, 2021

Gold catalysis has proven to be an important breakthrough for organic synthesis. The tunable nature of gold catalysts, the unique properties gold, and mild reaction conditions required in many gold-catalyzed reactions have all contributed substantially this metal's popularity catalysis. However, still suffer from limitations such as low turnover numbers (TON). Optimization catalysts may significantly improve efficiency reactions. In review, we will present leading examples counterion or additive-regulated a mechanistic perspective. We pay special attention physical counterion/additive, affinity hydrogen bond basicity, discuss their effects on reactivity catalysts.

Language: Английский

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Recent Developments in Enantioselective Transition Metal Catalysis Featuring Attractive Noncovalent Interactions between Ligand and Substrate

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(18), P. 10672 - 10714

Published: Aug. 14, 2020

Enantioselective transition metal catalysis is an area very much at the forefront of contemporary synthetic research. The development processes that enable efficient synthesis enantiopure compounds unquestionable importance to chemists working within many diverse fields central science. Traditional approaches solving this challenge have typically relied on leveraging repulsive steric interactions between chiral ligands and substrates in order raise energy one diastereomeric states over other. By contrast, Review examines alternative tactic which a set attractive noncovalent operating are used control enantioselectivity. Examples where creative approach has been successfully applied render fundamental enantioselective presented discussed. In cases examined, ligand scaffold carefully designed accommodate these interactions, while others, critical was only elucidated subsequent computational mechanistic studies. Through exploration discussion recent reports encompassing wide range reaction classes, we hope inspire continue develop asymmetric transformations based powerful concept.

Language: Английский

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Main Avenues in Gold Coordination Chemistry

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(14), P. 8311 - 8363

Published: Feb. 9, 2021

In this contribution, we provide an overview of the main avenues that have emerged in gold coordination chemistry during last years. The unique properties motivated research chemistry, and especially regarding applications compounds catalysis, medicine, materials chemistry. advances synthesis knowledge been possible with design novel ligands becoming relevant motifs allowed preparation elusive complexes area research. Strong donor easily modulable electronic steric properties, such as stable singlet carbenes or cyclometalated ligands, decisive stabilization gold(0) species, fluoride complexes, hydrides, unprecedented π cluster derivatives. These new important not only from fundamental structure bonding studies but also for sophisticated catalysts to improve activity selectivity organic transformations. Moreover, they enabled facile oxidative addition gold(I) gold(III) a plethora specific properties.

Language: Английский

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Dirhodium-Catalyzed Asymmetric Transformations of Alkynes via Carbene Intermediates

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

ConspectusFunctionalization of alkynes is an established cornerstone organic synthesis. While numerous transition metals exhibit promising activities in the transformations via π-insertion or oxidative cyclometalation, Lewis π-acids offer a different approach. By coordinating with through π-bonding, facilitate nucleophilic addition, leading to formation alkenyl metal species. These species can undergo electron rearrangement generate carbenes, which are crucial intermediates for subsequent carbene transfer reactions. This reaction pathway provides versatile route alkyne functionalization, especially asymmetric manner. Although π-acid, gold(I), pioneered this mode, development variants remains challenging due linear coordination gold(I). Therefore, expanding range catalysts beyond gold(I) complexes other would further advances chiral molecule construction and exploration novel modes.In Account, we present concise review multifunctionalization dirhodium-catalyzed transformations, providing modulation strategies substrates plausible mechanisms. In aromatization-driven strategy, furanyl dirhodium generated from enynone, terminated by enantioselective intramolecular C-H insertion, cyclopropanation, aromatic substitution, Büchner reaction, giving dihydroindoles, dihydrobenzofurans, cyclopropane-fused tetrahydroquinolines, fluorenes, cyclohepta[b]benzofurans. The cap-tether strategy was developed study balance reactivity selectivity azo-enyne. gave first catalytic cycloisomerization azo-enyne, affording centrally axially isoindazole derivatives. synergistic activation i.e., EWG C-H···O interaction, introduced achieve enynes, cyclopropane-annulated bicyclic systems enynals. Benefiting these successes, difluoromethyl-substituted enynes were designed proven be effective substrates. With corresponding benzo-1,6-enynes as substrates, biscyclopropanation cascaded cyclopropanation/cyclopropenation achieved using dicarbene equivalents. Additionally, benzo-1,5-enynal vinyl carbene, reacted variety alkenes [2 + 1] cycloaddition, [4 3] formal allylation, spiro fused polycyclic heterocycles. Coupling desymmetrization, successfully diynals, constructing furan-fused dihydropiperidines alkyne-substituted aza-quaternary stereocenter. Notably, analyzing X-ray structures several dirhodium-alkyne π-complexes, together results DFT calculations control experiments, obtained evidence supporting making well-defined paddlewheel-like dirhodium(II) stand out among complexes. We anticipate that our research will significantly advance fields dirhodium, alkyne, chemistry.

