Nickel and Palladium Catalysis: Stronger Demand than Ever

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(2), P. 1180 - 1200

Published: Jan. 5, 2022

Key similarities and differences of Pd Ni in catalytic systems are discussed. Overall, catalyze a vast number similar C–C C–heteroatom bond-forming reactions. However, the smaller atomic radius lower electronegativity Ni, as well more negative redox potentials low-valent species, often provide higher reactivity oxidative addition or insertion reactions persistence alkyl-Ni intermediates against β-hydrogen elimination, thus enabling activation reluctant electrophiles, including alkyl electrophiles. Another key point relates to stability open-shell electronic configurations Ni(I) Ni(III) compared with Pd(I) Pd(III). Nickel very involve interconvertible Ni(n+) active species variable oxidation states (Ni(0), Ni(I), Ni(II), Ni(III)). In contrast, involving Pd(III) still relatively less developed may require facilitation by special ligands merging photo- electrocatalysis. high Pd(n+) ensure their facile reduction Pd(0) under assistance numerous reagents solvents, providing concentrations molecular Pd1(0) complexes that can reversibly aggregate into Pdn clusters nanoparticles form cocktail Pdn(0) various nuclearities (i.e., values "n"). Ni(0) strong reductants; they sensitive deactivation air other oxidizers and, consequence, operate at catalyst loadings than palladium same The ease robustness versatility for catalysis, whereas variety enables diverse uncommon reactivity, albeit requiring efforts stabilization nickel systems. As discussion, we note easily "cocktail particles" different but (Pd1, Pdn, NPs), behave species" is stable nuclearities. Undoubtedly, there stronger demand ever not only develop improved efficient catalysts also understand mechanisms

Language: Английский

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Classes of Amides that Undergo Selective N–C Amide Bond Activation: The Emergence of Ground-State Destabilization

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 88(19), P. 13371 - 13391

Published: Sept. 2, 2022

Ground-state destabilization of the N–C(O) linkage represents a powerful tool to functionalize historically inert amide bond. This burgeoning reaction manifold relies on availability bond precursors that participate in weakening nN → π*C=O conjugation through N–C twisting, N pyramidalization, and electronic delocalization. Since 2015, acyl activation ground-state has been achieved by transition-metal-catalyzed oxidative addition bond, generation radicals, transition-metal-free addition. Perspective summarizes contributions our laboratory development new ground-state-destabilized enabled twist synthetic utility amides cross-coupling reactions reactions. The use as electrophiles enables plethora previously unknown transformations such coupling, decarbonylative radical coupling forge C–C, C–N, C–O, C–S, C–P, C–B bonds. Structural studies activated catalytic systems developed past decade enable view change from "traditionally inert" "readily modifiable" functional group with continuum reactivity dictated destabilization.

Language: Английский

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L‐Shaped Heterobidentate Imidazo[1,5‐a]pyridin‐3‐ylidene (N,C)‐Ligands for Oxidant‐Free Au^I/Au^III Catalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(12)

Published: Jan. 25, 2023

In the last decade, major advances have been made in homogeneous gold catalysis. However, Au

Language: Английский

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%V_Bur index and steric maps: from predictive catalysis to machine learning

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 53(2), P. 853 - 882

Published: Dec. 19, 2023

Steric indices are parameters used in chemistry to describe the spatial arrangement of atoms or groups molecules.

Language: Английский

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Divergent Acyl and Decarbonylative Liebeskind–Srogl Cross-Coupling of Thioesters by Cu-Cofactor and Pd–NHC (NHC = N-Heterocyclic Carbene) Catalysis

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(3), P. 1848 - 1855

Published: Jan. 17, 2023

Transition-metal-catalyzed cross-coupling reactions of thioesters by selective acyl C(O)–S cleavage have emerged as a powerful platform for the preparation complex molecules. Herein, we report divergent Liebeskind–Srogl Pd–NHC (NHC = N-heterocyclic carbene) catalysis. The reaction provides straightforward access to functionalized ketones highly C(acyl)–S under mild conditions. Most crucially, conditions enable direct functionalization range pharmaceuticals decorated with palette sensitive functional groups, providing attractive products medicinal chemistry programs. Furthermore, decarbonylative C(acyl)–S/C(aryl)–C(O) is reported. Cu metal cofactor directs pathway an or pathway. This reactivity applicable pharmaceuticals. represents mildest Suzuki discovered date. Cu-directed and opens up chemical space in molecule synthesis.

Language: Английский

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The influential IPr: 25 years after its discovery

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

25 Years after the discovery of most influential NHC ligand, we revisit and highlight studies involving IPr that have shaped field NHC-transition metal catalysis.

Language: Английский

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Palladium-NHC (NHC = N-heterocyclic Carbene)-Catalyzed Suzuki–Miyaura Cross-Coupling of Alkyl Amides

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(4), P. 2426 - 2433

Published: Feb. 2, 2022

We report the Pd-catalyzed Suzuki–Miyaura cross-coupling of aliphatic amides. Although tremendous advances have been made in aromatic amides, C–C bond formation from amides by selective N–C(O) cleavage has remained a major challenge. This longstanding problem Pd catalysis addressed herein combination (1) discovery N,N-pym/Boc as class readily accessible amide-based reagents for and (2) steric tuning well-defined Pd(II)-NHC catalysts cross-coupling. The methodology is effective an array 3°, 2°, 1° amide derivatives. catalyst system user-friendly, since are available air- bench-stable. Mechanistic studies strongly support twist external nN → π*C═O/Ar delocalization unified enabling feature activation. method provides rare example Pd-NHC-catalyzed acyl electrophiles.

Language: Английский

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Tailoring metal complexes with N-heterocyclic carbene ligands using Electron-Withdrawing Groups: Impact on catalytic activity and property development

Coordination Chemistry Reviews, Journal Year: 2024, Volume and Issue: 516, P. 215897 - 215897

Published: May 28, 2024

Language: Английский

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[(NHC)PdCl₂(Aniline)] Complexes: Easily Synthesized, Highly Active Pd(II)–NHC Precatalysts for Cross-Coupling Reactions

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(21), P. 15648 - 15657

Published: Oct. 8, 2021

We report the synthesis, characterization, and reactivity of [(NHC)PdCl

Language: Английский

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Thiazol-2-ylidenes as N-Heterocyclic carbene ligands with enhanced electrophilicity for transition metal catalysis

Communications Chemistry, Journal Year: 2022, Volume and Issue: 5(1)

Published: May 6, 2022

Over the last 20 years, N-heterocyclic carbenes (NHCs) have emerged as a dominant direction in ligand development transition metal catalysis. In particular, strong σ-donation combination with tunable steric environment make NHCs to be among most common ligands used for C-C and C-heteroatom bond formation. Herein, we report study on electronic properties of thiazol-2-ylidenes. We demonstrate that thiazole heterocycle enhanced π-electrophilicity result class highly active carbene electrophilic cyclization reactions form valuable oxazoline heterocycles. The evaluation steric, electron-donating π-accepting well structural characterization coordination chemistry is presented. This mode catalysis can applied late-stage drug functionalization furnish attractive building blocks medicinal chemistry. Considering key role ligands, anticipate N-aryl thiazol-2-ylidenes will broad interest modern chemical synthesis.

Language: Английский

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