Asymmetric hydrogenation catalyzed by first-row transition metal complexes

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(5), P. 3211 - 3237

Published: Jan. 1, 2021

This review focuses on asymmetric direct and transfer hydrogenation with first-row transition metal complexes. The reaction mechanisms the models of enantiomeric induction were summarized emphasized.

Language: Английский

---

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

---

Ni-Catalyzed Ligand-Controlled Regiodivergent Reductive Dicarbofunctionalization of Alkenes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(27), P. 10282 - 10291

Published: June 24, 2021

Transition-metal-catalyzed dicarbofunctionalization of alkenes involving intramolecular Heck cyclization followed by intermolecular cross-coupling has emerged as a powerful engine for building heterocycles with sterically congested quaternary carbon centers. However, only exo-cyclization/cross-coupling products can be obtained; endo-selective cyclization/cross-coupling not been reported yet and still poses formidable challenge. We herein report the first example catalyst-controlled regiodivergent synthesis five- six-membered benzo-fused lactams bearing all-carbon Using chiral Pyrox- or Phox-type bidentate ligand, 5-exo cyclization/cross-couplings proceed favorably to produce indole-2-ones in good yields excellent regioselectivity enantioselectivities (up 98% ee). When C6-carboxylic acid-modified 2,2′-bipyridine was used 3,4-dihydroquinolin-2-ones were obtained through 6-endo-selective processes. This transformation is modular tolerant variety functional groups. The ligand rather than substrate structures precisely dictates pattern. Moreover, synthetic value this protocol demonstrated preparation biologically relevant molecules structural scaffolds.

Language: Английский

---

Palladium-catalyzed asymmetric hydrophosphination of internal alkynes: Atroposelective access to phosphine-functionalized olefins

Chem, Journal Year: 2022, Volume and Issue: 8(12), P. 3346 - 3362

Published: Sept. 23, 2022

Language: Английский

---

Cross-Electrophile Coupling: Principles, Methods, and Applications in Synthesis

Chemical Reviews, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 26, 2024

Cross-electrophile coupling (XEC), defined by us as the cross-coupling of two different σ-electrophiles that is driven catalyst reduction, has seen rapid progression in recent years. As such, this review aims to summarize field from its beginnings up until mid-2023 and provide comprehensive coverage on synthetic methods current state mechanistic understanding. Chapters are split type bond formed, which include C(sp

Language: Английский

---

Recyclable nano-CuI immobilized on UiO-66-NH2 coated with porous sodium alginate-polysulfonamide for synthesis of phenols

Carbohydrate Polymer Technologies and Applications, Journal Year: 2025, Volume and Issue: unknown, P. 100665 - 100665

Published: Jan. 1, 2025

Language: Английский

---

Structure–Reactivity Relationships of Buchwald-Type Phosphines in Nickel-Catalyzed Cross-Couplings

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(42), P. 19635 - 19648

Published: Oct. 17, 2022

The dialkyl-ortho-biaryl class of phosphines, commonly known as Buchwald-type ligands, are among the most important phosphines in Pd-catalyzed cross-coupling. These ligands have also been successfully applied to several synthetically valuable Ni-catalyzed cross-coupling methodologies and, demonstrated this work, top performing Suzuki Miyaura Coupling (SMC) and C-N coupling reactions, even outperforming employed bisphosphines like dppf many circumstances. However, little is about their structure-reactivity relationships (SRRs) with Ni, limited examples well-defined, catalytically relevant Ni complexes exist. In we report analysis phosphine SRRs four representative reactions. Our study was guided by data-driven classification analysis, which together mechanistic organometallic studies structurally characterized Ni(0), Ni(I), Ni(II) allowed us rationalize reactivity patterns catalysis. Overall, expect that will serve a platform for further exploration ligand organonickel chemistry well development new methodologies.

