Cobalt(II)-Catalyzed Selective Three-Component Oxyalkylation of N-Aryl Glycinates: A Route to CF3-Labeled Threonine Analogues DOI
Yadong Li, Dengfu Lu, Yuefa Gong

et al.

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(24), P. 17010 - 17023

Published: Nov. 30, 2023

Glycinates, protected enols, and an electrophilic trifluoromethylating reagent were employed to assemble CF3-labeled threonine analogues through a radical addition cascade. To suppress the competing oxidation of oxyalkyl intermediate, various redox catalysts evaluated Co(II) exhibited supreme selectivity control with proper counterion. A series glycinate related peptides thus successfully modified under Co-catalysis. Mechanistic studies revealed that N-aryl could be preferentially oxidized by cobalt over generate imine key this ascribed prechelation glycinate, as well weakly basic carboxylate

Language: Английский

In situ Generated Iridium Nanoparticles as Hydride Donors in Photoredox‐Catalyzed Hydrogen Isotope Exchange Reactions with Deuterium and Tritium Gas DOI Open Access

Henrik Kramp,

Remo Weck,

Martin Sandvoß

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(36)

Published: July 15, 2023

We have studied the photoredox-catalyzed hydrogen isotope exchange (HIE) reaction with deuterium or tritium gas as sources and in situ formed transition metal nanoparticles atom transfer pre-catalysts. By this means we found synergistic reactivities applying two different HIE mechanisms, namely CH-functionalization leading to synthesis of highly deuterated complex molecules. Finally, adopted these findings successfully chemistry.

Language: Английский

Citations

12
Visible-light-driven asymmetric aldol reaction of ketones and glycinates via synergistic Lewis acid/photoredox catalysis DOI Creative Commons
Jiuqi Tan, Longqing Yang,

Hanyu Su

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(39), P. 16050 - 16058

Published: Jan. 1, 2024

We have synthesized β-diaryl-β-hydroxyl-α-amino acid derivatives through radical addition-type aldol reaction, which was confirmed by spectroscopic experiments, control and DFT calculations.

Language: Английский

Citations

4
Visible-Light Photocatalytic Nucleophilic Addition of 4-Pyridylphosphonium Salts to CO2 and Carbonyl Compounds DOI

Wenwen Cui,

Bin Li, Baiquan Wang

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: March 24, 2025

A visible-light photocatalytic nucleophilic addition of 4-pyridylphosphonium salts to CO2 and carbonyl compounds is reported. The reaction has mild conditions, good functional group tolerance, a wide range substrates. Mechanistic studies show that the may occur through pyridylphosphonium salt radical anion, pyridyl radical, anion intermediates. By combination with C4-H phosphination, this method can be applied late-stage C-H functionalization drugs containing pyridine unit.

Language: Английский

Citations

0
Photocatalytic and Chemoselective H/D Exchange at α-Thio C(sp3)-H Bonds DOI

Riku Ogasahara,

Miyu Mae,

Yuki Itabashi

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 23, 2025

Deuterated compounds used in drug discovery and live-cell imaging have recently gained the attention of various scientific fields. Although hydrogen-deuterium (H/D) exchange reactions are straightforward deuteration methods, achieving perfect chemoselectivity is challenging. We report highly chemoselective α-thio C(sp3)-H bonds using a thioxanthone or anthraquinone organic photocatalyst bearing an aromatic ketone skeleton D2O as inexpensive deuterium source under 390 nm irradiation. Notably, incorporation at α-positions O/N atoms, benzylic positions, rings was not observed. The present accomplished via single electron transfer mechanism between S-containing substrates, proven by laser-induced time-resolved transient absorption spectroscopic measurements. Furthermore, proposed method could be applied to including pharmaceuticals biologically active with high regioselectivities. available deuterated novel alkylation reagents for future materials Raman were also demonstrated.

Language: Английский

Citations

0
Visible Light‐Enhanced C−H Amination of Cyclic Ethers with Iminoiodinanes DOI Creative Commons
Igor D. Jurberg, René A. Nome, Stefano Crespi

et al.

