Photoinduced copper-catalyzed C–N coupling with trifluoromethylated arenes

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Дек. 14, 2023

Selective defluorinative functionalization of trifluoromethyl group (-CF3) is an attractive synthetic route to the pharmaceutically privileged fluorine-containing moiety. Herein, we report a strategy based on photoexcited copper catalysis activate C-F bond di- or trifluoromethylated arenes for divergent radical C-N coupling with carbazoles and aromatic amines. The use different ligands can tune reaction products diversity. A range substituted, structurally diverse α,α-difluoromethylamines be obtained from via carbazoles, while interesting double ready difluoromethylated arenes. Based this success, carbazole-centered PNP ligand designed optimal ligand, enabling copper-catalyzed construction imidoyl fluorides amines through functionalization. Interestingly, 1,2-difluoroalkylamination styrenes also developed, delivering γ,γ-difluoroalkylamines, bioisostere β-aminoketones, in synthetically useful yields. DFT studies reveal inner-sphere electron transfer mechanism Cu-catalyzed selective activation C(sp3)-F bonds.

Язык: Английский

---

Catalytically Relevant Organocopper(III) Complexes Formed through Aryl-Radical-Enabled Oxidative Addition

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15176 - 15185

Опубликована: Май 21, 2024

Stepwise oxidative addition of copper(I) complexes to form copper(III) species via single electron transfer (SET) events has been widely proposed in copper catalysis. However, direct observation and detailed investigation these fundamental steps remain elusive owing largely the typically slow rate instability species. We report herein a novel aryl-radical-enabled stepwise pathway that allows for formation well-defined alkyl–CuIII from CuI complexes. The process is enabled by SET an aryl diazonium salt CuII radical. Subsequent iodine abstraction alkyl iodide radical affords radical, which then reacts with complex. structure resultant [(bpy)CuIII(CF3)2(alkyl)] characterized NMR spectroscopy X-ray crystallography. Competition experiments have revealed at different iodides undergo consistent carbon-centered radicals. intermediate formed during identified as four-coordinate complex, [CuII(CH3CN)2(CF3)2], through electronic paramagnetic resonance (EPR) studies. catalytic relevance high-valent organo-CuIII demonstrated C–C bond-forming reductive elimination reactivity. Finally, localized orbital bonding analysis formal CuIII indicates inverted ligand fields σ(Cu–CH2) bonds. These results demonstrate catalysis provide general strategy investigate

Язык: Английский

---

Recent advances in C(sp³)–N bond formation via metallaphoto-redox catalysis

Chemical Communications, Год журнала: 2024, Номер 60(50), С. 6340 - 6361

Опубликована: Янв. 1, 2024

In this review, the state-of-the-art advances in radical-involved C(sp 3 )–N bond formation via metallaphotoredox catalysis have been highlighted, which are organized according to different catalytic modes, reaction types, and substrate classes.

Язык: Английский

---

NIR-II emissive anionic copper nanoclusters with intrinsic photoredox activity in single-electron transfer

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июнь 1, 2024

Abstract Ultrasmall copper nanoclusters have recently emerged as promising photocatalysts for organic synthesis, owing to their exceptional light absorption ability and large surface areas efficient interactions with substrates. Despite significant advances in cluster-based visible-light photocatalysis, the types of transformations that can catalyze remain limited date. Herein, we report a structurally well-defined anionic Cu 40 nanocluster emits second near-infrared region (NIR-II, 1000−1700 nm) after photoexcitation conduct single-electron transfer fluoroalkyl iodides without need external ligand activation. This photoredox-active efficiently catalyzes three-component radical couplings alkenes, iodides, trimethylsilyl cyanide under blue-LED irradiation at room temperature. A variety fluorine-containing electrophiles nucleophile be added onto an array including styrenes aliphatic olefins. Our current work demonstrates viability using readily accessible metal establish photocatalytic systems high degree practicality reaction complexity.

Язык: Английский

---

Photoexcited Palladium-Catalyzed Deracemization of Allenes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(30), С. 21137 - 21146

Опубликована: Июль 18, 2024

The different enantiomers of specific chiral molecules frequently exhibit disparate biological, physiological, or pharmacological properties. Therefore, the efficient synthesis single is particular importance not only to pharmaceutical sector but also other industrial sectors, such as agrochemical and fine chemical industries. Deracemization, a process during which racemic mixture converted into nonracemic product with 100% atom economy theoretical yield, most straightforward method access enantioenriched challenging task due decrease in entropy microscopic reversibility. Axially allenes bear distinctive structure two orthogonal cumulative π-systems are acknowledged synthetically versatile synthons organic synthesis. selective creation axially high optical purity under mild reaction conditions has always been very popular hot topic remains challenging. Herein, photoexcited palladium-catalyzed deracemization nonprefunctionalized disubstituted disclosed. This provides an economical strategy accommodate broad scope good enantioselectivities yields (53 examples, up 96% yield 95% ee). use suitable palladium complex visible light irradiation essential factor achieving this transformation. A metal-to-ligand charge transfer mechanism was proposed based on control experiments density functional theory calculations. Quantum mechanical studies implicate dual modes asymmetric induction behind our new protocol: (1) sterically controlled stereoselective binding one allene enantiomer ground-state (2) facile, noncovalent interaction-driven excited-state isomerization toward opposite enantiomer. success newly established photochemical should provide inspiration for expansion multisubstituted will open mode enantioselective catalysis.

