Quenching Rate Constants of Lewis Base‐Boryl Radical by Substrates: a Laser Flash Photolysis Study DOI
Fan Zhang, Yuanming Li, Xi Zhou

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 31(8)

Published: Nov. 13, 2024

The advanced strategy using Lewis base-boryl radicals (LBRs) has recently been proposed for the addition of alkyl substituents to full-carbon quaternary center an organic molecule. However, as rate-determining step in whole route, reaction rate constants LBRs with substrates are extremely lacking. In this paper, 4-dimethylaminopyridine (DMAP)-BH2⋅ was selected a representative LBRs, and its reactions six monochloro-substituted substrates, including three methyl chlorobenzoates chlorinated acetanilides were studied experiments theoretical calculations. bimolecular constants, kq, determined laser flash photolysis approach. By comparing activation energies along two pathways, we have clarified attacking carbonyl oxygen instead chlorine atom. Furthermore, noncovalent interaction (NCI) analyses on these indicate that weak interactions, such hydrogen-bonding van der Waals significant influence reactivity substrates. Our study provides concrete clues extend synthetic strategy.

Language: Английский

Amine-Borane-Mediated, Nickel/Photoredox-Catalyzed Cross-Electrophile Coupling between Alkyl and Aryl Bromides DOI

Ke-Rong Li,

Xian‐Chen He,

Jie Gao

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(17), P. 12658 - 12667

Published: Aug. 19, 2024

Nickel/photoredox catalysis has emerged as a powerful platform for exploring nontraditional and challenging cross-couplings. Herein, metallaphotoredox catalytic protocol been developed on the basis of tertiary amine-ligated boryl radical-induced halogen atom transfer process under blue-light irradiation. A wide variety aryl heteroaryl bromides featuring different functional groups pharmaceutical moieties were facilely coupled to rapidly install C(sp3)-enriched aromatic scaffolds. The compatibility Lewis base-ligated borane with nickel was well exemplified extend chemical space Ni-catalyzed cross-electrophile coupling.

Language: Английский

Citations

8
Visible light-induced halogen-atom transfer by N-heterocyclic carbene-ligated boryl radicals for diastereoselective C(sp3)–C(sp2) bond formation DOI Creative Commons
Luca Capaldo,

Ting Wan,

Robin Mulder

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(36), P. 14844 - 14850

Published: Jan. 1, 2024

In this work, we report the synthesis of vinyl chlorides from chloroalkynes via ligated boryl radicals-mediated XAT under visible light. This study introduces first protocol using to establish a C(sp 3 )–C(sp 2 ) bond through radical addition.

Language: Английский

Citations

5
Controllable Hydrodebromination of Tribromomethyl Groups via Lewis Base–Borane-Mediated Ionic and Radical Pathways DOI
Feng‐Lian Zhang, Yi‐Feng Wang, Yan Liu

et al.

Synthesis, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Abstract Compounds bearing mono- and dibromomethyl groups are extensively utilized in synthetic medicinal chemistry. In this regard, selective debromination of readily or easily accessible tribromomethyl compounds offers a direct efficient method to access those two moieties. work, we introduced Lewis base–borane-mediated hydrodebromination via ionic radical pathway. Using 4-(dimethylamino)pyridine–borane (DMAP-BH3) as hydride donor, monohydrodebromination was achieved nucleophilic substitution by hydride, delivering groups. On the other hand, treatment with an N-heterocyclic carbene–borane (NHC-BH2CN) boryl precursor presence dilauroyl peroxide (DLP) initiator afforded monobromomethyl through consecutive bromine atom abstractions cleave C–Br bonds. Various group acetamides acetates were applied developed protocol, showcasing good functional tolerance broad substrate scope.

Language: Английский

Citations

0
Modular assembly of amines and diborons with photocatalysis enabled halogen atom transfer of organohalides for C(sp3)–C(sp3) bond formation DOI Creative Commons

Rong‐Bin Liang,

Tingting Miao, Xiang-Rui Li

et al.