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(23), P. 4061 - 4068

Published: Nov. 5, 2022

Abstract A two‐step protocol allowing the C−H amination of cyclic ethers with iminoiodinanes, followed by reduction resulting intermediate has been developed for preparation amino alcohols. The initial functionalization is accelerated visible light, improving reactivity compared to thermal process performed in dark. effect different substituents on photochemical iminoiodinanes studied both experimentally and computationally. Photophysical measurements DFT calculations were better understand observed reactivities corroborate proposed mechanistic proposal. magnified image

Language: Английский

Citations

15
Visible-Light-Mediated Nucleophilic Addition of Alkene with Aldehyde: Synthesis of Secondary Alcohols DOI

D. Hu,

Huu Phuong Dang,

Zhen Liang

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 10, 2024

Herein, a photocatalytic strategy for the synthesis of secondary alcohols by nucleophilic addition an alkene with aldehyde is described. This operationally simple methodology opens approach using commercially available reagents in moderate to excellent yields. Mechanistic studies indicate that formation radical anion from via single-electron transfer key step this reaction.

Language: Английский

Citations

3
Alkyl Radical Generation via C–C Bond Cleavage in 2-Substituted Oxazolidines DOI Creative Commons
Adrián Luguera Ruiz,

Marta La Mantia,

Daniele Merli

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(19), P. 12469 - 12476

Published: Sept. 29, 2022

There is an urgent need to develop uncharged radical precursors be activated under mild photocatalyzed conditions. 2-Substituted-1,3-oxazolidines (Eox < 1.3 V vs SCE, smoothly prepared from the corresponding aldehydes) have been herein employed for successful release of tertiary, α-oxy, and α-amido radicals photo-organo redox catalysis. The reaction relies on unprecedented C–C cleavage occurring cation these heterocyclic derivatives. Such a protocol applied visible-light-driven conjugate addition onto Michael acceptors vinyl (hetero)arenes metal-free

Language: Английский

Citations

14
Site-selective α-C(sp3)–H arylation of dialkylamines via hydrogen atom transfer catalysis-enabled radical aryl migration DOI Creative Commons
Jie Xu, Ruihan Li,

Yijian Ma

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 8, 2024

Site-selective C(sp3)–H arylation is an appealing strategy to synthesize complex arene structures but remains a challenge facing synthetic chemists. Here we report the use of photoredox-mediated hydrogen atom transfer (HAT) catalysis accomplish site-selective α-C(sp3)–H dialkylamine-derived ureas through 1,4-radical aryl migration, by which wide array benzylamine motifs can be incorporated medicinally relevant systems in late-stage installation steps. In contrast previous efforts, this C–H protocol exhibits specific site-selectivity, proforming predominantly on sterically more-hindered secondary and tertiary α-amino carbon centers, while functionalization less-hindered N-methyl group effectively circumvented most cases. Moreover, diverse range multi-substituted piperidine derivatives obtained with excellent diastereoselectivity. Mechanistic computational studies demonstrate that rate-determining step for methylene initial H abstraction, whereas radical ipso cyclization bears highest energy barrier functionalization. The relatively lower activation free energies compared methylic bond lead exceptional site-selectivity. authors migration.

Language: Английский

Citations

2
Diquat Based Dyes: A New Class of Photoredox Catalysts and Their Use in Aerobic Thiocyanation DOI Creative Commons

Armin Meier,

S. V. Badalov, Timur Biktagirov

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(22)

Published: Jan. 26, 2023

A series of new organic donor-π-acceptor dyes incorporating a diquat moiety as novel electron-acceptor unit have been synthesized and characterized. The analytical data were supported by DFT calculations. These explored in the aerobic thiocyanation indoles pyrroles. Here they showed high photocatalytic activity under visible light, giving isolated yields up to 97 %. In addition, standalone methyl viologen through formation an electron donor acceptor complex is presented.

Language: Английский

Citations

6
Electroselective C(sp3)–H deuteration of isoindolinones DOI

Qiansong Gao,

Lianyou Zheng,

Shulin Ning

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(24), P. 6212 - 6218

Published: Jan. 1, 2023

An efficient paired electrochemical method for selective deuteration of isoindolinones was realized via H/D exchange. Its utility has been well exemplified in the late-stage modification bioactive molecules and their further transformation.

Language: Английский

Citations

5