Language: Английский

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Yne–Enones Enable Diversity-Oriented Catalytic Cascade Reactions: A Rapid Assembly of Complexity

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(10), P. 2358 - 2371

Published: Oct. 1, 2020

ConspectusA small-molecule collection with structural diversity and complexity is a prerequisite to using either drug candidates or chemical probes for discovery chemical–biology investigations, respectively. Over the past 12 years, we have engaged in developing efficient diversity-oriented cascade strategies synthesis of topologically diverse skeletons incorporating biologically relevant motifs such as O- N-heterocycles, fused polycycles, multifunctionalized allenes. In particular, highlighted use simple, linear, densely functionalized molecular platforms these reactions.This account details our efforts design novel metal- organo-catalyzed reactions, which include 2-(1-alknyl)-2-alken-1-ones (yne–enones) heterocyclization/cross-coupling cascades, heterocyclization/cycloaddition nucleophilic addition/cross-coupling addition/heterocyclization so on. Moreover, this Account outlines corresponding mechanistic insights, computational information, applications cascades construction various highly substituted carbo- heterocycles well acyclic compounds, e.g., allenes dienes. addition yne–enones, evolved functional groups original yne–enones provide series yne–enone variants, resulted products complementary reactivities.The reactivity profile defined by presence an alkyne moiety conjugated enone unit their mutual through-bond connectivity. Owing conceptually rapid development carbophilic activation, identified catalytic systems consisting metal catalysts, including Pd, Au, Rh complexes, catalysis, allowing unprecedented reactions be achieved through different-types reaction intermediates, all-carbon 1,n-dipoles, furan-based o-quinodimethanes (oQDMs), allenyl-metal species. commonly known transition-metal activity, Lewis acidity complexes crucial accomplish transformation. addition, enantioselective gold(I)-catalyzed variants were application bisphosphines (e.g., Cn-TunePhos), monophosphines, developed "Ming–Phos" chiral ligands. Importantly, Ming–Phos ligands exhibited excellent performance gold-catalyzed mechanistically distinct [3 + n]-cycloaddition sulfinamide possibly responsible interaction substrate control enantioselectivity. Subsequently, demonstrated that easily prepared polymer-supported ligand could applied heterogeneously asymmetric cycloaddition good stereocontrol. With metal-free divergent functionalization provides numerous synthetic outlets structure diversification. For example, are particularly attractive precursors achiral heterocycles, pyrazoles, isoxazoles, pyrroles, pyrans, etc.

Language: Английский

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Recent Advances in the Development of Chiral Gold Complexes for Catalytic Asymmetric Catalysis

Chemistry - An Asian Journal, Journal Year: 2021, Volume and Issue: 16(5), P. 364 - 377

Published: Jan. 2, 2021

Asymmetric gold catalysis has been rapidly developed in the past ten years. Breakthroughs have made by rational design and meticulous selection of chiral ligands. This review summarizes newly gold-catalyzed enantioselective organic transformations recent progress ligand (since 2016), organized according to different types ligands, including bisphosphine monophosphine phosphite-derived N-heterocyclic carbene ligands for asymmetric gold(I) as well heterocyclic oxazoline gold(III) catalysis.

Language: Английский

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H-Bonded Counterion-Directed Enantioselective Au(I) Catalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(8), P. 3497 - 3509

Published: Feb. 9, 2022

A new strategy for enantioselective transition-metal catalysis is presented, wherein a H-bond donor placed on the ligand of cationic complex allows precise positioning chiral counteranion responsible asymmetric induction. The successful implementation this paradigm demonstrated in 5-exo-dig and 6-endo-dig cyclizations 1,6-enynes, combining an achiral phosphinourea Au(I) chloride with BINOL-derived phosphoramidate Ag(I) salt thus allowing first general use anions Au(I)-catalyzed reactions challenging alkyne substrates. Experiments modified complexes anions, 1H NMR titrations, kinetic data, studies solvent nonlinear effects substantiate key H-bonding interaction at heart catalytic system. This conceptually novel approach, which lies intersection metal catalysis, organocatalysis, counterion-directed provides blueprint development supramolecularly assembled ligands complexes.

Language: Английский

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Distal Ionic Substrate–Catalyst Interactions Enable Long-Range Stereocontrol: Access to Remote Quaternary Stereocenters through a Desymmetrizing Suzuki–Miyaura Reaction

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(1), P. 123 - 129

Published: Jan. 3, 2022

Spatial distancing of a substrate's reactive group and nonreactive catalyst-binding from its pro-stereogenic element presents substantial hurdles in asymmetric catalysis. In this context, we report desymmetrizing Suzuki–Miyaura reaction that establishes chirality at remote quaternary carbon. The anionic, chiral catalyst exerts stereocontrol through electrostatic steering substrates, even as the charged become increasingly distanced. This study demonstrates precise long-range is achievable by engaging ionic substrate–ligand interactions distal position.

Language: Английский

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Chiral Hemilabile P,N‐Ligand‐Assisted Gold Redox Catalysis for Enantioselective Alkene Aminoarylation

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(34)

Published: April 14, 2022

Enantioselective, intermolecular alkene arylamination was achieved through gold redox catalysis. Screening of ligands revealed chiral P,N as the optimal choice, giving aminoarylation with good yields (up to 80 %) and excellent stereoselectivity 99 : 1 er). As first example enantioselective catalysis, this work confirmed feasibility applying a ligand at gold(I) stage, stereodetermining step (SDS) gold(III) intermediate, thus opening up new way conduct catalysis stereochemistry control.

Language: Английский

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Enantioselective C−H Functionalization Reactions under Gold Catalysis

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(20)

Published: Jan. 11, 2022

Abstract Transition metal‐catalyzed enantioselective functionalization of ubiquitous C−H bonds has proven to be promising field as it offers the construction chiral molecular complexity in a step‐ and atom‐economical manner. In recent years, gold emerged an attractive contender for catalyzing such reactions. The unique reactivities selectivities offered by catalysts have been exploited access numerous asymmetric transformations based on gold‐catalyzed processes. Herein, this review critically highlights major advances discoveries made under catalysis which is accompanied mechanistic insights at appropriate places.

Language: Английский

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