The Buchwald–Hartwig Amination After 25 Years

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(48), P. 17118 - 17129

Published: June 5, 2019

Abstract The Pd‐catalyzed coupling of aryl (pseudo)halides and amines is one the most powerful approaches for formation C(sp 2 )−N bonds. pioneering reports from Migita subsequently Buchwald Hartwig on aminostannanes bromides rapidly evolved into general practical tin‐free protocols with broad substrate scope, which led to establishment what now known as Buchwald–Hartwig amination. This Minireview summarizes evolution this cross‐coupling reaction over course past 25 years illustrates some recent applications well‐established methodology.

Language: Английский

---

CuH-Catalyzed Olefin Functionalization: From Hydroamination to Carbonyl Addition

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(6), P. 1229 - 1243

Published: May 13, 2020

ConspectusIn organic synthesis, ligand-modified copper(I) hydride (CuH) complexes have become well-known reagents and catalysts for selective reduction, particularly toward Michael acceptors carbonyl compounds. Recently, our group others found that these undergo migratory insertion (hydrocupration) with relatively unactivated electronically unpolarized olefins, producing alkylcopper intermediates can be leveraged to forge a variety of useful bonds. The resulting formal hydrofunctionalization reactions formed the basis resurgence research in CuH catalysis. This Account chronicles development this concept group, highlighting its origin context asymmetric hydroamination, evolution more general C–X bond-forming reactions, applications addition olefin-derived nucleophiles derivatives.Hydroamination, an olefin into N–H bond amine, is process significant academic industrial interest, due potential transform widely available alkenes alkynes valuable complex amines. We developed polarity-reversed strategy catalytic enantioselective hydroamination relying on reaction olefins generate chiral organocopper intermediates, which are intercepted by electrophilic amine reagents. By engineering auxiliary ligand, electrophile, conditions, scope method has since been extended include many types including challenging internal olefins. Further, expanded enable synthesis primary, secondary, tertiary amines as well amides, N-alkylated heterocycles, anilines. All exhibit high regio- stereoselectivity and, mild conditions required, excellent tolerance heterocycles polar functional groups.Though generation species from was originally devised means solve problem, we soon could react efficiently unexpectedly broad range electrophiles, alkyl halides, silicon reagents, arylpalladium species, derivatives. ability function precursors nucleophilic proved advantageous because it overcomes disadvantages associated traditional organometallic removing need pregeneration nucleophile separate operation, CuH-catalyzed feature improved step economy, enhanced tolerance, catalyst control over stereoselectivity. Following paradigm, feedstock such allene, butadiene, styrene employed alkylation ketones, imines, aldehydes.

Language: Английский

---

A Comprehensive Discovery Platform for Organophosphorus Ligands for Catalysis

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(3), P. 1205 - 1217

Published: Jan. 12, 2022

The design of molecular catalysts typically involves reconciling multiple conflicting property requirements, largely relying on human intuition and local structural searches. However, the vast number potential requires pruning candidate space by efficient prediction with quantitative structure–property relationships. Data-driven workflows embedded in a library can be used to build predictive models for catalyst performance serve as blueprint novel designs. Herein we introduce kraken, discovery platform covering monodentate organophosphorus(III) ligands providing comprehensive physicochemical descriptors based representative conformer ensembles. Using quantum-mechanical methods, calculated 1558 ligands, including commercially available examples, trained machine learning predict properties over 300000 new ligands. We demonstrate application kraken systematically explore organophosphorus how existing data sets catalysis accelerate ligand selection during reaction optimization.

Language: Английский

---

C–N Cross-Couplings for Site-Selective Late-Stage Diversification via Aryl Sulfonium Salts

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(34), P. 13346 - 13351

Published: Aug. 14, 2019

We report diverse C-N cross-coupling reactions of aryl thianthrenium salts that are formed site-selectively by direct C-H functionalization. The scope N-nucleophiles ranges from primary and secondary alkyl amines to various N-containing heterocycles, the overall transformation is applicable late-stage functionalization complex, drug-like small molecules.