Language: Английский

---

Asymmetric Redox Allylic Alkylation to Access 3,3′‐Disubstituted Oxindoles Enabled by Ni/NHC Cooperative Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(22)

Published: March 3, 2022

The feasibility of cooperative catalysis between chiral N-heterocyclic carbenes and nickel in asymmetric reactions has been demonstrated convincingly. high efficiency this catalytic system enables the allylic alkylation isatin-derived enals with carbonates [3+3] annulation racemic vinyl epoxides to provide straightforward access highly enantioenriched 3,3'-disubstituted oxindoles. great practicality method organic synthesis showcased by facile product modification enantioselective key building block (-)-debromoflustramine B.

Language: Английский

---

Nickel-Catalyzed Radical Mechanisms: Informing Cross-Coupling for Synthesizing Non-Canonical Biomolecules

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(24), P. 3640 - 3653

Published: Nov. 30, 2023

ConspectusNickel excels at facilitating selective radical chemistry, playing a pivotal role in metalloenzyme catalysis and modern cross-coupling reactions. Radicals, being nonpolar neutral, exhibit orthogonal reactivity to nucleophilic basic functional groups commonly present biomolecules. Harnessing this compatibility, we delve into the application of nickel-catalyzed pathways synthesis noncanonical peptides carbohydrates, critical for chemical biology studies drug discovery.We previously characterized sequential reduction mechanism that accounts chemoselectivity cross-electrophile coupling This catalytic cycle begins with nickel(I)-mediated generation from alkyl halides, followed by carbon capture nickel(II) complexes, concludes reductive elimination. These steps resonate mechanistic proposals cross-coupling, photoredox, electrocatalytic Herein, our insights each step involving radicals, including initiation, propagation, termination, nuances kinetics, origins selectivity, ligand effects.Radical C(sp3) electrophiles via one-electron oxidative addition low-valent nickel intermediates provides basis stereoconvergent couplings. Our electroanalytical elucidate concerted halogen atom abstraction mechanism, where electron transfer is coupled halide dissociation. Using pathway, have developed stereoselective dehydroalanine, peptides. In application, chiral ligands modulate stereochemical outcome through asymmetric protonation nickel-enolate intermediate.The expands scope promotes elimination formation high-valent nickel(III) species, governs chemo- stereoselectivity. We discovered nickel(II)-aryl efficiently traps radicals barrier ranging 7 9 kcal/mol, fast contrast, nickel(II)-alkyl captures form which was EPR spectroscopy. However, subsequent slow resulted minimal product formation. The observed high diastereoselectivity inspired investigations C-aryl C-acyl glycosylation redox auxiliary readily couples natural carbohydrates produces glycosyl upon photoredox activation. Nickel-catalyzed bromoarenes carboxylic acids leads diverse non-natural glycosides can facilitate discovery.Stoichiometric on well-defined d8-nickel complexes showcased means promote elimination, association, oxidation, addition.In final section, address influence electronic structure activity organonickel intermediates. Synthesis series characterization their structures led us postulate correlates coordination geometry. data reveal change shift potentials reaction intermediates, potentially altering Moreover, coordinating additives solvents may stabilize during adjusting activity, consistent known conditions.

Language: Английский

---

Heterogenized Molecular Rhodium Phosphine Catalysts within Metal–Organic Frameworks for Alkene Hydroformylation

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(7), P. 4193 - 4204

Published: March 13, 2023

Molecularly defined organometallic rhodium phosphine complexes were efficiently heterogenized within a MOF structure without affecting neither their molecular nature nor catalytic behavior. Phosphine-functionalized MOF-808 served as solid ligand in series of eight catalysts. These MOF-heterogenized catalysts showed activity up to 2100 h–1 for ethylene hydroformylation toward propionaldehyde the sole carbon-containing product. The combined experimental and computational methods applied this unique MOF-based system allowed unraveling evolution active Rh species under conditions, line with mechanisms at play during reaction. catalyst also successfully catalyzed longer bulkier alkenes similar selectivity than that obtained its homogeneous counterpart. MOF-808, designed porous crystalline macroligand well-defined catalysts, allows benefiting from scale understanding interactions well stabilization through site isolation recycling ability.

Language: Английский

---