Язык: Английский

---

Copper-Catalyzed Enantioconvergent Radical N-Alkylation of Diverse (Hetero)aromatic Amines

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(13), С. 9444 - 9454

Опубликована: Март 21, 2024

The 3d transition metal-catalyzed enantioconvergent radical cross-coupling provides a powerful tool for chiral molecule synthesis. In the classic mechanism, bond formation relies on interaction between nucleophile-sequestered metal complexes and radicals, limiting nucleophile scope to sterically uncongested ones. coupling of congested nucleophiles poses significant challenge due difficulties in transmetalation, restricting reaction generality. Here, we describe probable outer-sphere nucleophilic attack mechanism that circumvents challenging transmetalation associated with nucleophiles. This strategy enables general copper-catalyzed N-alkylation aromatic amines secondary/tertiary alkyl halides exhibits catalyst-controlled stereoselectivity. It accommodates diverse amines, especially bulky secondary primary ones deliver value-added (>110 examples). is expected inspire more nucleophiles, particularly ones, accelerate

Язык: Английский

---

Transition-metal-catalyzed enantioselective C–N cross-coupling

Chemical Society Reviews, Год журнала: 2024, Номер 53(19), С. 9560 - 9581

Опубликована: Янв. 1, 2024

Chiral amine scaffolds are among the most important building blocks in natural products, drug molecules, and functional materials, which have prompted chemists to focus more on their synthesis. Among accomplishments chiral synthesis, transition-metal-catalyzed enantioselective C-N cross-coupling is considered one of efficient protocols. This approach combines traditional C(sp

Язык: Английский

---

Photoexcited Chiral Copper Complex-Mediated Alkene E → Z Isomerization Enables Kinetic Resolution

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(24), С. 10958 - 10967

Опубликована: Июнь 8, 2022

While asymmetric synthesis has been established as a powerful synthetic tool for the construction of versatile enantioenriched molecules in most efficient and practical manner, resolution racemates is still universal industrial approach to chiral compounds. However, direct formation enantiopure Z-isomers through catalytic nonenzymatic kinetic racemic E-alkenes remains challenging. Herein, we disclose an unprecedented enantioselective E → Z isomerization mediated by photoexcited copper complex. This system enables 2-styrylpyrrolidines. process difficult realize under thermal conditions. Mechanistic experiments density functional theory (DFT) calculations revealed that different overall sensitization rates substrate–catalyst complex two enantiomers led observed excellent efficiency. photochemical transformation expands potential beyond their ground-state reactivity, furnishing novel reaction mode catalysis at its excited state.

Язык: Английский

---

Tetrasubstituted Carbon Stereocenters via Copper-Catalyzed Asymmetric Sonogashira Coupling Reactions with Cyclic gem-Dihaloketones and Tertiary α-Carbonyl Bromides

ACS Catalysis, Год журнала: 2022, Номер 12(16), С. 9944 - 9952

Опубликована: Авг. 1, 2022

The construction of chiral tetrasubstituted carbon stereocenters is an ongoing challenge in synthetic organic chemistry due to its prevalence multiple disciplines. One efficient approach the catalytic asymmetric C–C coupling reactions a readily available racemic tertiary alkyl electrophile by simple nucleophiles. While variety secondary halides succeeded Cu-catalyzed Sonogashira-type cross-coupling with diverse alkynes, have rarely been used this kind reaction. Herein, we demonstrate that bromides can serve as partners copper/bisoxazoline phenyl amine (BOPA)-catalyzed alkynylation, leading synthetically and medicinally valuable C–F all-carbon quaternary stereocenters.

Язык: Английский

---

Copper-Catalyzed Enantioconvergent Radical C(sp³)–N Cross-Coupling of Activated Racemic Alkyl Halides with (Hetero)aromatic Amines under Ambient Conditions

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(27), С. 14686 - 14696

Опубликована: Июль 1, 2023

The enantioconvergent C(sp3)-N cross-coupling of racemic alkyl halides with (hetero)aromatic amines represents an ideal means to afford enantioenriched N-alkyl yet has remained unexplored due the catalyst poisoning specifically for strong-coordinating heteroaromatic amines. Here, we demonstrate a copper-catalyzed radical activated under ambient conditions. key success is judicious selection appropriate multidentate anionic ligands through readily fine-tuning both electronic and steric properties formation stable rigid chelating Cu complex. Thus, this kind ligand could not only enhance reducing capability copper provide pathway but also avoid coordination other coordinating heteroatoms, thereby overcoming and/or chiral displacement. This protocol covers wide range coupling partners (89 examples secondary/tertiary bromides/chlorides amines) high functional group compatibility. When allied follow-up transformations, it provides highly flexible platform access synthetically useful amine building blocks.

Язык: Английский

---