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

Published: Jan. 1, 2025

A new photocatalytic approach by using the assembly of DABCO A1 and B 2 Nep B1 has been established to enable cross-coupling organohalides alkenes for C(sp 3 )–C(sp ) bond formation.

Language: Английский

Citations

0
Photocatalytic Borylation of Imines and Alkenes via Decarboxylation of Trimethylamine Carboxyborane: A New Approach for Generating Boryl Radicals DOI
Haowen Jiang,

Hao-Ni Qin,

Ai-Lian Wang

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(43), P. 9282 - 9287

Published: Oct. 23, 2024

In this study, we investigated the photocatalytic decarboxylation of trimethylamine carboxyborane under mild conditions, successfully generating boryl radicals for subsequent borylation reactions with imines and various alkenes. This method exhibited broad substrate compatibility, including functionalization biologically relevant molecules. Our findings expand utility beyond its role as a carbon-monoxide- drug-releasing agent, highlighting potential in radical chemistry through decarboxylation. work establishes robust foundation further exploration synthetic application carboxyborane.

Language: Английский

Citations

3
Mechanistic Exploration of N-Heterocyclic Carbene Boranes as the Hydrogen Atom Transfer Reagent in Selective Hydrodefluorination Reactions DOI
Amit Jaiswal, Bastian Bjerkem Skjelstad, Satoshi Maeda

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 17547 - 17555

Published: Nov. 13, 2024

In the modern era of organic synthesis, mechanisms centered on radical intermediates have become increasingly impactful. Among all these, hydrogen atom transfer (HAT) represents one most fundamental chemical reaction steps and has found applications in designing practical transformations. Herein, we present a detailed case study selective hydrodefluorination trifluoromethylarenes utilizing N-heterocyclic carbene boranes (NHC-boranes) as donor. Under optimal conditions featuring an acridine-based photocatalyst, complete selectivity for mono-hydrodefluorination was achieved across wide array substrates. Comprehensive mechanistic studies combining experimental computational approaches disproved chain process involving fluorine but rather pointed to HAT non-chain mechanism, where key step involves difluorobenzylic abstracting from NHC-borane generate boryl polarity-matched fashion. Evaluation selection Lewis base-ligated revealed molecular descriptors critical outcomes this reaction, classification model built explain structure–reactivity relationship how various elementary can be influenced. These results collectively provide valuable information future design increase utility chemistry.

Language: Английский

Citations

2
Boryl Radical Mediated Hydro(gem-diboryl)alkylation of Alkenes with Sterically Hindered NHC Boranes DOI

Ruizeng Zhang,

Hao Zhang,

Pan Xu

et al.

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

Published: Dec. 9, 2024

NHC boryl radical mediated halogen atom transfer (XAT) is useful in organic synthesis. Yet, most of the reaction ends only with reducing to hydrogen, that is, C-X C-H. This especially dominant for electron-deficient alkyl halides, where formed electrophilic reacts rapidly boranes. Herein, by employing a sterically hindered borane as precursor (IPr·BH

Language: Английский

Citations

1
Quenching Rate Constants of Lewis Base‐Boryl Radical by Substrates: a Laser Flash Photolysis Study DOI
Fan Zhang, Yuanming Li, Xi Zhou

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 31(8)

Published: Nov. 13, 2024

The advanced strategy using Lewis base-boryl radicals (LBRs) has recently been proposed for the addition of alkyl substituents to full-carbon quaternary center an organic molecule. However, as rate-determining step in whole route, reaction rate constants LBRs with substrates are extremely lacking. In this paper, 4-dimethylaminopyridine (DMAP)-BH2⋅ was selected a representative LBRs, and its reactions six monochloro-substituted substrates, including three methyl chlorobenzoates chlorinated acetanilides were studied experiments theoretical calculations. bimolecular constants, kq, determined laser flash photolysis approach. By comparing activation energies along two pathways, we have clarified attacking carbonyl oxygen instead chlorine atom. Furthermore, noncovalent interaction (NCI) analyses on these indicate that weak interactions, such hydrogen-bonding van der Waals significant influence reactivity substrates. Our study provides concrete clues extend synthetic strategy.

Language: Английский

Citations

0