Gold-Catalyzed Synthesis of Small Rings

Chemical Reviews, Journal Year: 2020, Volume and Issue: 121(14), P. 8613 - 8684

Published: Nov. 2, 2020

Three- and four-membered rings, widespread motifs in nature medicinal chemistry, have fascinated chemists ever since their discovery. However, due to energetic considerations, small rings are often difficult assemble. In this regard, homogeneous gold catalysis has emerged as a powerful tool construct these highly strained carbocycles. This review aims provide comprehensive summary of all the major advances discoveries made gold-catalyzed synthesis cyclopropanes, cyclopropenes, cyclobutanes, cyclobutenes, corresponding heterocyclic or heterosubstituted analogs.

Language: Английский

---

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

---

Synthesis of a Mechanically Planar Chiral Rotaxane Ligand for Enantioselective Catalysis

Chem, Journal Year: 2020, Volume and Issue: 6(4), P. 994 - 1006

Published: March 9, 2020

Rotaxanes are interlocked molecules in which a molecular ring is trapped on dumbbell-shaped axle because of its inability to escape over the bulky end groups, resulting so-called mechanical bond. Interlocked have mainly been studied as components machines, but crowded, flexible environment created by threading one molecule through another has also explored catalysis and sensing. However, so far, applications most intriguing properties molecules, their ability display stereogenic units that do not rely stereochemistry covalent subunits, termed "mechanical chirality," yet be properly explored, prototypical demonstration mechanically chiral rotaxanes remain scarce. Here, we describe planar rotaxane-based Au complex mediates cyclopropanation reaction with stereoselectivities comparable best conventional catalyst reported for this reaction.

Language: Английский

---

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

---

Dinuclear gold catalysis

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 50(3), P. 1874 - 1912

Published: Dec. 14, 2020

Gold chemistry has developed extensively in the past decade, and a dozen good reviews have been presented discussing this progress. Few however paid close attention to progress organic synthesis of dinuclear gold-catalysis. A gold catalyst is defined here as complex with two centers linked by bidentate ligand. With theoretical analysis some representative studies recent years, comprehensive review highlights particular properties gold-complexes, especially aurophilic interactions, systematically summarizes achievements gold-catalyzed coupling reactions, asymmetric catalysis, photocatalysis, where catalysts tend show greater advantage than mononuclear catalysts.

Language: Английский

---

Tethered Counterion-Directed Catalysis: Merging the Chiral Ion-Pairing and Bifunctional Ligand Strategies in Enantioselective Gold(I) Catalysis

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(8), P. 3797 - 3805

Published: Feb. 3, 2020

Tethering a metal complex to its phosphate counterion via phosphine ligand enables new strategy in asymmetric counteranion-directed catalysis (ACDC). A straightforward, scalable synthetic route gives access the gold(I) of displaying chiral phosphoric acid function. The generates catalytically active species with an unprecedented intramolecular relationship between cationic Au(I) center and counterion. benefits tethering two functions catalyst are demonstrated here tandem cycloisomerization/nucleophilic addition reaction, by attaining high enantioselectivity levels (up 97% ee) at unusually low 0.2 mol % loading. Remarkably, method is also compatible silver-free protocol.

Language: Английский

---

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

---

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

---

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

---

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

---