Language: Английский

---

Transition-Metal-Catalyzed C–S, C–Se, and C–Te Bond Formations via Cross-Coupling and Atom-Economic Addition Reactions. Achievements and Challenges

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(21), P. 16110 - 16293

Published: Sept. 16, 2022

In the present review, we discuss recent progress in field of C–Z bond formation reactions (Z = S, Se, Te) catalyzed by transition metals. Two complementary methodologies are considered─catalytic cross-coupling and catalytic addition reactions. The development advanced systems is aimed at improved catalyst efficiency, reduced loading, better cost environmental concerns, higher selectivity yields. important rise research efforts sustainability green chemistry areas critically assessed. paramount role mechanistic studies a new generation addressed, key achievements, problems, challenges summarized for this field.

Language: Английский

---

Tackling Solubility Issues in Organic Synthesis: Solid-State Cross-Coupling of Insoluble Aryl Halides

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(16), P. 6165 - 6175

Published: March 30, 2021

Conventional organic synthesis generally relies on the use of liquid solvents to dissolve reactants. Therefore, reactions sparingly soluble or insoluble substrates are challenging and often ineffective. The development a solvent-independent solid-state approach that overcomes this longstanding solubility issue would provide innovative synthetic solutions access new areas chemical space. Here, we report extremely fast highly efficient palladium-catalyzed Suzuki-Miyaura cross-coupling via high-temperature ball-milling technique. This protocol enables cross-couplings aryl halides with large polyaromatic structures barely reactive under conventional solution-based conditions. Notably, discovered luminescent material strong red emission. was prepared coupling Pigment violet 23, compound has so far not been involved in molecular transformations due its low solubility. study thus provides practical method for accessing unexplored space through compounds cannot be carried out by any other approach.

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

---

Emerging Trends in Cross-Coupling: Twelve-Electron-Based L₁Pd(0) Catalysts, Their Mechanism of Action, and Selected Applications

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(23), P. 16983 - 17027

Published: Oct. 3, 2022

Monoligated palladium(0) species, L

Language: Английский

---

A machine-learning tool to predict substrate-adaptive conditions for Pd-catalyzed C–N couplings

Science, Journal Year: 2023, Volume and Issue: 381(6661), P. 965 - 972

Published: Aug. 31, 2023

Machine-learning methods have great potential to accelerate the identification of reaction conditions for chemical transformations. A tool that gives substrate-adaptive palladium (Pd)-catalyzed carbon-nitrogen (C-N) couplings is presented. The design and construction this required generation an experimental dataset explores a diverse network reactant pairings across set conditions. large scope C-N was actively learned by neural models using systematic process experiments. showed good performance in validation: Ten products were isolated more than 85% yield from range with out-of-sample reactants designed challenge models. Importantly, developed workflow continually improves prediction capability as corpus data grows.

Language: Английский

---

Mechanochemistry-Directed Ligand Design: Development of a High-Performance Phosphine Ligand for Palladium-Catalyzed Mechanochemical Organoboron Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(12), P. 6823 - 6837

Published: March 9, 2023

Mechanochemical synthesis that uses transition-metal catalysts has attracted significant attention due to its numerous advantages, including low solvent waste, short reaction times, and the avoidance of problems associated with solubility starting materials. However, even though mechanochemical environment is largely different from homogeneous solution systems, catalysts, which were originally developed for use in solution, have been used directly reactions without any molecular-level modifications ensure their suitability mechanochemistry. Alas, this limited development more efficient cross-coupling processes. Here, we report a conceptually distinct approach, whereby mechanochemistry-directed design develop ligands Suzuki-Miyaura reactions. The ligand was guided by experimental observation catalyst deactivation via aggregation palladium species, problem particularly prominent solid-state By embedding into poly(ethylene glycol) (PEG) polymer, found phosphine-ligated palladium(0) species could be immobilized fluid phase created PEG chains, preventing physical mixing crystalline solid thus undesired deactivation. This catalytic system showed high activity polyaromatic substrates close room temperature. These usually require elevated temperatures reactive presence systems conventional such as SPhos. present study hence provides important insights high-performance potential inspire industrially attractive, almost solvent-free technologies.

Language: Английский

---